Publications by authors named "Enrico Radaelli"

90 Publications

Toxicity after AAV delivery of RNAi expression constructs into nonhuman primate brain.

Nat Med 2021 Oct 18. Epub 2021 Oct 18.

Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA.

RNA interference (RNAi) for spinocerebellar ataxia type 1 can prevent and reverse behavioral deficits and neuropathological readouts in mouse models, with safety and benefit lasting over many months. The RNAi trigger, expressed from adeno-associated virus vectors (AAV.miS1), also corrected misregulated microRNAs (miRNA) such as miR150. Subsequently, we showed that the delivery method was scalable, and that AAV.miS1 was safe in short-term pilot nonhuman primate (NHP) studies. To advance the technology to patients, investigational new drug (IND)-enabling studies in NHPs were initiated. After AAV.miS1 delivery to deep cerebellar nuclei, we unexpectedly observed cerebellar toxicity. Both small-RNA-seq and studies using AAVs devoid of miRNAs showed that this was not a result of saturation of the endogenous miRNA processing machinery. RNA-seq together with sequencing of the AAV product showed that, despite limited amounts of cross-packaged material, there was substantial inverted terminal repeat (ITR) promoter activity that correlated with neuropathologies. ITR promoter activity was reduced by altering the miS1 expression context. The surprising contrast between our rodent and NHP findings highlight the need for extended safety studies in multiple species when assessing new therapeutics for human application.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-021-01522-3DOI Listing
October 2021

Increased tumor-infiltrating lymphocyte density is associated with favorable outcomes in a comparative study of canine histiocytic sarcoma.

Cancer Immunol Immunother 2021 Aug 20. Epub 2021 Aug 20.

Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Histiocytic sarcoma (HS) is a rare and aggressive tumor in humans with no universally agreed standard of care therapy. Spontaneous canine HS exhibits increased prevalence in specific breeds, shares key genetic and biologic similarities with the human disease, and occurs in an immunocompetent setting. Previous data allude to the immunogenicity of this disease in both species, highlighting the potential for their successful treatment with immunotherapy. Quantification of CD3 tumor-infiltrating lymphocytes (TIL) in five cases of human HS revealed variable intra-tumoral T cell infiltration. Due to the paucity of human cases and lack of current model systems in which to appraise associations between anti-tumor immunity and treatment-outcome in HS, we analyzed clinical data and quantified TIL in 18 dogs that were previously diagnosed with localized HS and treated with curative-intent tumor resection with or without adjuvant chemotherapy. As in humans, assessment of TIL in biopsy tissues taken at diagnosis reveal a spectrum of immunologically "cold" to "hot" tumors. Importantly, we show that increased CD3 and granzyme B TIL are positively associated with favorable outcomes in dogs following surgical resection. NanoString transcriptional analyses revealed increased T cell and antigen presentation transcripts associated with prolonged survival in canine pulmonary HS and a decreased tumor immunogenicity profile associated with shorter survivals in splenic HS. Based on these findings, we propose that spontaneous canine HS is an accessible and powerful novel model to study tumor immunology and will provide a unique platform to preclinically appraise the efficacy and tolerability of anti-cancer immunotherapies for HS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00262-021-03033-zDOI Listing
August 2021

FLASH Proton Radiotherapy Spares Normal Epithelial and Mesenchymal Tissues While Preserving Sarcoma Response.

Cancer Res 2021 Sep 28;81(18):4808-4821. Epub 2021 Jul 28.

Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.

In studies of electron and proton radiotherapy, ultrahigh dose rates of FLASH radiotherapy appear to produce fewer toxicities than standard dose rates while maintaining local tumor control. FLASH-proton radiotherapy (F-PRT) brings the spatial advantages of PRT to FLASH dose rates (>40 Gy/second), making it important to understand if and how F-PRT spares normal tissues while providing antitumor efficacy that is equivalent to standard-proton radiotherapy (S-PRT). Here we studied PRT damage to skin and mesenchymal tissues of muscle and bone and found that F-PRT of the C57BL/6 murine hind leg produced fewer severe toxicities leading to death or requiring euthanasia than S-PRT of the same dose. RNA-seq analyses of murine skin and bone revealed pathways upregulated by S-PRT yet unaltered by F-PRT, such as apoptosis signaling and keratinocyte differentiation in skin, as well as osteoclast differentiation and chondrocyte development in bone. Corroborating these findings, F-PRT reduced skin injury, stem cell depletion, and inflammation, mitigated late effects including lymphedema, and decreased histopathologically detected myofiber atrophy, bone resorption, hair follicle atrophy, and epidermal hyperplasia. F-PRT was equipotent to S-PRT in control of two murine sarcoma models, including at an orthotopic intramuscular site, thereby establishing its relevance to mesenchymal cancers. Finally, S-PRT produced greater increases in TGFβ1 in murine skin and the skin of canines enrolled in a phase I study of F-PRT versus S-PRT. Collectively, these data provide novel insights into F-PRT-mediated tissue sparing and support its ongoing investigation in applications that would benefit from this sparing of skin and mesenchymal tissues. SIGNIFICANCE: These findings will spur investigation of FLASH radiotherapy in sarcoma and additional cancers where mesenchymal tissues are at risk, including head and neck cancer, breast cancer, and pelvic malignancies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/0008-5472.CAN-21-1500DOI Listing
September 2021

Palisading granulomatous dermatitis and panniculitis (palisading granuloma) of dogs.

Vet Pathol 2021 Jul 16:3009858211030525. Epub 2021 Jul 16.

University of Pennsylvania, Philadelphia, PA, USA.

