Publications by authors named "E A Pfister"

108 Publications

N-3 Polyunsaturated fatty acid ethyl esters decrease the invasion, but not the proliferation, of human colorectal cancer cells via a PI3K-dependent mechanism in vitro.

Prostaglandins Leukot Essent Fatty Acids 2021 Apr 24;167:102273. Epub 2021 Mar 24.

Nutrition and Foods Program, School of Family and Consumer Sciences, Texas State University, 601 University Dr., San Marcos, TX, USA, 78666. Electronic address:

N-3 polyunsaturated fatty acid (PUFA) ethyl esters have been approved by the FDA for the treatment of dyslipidemia and are promising cancer therapeutics. The study objectives were to determine if and how n-3 PUFA ethyl esters affected the proliferation and invasion of colorectal cancer cells. SW620 and HCT-116 parental and HCT-116 mutant cells isogenic for constitutively active PI3K were treated with free or ethyl esterified n-3 PUFAs and counted 72 h later. Cells were also administered n-3 PUFA ethyl esters to determine if these compounds decreased invasion through Boyden chambers and PI3K activity via western blot analysis of phosphorylated Akt. Free and n-3 PUFA ethyl esters decreased the proliferation of all cell lines. The invasion and Akt phosphorylation of both parental cell lines was decreased following treatment but this did not occur in mutant cells. The ability of n-3 PUFA ethyl esters to decrease proliferation and invasion in vitro indicates these compounds may be effective in vivo.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.plefa.2021.102273DOI Listing
April 2021

Low-dose steroids do make a difference: Independent risk factors for impaired linear growth after pediatric liver transplantation.

Pediatr Transplant 2021 Mar 10:e13989. Epub 2021 Mar 10.

Division of Pediatric Gastroenterology, Hepatology and Liver Transplantation, Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.

Growth failure persists after pediatric liver transplantation and impairs pediatric development and quality of life. Steroid dose minimization attempts to prevent growth impairment, yet long-term assessment in pediatric liver recipients is lacking. We identified risk factors for impaired linear growth after pediatric liver transplantation, with a special focus on low-dose steroid therapy. This is a single-center retrospective analysis of height development in pediatric liver recipients up to 5 years after transplantation. Risk factors for impaired linear growth (height Z-scores≤-2) at transplantation, after two (n = 347) and five years (n = 210) were identified by univariate and multivariate logistic regression. At transplantation, growth retardation was found in 52.2%, predominantly younger children. Height Z-scores improved from -2.23 to -1.40 (SE 0.11; 95%CI 0.74-1.16; p < .001) two years and -1.19 (SE 0.07;0.08-0.34; p = .017) five years post-transplant. Multivariate analysis showed previous growth impairment (OR=1.484; 95%-CI=1.107-1.988; p = .004), graft loss (49.006;2.232-1076; p = .006), and prolonged cold ischemic time (1.034;1.007-1.061; p = .011) as main long-term risk factors; steroid use was a significant predictor of 2-year but not 5-year growth impairment. In univariate analysis, impaired growth after 2 and 5 years was associated with continuous low-dose (2.5 mg/m BSA) steroid therapy (OR=3.323;1.578-6.996; p < .001/OR=8.352;1.089-64.07; p = .006)and graft loss (OR=2.513;1.395-4.525; p = .003/OR=3.378;1.815-7.576; p < .001). Furthermore, indication and era of transplantation affected growth. Our results show significant catch-up growth after pediatric liver transplantation, yet growth failure strongly affects particularly young liver recipients. The main influenceable long-term risk factor is pre-existing growth failure, emphasizing the importance of early aggressive nutritional therapy. Moreover, low-dose steroid therapy might impair growth and should therefore be critically questioned in long-term immunosuppression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/petr.13989DOI Listing
March 2021

Centralization of Biliary Atresia: Has Germany Learned Its Lessons?

Eur J Pediatr Surg 2021 Mar 4. Epub 2021 Mar 4.

Department of Pediatric Surgery, Hannover Medical School, Hannover, Germany.

Introduction:  The majority of pediatric surgeons and hepatologists recommend the centralization of biliary atresia (BA) treatment within experienced liver units. We aimed to investigate whether voluntary self-restriction and acceptance of the need for this change in practice changed the BA referral policy in Germany during the last decade.

Materials And Methods:  In cooperation with pediatric surgeons, gastroenterologists or hepatologists, and pediatric liver transplant units, the 2-year follow-up data of infants with BA born in Germany between 2010 and 2014 were collected using www.bard-online.com or pseudonymized data transfer. Results were compared with our previous analysis of the outcome data of infants with BA born between 2001 and 2005 in Germany.

Result:  Overall, 173 infants with BA were identified, of whom 160 underwent Kasai portoenterostomy (KPE; 92.5%) and 13 (7.5%) underwent primary liver transplantation at 21 German centers. At 2-year follow-up, overall survival was 87.7% (vs. 81.9% in 2001-2005 [ = 0.19]), survival with native liver post-KPE was 29.2% (vs. 22.8% in 2001-2005 [ = 0.24]), and jaundice-free survival with native liver post-KPE was 24.0% (vs. 20.1% in 2001-2005 [ = 0.5]). Compared with the 2001-2005 analysis, all criteria showed improvement but the differences are statistically not significant.

Conclusion:  Our observation shows that KPE management requires improvement in Germany. Centralization of BA patients to German reference liver units is not yet mandatory. However, European and national efforts with regard to the centralization of rare diseases support our common endeavor in this direction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0041-1723994DOI Listing
March 2021

Dubin-Johnson Syndrome as Differential Diagnosis for Neonatal Cholestasis.

J Pediatr Gastroenterol Nutr 2021 May;72(5):e105-e111

Division for Pediatric Gastroenterology and Hepatology, Department of Pediatric Kidney, Liver, and Metabolic Diseases.

Objectives: Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder in which multidrug-resistance-associated protein 2 (MRP2) deficiency causes an excretion disorder of conjugated bilirubin from hepatocytes into bile canaliculi. Its clinical presentation as neonatal cholestasis (NC) is rare but represents an important differential diagnosis. We aimed to define DJS-specific characteristics in NC, in particular in contrast to biliary atresia (BA) patients, and to highlight diagnostic tools that can help to avoid invasive diagnostic tests.

Methods: We performed a review of case records from 2006 to 2020 and compared 4 DJS patients to 26 patients with proven BA consecutively diagnosed from 2014 to 2017. DJS was diagnosed by urine coproporphyrin analysis (UCA) and by genetic analysis (GA) for disease-associated ABCC2 variants.

Results: Four male patients with NC were diagnosed with DJS by UCA and GA. DJS patients presenting as NC showed significantly lower values for aspartate aminotransferase (AST) (P < 0.001), for alanine aminotransferase (ALT) (P = 0.002) and for gamma-glutamyl transferase (GGT) (P < 0.001) compared with BA patients. Other examinations, however, could not clearly discriminate them (e.g.: stool colour, serum bile acids, total serum bilirubin).

