Publications by authors named "Luigi Villa"

32 Publications

Implementation of a telemedicine geriatric co-evaluation in the emergency department: a prospective pilot study.

Swiss Med Wkly 2021 04 5;151:w20500. Epub 2021 May 5.

Emergency Department, University Hospital, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, Germany.

  INTRODUCTION: Complex drug management is a common challenge in the treatment of geriatric patients. Pandemic scenarios, such as the current one (COVID-19), call for a reduction of face-to-face meetings, especially for elderly patients. Therefore, the aim of the present study was to compare the innovative concept of applying telemedical assessment to geriatric patients in the emergency department (ED) with ED standard treatment. The therapeutic recommendations regarding drug management from the two assessments were compared. A special focus was the use of potentially inadequate drugs (PIMs) for geriatric patients according to the “Fit for the Aged” (FORTA) classification.

Methods: 50 patients (40% female) aged ≥70 years and assessed with an Identification of Seniors at Risk Score (ISAR score) of ≥2 admitted to the ED were prospectively enrolled in this study between November 2017 and February 2018. In addition to the standard treatment in the ED, co-evaluation via video transmission was independently carried out by a board-certified geriatrician. Drug recommendations by ED physicians (A) and the geriatrician (B) were compared.

Results: There was a significantly higher frequency of recommendations regarding changes to preexisting medication (p <0.001, n = 50) via geriatric telemedicine in comparison with standard ED treatment. The geriatrician intervened significantly more often than the ED physicians: discontinuation of a drug, p <0.001; start of a new drug, p = 0.004; dose change of a drug, p = 0.001; n = 50). Based on the additional therapy recommendations of the geriatrician, the amount of medication taken by the patient was significantly reduced compared with standard ED treatment (ED assessment t(49) = 0.622 vs geriatrician’s assessment t(49) = 4.165; p <0.001; n = 50). Additionally, the number of PIMs was significantly reduced compared with standard medical treatment (p <0.001). The geriatrician changed 53.9% of the drugs (35/65) whereas the ED physicians changed only 12.3% (8/65). Recommendations for immediate drug therapy, however, were made more frequently by ED physicians (p <0.039, n = 50).

Discussion: An early assessment of elderly emergency patients by a geriatrician had a significant impact on the number of drug interventions in the ED. The number of PIMs could be significantly reduced. Whether this also has a positive effect on the further inpatient course needs to be investigated in further prospective studies. The study was retrospectively registered at ClinicalTrials.gov (NCT04148027).  .
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http://dx.doi.org/10.4414/smw.2021.20500DOI Listing
April 2021

Time on previous renal replacement therapy is associated with worse outcomes of COVID-19 in a regional cohort of kidney transplant and dialysis patients.

Medicine (Baltimore) 2021 Mar;100(10):e24893

Department of Nephrology and Rheumatology.

Abstract: Chronic renal replacement therapy by either a kidney transplant (KTX) or hemodialysis (HD) predisposes patients to an increased risk for adverse outcomes of COVID-19. However, details on this interaction remain incomplete. To provide further characterization, we undertook a retrospective observational cohort analysis of the majority of the hemodialysis and renal transplant population affected by the first regional outbreak of severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) in Germany. In a region of 250,000 inhabitants we identified a total of 21 cases with SARS-CoV-2 among 100 KTX and 260 HD patients, that is, 7 KTX with COVID-19, 14 HD with COVID-19, and 3 HD with asymptomatic carrier status. As a first observation, KTX recipients exhibited trends for a higher mortality (43 vs 18%) and a higher proportion of acute respiratory distress syndrome (ARDS) (57 vs 27%) when compared to their HD counterparts. As a novel finding, development of ARDS was significantly associated with the time spent on previous renal replacement therapy (RRT), defined as the composite of dialysis time and time on the transplant (non-ARDS 4.3 vs ARDS 10.6 years, P = .016). Multivariate logistic regression analysis showed an OR of 1.7 per year of RRT. The association remained robust when analysis was confined to KTX patients (5.1 vs 13.2 years, P = .002) or when correlating the time spent on a renal transplant alone (P = .038). Similarly, longer RRT correlated with death vs survival (P = .0002). In conclusion our data suggest renal replacement vintage as a novel risk factor for COVID-19-associated ARDS and death. The findings should be validated by larger cohorts.
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http://dx.doi.org/10.1097/MD.0000000000024893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7969209PMC
March 2021

The assessment of dermatological emergencies in the emergency department via telemedicine is safe: a prospective pilot study.