Palisading granulomatous dermatitis and panniculitis is recognized in various cutaneous inflammatory lesions secondary to presumed collagen damage. Cutaneous nodules with a palisading arrangement of histiocytes surrounding foci of collagen degeneration have been clinically termed palisading granuloma in dogs. Study aims were to characterize the cellular infiltrate of canine palisading granuloma and document salient clinical features. Inclusion criteria were met for 36 dogs and encompassed nodular dermal and subcutaneous histiocyte-predominant cellular infiltrates targeting and enveloping collagen fibers/necrotic foci with palisading configurations. Infectious causes were ruled out via standard histochemical stains and/or clinical data. Medical records were reviewed for signalment, clinical features, treatment, outcome, and comorbidities. Immunohistochemistry (IBA1, CD204, E-cadherin) and Masson's trichrome stain were used to assess histiocytic populations and dermal collagen, respectively. The histiocytes had moderate or strong immunolabeling for IBA1 and CD204 in 36/36 dogs (100%) and mild positive immunolabeling for E-cadherin in 3/36 dogs (8%). Alteration of collagen was graded as moderate or strong in 32/36 dogs (89%) and mild in 3/36 dogs (8%). Large breeds predominated with 30/36 dogs (83%) being ≥23 kg. Focal nodules were identified in 31/36 dogs (86%). The head/face were involved in 19/36 dogs (53%) and the extremities in 18/36 dogs (50%). Lesions from the 5/36 dogs (14%) with multiple nodules contained prominent eosinophilic infiltrates. Following excision, there was no evidence of recurrence. In conclusion, palisading granulomas are a distinct, non-neoplastic, histiocyte-predominant inflammatory condition in dogs associated with altered dermal collagen and favorable prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/03009858211030525DOI Listing
July 2021

RIPK1 activates distinct gasdermins in macrophages and neutrophils upon pathogen blockade of innate immune signaling.

Proc Natl Acad Sci U S A 2021 Jul;118(28)

Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland;

Injection of effector proteins to block host innate immune signaling is a common strategy used by many pathogenic organisms to establish an infection. For example, pathogenic species inject the acetyltransferase YopJ into target cells to inhibit NF-κB and MAPK signaling. To counteract this, detection of YopJ activity in myeloid cells promotes the assembly of a RIPK1-caspase-8 death-inducing platform that confers antibacterial defense. While recent studies revealed that caspase-8 cleaves the pore-forming protein gasdermin D to trigger pyroptosis in macrophages, whether RIPK1 activates additional substrates downstream of caspase-8 to promote host defense is unclear. Here, we report that the related gasdermin family member gasdermin E (GSDME) is activated upon detection of YopJ activity in a RIPK1 kinase-dependent manner. Specifically, GSDME promotes neutrophil pyroptosis and IL-1β release, which is critical for anti- defense. During in vivo infection, IL-1β neutralization increases bacterial burden in wild-type but not -deficient mice. Thus, our study establishes GSDME as an important mediator that counteracts pathogen blockade of innate immune signaling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.2101189118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8285957PMC
July 2021

Mechanisms of Regulated Cell Death: Current Perspectives.

Vet Pathol 2021 Jul 27;58(4):596-623. Epub 2021 May 27.

Department of Pathobiology, School of Veterinary Medicine, 6572University of Pennsylvania, Philadelphia, PA, USA.

Balancing cell survival and cell death is fundamental to development and homeostasis. Cell death is regulated by multiple interconnected signaling pathways and molecular mechanisms. Regulated cell death (RCD) is implicated in fundamental processes such as organogenesis and tissue remodeling, removal of unnecessary structures or cells, and regulation of cell numbers. RCD can also be triggered by exogenous perturbations of the intracellular or extracellular microenvironment when the adaptive processes that respond to stress fail. During the past few years, many novel forms of non-apoptotic RCD have been identified, and the characterization of RCD mechanisms at a molecular level has deepened our understanding of diseases encountered in human and veterinary medicine. Given the complexity of these processes, it has become clear that the identification of RCD cannot be based simply on morphologic characteristics and that descriptive and diagnostic terms presently used by pathologists-such as individual cell apoptosis or necrosis-appear inadequate and possibly misleading. In this review, the current understanding of the molecular machinery of each type of non-apoptotic RCD mechanisms is outlined. Due to the continuous discovery of new mechanisms or nuances of previously described processes, the limitations of the terms and to indicate microscopic findings are also reported. In addition, the need for a standard panel of biomarkers and functional tests to adequately characterize the underlying RCD and its role as a mechanism of disease is considered.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/03009858211005537DOI Listing
July 2021

Regulation of intercellular biomolecule transfer-driven tumor angiogenesis and responses to anticancer therapies.

J Clin Invest 2021 05;131(10)

Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

Intercellular biomolecule transfer (ICBT) between malignant and benign cells is a major driver of tumor growth, resistance to anticancer therapies, and therapy-triggered metastatic disease. Here we characterized cholesterol 25-hydroxylase (CH25H) as a key genetic suppressor of ICBT between malignant and endothelial cells (ECs) and of ICBT-driven angiopoietin-2-dependent activation of ECs, stimulation of intratumoral angiogenesis, and tumor growth. Human CH25H was downregulated in the ECs from patients with colorectal cancer and the low levels of stromal CH25H were associated with a poor disease outcome. Knockout of endothelial CH25H stimulated angiogenesis and tumor growth in mice. Pharmacologic inhibition of ICBT by reserpine compensated for CH25H loss, elicited angiostatic effects (alone or combined with sunitinib), augmented the therapeutic effect of radio-/chemotherapy, and prevented metastatic disease induced by these regimens. We propose inhibiting ICBT to improve the overall efficacy of anticancer therapies and limit their prometastatic side effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI144225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8121529PMC
May 2021

IL-33 promotes innate lymphoid cell-dependent IFN-γ production required for innate immunity to .