Conclusions: DJS is not only a rare differential diagnosis in NC with a suspicious phenotype (almost normal AST, ALT) but also shows overlapping features with BA. It should, therefore, be considered in every infant with NC and an atypical liver enzyme pattern to protect patients from unnecessary, invasive examinations. For this, UCA is a fast and reliable diagnostic tool. Confirmation based on GA is recommended. DJS patients have a good long-term prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MPG.0000000000003061DOI Listing
May 2021

Huntington's Disease: Les Jeux Sont Faits?

Trends Mol Med 2020 10 4;26(10):889-890. Epub 2020 Sep 4.

Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA. Electronic address:

In a meticulous study, Humbert, Durr, and colleagues showed evidence for aberrant neurodevelopment in both Huntington's disease (HD) and mouse models of HD. We consider the implications of prenatal pathological changes for the onset and progression of HD and their relatedness to current therapeutic plans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molmed.2020.08.004DOI Listing
October 2020

Hepatitis-associated Aplastic Anaemia in Children.

Klin Padiatr 2020 May 19;232(3):151-158. Epub 2020 Mar 19.

Clinic for Pediatric Nephrology, Hepatology and Metabolic Disorders, Hannover Medical School, Hannover, Germany.

Background: Children with idiopathic acute liver failure (IALF) are at a high risk of developing life-threatening bone marrow failure (BMF). The aim of the study was to describe the development, therapy and prognosis of this hepatitis-associated aplastic anaemia (HAAA) in comparison to isolated acquired aplastic anaemia.

Results: We retrospectively found 18 patients (9 female) of HAAA between 1984 and 2017 with an age of 1.4-16.4 years. Fifteen of them fulfilled the SAA criteria, 3 had a bone marrow hypoplasia. Eleven of these children received liver transplantation (LTx) (these were 11 of 42 (26%) children receiving LTx for IALF), 6 patients recovered without LTx. The first signs of BMF, thrombocytopaenia and leucocytopaenia, occurred before LTx in all cases. During the follow-up period 8 patients reached haematological remission, 6 received haematopoietic stem cell transplantation (HSCT). Seven children died in a median of 304 days after the first symptoms mostly because of bleedings and infections. To date, extensive investigations failed to detect a genetically, viral or immunological aetiology. No AA was diagnosed in the 41 patients receiving liver transplants during the same period for ALF of known aetiology. As a comparison group, we collected the data of patients with isolated SAA. 73% achieved a remission after Immunosuppressive therapy (IST) without HSCT, and none of them died during the follow-up period.

Conclusion: Blood counts should be examined early and regularly (0-22 days after onset) in patients with IALF. Aggressive treatment with LTx, IST and HSCT appears to improve the prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1108-1553DOI Listing
May 2020

MTF1 binds to metal-responsive element e within the ATP7B promoter and is a strong candidate in regulating the ATP7B expression.

Ann Hum Genet 2020 03 9;84(2):195-200. Epub 2019 Oct 9.

Department of Human Genetics, Hannover Medical School, Hannover, Germany.

Wilson's disease is an autosomal recessive disorder resulting from copper excess. Some patients with clinical Wilson's disease symptoms exhibit no or only heterozygous pathogenic variants in the coding region of the disease-causing ATP7B gene. Therefore, the ATP7B promoter region is of special interest. Metal-responsive elements (MREs) located in the ATP7B promoter are promising motifs in modulating the ATP7B expression. We studied protein interaction of MREe, MREc, and MREd by electrophoretic mobility shift assays and revealed specific interactions for all MREs. We further narrowed down the specific binding site. Proteins potentially binding to the three MREs were identified by MatInspector analyses. Metal regulatory transcription factor 1 (MTF1) could be validated to bind to MREe by electrophoretic mobility shift assays. ATP7B promoter-driven reporter gene expression was significantly increased because of this interaction. MTF1 is a strong candidate in regulating the ATP7B expression through MREe binding.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ahg.12355DOI Listing
March 2020

High Burden of Subclinical Cardiovascular Target Organ Damage After Pediatric Liver Transplantation.

Liver Transpl 2019 05 25;25(5):752-762. Epub 2019 Mar 25.

Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.

Cardiovascular (CV) events account for 8%-13% of deaths after liver transplantation (LT) in adulthood. Although CV risk factors (RFs) are present, little is known about the prevalence of subclinical CV target organ damage (TOD) in children after LT. The aim of this prospective observational study was to assess the prevalence of subclinical CV TOD in children after LT and to identify RFs contributing to CV damage as potential targets for clinical intervention. In this study, 104 children after LT (54% female, 46% male; aged 11.5 ± 3.8 years) underwent cross-sectional assessment of subclinical TOD by carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (IMT), and left ventricular mass index (LVMI). Results were correlated with the presence of CV RFs (obesity, hypertension, dyslipidemia, renal impairment, anemia, and microinflammation). Of the patients, 22% were exposed to 2 CV RFs, and 36% displayed 3 or more CV RFs. Pathological results for PWV, IMT, and LVMI were found in 21.9%, 57.0%, and 11.1% of patients, respectively. In the multivariate analysis, diastolic blood pressure (P = 0.01) and estimated glomerular filtration rate (eGFR; P = 0.03) were independently associated with PWV, eGFR (P = 0.005), and age at LT (P = 0.048) with IMT and body mass index with LVMI (P = 0.004). In conclusion, patients after pediatric LT carry a substantial burden of subclinical CV TOD. Identification of modifiable CV RFs opens opportunities for targeted intervention in order to reduce CV morbidity and mortality in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/lt.25431DOI Listing
May 2019

Psychosocial outcome and resilience after paediatric liver transplantation in young adults.

Clin Res Hepatol Gastroenterol 2019 04 5;43(2):155-160. Epub 2019 Feb 5.

Division for Paediatric Gastroenterology and Hepatology, Centre for Paediatric and Adolescent Medicine, Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany. Electronic address:

Background And Objective: The long-term psychosocial outcome of young adults after paediatric liver transplantation (LT) was investigated with the focus on day-to-day living. We aimed to capture patients' subjective perceptions of well-being and autonomy based on key physical outcome parameters.

Methods: All patients following paediatric LT at Hannover Medical School born before 2002 with a post-transplant follow-up of at least four years were included in this study. This retrospective observational study compared psychosocial parameters obtained from a self-designed 77-item questionnaire with standard clinical outcome variables.

Results: Eighty-two patients (male: 57%) aged 13-41 years were included in the survey within a three-month period (response rate: 41%). With an adherence rate of 33%, all but two patients were immunosuppressed. In total, 53 patients had transitioned to adult care largely without problems. Eighty-three percent (n = 68) evaluated their current health status as "(very) good". Sixty-seven patients (82%) did not experience health-related anxiety in daily life.