Intern Emerg Med 2020 10 4;15(7):1275-1279. Epub 2020 Apr 4.

Emergency Department, University Hospital, Rheinisch-Westfälische Technische Hochschule [RWTH] Aachen, Aachen, Germany.

The aim of the study was to examine the feasibility and safety of telemedicine for dermatological emergency patients in the emergency department. This observational study was monocentric, open, prospective and two-arm randomized [control group (n = 50) and teledermatology group (n = 50)]. The control group was conventionally recruited directly by a dermatologist. In the teledermatology group patients, images of the skin lesions and clinical parameters were transferred to a tablet PC (personal computer) by an emergency physician and telemedically assessed by a dermatologist without patient contact. Subsequently, the dermatologist, who was previously telemedically contacted, then personally examined the patient in the emergency department. The treatment time between the control group and the teledermatology group was also recorded and compared. The agreement in suspected diagnosis between teledermatological evaluation and clinical evaluation of the same physician in the teledermatology group was 100%. The treatment time [mean (minutes) ± standard deviation] of the control group was 151 ± 71, that of the teledermatology group was 43 ± 38 (p < 0.001). The use of emergency telemedicine is safe and effective and provides a viable alternative for clinical care of emergency patients.
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http://dx.doi.org/10.1007/s11739-020-02323-1DOI Listing
October 2020

Blood pressure management and guideline adherence in hypertensive emergencies and urgencies: A comparison between telemedically supported and conventional out-of-hospital care.

J Clin Hypertens (Greenwich) 2017 Jul 30;19(7):704-712. Epub 2017 May 30.

Emergency Department, University Hospital RWTH Aachen, Aachen, Germany.

Prehospital hypertensive emergencies and urgencies are common, but evidence is lacking. Telemedically supported hypertensive emergencies and urgencies were prospectively collected (April 2014-March 2015) and compared retrospectively with a historical control group of on-scene physician care in the emergency medical service of Aachen, Germany. Blood pressure management and guideline adherence were evaluated. Telemedical (n=159) vs conventional (n=172) cases: blood pressure reductions of 35±24 mm Hg vs 44±23 mm Hg revealed a group effect adjusted for baseline differences (P=.0006). Blood pressure management in categories: no reduction 6 vs 0 (P=.0121); reduction ≤25% (recommended range) 113 vs 110 patients (P=.2356); reduction >25% to 30% 13 vs 29 (0.020); reduction >30% 12 vs 16 patients (P=.5608). The telemedical approach led to less pronounced blood pressure reductions and a tendency to improved guideline adherence. Telemedically guided antihypertensive care may be an alternative to conventional care especially for potentially underserved areas.
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http://dx.doi.org/10.1111/jch.13026DOI Listing
July 2017

IL-6 Trans-Signaling Drives Murine Crescentic GN.

J Am Soc Nephrol 2016 Jan 3;27(1):132-42. Epub 2015 Jun 3.

Division of Nephrology and Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen Germany;

The role of IL-6 signaling in renal diseases remains controversial, with data describing both anti-inflammatory and proinflammatory effects. IL-6 can act via classic signaling, engaging its two membrane receptors gp130 and IL-6 receptor (IL-6R). Alternatively, IL-6 trans-signaling requires soluble IL-6R (sIL-6R) to act on IL-6R-negative cells that express gp130. Here, we characterize the role of both pathways in crescentic nephritis. Patients with crescentic nephritis had significantly elevated levels of IL-6 in both serum and urine. Similarly, nephrotoxic serum-induced nephritis (NTN) in BALB/c mice was associated with elevated serum IL-6 levels. Levels of serum sIL-6R and renal downstream signals of IL-6 (phosphorylated signal transducer and activator of transcription 3, suppressor of cytokine signaling 3) increased over time in this model. Simultaneous inhibition of both IL-6 signaling pathways using anti-IL-6 antibody did not have a significant impact on NTN severity. In contrast, specific inhibition of trans-signaling using recombinant sgp130Fc resulted in milder disease. Vice versa, specific activation of trans-signaling using a recombinant IL-6-sIL-6R fusion molecule (Hyper-IL-6) significantly aggravated NTN and led to increased systolic BP in NTN mice. This correlated with increased renal mRNA synthesis of the Th17 cell cytokine IL-17A and decreased synthesis of resistin-like alpha (RELMalpha)-encoding mRNA, a surrogate marker of lesion-mitigating M2 macrophage subtypes. Collectively, our data suggest a central role for IL-6 trans-signaling in crescentic nephritis and offer options for more effective and specific therapeutic interventions in the IL-6 system.
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http://dx.doi.org/10.1681/ASN.2014111147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696576PMC
January 2016

Gp130-dependent signaling in the podocyte.