Elife 2021 04 30;10. Epub 2021 Apr 30.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, United States.

IL-33 is an alarmin required for resistance to the parasite , but its role in innate resistance to this organism is unclear. Infection with promotes increased stromal cell expression of IL-33, and levels of parasite replication correlate with release of IL-33 in affected tissues. In response to infection, a subset of innate lymphoid cells (ILC) emerges composed of IL-33R NK cells and ILC1s. In mice, where NK cells and ILC1 production of IFN-γ mediate innate resistance to , the loss of the IL-33R resulted in reduced ILC responses and increased parasite replication. Furthermore, administration of IL-33 to mice resulted in a marked decrease in parasite burden, increased production of IFN-γ, and the recruitment and expansion of inflammatory monocytes associated with parasite control. These protective effects of exogenous IL-33 were dependent on endogenous IL-12p40 and the ability of IL-33 to enhance ILC production of IFN-γ. These results highlight that IL-33 synergizes with IL-12 to promote ILC-mediated resistance to .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7554/eLife.65614DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8121546PMC
April 2021

Adoptive T cell immunotherapy for medullary thyroid carcinoma targeting GDNF family receptor alpha 4.

Mol Ther Oncolytics 2021 Mar 26;20:387-398. Epub 2021 Jan 26.

Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.

Metastatic medullary thyroid cancer (MTC) is a rare but often aggressive thyroid malignancy with a 5-year survival rate of less than 40% and few effective therapeutic options. Adoptive T cell immunotherapy using chimeric antigen receptor (CAR)-modified T cells (CAR Ts) is showing encouraging results in the treatment of cancer, but development is challenged by the availability of suitable target antigens. We identified glial-derived neurotrophic factor (GDNF) family receptor alpha 4 (GFRα4) as a putative antigen target for CAR-based therapy of MTC. We show that GFRα4 is highly expressed in MTC, in parafollicular cells within the thyroid from which MTC originates, and in normal thymus. We isolated two single-chain variable fragments (scFvs) targeting GFRα4 isoforms a and b by antibody phage display. CARs bearing the CD3ζ and the CD137 costimulatory domains were constructed using these GFRα4-specific scFvs. GFRα4-specific CAR Ts trigger antigen-dependent cytotoxicity and cytokine production , and they are able to eliminate tumors derived from the MTC TT cell line in an immunodeficient mouse xenograft model of MTC. These data demonstrate the feasibility of targeting GFRα4 by CAR T and support this antigen as a promising target for adoptive T cell immunotherapy and other antibody-based therapies for MTC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.omto.2021.01.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7879023PMC
March 2021

Special Focus on Regulated Cell Death: Emerging Mechanisms and Current Perspectives in Biology and Pathology.

Vet Pathol 2021 Jul 12;58(4):594-595. Epub 2021 Feb 12.

6572University of Pennsylvania, Philadelphia, PA, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0300985820985326DOI Listing
July 2021

Lentiviral vector ALS20 yields high hemoglobin levels with low genomic integrations for treatment of beta-globinopathies.

Mol Ther 2021 04 29;29(4):1625-1638. Epub 2021 Jan 29.

Division of Hematology, Children's Hospital of Philadelphia (CHOP), Philadelphia, PA, USA; Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Cell and Molecular Biology Affinity Group (CAMB), University of Pennsylvania, Philadelphia, PA, USA; Raymond G. Perelman Center for Cellular and Molecular Therapeutics, CHOP, Philadelphia, PA, USA; Penn Center for Musculoskeletal Disorders, CHOP, Philadelphia, PA, USA. Electronic address:

Ongoing clinical trials for treatment of beta-globinopathies by gene therapy involve the transfer of the beta-globin gene, which requires integration of three to four copies per genome in most target cells. This high proviral load may increase genome toxicity, potentially limiting the safety of this therapy and relegating its use to total body myeloablation. We hypothesized that introducing an additional hypersensitive site from the locus control region, the complete sequence of the second intron of the beta-globin gene, and the ankyrin insulator may enhance beta-globin expression. We identified a construct, ALS20, that synthesized significantly higher adult hemoglobin levels than those of other constructs currently used in clinical trials. These findings were confirmed in erythroblastic cell lines and in primary cells isolated from sickle cell disease patients. Bone marrow transplantation studies in beta-thalassemia mice revealed that ALS20 was curative at less than one copy per genome. Injection of human CD34 cells transduced with ALS20 led to safe, long-term, and high polyclonal engraftment in xenograft experiments. Successful treatment of beta-globinopathies with ALS20 could potentially be achieved at less than two copies per genome, minimizing the risk of cytotoxic events and lowering the intensity of myeloablation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ymthe.2020.12.036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8058492PMC
April 2021

Restricted Sensitivity of FJ-C Staining to Assess Neuronal Degeneration and Death in Preclinical Mouse Studies.

Vet Pathol 2021 Jul 5;58(4):643-649. Epub 2021 Jan 5.

6572University of Pennsylvania, Philadelphia, PA, USA.

Fluorescein-derived fluorochromes and anionic dyes such as Fluoro-Jade (FJ) stains have been introduced to facilitate recognition of dying neurons in tissue sections. However, the definition of what is really detected by FJ-based stains and its sensitivity in the detection of neuronal cell death is unclear. In our work, we evaluated the outcome of FJ-C staining in mouse brains from 4 different well-characterized models of neurodegeneration. Neuronal degeneration and loss were highlighted with high sensitivity by FJ-C stain in mice with dysfunctional γ-secretase in the glutamatergic neurons and in mice affected by acute cerebral ischemia. Histopathologically, acute eosinophilic necrosis or "red dead" neurons were associated with FJ-C staining in both settings. Conversely, in mice affected by chronic cerebral microinfarcts due to tumor lysis syndrome as well as in a model of mitochondrial encephalopathy, FJ-C staining failed to detect neuronal death. Histopathologically, these models were characterized by extensive neuronal vacuolation associated with fading neurons ("ghost cells"). Therefore, contrary to the widespread belief that FJ-C stain has high affinity for all degenerating neurons regardless of the underlying cell death mechanism, we observed restricted sensitivity of the technique to specific conditions of neuronal cell death. As such, complementary techniques are essential to evaluate the presence of neurodegeneration in the absence of a positive FJ-C signal.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0300985820985290DOI Listing
July 2021

Pathology of macrophage activation syndrome in humanized NSGS mice.