Conclusions: Our results demonstrate psychological stability and high self-esteem of young patients, as well as good integration into society and a high degree of normality during daily life after LT. Adherence rates are lower than anticipated and do not correlate with patients' understanding of their medical condition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clinre.2018.08.017DOI Listing
April 2019

Homozygous frame shift variant in ATP7B exon 1 leads to bypass of nonsense-mediated mRNA decay and to a protein capable of copper export.

Eur J Hum Genet 2019 06 5;27(6):879-887. Epub 2019 Feb 5.

Department of Human Genetics, Hannover Medical School, Hannover, Germany.

Wilson disease (WD) is an autosomal recessive disease of copper excess due to pathogenic variants in the ATP7B gene coding for a copper-transporting ATPase. We present a 5-year-old girl with the homozygous frame shift variant NM_000053.3: c.19_20del in exon 1 of ATP7B (consecutive exon numbering with c.1 as first nucleotide of exon 1), detected by whole-exome sequencing as a secondary finding. The variant leads to a premature termination codon in exon 2. The girl exhibited no WD symptoms and no abnormalities in liver biopsy. ATP7B liver mRNA expression was comparable to healthy controls suggesting that nonsense-mediated mRNA decay (NMD) could be bypassed by the mechanism of translation reinitiation. To verify this hypothesis, a CMV-driven ATP7B minigene (pcDNA3) was equipped with the authentic ATP7B 5' untranslated region  and a truncated intron 2. We introduced c.19_20del by site-directed mutagenesis and overexpressed the constructs in HEK293T cells. We analyzed ATP7B expression by qRT-PCR, northern and western blot, and examined protein function by copper export capacity assays. Northern blot, qRT-PCR, and western blot revealed that c.19_20del ATP7B mRNA and protein is expressed in size and amount comparable to wild-type. Copper export capacity was also comparable to wild-type. Our results indicate that c.19_20del in ATP7B is able to bypass NMD by translation reinitiation, demonstrating that the classification of truncating variants as pathogenic without additional investigations should be done carefully.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41431-019-0345-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777614PMC
June 2019

Impact of Immunosuppression on Executive Functioning After Pediatric Liver Transplantation: An Observational Cohort Study.

J Pediatr Gastroenterol Nutr 2019 04;68(4):480-487

Department of Paediatric Gastroenterology and Hepatology, Hannover Medical School, Hannover.

Objectives: Children after liver transplantation show increased rates of impaired cognitive functioning. We aimed to assess the potential effects of immunosuppressive therapy on executive functioning measured by the Children's Color Trail Test and the cognitive functioning module of the PedsQL (cogPedsQL) in liver transplanted children to explore potential targets for intervention to improve executive functioning.

Methods: We performed a cross-sectional study in 155 children (78 girls) aged 10.4 (2-18) years at 5.0 (0.1-17) years after liver transplantation, with follow-up at 6 months in n = 114. Executive functioning was assessed by Children's Color Trail Test (ages 8-16) and by patients and parent-proxy cogPedsQL (ages 5-18/2-18, respectively). Results were correlated with clinical parameters. Stability of results over time was compared between n = 23 patients who for clinical reasons switched from twice daily calcineurin inhibitor (CNI) to once-daily slow-release tacrolimus (Tac) during the study period, and patients with unchanged CNI.

Results: Worse executive functioning was associated with longer stay in the intensive care unit and longer time elapsed since transplantation. No difference was found between users of cyclosporine and Tac. Children on once-daily slow-release Tac performed better than children on twice-daily Tac. In children who switched from twice-daily CNI to once-daily Tac, parent-proxy cogPedsQL improved significantly compared to stable results in the nonswitch group.

Conclusions: In addition to a strong impact of disease burden around transplantation, executive functioning appears to deteriorate over time. Although there is no clear-cut advantage of any CNI, once-daily Tac appears to be advantageous compared to twice-daily Tac.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MPG.0000000000002274DOI Listing
April 2019

Selective Neuronal Uptake and Distribution of AAVrh8, AAV9, and AAVrh10 in Sheep After Intra-Striatal Administration.

J Huntingtons Dis 2018 ;7(4):309-319

Department of Medicine and RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA.

Background: Transgenic sheep are currently the only large animal model of Huntington's disease expressing full-length mutant human huntingtin. These transgenic sheep provide an opportunity to test adeno associated virus (AAV) therapies directly targeting the huntingtin gene. A recent study demonstrated that self-complementary (sc) AAV with artificial miRNA against human huntingtin reduced mutant human huntingtin in caudate and putamen after a single injection near the internal capsule.

Objective: To identify an AAV serotype among AAVrh8, AAV9 and AAVrh10 with the highest neuronal uptake and distribution, with no obvious cell loss in the neostriatum of the sheep.

Methods: We tested AAVrh8, AAV9 and AAVrh10 by stereotactic direct unilateral injection into the neostriatum of sheep, near the internal capsule. Four weeks after administration, we examined the viral spread and neuronal uptake of each serotype of AAV containing GFP. We compared single stranded (ss) and scAAVs. Further, we measured the distribution of AAVrh8 and AAV9 to a variety of tissues outside the brain.

Results: Sc AAV9 had the best combination of neuronal uptake and distribution throughout the neostriatum. scAAVrh10 demonstrated good spread, but was not taken up by neurons. scAAVrh8 demonstrated good spread, but had less neuronal uptake than AAV9. Six hours after convection-enhanced administration to the neostriatum, both AAVrh8 and AAV9 viral genomes were detected in blood, saliva, urine, feces and wool. By four weeks, viral genomes were detected in wool only. Administration of AAVrh8, AAV9 and AAVrh10 was not associated with loss of neostriatal, medium spiny neuron number as measured by DARPP32 immunohistochemistry.

Conclusions: Altogether, we found scAAV9 had the best neuronal uptake and spread, showed no loss of neurons at one-month post-injection, and was not measurable in body fluids one month after injection. This information will guide future clinical experiments requiring brain injection of AAV for therapeutics for gene or miRNA deliveries in sheep transgenic for the human huntingtin gene.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3233/JHD-180302DOI Listing
October 2019

Characterization of Glomerular Sox9 Cells in Anti-Glomerular Basement Membrane Nephritis in the Rat.

Am J Pathol 2018 11 7;188(11):2529-2541. Epub 2018 Sep 7.