Am J Physiol Renal Physiol 2014 Aug 4;307(3):F346-55. Epub 2014 Jun 4.

Division of Nephrology and Immunology, RWTH Aachen University, Aachen Germany;

Renal inflammation, in particular glomerular, is often characterized by increased IL-6 levels. The in vivo relevance of IL-6 signaling in glomerular podocytes, which play central roles in most glomerular diseases, is unknown. Here, we show that in normal mice, podocytes express gp130, the common signal-transducing receptor subunit of the IL-6 family of cytokines. Following systemic IL-6 or LPS injection in mice, podocyte IL-6 signaling was evidenced by downstream STAT3 phosphorylation. Next, we generated mice deficient for gp130 in podocytes. Expectedly, these mice exhibited abrogated IL-6 downstream signaling in podocytes. At the age of 40 wk, they did not show spontaneous renal pathology or abnormal renal function. The mice were then challenged using two LPS injury models as well as nephrotoxic serum to induce crescentic nephritis. Under all conditions, circulating IL-6 levels increased markedly and the mice developed the pathological hallmarks of the corresponding injury models such as proteinuria and development of glomerular crescents, respectively. However, despite the capacity of normal podocytes to transduce IL-6 family signals downstream, there were no significant differences between mice bearing the podocyte-specific gp130 deletion and their control littermates in any of these models. In conclusion, under the different conditions tested, gp130 signaling was not a critical component of the (patho-)biology of the podocyte in vivo.
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http://dx.doi.org/10.1152/ajprenal.00620.2013DOI Listing
August 2014

Late angiotensin II receptor blockade in progressive rat mesangioproliferative glomerulonephritis: new insights into mechanisms.

J Pathol 2013 Apr 5;229(5):672-84. Epub 2013 Mar 5.

Division of Nephrology, RWTH Aachen University Hospital, Germany.

Mesangioproliferative glomerulonephritis is the most common nephritis worldwide. We examined the effects of low- and high-dose telmisartan, an angiotensin II receptor blocker, in rats with progressive anti-Thy1.1 mesangioproliferative glomerulonephritis in a clinically relevant situation of established renal damage. Uninephrectomized nephritic rats were randomized on day 28 to remain untreated (control treatment; CT), or to receive low- (0.1 mg/kg/day, LT) or high-dose telmisartan (10 mg/kg/day, HT), hydrochlorothiazide + hydralazine (8 + 32 mg/kg/day, HCT + H), or atenolol (100 mg/kg/day, AT). CT and LT rats were hypertensive, whereas HT, HCT + H and AT treatment normalized blood pressures. On day 131, despite similar blood lowering effects, only HT, but not AT or HCT + H, prevented loss of renal function and reduced proteinuria compared to CT. Only HT potently ameliorated glomerulosclerosis, tubulointerstitial damage, cortical matrix deposition, podocyte damage and macrophage infiltration. HT reduced cortical expression of platelet derived growth factor receptor-α and -β as well as transforming growth factor-β1. LT exhibited minor but significant efficacy even in the absence of antihypertensive effects. Transcript array analyses revealed a four-fold down-regulation of renal cortical chemokine (C-C motif) receptor 6 (CCR6) mRNA by HT, which was confirmed at the protein level. Silencing of CCR6 did not alter podocyte function in vitro, thus indicating a predominant role in the tubulo-interstitium. In human kidney biopsies, CCR6 mRNA and mRNA of its ligand chemokine (C-C motif) ligand 20 was up-regulated in patients with progressive IgA nephropathy compared to stable disease. Thus, delayed treatment with high-dose telmisartan exerted a pronounced benefit in progressive mesangioproliferative glomerulonephritis, which extended beyond that of equivalent blood pressure lowering. We identified down-regulation of platelet-derived growth factor receptors and CCR6 as potential mediators of telmisartan-related renoprotection. CCR6 may also regulate the renal outcome in human mesangioprolfierative glomerulonephritis.
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http://dx.doi.org/10.1002/path.4151DOI Listing
April 2013

Induction of progressive glomerulonephritis by podocyte-specific overexpression of platelet-derived growth factor-D.