Res Vet Sci 2021 Jan 16;134:137-146. Epub 2020 Dec 16.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA.

"Humanized" immunodeficient mice generated via the transplantation of CD34+ human hematopoietic stem cells (hHSC) are an important preclinical model system. The triple transgenic NOD.Cg-PrkdcIl2rg Tg(CMV-IL3,CSF2,KITLG)1Eav/MloySzJ (NSGS) mouse line is increasingly used as recipient for CD34+ hHSC engraftment. NSGS mice combine the features of the highly immunodeficient NSG mice with transgenic expression of the human myeloid stimulatory cytokines GM-CSF, IL-3, and Kit ligand. While generating humanized NSGS (huNSGS) mice from two independent cohorts, we encountered a fatal macrophage activation syndrome (MAS)-like phenotype resulting from the transplantation of CD34+ hHSC. huNSGS mice exhibiting this phenotype declined clinically starting at approximately 10 weeks following CD34+ hHSC engraftment, with all mice requiring euthanasia by 16 weeks. Gross changes comprised small, irregular liver, splenomegaly, cardiomegaly, and generalized pallor. Hematological abnormalities included severe thrombocytopenia and anemia. Pathologically, huNSGS spontaneously developed a disseminated histiocytosis with infiltrates of activated macrophages and hemophagocytosis predominantly affecting the liver, spleen, bone marrow, and pancreas. The infiltrates were chimeric with a mixture of human and mouse macrophages. Immunohistochemistry suggested activation of the inflammasome in both human and murine macrophages. Active Epstein-Barr virus infection was not a feature. Although the affected mice exhibited robust chimerism of the spleen and bone marrow, the phenotype often developed in the face of low chimerism of the peripheral blood. Given the high penetrance and early lethality associated with the MAS-like phenotype here described, we urge caution when considering the use of huNSGS mice for the development of long-term studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rvsc.2020.12.003DOI Listing
January 2021

Classification and Grading of Melanocytic Lesions in a Mouse Model of -driven Melanomagenesis.

J Histochem Cytochem 2021 03 7;69(3):203-218. Epub 2020 Dec 7.

Department of Pathobiology, University of Pennsylvania, Philadelphia, PA.

The mouse line carrying the Tg(Tyr-NRAS*Q61K)1Bee transgene is widely used to model in vivo -driven melanomagenesis. Although the pathological features of this model are well described, classification and interpretation of the resulting proliferative lesions-including their origin, evolution, grading, and pathobiological significance-are still unclear and not supported by molecular and biological evidence. Focusing on their classification and grading, this work combines histopathology and expression analysis (using both immunohistochemistry [IHC] and quantitative PCR) of selected biomarkers to study the full spectrum of cutaneous and lymph nodal melanocytic proliferations in the Tg(Tyr-NRAS*Q61K)1Bee mouse. The analysis of cutaneous and lymph nodal melanocytic proliferations has demonstrated that a linear correlation exists between tumor grade and Ki-67, microphthalmia-associated transcription factor (MITF), gp100, and nestin IHC, with a significantly increased expression in high-grade lesions compared with low-grade lesions. The accuracy of the assessment of MITF IHC in melanomas was also confirmed by quantitative PCR analysis. In conclusion, we believe the incorporation of MITF, Ki-67, gp100, and nestin analysis into the histopathological classification/grading scheme of melanocytic proliferations described for this model will help to assess with accuracy the nature and evolution of the phenotype, monitor disease progression, and predict response to experimental treatment or other preclinical manipulations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1369/0022155420977970DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7905489PMC
March 2021

Metastatic Mixed Germ Cell Tumour with Embryonal Carcinoma and Choriocarcinoma in a Female Eurasian Harvest Mouse (Micromys minutus).

J Comp Pathol 2020 Oct 16;180:122-127. Epub 2020 Oct 16.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, USA.

Mixed germ cell tumours occur rarely in veterinary species. This report describes a case of metastatic mixed germ cell tumour in a female Eurasian harvest mouse (Micromys minutus). The tumour was extensive in one ovary and the uterus, and was characterized by two distinct tumour cell populations with features typical of embryonal carcinoma (EC) and choriocarcinoma (CC). Metastases of CC to the lungs and liver were observed. The exact origin of the CC was unclear, but the possibility of a non-gestational CC is favoured, given the context of a mixed germ cell tumour and lack of p53 expression. EC diagnosis was confirmed by immunohistochemical labelling of CD30 and lack of immunoreactivity for c-Kit. In addition, membranous β-catenin expression was present in the EC component, indicating an inactive Wnt/β-catenin pathway, which is required for the maintenance of pluripotency.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcpa.2020.09.007DOI Listing
October 2020

Caspase-8-dependent gasdermin D cleavage promotes antimicrobial defense but confers susceptibility to TNF-induced lethality.

Sci Adv 2020 Nov 18;6(47). Epub 2020 Nov 18.

Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland.