Department of Nephropathology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. Electronic address:

Mechanisms of glomerular crescent formation and podocyte repair processes are still unclear. Therefore, we investigated the expression of the transcription factor Sox9 as a potential marker of a subpopulation of parietal epithelial cells (PECs) with potential regenerative properties. Glomerular Sox9 expression was characterized in detail in a rat anti-glomerular basement membrane (GBM) nephritis model using immunofluorescence and confocal laser scanning microscopy. In healthy kidneys Sox9 is expressed in a subpopulation of PECs restricted to approximately 20% to 50% of PEC nuclei and was highly conserved in all investigated species. During rat anti-GBM nephritis the number of glomerular Sox9 cells increased and was associated with proliferation activity. In nephritic glomeruli Sox9 expression was not restricted to Bowman's capsule lining but was also found on cells of the glomerular tuft. Nearly all Sox9 cells also expressed the PEC marker Pax8, whereas endothelial cells, mesangial cells, macrophages, and T lymphocytes lacked Sox9 expression. At the margins of crescents Sox9/Pax8 cells additionally expressed podocyte markers. In contrast, in sclerotic lesions a minority of Sox9/Pax8 cells expressed the myofibroblast marker α-smooth muscle actin. In glomerular Sox9 cells Jagged 1 was up-regulated. During anti-GBM nephritis Sox9 PECs proliferate and migrate onto the glomerular tuft. Future studies are needed to confirm the origin of Sox9 cells from PECs and differentiation in both podocytes and/or myofibroblasts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajpath.2018.07.023DOI Listing
November 2018

Quality of Life in Patients With Progressive Familial Intrahepatic Cholestasis: No Difference Between Post-liver Transplantation and Post-partial External Biliary Diversion.

J Pediatr Gastroenterol Nutr 2018 11;67(5):643-648

Department of Pediatric Surgery.

Objectives: In patients with progressive familial intrahepatic cholestasis (PFIC), partial external biliary diversion (PEBD), which is associated with a permanent stoma, is recommended as first-line therapy, whereas primary liver transplantation (LTx) is restricted to those with cirrhosis. Our aim was to quantify the health-related quality of life (HRQOL) in patients with PFIC and to evaluate whether there is a difference in their HRQOL depending on the surgical approach.

Methods: A prospective HRQOL study on a consecutive series of PFIC was conducted using Pediatric Quality of Life Inventory 4.0 child-self and parent-proxy reports. Patients with PFIC after PEBD who still lived with their native livers were compared to those after LTx. Both groups were compared to healthy children.

Results: A total of 32 patients (53% girls) patients with a mean age of 17.7 ± 7.3 years were studied. Twenty-two had undergone LTx at a mean age of 7.8 ± 3.8 years and 10 had undergone PEBD at a mean age of 4.1 ± 3.9 years. At the time of HRQOL assessment, the mean age was 18.9 ± 7.5 years in the LTx group and 15.3 ± 6.5 years in the PEBD group. Child-self and parent-proxy reports showed no significant difference in HRQOL between patients with PFIC after LTx and those after PEBD except for marginal difference in physical functioning/health (P = 0.07). Except for a lower score in patient school functioning of patients after LTx (P = 0.01), HRQOL-results showed no difference from healthy children in any group.

Conclusions: The HRQOL of patients with PFIC after PEBD was similar to those after LTx. The HRQOL in both groups was also similar to that of healthy children. Thus, our data support the current policy of PEBD as primary surgical treatment for patients with PFIC without cirrhosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MPG.0000000000002118DOI Listing
November 2018

Predictive Factors for Survival in Children Receiving Liver Transplants for Wilson's Disease: A Cohort Study Using European Liver Transplant Registry Data.

Liver Transpl 2018 09;24(9):1186-1198

Department of Hepatology and Liver Transplant Unit, AP-HP Henri Mondor Hospital, Paris Est University, Créteil, France.

Liver transplantation (LT) is a rescue therapy for life-threatening complications of Wilson's disease (WD). However, data on the outcome of WD patients after LT are scarce. The aim of our study was to analyze a large pediatric WD cohort with the aim of investigating the longterm outcome of pediatric WD patients after LT and to identify predictive factors for patient and transplant survival. This is a retrospective cohort study using data of all children (<18 years) transplanted for WD enrolled in the European Liver Transplant Registry from January 1968 until December 2013. In total, 338 patients (57.6% female) transplanted at 80 different European centers (1-26 patients per center) were included in this study. The median age at transplantation was 14.0 years (interquartile range [IQR], 11.2-16.1 years); patients were followed up for a median of 5.4 years (IQR, 1.0-10.9 years) after LT. Overall patient survival rates were high with 87% (1-year survival), 84% (5-year survival), and 81% (10-year survival); survival rates increased considerably with the calendar year (P < 0.001). Early age at LT, living donation, and histidine tryptophan ketoglutarate preservation liquid were identified as risk factors for poor patient survival in the multivariate analysis. LT is an excellent treatment option for pediatric patients with WD and associated end-stage liver disease. Longterm outcome in these patients is similar to other pediatric causes for LT. Overall patient and graft survival rates improved considerably over the last decades. To improve future research in the field, the vast variability of allocation strategies should be harmonized and a generally accepted definition or discrimination of acute versus chronic WD needs to be found.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/lt.25308DOI Listing
September 2018

Immune monitoring after pediatric liver transplantation - the prospective ChilSFree cohort study.

BMC Gastroenterol 2018 May 16;18(1):63. Epub 2018 May 16.

Division of Paediatric Gastroenterology and Hepatology, Department of Paediatric Liver, Kidney and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany.

Background: Although trough levels of immunosuppressive drugs are largely used to monitor immunosuppressive therapy after solid organ transplantation, there is still no established tool that allows for a validated assessment of functional degree of immunosuppression or the identification of clinically relevant over- or under-immunosuppression, depending on graft homeostasis. Reliable non-invasive markers to predict biopsy proven acute rejection (BPAR) do not exist. Literature data suggest that longitudinal measurements of immune markers might be predictive of BPAR, but data in children are scarce. We therefore propose an observational prospective cohort study focusing on immune monitoring in children after liver transplantation. We aim to describe immune function in a cohort of children before and during the first year after liver transplantation and plan to investigate how the immune function profile is associated with clinical and laboratory findings.

Methods: In an international multicenter prospective approach, children with end-stage liver disease who undergo liver transplantation are enrolled to the study and receive extensive immune monitoring before and at 1, 2, 3, 4 weeks and 3, 6, 12 months after transplantation, and whenever a clinically indicated liver biopsy is scheduled. Blood samples are analyzed for immune cell numbers and circulating levels of cytokines, chemokines and factors of angiogenesis reflecting immune cell activation. Statistical analysis will focus on the identification of trajectorial patterns of immune reactivity predictive for systemic non-inflammatory states, infectious complications or BPAR using joint modelling approaches.