Kidney Int 2011 Dec 24;80(12):1292-305. Epub 2011 Aug 24.

Division of Nephrology, RWTH Aachen University Hospital, Aachen, Germany.

Platelet-derived growth factor-D (PDGF-D), normally expressed in podocytes, mediates mesangial cell proliferation in vivo. To study this further, we created transgenic mice with podocyte-specific overexpression of PDGF-D. Hemizygous mice were grossly indistinguishable from wild-type littermates through 11 months of age; however, hemizygous mice older than 4 weeks commonly exhibited increased cell proliferation within the glomerular tuft. Many hemizygous mice also developed widespread segmental glomerulosclerosis and focal extracapillary proliferation with fibrin/fibrinogen deposition, extensive tubulointerstitial damage, proteinuria, and renal insufficiency. Electron microscopy found focal foot process effacement. Renal mRNA expression of podocin and nephrin, as well as the number of glomerular WT-1-positive cells, were significantly reduced in hemizygous compared to wild-type mice, indicating loss and/or dedifferentation of podocytes. PDGF-A, -B, and both PDGF receptor chain mRNAs, fibronectin, type IV collagen, RANTES, MCP-1, and CCR-2 mRNAs were all increased in the renal cortex of PDGF-D transgenic mice. Only 8.5% of newborn mice were homozygous overexpressors exhibiting a mortality rate of 37% at 4 weeks. Thus, podocyte-specific overexpression of PDGF-D caused mesangioproliferative disease, glomerulosclerosis, and crescentic glomerulonephritis. Hence, podocyte-specific growth factor overexpression can induce paracrine mesangial cell proliferation upstream of the filtration flow.
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http://dx.doi.org/10.1038/ki.2011.278DOI Listing
December 2011

The peroxisome proliferator-activated receptor-α agonist, BAY PP1, attenuates renal fibrosis in rats.

Kidney Int 2011 Dec 3;80(11):1182-97. Epub 2011 Aug 3.

Department of Clinical and Experimental Pharmacotherapy, Research Base of Slovak Medical University, Bratislava, Slovakia.

Recent studies have shown renoprotective effects of the peroxisome proliferator-activated receptor-α (PPAR-α), but its role in kidney fibrosis is unknown. In order to gain insight into this, we examined the effect of a novel PPAR-α agonist, BAY PP1, in two rat models of renal fibrosis: unilateral ureteral obstruction and the 5/6 nephrectomy. In healthy animals, PPAR-α was expressed in tubular but not in interstitial cells. Upon induction of fibrosis, PPAR-α was significantly downregulated, and treatment with BAY PP1 significantly restored its expression. During ureteral obstruction, treatment with BAY PP1 significantly reduced tubulointerstitial fibrosis, proliferation of interstitial fibroblasts, and TGF-β(1) expression. Treatment with a less potent PPAR-α agonist, fenofibrate, had no effects. Treatment with BAY PP1, initiated in established disease in the 5/6 nephrectomy, halted the decline of renal function and significantly ameliorated renal fibrosis. In vitro, BAY PP1 had no direct effect on renal fibroblasts but reduced collagen, fibronectin, and TGF-β(1) expression in tubular cells. Conditioned media of BAY PP1-treated tubular cells reduced fibroblast proliferation. Thus, renal fibrosis is characterized by a reduction of PPAR-α expression, and treatment with BAY PP1 restores PPAR-α expression and ameliorates renal fibrosis by modulating the cross-talk between tubular cells and fibroblasts. Hence, potent PPAR-α agonists might be useful in the treatment of renal fibrosis.
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http://dx.doi.org/10.1038/ki.2011.254DOI Listing
December 2011

Effects and mechanisms of angiotensin II receptor blockade with telmisartan in a normotensive model of mesangioproliferative nephritis.

Nephrol Dial Transplant 2011 Oct 17;26(10):3131-43. Epub 2011 Mar 17.

Division of Nephrology, University Hospital RWTH Aachen, Aachen, Germany.

Background: Renoprotective actions of angiotensin receptor blockers are not well established in normotensive, low-grade proteinuric glomerular diseases. We examined the effect of low-dose telmisartan (LT) and high-dose telmisartan (HT) versus conventional antihypertensive therapy in the rat anti-Thy1.1 model of glomerulonephritis.