Gasdermin D (GSDMD) is a pore-forming protein that promotes pyroptosis and release of proinflammatory cytokines. Recent studies revealed that apoptotic caspase-8 directly cleaves GSDMD to trigger pyroptosis. However, the molecular requirements for caspase-8-dependent GSDMD cleavage and the physiological impact of this signaling axis are unresolved. Here, we report that caspase-8-dependent GSDMD cleavage confers susceptibility to tumor necrosis factor (TNF)-induced lethality independently of caspase-1 and that GSDMD activation provides host defense against infection. We further demonstrate that GSDMD inactivation by apoptotic caspases at aspartate 88 (D88) suppresses TNF-induced lethality but promotes anti- defense. Last, we show that caspase-8 dimerization and autoprocessing are required for GSDMD cleavage, and provide evidence that the caspase-8 autoprocessing and activity on various complexes correlate with its ability to directly cleave GSDMD. These findings reveal GSDMD as a potential therapeutic target to reduce inflammation associated with mutations in the death receptor signaling machinery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciadv.abc3465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673803PMC
November 2020

Antigen-specific B cell depletion for precision therapy of mucosal pemphigus vulgaris.

J Clin Invest 2020 12;130(12):6317-6324

Department of Dermatology.

Desmoglein 3 chimeric autoantibody receptor T cells (DSG3-CAART) expressing the pemphigus vulgaris (PV) autoantigen DSG3 fused to CD137-CD3ζ signaling domains, represent a precision cellular immunotherapy approach for antigen-specific B cell depletion. Here, we present definitive preclinical studies enabling a first-in-human trial of DSG3-CAART for mucosal PV. DSG3-CAART specifically lysed human anti-DSG3 B cells from PV patients and demonstrated activity consistent with a threshold dose in vivo, resulting in decreased target cell burden, decreased serum and tissue-bound autoantibodies, and increased DSG3-CAART engraftment. In a PV active immune model with physiologic anti-DSG3 IgG levels, DSG3-CAART inhibited antibody responses against pathogenic DSG3 epitopes and autoantibody binding to epithelial tissues, leading to clinical and histologic resolution of blisters. DSG3 autoantibodies stimulated DSG3-CAART IFN-γ secretion and homotypic clustering, consistent with an activated phenotype. Toxicology screens using primary human cells and high-throughput membrane proteome arrays did not identify off-target cytotoxic interactions. These preclinical data guided the trial design for DSG3-CAART and may help inform CAART preclinical development for other antibody-mediated diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI138416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7685721PMC
December 2020

Loss of IL-27Rα Results in Enhanced Tubulointerstitial Fibrosis Associated with Elevated Th17 Responses.

J Immunol 2020 07 10;205(2):377-386. Epub 2020 Jun 10.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104;

Clinical and experimental studies have established that immune cells such as alternatively activated (M2) macrophages and Th17 cells play a role in the progression of chronic kidney disease, but the endogenous pathways that limit these processes are not well understood. The cytokine IL-27 has been shown to limit immune-mediated pathology in other systems by effects on these cell types, but this has not been thoroughly investigated in the kidney. Unilateral ureteral obstruction was performed on wild-type and IL-27Rα mice. After 2 wk, kidneys were extracted, and the degree of injury was measured by hydroxyproline assay and quantification of neutrophil gelatinase-associated lipocalin mRNA. Immune cell infiltrate was evaluated by immunohistochemistry and flow cytometry. An anti-IL-17A mAb was subsequently administered to IL-27Rα mice every 2 d from day of surgery with evaluation as described after 2 wk. After unilateral ureteral obstruction, IL-27 deficiency resulted in increased tissue injury and collagen deposition associated with higher levels of chemokine mRNA and increased numbers of M2 macrophages. Loss of the IL-27Rα led to increased infiltration of activated CD4 T cells that coproduced IL-17A and TNF-α, and blockade of IL-17A partially ameliorated kidney injury. Patients with chronic kidney disease had elevated serum levels of IL-27 and IL-17A, whereas expression of transcripts for the IL-27RA and the IL-17RA in the tubular epithelial cells of patients with renal fibrosis correlated with disease severity. These data suggest that endogenous IL-27 acts at several points in the inflammatory cascade to limit the magnitude of immune-mediated damage to the kidney.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1901463DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7368461PMC
July 2020

Molecular subtypes in canine hemangiosarcoma reveal similarities with human angiosarcoma.

PLoS One 2020 25;15(3):e0229728. Epub 2020 Mar 25.

Department of Pathology and Laboratory Medicine, Raymond and Ruth Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America.

Angiosarcoma (AS) is a rare neoplasm with limited treatment options and a poor survival rate. Development of effective therapies is hindered by the rarity of this disease. Dogs spontaneously develop hemangiosarcoma (HSA), a common, histologically similar neoplasm. Metastatic disease occurs rapidly and despite chemotherapy, most dogs die several months after diagnosis. These features suggest that HSA might provide a tractable model to test experimental therapies in clinical trials. We previously reported whole exome sequencing of 20 HSA cases. Here we report development of a NGS targeted resequencing panel to detect driver mutations in HSA and other canine tumors. We validated the panel by resequencing the original 20 cases and sequenced 30 additional cases. Overall, we identified potential driver mutations in over 90% of the cases, including well-documented (in human cancers) oncogenic mutations in PIK3CA (46%), PTEN (6%), PLCG1(4%), and TP53 (66%), as well as previously undetected recurrent activating mutations in NRAS (24%). The driver role of these mutations is further demonstrated by augmented downstream signaling crucial to tumor growth. The recurrent, mutually exclusive mutation patterns suggest distinct molecular subtypes of HSA. Driver mutations in some subtypes closely resemble those seen in some AS cases, including NRAS, PLCG1, PIK3CA and TP53. Furthermore, activation of the MAPK and PI3K pathways appear to be key oncogenic mechanisms in both species. Together, these observations suggest that dogs with spontaneous HSA could serve as a useful model for testing the efficacy of targeted therapies, some of which could potentially be of therapeutic value in AS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0229728PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094861PMC
June 2020

Generation and Validation of an Antibody to Canine CD19 for Diagnostic and Future Therapeutic Purposes.