Discussion: The ChilSFree study will help to understand the immune response after pLTx in different states of infection or rejection. It may provide insight into response mechanisms eventually facilitating immune tolerance towards the graft. Our analysis may yield an applicable immune panel for non-invasive early detection of acute cellular rejection, with the prospect of individually tailoring immunosuppressive therapy. The international collaborative set-up of this study allows for an appropriate sample size which is otherwise difficult to achieve in the field of pediatric liver transplantation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12876-018-0795-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5956961PMC
May 2018

Phenotypic spectrum and diagnostic pitfalls of ABCB4 deficiency depending on age of onset.

Hepatol Commun 2018 May 22;2(5):504-514. Epub 2018 Mar 22.

Hannover Medical School, Division of Pediatric Gastroenterology and Hepatology, Department of Pediatric Kidney, Liver, and Metabolic Diseases Hannover Germany.

Genetic variants in the adenosine triphosphate-binding cassette subfamily B member 4 () gene, which encodes hepatocanalicular phosphatidylcholine floppase, can lead to different phenotypes, such as progressive familial intrahepatic cholestasis (PFIC) type 3, low phospholipid-associated cholelithiasis, and intrahepatic cholestasis of pregnancy. The aim of this multicenter project was to collect information on onset and progression of this entity in different age groups and to assess the relevance of this disease for the differential diagnosis of chronic liver disease. Clinical and laboratory data of 38 patients (17 males, 21 females, from 29 families) with homozygous or (compound) heterozygous mutations were retrospectively collected. For further analysis, patients were grouped according to the age at clinical diagnosis of -associated liver disease into younger age (<18 years) or adult age (≥18 years). All 26 patients diagnosed in childhood presented with pruritus (median age 1 year). Hepatomegaly and splenomegaly were present in 85% and 96% of these patients, respectively, followed by jaundice (62%) and portal hypertension (69%). Initial symptoms preceded diagnosis by 1 year, and 13 patients received a liver transplant (median age 6.9 years). Of note, 9 patients were misdiagnosed as biliary atresia, Alagille syndrome, or PFIC type 1. In the 12 patients with diagnosis in adulthood, the clinical phenotype was generally less severe, including intrahepatic cholestasis of pregnancy, low phospholipid-associated cholelithiasis, or (non)cirrhotic PFIC3. ABCB4 deficiency with onset in younger patients caused a more severe PFIC type 3 phenotype with the need for liver transplantation in half the children. Patients with milder phenotypes are often not diagnosed before adulthood. One third of the children with PFIC type 3 were initially misdiagnosed, indicating the need for better diagnostic tools and medical education. ( 2018;2:504-514).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hep4.1149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944585PMC
May 2018

Side effects and efficacy of renal sparing immunosuppression in pediatric liver transplantation-A single center matched cohort study.

Pediatr Transplant 2018 08 5;22(5):e13207. Epub 2018 May 5.

Division of Pediatric Gastroenterology and Hepatology, Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.

Immunosuppressive combination therapy with MMF can reduce CNI associated nephrotoxicity. We investigated effectiveness and safety of de novo MMF-tacrolimus based immunosuppression after pLTx. Patients after pLTx receiving immunosuppression with MMF/tacrolimus (MMF/TAC) were compared to retrospectively selected age- and diagnosis-matched patients with tacrolimus monotherapy (TAC) and cyclosporine/prednisolone therapy (CSA) (19 patients each, n = 57). Effectiveness, renal function and side effects were analyzed for 1 year after pLTx. Tacrolimus reduction in combination therapy (0.7 μg/L over the year) was lower than aspired (2 μg/L). Acute BPAR occurred equally in MMF/TAC and TAC groups (31.6% each), being slightly higher in CSA group (42.1%; OR = 1.5; 95% CI = 0.42-5.44; P = .5). GFR deteriorated comparably in all 3 groups (P < .01 each) without significant differences between the groups. Septicemia was detected significantly more often in MMF/TAC (73.6%) than in TAC (31.6%) (OR 4.17; 1.07-16.27; P = .04). EBV reactivation occurred more often in CSA patients (84.2%) than in MMF/TAC (47.4%; OR 5.16; 0.98-27.19; P = .05) and TAC patients (52.6%; OR 8.16; 1.48-44.89; P = .02) the same was true for other viral infections (47.4% (CSA) vs 15.8% (TAC); OR 4.21; 0.95-18.55; P = .05). Our study does not provide additional evidence for a benefit of initial use of MMF/TAC over TAC regarding renal function, but raises concerns regarding a potentially increased risk of serious infections under MMF/TAC compared to TAC monotherapy at equivalent renal outcome; our study is, however, limited by the minor CNI reduction in combination therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/petr.13207DOI Listing
August 2018

Pediatric cirrhotic cardiomyopathy: Impact on liver transplant outcomes.

Liver Transpl 2018 06;24(6):820-830

Paediatric Gastroenterology and Hepatology.

In adults, cirrhotic cardiomyopathy (CCM) has a significant incidence and impact on liver transplantation. For pediatric liver transplantation (pLT), data on liver-induced cardiac changes are scarce, and in particular, the comparison between cirrhotic and noncirrhotic liver disease has not been investigated. We retrospectively evaluated cardiac changes associated with CCM by echocardiography and 12-lead electrocardiogram in 198 pLT-candidates (median age 4.1 years) 4.2 before and 12 months after pLT. Results were correlated with the stage of liver fibrosis and cholestasis before transplantation. The left ventricular end-diastolic diameter (LVIDd) z score, left ventricular mass z score, and left ventricular mass index were significantly higher in cirrhotic patients (-0.10 versus 0.98, P < 0.001; -1.55 versus -0.42, P = 0.001; 78.99 versus 125.64 g/m , P = 0.001, respectively) compared with children with noncirrhotic liver disease. Pathological z scores (>2SDS) for the LVIDd occurred more frequently in cirrhotic patients compared with patients with noncirrhotic liver disease (31/169 versus 1/29; P = 0.03) and were significantly associated with cholestasis. All observed cardiac changes were reversible 1 year after pLT. Pathological LVIDd z scores correlated highly with intensive care unit (ICU) stay (9.6 days versus 17.1 days, respectively, P = 0.002) but not with patient survival pre-LT or post-LT. In contrast to other studies, prolonged QTc time was not associated with liver cirrhosis in our patients. In conclusion, CCM-associated cardiac changes in pLT candidates with cirrhotic liver disease are frequent, mild, and associated with cholestasis and reversible after pLT. They may impact peritransplant care and posttransplant hospitalization time. Further prospective evaluation is warranted. In particular, for QTc time prolongation etiological factors, possible protective effects of ursodeoxycholic acid treatment and the use as a screening parameter for CCM should be verified. Liver Transplantation 24 820-830 2018 AASLD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/lt.25076DOI Listing
June 2018

Artificial miRNAs Reduce Human Mutant Huntingtin Throughout the Striatum in a Transgenic Sheep Model of Huntington's Disease.

Hum Gene Ther 2018 06 23;29(6):663-673. Epub 2018 Feb 23.