Vet Pathol 2020 03 21;57(2):241-252. Epub 2020 Feb 21.

Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.

The B-cell coreceptor, CD19 is a transmembrane protein expressed throughout B-cell ontogeny from pro-B cell to plasmablast. It plays an important role in B-cell development and function and is an attractive target for antibody-directed immunotherapies against B-cell malignancies, including acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), and non-Hodgkin lymphoma (B-NHL) in humans. With the rapid development of next-generation immunotherapies aimed at improving therapeutic efficacy, there is a pressing need for a clinically relevant, immune-competent, spontaneous animal model to derisk these new approaches and inform human immunotherapy clinical trials. Pet dogs develop spontaneous B-cell malignancies, including B-NHL and leukemias that share comparable oncogenic pathways and similar immunosuppressive features to human B-cell malignancies. Despite treatment with multiagent chemotherapy, durable remissions in canine B-NHL are rare and most dogs succumb to their disease within 1 year of diagnosis. Here we report the development and validation of an anti-canine CD19-targeting monoclonal antibody and its single-chain derivatives, which enable next-generation CD19-targeted immunotherapies to be developed and evaluated in client-owned dogs with spontaneous B-NHL. These future in vivo studies aim to provide important information regarding the safety and therapeutic efficacy of CD19-targeted mono- and combination therapies and identify correlative biomarkers of response that will help to inform human clinical trial design. In addition, development of canine CD19-targeted immunotherapies aims to provide better therapeutic options for pet dogs diagnosed with B-cell malignancies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0300985819900352DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7462180PMC
March 2020

The estrogen effect; clinical and histopathological evidence of dichotomous influences in dogs with spontaneous mammary carcinomas.

PLoS One 2019 25;14(10):e0224504. Epub 2019 Oct 25.

Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania - New Bolton Center, Kennett Square, Pennsylvania, United States of America.

The purpose of this study was to investigate the associations and explore the relationships between hormonal factors (serum estrogen, estrogen receptors and ovariohysterectomy) and other clinical/histological prognostic factors and their impact on outcome in dogs with mammary carcinomas. Data from two separate prospective studies on dogs with spontaneous mammary carcinomas were used for this research. All dogs underwent standardized diagnostic testing, staging, surgery and follow-up examinations. Serum estrogen was analyzed by competitive enzyme immunoassay or radioimmunoassay, and tumor estrogen receptor (ER) expression was analyzed by immunohistochemistry. A total of 159 dogs were included; 130 were spayed and 29 remained. High serum estrogen was associated with an overall longer time to metastasis (p = 0.021). When stratifying based on spay group, the effect was only significant in spayed dogs, (p = 0.019). Positive tumor ER expression was also associated with a longer time to metastasis (p = 0.025), but similar to above, only in dogs that were spayed (p = 0.049). Further subgroup analysis revealed that high serum estrogen was significantly associated with improved survival in dogs with ER positive tumors, but only in spayed dogs (p = 0.0052). Interestingly, the effect of spaying was the opposite in dogs with ER negative tumors; here, intact dogs with high serum estrogen but ER negative tumors had a significantly longer time to metastasis (p = 0.036). Low serum estrogen was associated with increased risk for the development of non-mammary tumors in the post-operative period (p = 0.012). These results highlight the dual effect of estrogen in cancer: Estrogen acts as a pro-carcinogen in ER positive mammary tumors, but a may have a protective effect in ER negative tumors, potentially via non-receptor mechanisms. The latter is supported by the decreased risk for non-mammary tumors in dogs with high serum estrogen, and explains the increased incidence of certain non-mammary tumors in in dogs spayed at an early age.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224504PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6814212PMC
March 2020

Prenatal hypoxemia alters microglial morphology in fetal sheep.

J Thorac Cardiovasc Surg 2019 Aug 28. Epub 2019 Aug 28.

Division of Cardiothoracic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pa. Electronic address:

Objective: Neuroimmune cells, particularly microglia and astrocytes, play a critical role in neurodevelopment. Neurocognitive delays are common in children with congenital heart disease, but their etiology is poorly understood. Our objective was to determine whether prenatal hypoxemia, at levels common in congenital heart disease, induced neuroimmune activation to better understand the origins of neurobehavioral disorders in congenital heart disease.

Methods: Eight fetal sheep at gestational age 109 ± 3 days (term ∼145 days) were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 22 ± 2 days under normoxic (n = 4) or hypoxic (n = 4) conditions. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were stained with ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein antibodies to quantify microglia and astrocytes, respectively, in gray and white matter in frontotemporal and cerebellar sections. Microglia were classified into 4 morphologic types based on cell shape. Data were analyzed with 1-way analysis of variance or Fisher exact test, as appropriate.

Results: Oxygen delivery was significantly reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min; P < .01). Rates of apoptosis were similar in hypoxic, normoxic, and intrauterine control animals in all examined areas. There were also no differences between groups in area occupied by glial fibrillary acidic protein-labeled astrocytes or ionized calcium-binding adaptor molecule 1-labeled microglia in all examined areas. However, round microglia were significantly increased in hypoxic animals compared with normoxic animals (33% vs 6%; P < .01) and control animals (33% vs 11%; P < .01).

Conclusions: Prenatal hypoxemia altered microglial morphology without significant gliosis. Additional studies characterizing these mechanisms may provide insight into the origins of neurobehavioral disabilities in children with congenital heart disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtcvs.2019.06.102DOI Listing
August 2019

Spontaneous Incidental Brain Lesions in C57BL/6J Mice.

Vet Pathol 2020 01 4;57(1):172-182. Epub 2019 Jul 4.

Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA.

Genetically engineered mouse lines on a C57BL/6J background are widely employed as preclinical models to study neurodegenerative human disorders and brain tumors. However, because of the lack of comprehensive data on the spontaneous background neuropathology of the C57BL/6J strain, discriminating between naturally occurring changes and lesions caused by experimental mutations can be challenging. In this context, this study aims at defining the spectrum and frequency of spontaneous brain changes in a large cohort of C57BL/6J mice and their association with specific biological variables, including age and sex. Brains from 203 experimentally naive and clinically unremarkable C57BL/6J mice were collected and analyzed by means of histopathology and immunohistochemistry. Mice ranged in age from 3 to 110 weeks with 89 females, 111 males, and 3 unknowns. Sixteen different spontaneous lesion categories were described in this cohort. Age-related neurodegenerative and/or neuroinflammatory findings represented the most common pathologic changes and included (1) Hirano-like inclusions in the thalamic neurons, (2) neuroaxonal dystrophy in the medulla oblongata, (3) periodic acid-Schiff-positive granular deposits in the neuropil of the hippocampus, and (4) progressive neuroinflammation characterized by microgliosis and astrogliosis. Neoplastic conditions, developmental abnormalities, and circulatory disorders were rarely observed incidental findings. In conclusion, this study describes spontaneous age-related brain lesions of the C57BL/6J mouse and provides a reference for evaluating and interpreting the neuropathological phenotype in genetically engineered mouse models developed and maintained on this congenic background.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0300985819859878DOI Listing
January 2020

Validation of the Fetal Lamb Model of Spina Bifida.

Sci Rep 2019 06 27;9(1):9327. Epub 2019 Jun 27.

Department of Development and Regeneration, Cluster Urogenital, Abdominal and Plastic surgery, Biomedical Sciences, Katholieke Universiteit (KU) Leuven, Leuven, Belgium.

A randomized trial demonstrated that fetal spina bifida (SB) repair is safe and effective yet invasive. New less invasive techniques are proposed but are not supported by adequate experimental studies. A validated animal model is needed to bridge the translational gap to the clinic and should mimic the human condition. Introducing a standardized method, we comprehensively and reliably characterize the SB phenotype in two lamb surgical models with and without myelotomy as compared to normal lambs. Hindbrain herniation measured on brain magnetic resonance imaging (MRI) was the primary outcome. Secondary outcomes included gross examination with cerebrospinal fluid (CSF) leakage test, neurological examination with locomotor assessment, whole-body MRI, motor and somatosensory evoked potentials; brain, spinal cord, hindlimb muscles, bladder and rectum histology and/or immunohistochemistry. We show that the myelotomy model best phenocopies the anatomy, etiopathophysiology and symptomatology of non-cystic SB. This encompasses hindbrain herniation, ventriculomegaly, posterior fossa anomalies, loss of brain neurons; lumbar CSF leakage, hindlimb somatosensory-motor deficit with absence of motor and somatosensory evoked potentials due to loss of spinal cord neurons, astroglial cells and myelin; urinary incontinence. This model obtains the highest validity score for SB animal models and is adequate to assess the efficacy of novel fetal therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-45819-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6597719PMC
June 2019

Immune Relevant and Immune Deficient Mice: Options and Opportunities in Translational Research.

ILAR J 2018 12;59(3):211-246

Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland.

In 1989 ILAR published a list and description of immunodeficient rodents used in research. Since then, advances in understanding of molecular mechanisms; recognition of genetic, epigenetic microbial, and other influences on immunity; and capabilities in manipulating genomes and microbiomes have increased options and opportunities for selecting mice and designing studies to answer important mechanistic and therapeutic questions. Despite numerous scientific breakthroughs that have benefitted from research in mice, there is debate about the relevance and predictive or translational value of research in mice. Reproducibility of results obtained from mice and other research models also is a well-publicized concern. This review summarizes resources to inform the selection and use of immune relevant mouse strains and stocks, aiming to improve the utility, validity, and reproducibility of research in mice. Immune sufficient genetic variations, immune relevant spontaneous mutations, immunodeficient and autoimmune phenotypes, and selected induced conditions are emphasized.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ilar/ily026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7114723PMC
December 2018

Infection-Induced Intestinal Dysbiosis Is Mediated by Macrophage Activation and Nitrate Production.

mBio 2019 05 28;10(3). Epub 2019 May 28.

Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA

Oral infection of C57BL/6J mice with results in a marked bacterial dysbiosis and the development of severe pathology in the distal small intestine that is dependent on CD4 T cells and interferon gamma (IFN-γ). This dysbiosis and bacterial translocation contribute to the development of ileal pathology, but the factors that support the bloom of bacterial pathobionts are unclear. The use of microbial community profiling and shotgun metagenomics revealed that infection induces a dysbiosis dominated by and an increased potential for nitrate respiration. experiments using bacterial metabolic mutants revealed that during this infection, host-derived nitrate supports the expansion of in the ileum via nitrate respiration. Additional experiments with infected mice indicate that the IFN-γ/STAT1/iNOS axis, while essential for parasite control, also supplies a pool of nitrate that serves as a source for anaerobic respiration and supports overgrowth of Together, these data reveal a trade-off in intestinal immunity after oral infection of C57BL/6J mice with , in which inducible nitric oxide synthase (iNOS) is required for parasite control, while this host enzyme is responsible for specific modification of the composition of the microbiome that contributes to pathology. is a protozoan parasite and a leading cause of foodborne illness. Infection is initiated when the parasite invades the intestinal epithelium, and in many host species, this leads to intense inflammation and a dramatic disruption of the normal microbial ecosystem that resides in the healthy gut (the so-called microbiome). One characteristic change in the microbiome during infection with -as well as numerous other pathogens-is the overgrowth of or similar bacteria and a breakdown of commensal containment leading to seeding of peripheral organs with gut bacteria and subsequent sepsis. Our findings provide one clear explanation for how this process is regulated, thereby improving our understanding of the relationship between parasite infection, inflammation, and disease. Furthermore, our results could serve as the basis for the development of novel therapeutics to reduce the potential for harmful bacteria to bloom in the gut during infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/mBio.00935-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538788PMC
May 2019

Mitochondrially targeted cytochrome P450 2D6 is involved in monomethylamine-induced neuronal damage in mouse models.