1 Department of Medicine, University of Massachusetts Medical School , Worcester, Massachusetts.

Huntington's disease (HD) is a fatal neurodegenerative disease caused by a genetic expansion of the CAG repeat region in the huntingtin (HTT) gene. Studies in HD mouse models have shown that artificial miRNAs can reduce mutant HTT, but evidence for their effectiveness and safety in larger animals is lacking. HD transgenic sheep express the full-length human HTT with 73 CAG repeats. AAV9 was used to deliver unilaterally to HD sheep striatum an artificial miRNA targeting exon 48 of the human HTT mRNA under control of two alternative promoters: U6 or CβA. The treatment reduced human mutant (m) HTT mRNA and protein 50-80% in the striatum at 1 and 6 months post injection. Silencing was detectable in both the caudate and putamen. Levels of endogenous sheep HTT protein were not affected. There was no significant loss of neurons labeled by DARPP32 or NeuN at 6 months after treatment, and Iba1-positive microglia were detected at control levels. It is concluded that safe and effective silencing of human mHTT protein can be achieved and sustained in a large-animal brain by direct delivery of an AAV carrying an artificial miRNA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/hum.2017.199DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6909722PMC
June 2018

Bi-nucleation of podocytes is uniformly accompanied by foot processes widening in renal disease.

Nephrol Dial Transplant 2018 05;33(5):796-803

Department of Nephropathology, Friedrich-Alexander University (FAU) Erlangen-Nürnberg, Erlangen, Germany.

Background: Podocytes are terminally differentiated glomerular cells expressing a highly complex architecture and lacking the ability to proliferate. However, during renal injury or stress these cells can re-enter into the cell cycle but fail to divide. As a consequence, bi- and multi-nucleated podocytes can be identified in renal biopsies from patients with various kidney diseases. It is still unclear whether the occurrence of such cells is dependent on or correlates with renal damage and if bi- or multi-nucleation results in ultrastructural alterations such as e.g. foot process effacement. Therefore, we investigated the frequency, correlation with clinical parameters and morphological consequences of podocyte bi- or multi-nucleation in a cohort of 377 patients suffering from different renal diseases.

Methods: Renal biopsies from patients with minimal change disease (MCD; n = 93), IgA-glomerulonephritis (IgA-GN, n = 95), lupus nephritis (LN; n = 90) and diabetic nephropathy (DN; n = 99) were investigated for the occurrence of bi-nucleated or multi-nucleated podocytes using semi-thin sections and light-microscopy at 1000× magnification. The frequency of bi-nucleation and multi-nucleation in podocytes was correlated with clinical parameters and markers of renal injury. In addition, ultrastructural morphological features associated with podocyte bi- or multi-nucleation were analysed by scanning transmission electron microscopy at various magnifications.

Results: Ultrastructural analysis of podocyte nuclear morphology revealed a broad spectrum of nuclear appearances. Therefore, podocytes were classified in cells with mono-nucleated, lobulated, potential bi-nucleated, symmetrically bi-nucleated, asymmetrically bi-nucleated and multi-nucleated nuclear morphology. In 65-80% of all investigated glomeruli only mono-nuclear podocytes were identified. The highest frequency of bi-nucleated podocytes was found in patients with IgA-GN (18.6%) and the lowest in patients with DN (5.6%). The proportion of bi-nucleated podocytes with asymmetric nuclear morphology was about 50% of all bi-nucleated podocytes and independent of the underlying renal disease. In addition, ultrastructural analysis by electron microscopy showed significant widening of foot processes in bi-nucleated compared with mono-nucleated podocytes. Interestingly, foot process width of podocytes with lobulated nuclei was also significantly increased compared with podocytes with normal mono-nuclear morphology. Furthermore, podocyte density per glomerular area was significantly lower in glomeruli with bi-nucleated podocytes. Due to the relatively low frequency of bi- and multi-nucleated podocytes, correlations with clinical parameters were weak and dependent on renal disease.

Conclusions: The frequency of bi-nucleated podocytes was highest in IgA-GN but can also be observed in all investigated renal diseases. In podocytes with altered nuclear morphology particularly in bi- and multi-nucleated podocytes ultrastructural analysis of podocytes revealed significant widening of foot processes as a potential maladaptive structural consequence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfx201DOI Listing
May 2018

[Wilson's disease : What has been confirmed in diagnostic and therapy?]

Authors:
E-D Pfister

Internist (Berl) 2017 Dec;58(12):1233-1241

Pädiatrische Gastroenterologie, Hepatologie und Lebertransplantation, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Deutschland.

Wilson's disease (WD) is a rare autosomal recessive disorder characterized by abnormal copper accumulation. Presenting a broad variety of phenotypes and, thus, being a chameleon within the group of metabolic diseases, the manifold clinical symptoms of WD can include hepatologic, neurologic, and psychiatric manifestations. Early onset presentations in infancy and late-onset manifestations in adults older than 70 years of age have been described. If the typical laboratory blood test values are missing, the diagnosis of WD may be difficult and often involves a combination of different parameters. Novel test methods like the identification of the relative exchangeable copper have not been validated within a sufficient cohort of WD patients as of yet and therefore do not currently play a crucial role within the clinical setting. Consequently any patient with reasonable suspected diagnosis of WD needs to be presented to a (pediatric) gastroenterologist and/or (pediatric) neurologist. Different medical treatments including drugs such as copper chelating agents are commonly used in the clinical setting. Liver transplantation may be the ultima ratio in selected patients. Dietary changes involving a low copper diet play only a minor role. Due to the fact the use of tetrathiomolybdate is still not approved, the treatment of advanced and progressive neurologic symptoms remains a major challenge. In any case, life-long medical supervision and treatment governed by a specialist is absolutely essential. Early diagnosis and early and life-long treatment lead to better prognoses and do not negatively influence the overall life expectancy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00108-017-0342-9DOI Listing
December 2017

Alterations in mRNA 3' UTR Isoform Abundance Accompany Gene Expression Changes in Human Huntington's Disease Brains.

Cell Rep 2017 Sep;20(13):3057-3070

Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA. Electronic address:

The huntingtin gene has two mRNA isoforms that differ in their 3' UTR length. The relationship of these isoforms with Huntington's disease is not established. We provide evidence that the abundance of huntingtin 3' UTR isoforms differs between patient and control neural stem cells, fibroblasts, motor cortex, and cerebellum. Huntingtin 3' UTR isoforms, including a mid-3' UTR isoform, have different localizations, half-lives, polyA tail lengths, microRNA sites, and RNA-binding protein sites. Isoform shifts in Huntington's disease motor cortex are not limited to huntingtin; 11% of alternatively polyadenylated genes change the abundance of their 3' UTR isoforms. Altered expression of RNA-binding proteins may be associated with aberrant isoform abundance; knockdown of the RNA-binding protein CNOT6 in control fibroblasts leads to huntingtin isoform differences similar to those in disease fibroblasts. These findings demonstrate that mRNA 3' UTR isoform changes are a feature of molecular pathology in the Huntington's disease brain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.celrep.2017.09.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5625827PMC
September 2017

Diagnosis of monogenic liver diseases in childhood by next-generation sequencing.