J Biol Chem 2019 06 20;294(26):10336-10348. Epub 2019 May 20.

From the Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104,

Parkinson's disease (PD) is a major human disease associated with degeneration of the central nervous system. Evidence suggests that several endogenously formed 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mimicking chemicals that are metabolic conversion products, especially β-carbolines and isoquinolines, act as neurotoxins that induce PD or enhance progression of the disease. We have demonstrated previously that mitochondrially targeted human cytochrome P450 2D6 (CYP2D6), supported by mitochondrial adrenodoxin and adrenodoxin reductase, can efficiently catalyze the conversion of MPTP to the toxic 1-methyl-4-phenylpyridinium ion. In this study, we show that the mitochondrially targeted CYP2D6 can efficiently catalyze MPTP-mimicking compounds, 2-methyl-1,2,3,4-tetrahydroisoquinoline, 2-methyl-1,2,3,4-tetrahydro-β-carboline, and 9-methyl-norharmon, suspected to induce PD in humans. Our results reveal that activity and respiration in mouse brain mitochondrial complex I are significantly affected by these toxins in WT mice but remain unchanged in Cyp2d6 locus knockout mice, indicating a possible role of CYP2D6 in the metabolism of these compounds both and These metabolic effects were minimized in the presence of two CYP2D6 inhibitors, quinidine and ajmalicine. Neuro-2a cells stably expressing predominantly mitochondrially targeted CYP2D6 were more sensitive to toxin-mediated respiratory dysfunction and complex I inhibition than cells expressing predominantly endoplasmic reticulum-targeted CYP2D6. Exposure to these toxins also induced the autophagic marker Parkin and the mitochondrial fission marker Dynamin-related protein 1 (Drp1) in differentiated neurons expressing mitochondrial CYP2D6. Our results show that monomethylamines are converted to their toxic cationic form by mitochondrially directed CYP2D6 and result in neuronal degradation in mice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.RA119.008848DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6664168PMC
June 2019

Chronic intrauterine hypoxia alters neurodevelopment in fetal sheep.

J Thorac Cardiovasc Surg 2019 05 11;157(5):1982-1991. Epub 2019 Jan 11.

Division of Cardiothoracic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pa. Electronic address:

Objective: We tested the hypothesis that chronic fetal hypoxia, at a severity present in many types of congenital heart disease, would lead to abnormal neurodevelopment.

Methods: Eight mid-gestation fetal sheep were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid-filled environment for 22 ± 2 days under normoxic or hypoxic conditions. Total parenteral nutrition was provided. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were fixed for histopathology. Neurons were quantified in white matter tracts, and the thickness of the external granular layer of the cerebellum was measured to assess neuronal migration. Capillary density and myelination were quantified in white matter. Data were analyzed with unpaired Student t tests or 1-way analysis of variance, as appropriate.

Results: Oxygen delivery was reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min, P < .01), but umbilical blood flow and caloric delivery were not different between the 2 groups. Compared with normoxic and control animals, hypoxic fetuses had reduced neuronal density and increased external granular layer thickness. Compared with normoxic and control animals, hypoxic fetuses had increased capillary density in white matter. Cortical myelin integrity score was lower in the hypoxic group compared with normoxic and control animals. There was a significant negative correlation between myelin integrity and capillary density.

Conclusions: Chronic fetal hypoxia leads to white matter hyper-vascularity, decreased neuronal density, and impaired myelination, similar to the neuropathologic findings observed in children with congenital heart disease. These findings support the hypothesis that fetal hypoxia, even in the setting of normal caloric delivery, impairs neurodevelopment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtcvs.2018.12.093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6690589PMC
May 2019

PARL deficiency in mouse causes Complex III defects, coenzyme Q depletion, and Leigh-like syndrome.

Proc Natl Acad Sci U S A 2019 01 21;116(1):277-286. Epub 2018 Dec 21.

VIB Center for Brain and Disease Research, 3000 Leuven, Belgium;

The mitochondrial intramembrane rhomboid protease PARL has been implicated in diverse functions in vitro, but its physiological role in vivo remains unclear. Here we show that ablation in mouse causes a necrotizing encephalomyelopathy similar to Leigh syndrome, a mitochondrial disease characterized by disrupted energy production. Mice with conditional PARL deficiency in the nervous system, but not in muscle, develop a similar phenotype as germline KOs, demonstrating the vital role of PARL in neurological homeostasis. Genetic modification of two major PARL substrates, PINK1 and PGAM5, do not modify this severe neurological phenotype. brain mitochondria are affected by progressive ultrastructural changes and by defects in Complex III (CIII) activity, coenzyme Q (CoQ) biosynthesis, and mitochondrial calcium metabolism. PARL is necessary for the stable expression of TTC19, which is required for CIII activity, and of COQ4, which is essential in CoQ biosynthesis. Thus, PARL plays a previously overlooked constitutive role in the maintenance of the respiratory chain in the nervous system, and its deficiency causes progressive mitochondrial dysfunction and structural abnormalities leading to neuronal necrosis and Leigh-like syndrome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1811938116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6320509PMC
January 2019
-->