Clin Genet 2018 03 12;93(3):665-670. Epub 2017 Dec 12.

Department of Kidney, Liver and Metabolic Disease, Division of Pediatric Gastroenterology and Hepatology, Hannover Medical School, Hannover, Germany.

Next-generation sequencing (NGS) has opened up novel diagnostic opportunities for children with unidentified, but suspected inherited diseases. We describe our single-center experience with NGS diagnostics in standard clinical scenarios in pediatric hepatology. We investigated 135 children with suspected inherited hepatopathies, where initially no causative pathogenic variant had been identified, with an amplicon-based NGS panel of 21 genes associated with acute and chronic hepatopathies. In 23 of these patients, we detected pathogenic or likely pathogenic variants in 10 different genes. We present 6 novel variants. A total of 14 of these patients presented with the characteristic phenotype of the related hepatopathy. Nine patients showed only few or atypical clinical symptoms or presented with additional signs. In another 13 out of 135 cases, we detected variants of unknown significance (VUS) in 9 different genes. Only 2 of these patients showed characteristic phenotypes conclusive with the detected variants, whereas 11 patients showed unspecific or atypical phenotypes. Our multi-gene panel is a fast and comprehensive tool to diagnose inherited pediatric hepatopathies. We also illustrate the challenge of dealing with genetic variants and highlight arising clinical questions, especially in patients with atypical phenotypes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cge.13120DOI Listing
March 2018

Sequencing of FIC1, BSEP and MDR3 in a large cohort of patients with cholestasis revealed a high number of different genetic variants.

J Hepatol 2017 12 19;67(6):1253-1264. Epub 2017 Jul 19.

Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany. Electronic address:

Background & Aims: The bile salt export pump (BSEP, ABCB11), multidrug resistance protein 3 (MDR3, ABCB4) and the ATPase familial intrahepatic cholestasis 1 (FIC1, ATP8B1) mediate bile formation. This study aimed to determine the contribution of mutations and common variants in the FIC1, BSEP and MDR3 genes to cholestatic disorders of differing disease onset and severity.

Methods: Coding exons with flanking intron regions of ATP8B1, ABCB11, and ABCB4 were sequenced in cholestatic patients with assumed genetic cause. The effects of new variants were evaluated by bioinformatic tools and 3D protein modeling.

Results: In 427 patients with suspected inherited cholestasis, 149 patients carried at least one disease-causing mutation in FIC1, BSEP or MDR3, respectively. Overall, 154 different mutations were identified, of which 25 were novel. All 13 novel missense mutations were disease-causing according to bioinformatics analyses and homology modeling. Eighty-two percent of patients with at least one disease-causing mutation in either of the three genes were children. One or more common polymorphism(s) were found in FIC1 in 35.3%, BSEP in 64.3% and MDR3 in 72.6% of patients without disease-causing mutations in the respective gene. Minor allele frequencies of common polymorphisms in BSEP and MDR3 varied in our cohort compared to the general population, as described by gnomAD. However, differences in ethnic background may contribute to this effect.

Conclusions: In a large cohort of patients, 154 different variants were detected in FIC1, BSEP, and MDR3, 25 of which were novel. In our cohort, frequencies for risk alleles of BSEP (p.V444A) and MDR3 (p.I237I) polymorphisms were significantly overrepresented in patients without disease-causing mutation in the respective gene, indicating that these common variants can contribute to a cholestatic phenotype.

Lay Summary: FIC1, BSEP, and MDR3 represent hepatobiliary transport proteins essential for bile formation. Genetic variants in these transporters underlie a broad spectrum of cholestatic liver diseases. To confirm a genetic contribution to the patients' phenotypes, gene sequencing of these three major cholestasis-related genes was performed in 427 patients and revealed 154 different variants of which 25 have not been previously reported in a database. In patients without a disease-causing mutation, common genetic variants were detected in a high number of cases, indicating that these common variants may contribute to cholestasis development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhep.2017.07.004DOI Listing
December 2017

Safe and Efficient Silencing with a Pol II, but Not a Pol lII, Promoter Expressing an Artificial miRNA Targeting Human Huntingtin.

Mol Ther Nucleic Acids 2017 Jun 14;7:324-334. Epub 2017 Apr 14.

Department of Pediatrics and Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA 01605, USA. Electronic address:

Huntington's disease is a devastating, incurable neurodegenerative disease affecting up to 12 per 100,000 patients worldwide. The disease is caused by a mutation in the Huntingtin (Htt) gene. There is interest in reducing mutant Huntingtin by targeting it at the mRNA level, but the maximum tolerable dose and long-term effects of such a treatment are unknown. Using a self-complementary AAV9 vector, we delivered a mir-155-based artificial miRNA under the control of the chicken β-actin or human U6 promoter. In mouse brain, the artificial miRNA reduced the human huntingtin mRNA by 50%. The U6, but not the CβA promoter, produced the artificial miRNA at supraphysiologic levels. Embedding the antisense strand in a U6-mir-30 scaffold reduced expression of the antisense strand but increased the sense strand. In mice treated with scAAV9-U6-mir-155-HTT or scAAV9-CβA-mir-155-HTT, activated microglia were present around the injection site 1 month post-injection. Six months post-injection, mice treated with scAAV9-CβA-mir-155-HTT were indistinguishable from controls. Those that received scAAV9-U6-mir-155-HTT showed behavioral abnormalities and striatal damage. In conclusion, miRNA backbone and promoter can be used together to modulate expression levels and strand selection of artificial miRNAs, and in brain, the CβA promoter can provide an effective and safe dose of a human huntingtin miRNA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.omtn.2017.04.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5424568PMC
June 2017

Allele-Selective Suppression of Mutant Huntingtin in Primary Human Blood Cells.

Sci Rep 2017 04 24;7:46740. Epub 2017 Apr 24.

Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK.

Post-transcriptional gene silencing is a promising therapy for the monogenic, autosomal dominant, Huntington's disease (HD). However, wild-type huntingtin (HTT) has important cellular functions, so the ideal strategy would selectively lower mutant HTT while sparing wild-type. HD patients were genotyped for heterozygosity at three SNP sites, before phasing each SNP allele to wild-type or mutant HTT. Primary ex vivo myeloid cells were isolated from heterozygous patients and transfected with SNP-targeted siRNA, using glucan particles taken up by phagocytosis. Highly selective mRNA knockdown was achieved when targeting each allele of rs362331 in exon 50 of the HTT transcript; this selectivity was also present on protein studies. However, similar selectivity was not observed when targeting rs362273 or rs362307. Furthermore, HD myeloid cells are hyper-reactive compared to control. Allele-selective suppression of either wild-type or mutant HTT produced a significant, equivalent reduction in the cytokine response of HD myeloid cells to LPS, suggesting that wild-type HTT has a novel immune function. We demonstrate a sequential therapeutic process comprising genotyping and mutant HTT-linkage of SNPs, followed by personalised allele-selective suppression in a small patient cohort. We further show that allele-selectivity in ex vivo patient cells is highly SNP-dependent, with implications for clinical trial target selection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep46740DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402279PMC
April 2017

Vascular architecture as a diagnostic marker for differentiation of World Health Organization thymoma subtypes and thymic carcinoma.

Histopathology 2017 Apr 18;70(5):693-703. Epub 2017 Jan 18.

Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany.

Aims: Thymomas and thymic squamous cell carcinomas (TSQCCs) are rare thymic epithelial tumours. Data on angiogenesis and vascular phenotype in these tumours are limited, and no study has taken histological World Health Organization (WHO) subtypes into account. The aim of this study was to compare vascularization, pericytes coverage and expression of angiogenic growth factors in different WHO-defined subtypes of thymoma METHODS AND RESULTS: Vascular density, diameter and architecture and expression of α-smooth muscle actin (SMA), platelet-derived growth factor (PDGF) receptor-β (PDGFRβ), vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) and VEGF receptor 2 (VEGFR2) were investigated in WHO type A, AB, B1, B2 and B3 thymomas and TSQCCs, by the use of immunostaining, quantitative morphometry, and tumour vessel isolation by trypsin digestion. Expression levels of angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), VEGF-A, PDGF-B and Hif-1α were examined by quantitative reverse transcription polymerase chain reaction. A and AB thymomas were characterized by a dense network of capillary-like vessels with tight pericyte coverage, whereas B thymomas showed a loose vascular network with increasing vascular diameters and increasing expression of SMA and PDGFRβ from B1 to B3 thymomas and TSQCCs. VEGFR1 and VEGFR2 were expressed in vessels of all analysed tumour entities, and at higher levels in epithelial cells of A and B3 thymomas and TSQCCs. mRNA of Ang-2, but not of Ang-1, was significantly up-regulated in all thymoma subtypes, with the highest levels being found in A thymomas. In TSQCCs, Ang-1 and VEGF were the predominantly up-regulated growth factors. Hif-1α was only up-regulated in B3 thymomas and TSQCCs.

Conclusion: Thymomas and TSQCCs differ significantly in their vascular architecture and expression of key angiogenic growth factors. The findings could help to improve the differential diagnosis of difficult-to-classify thymic epithelial tumours, and indicate different mechanisms of tumour angiogenesis and functional differences of tumour vessels of major thymoma subtypes and TSQCCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/his.13114DOI Listing
April 2017

Cellular Analysis of Silencing the Huntington's Disease Gene Using AAV9 Mediated Delivery of Artificial Micro RNA into the Striatum of Q140/Q140 Mice.

J Huntingtons Dis 2016 10;5(3):239-248

Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA.

Background: The genetic mutation in Huntington's disease (HD) is a CAG repeat expansion in the coding region of the huntingtin (Htt) gene. RNAi strategies have proven effective in substantially down-regulating Htt mRNA in the striatum through delivery of siRNAs or viral vectors based on whole tissue assays, but the extent of htt mRNA lowering in individual neurons is unknown.

Objective: Here we characterize the effect of an AAV9-GFP-miRHtt vector on Htt mRNA levels in striatal neurons of Q140/Q140 knock-in mice.

Methods: HD mice received bilateral striatal injections of AAV9-GFP-miRHtt or AAV9-GFP at 6 or 12 weeks and striata were evaluated at 6 months of age for levels of Htt mRNA and protein and for mRNA signal within striatal neurons using RNAscope multiplex fluorescence in situ hybridization.

Results: Compared to controls, the striatum of 6-month old mice treated at 6 or 12 weeks of age with AAV9-GFP-miRHtt showed a reduction of 40-50% in Htt mRNA and lowering of 25-40% in protein levels. The number of Htt mRNA foci in medium spiny neurons (MSNs) of untreated Q140/Q140 mice varied widely per cell (0 to 34 per cell), with ∼10% of MSNs devoid of foci. AAV9-GFP-miRHtt treatment shifted the distribution toward lower numbers and the percentage of cells without foci increased to 14-20%. The average number of Htt mRNA foci per MSN was reduced by 43%.

Conclusions: The findings here show that intrastriatal infusion of an AAV9-GFP-miRHtt vector lowers mRNA expression of Htt in striatum by ∼50%, through a partial reduction in the number of copies of mutant Htt mRNAs per cell. These findings demonstrate at the neuronal level the variable levels of Htt mRNA expression in MSNs and the neuronal heterogeneity of RNAi dependent Htt mRNA knockdown.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3233/JHD-160215DOI Listing
October 2016

Cell cycle re-entry sensitizes podocytes to injury induced death.

Cell Cycle 2016 07 27;15(14):1929-37. Epub 2016 May 27.

a Department of Nephropathology , Friedrich-Alexander University (FAU) Erlangen-Nürnberg , Erlangen , Germany.

Podocytes are terminally differentiated renal cells, lacking the ability to regenerate by proliferation. However, during renal injury, podocytes re-enter into the cell cycle but fail to divide. Earlier studies suggested that re-entry into cell cycle results in loss of podocytes, but a direct evidence for this is lacking. Therefore, we established an in vitro model to test the consequences of re-entry into the cell cycle on podocyte survival. A mouse immortalized podocyte cell line was differentiated to non-permissive podocytes and stimulated with e.g. growth factors. Stimulated cells were analyzed for mRNA-expression or stained for cell cycle analysis using flow cytometry and immunocytofluorescence microscopy. After stimulation to re-entry into cell cycle, podocytes were stressed with puromycin aminonucleoside (PAN) and analyzed for survival. During permissive stage more than 40% of immortalized podocytes were in the S-phase. In contrast, S-phase in non-permissive differentiated podocytes was reduced to 5%. Treatment with b-FGF dose dependently induced re-entry into cell cycle increasing the number of podocytes in the S-phase to 10.7% at an optimal bFGF dosage of 10 ng/ml. Forty eight hours after stimulation with bFGF the number of bi-nucleated podocytes significantly increased. A secondary injury stimulus significantly reduced podocyte survival preferentially in bi-nucleated podocytes In conclusion, stimulation of podocytes using bFGF was able to induce re-entry of podocytes into the cell cycle and to sensitize the cells for cell death by secondary injuries. Therefore, this model is appropriate for testing new podocyte protective substances that can be used for therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/15384101.2016.1191710DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4968909PMC
July 2016