Methods: Rats were randomized on Day 4 after disease induction to no treatment (CT, control), LT or HT or hydrochlorothiazide + hydralazine (HCT + H).

Results: All rats remained normotensive: HT and HCT + H reduced blood pressure by 15-20%. LT, HT and HCT + H reduced glomerular endothelial cell proliferation and glomerular and interstitial matrix deposition on Day 14. Only HT reduced podocyte damage and tubular cell dedifferentiation on Day 9 and mesangial cell activation on Day 14. By gene expression analysis arrays, we identified discs-large homolog 1 and angiopoietin-like 4 as potential mediators of the HT effects. In addition, we identified several pathways possibly related to the pleiotropic effects of HT, including growth factor signalling, mammalian target of rapamycin signalling, protein ubiquitination, the Wnt-beta catenin pathway and hypoxia signaling.

Conclusions: In summary, treatment with HT, initiated after the induction of disease, ameliorates glomerular and tubulointerstitial damage. We provide the first comprehensive insight into the mechanisms underlying the renoprotective effect of high-dose angiotensin II receptor blockers (ARBs). Our study lays the basis for future investigations on novel pathways affected by ARBs in renal disease.
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http://dx.doi.org/10.1093/ndt/gfr096DOI Listing
October 2011

Different immunohistochemical and ultrastructural phenotypes of squamous differentiation in bladder cancer.

Virchows Arch 2011 Mar 7;458(3):301-12. Epub 2010 Dec 7.

Institute of Pathology, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.

Besides worse prognosis of bladder cancer with squamous differentiation (pure squamous cell carcinoma (SCC) or mixed urothelial carcinoma (UC/SCC)), high-grade non-keratinising squamous differentiation is difficult to identify in haematoxylin-eosin stainings. This study aims to validate routine immunohistochemical markers for squamous differentiation in a larger cohort of patients. Tissue microarrays of 89 pure SCCs and mixed UC/SCCs, 66 urothelial carcinomas (UC), precursor lesions and normal urothelium were stained for cytokeratin (CK) 5/6, CK 5/14, CK 7, CK 20 and uroplakin III. Electron microscopy was performed to confirm the differentiation. Pure SCCs displayed staining throughout the epithelium for CK 5/6 (76.6% (36/47)) and CK 5/14 (95.8% (46/48)), focal staining for CK 7 (28.9% (13/45)) and no staining for CK 20 and uroplakin III (both 0% (0/48)). UCs exhibited a basal or diffuse staining for CK 5/6 (30.2% (16/53)) and CK 5/14 (57.1% (32/56)), focal positivity for CK 7 (83.6% (46/55)), CK 20 (50.9% (29/57)) and uroplakin III (21.8% (12/55)). Each marker discriminated SCC and UC significantly (p < 0.01). A third subgroup rarely showed full epithelial staining for CK 5/6 (14.3% (1/7)) and CK 5/14 (28.6% (2/7)), focal staining for CK 7 (85.7% (6/7)) and no staining for CK 20 and uroplakin III (both 0% (0/7)). Electron microscopy could prove both, SCC and UC characteristics, revealing a transient type. A staining pattern with CK 5/6- and CK 5/14-positivity plus CK 20- and uroplakin III-negativity identified squamous differentiation in bladder tumours and revealed a third type of squamous transdifferentiation.
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http://dx.doi.org/10.1007/s00428-010-1017-2DOI Listing
March 2011

PDGF-C mediates glomerular capillary repair.

Am J Pathol 2010 Jul 20;177(1):58-69. Epub 2010 May 20.

Division of Nephrology and Immunology, University Hospital Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany.

Glomerular endothelial cell injury is a key component of a variety of diseases. Factors involved in glomerular endothelial cell repair are promising therapeutic agents for such diseases. Platelet-derived growth factor (PDGF)-C has pro-angiogenic properties; however, nothing is known about such functions in the kidney. We therefore investigated the consequences of either PDGF-C infusion or inhibition in rats with mesangioproliferative glomerulonephritis, which is accompanied by widespread glomerular endothelial cell damage. We also assessed the role of PDGF-C in a mouse model of thrombotic microangiopathy as well as in cultured glomerular endothelial cells. PDGF-C infusion in nephritic rats significantly reduced mesangiolysis and microaneurysm formation, whereas glomerular endothelial cell area and proliferation increased. PDGF-C infusion specifically up-regulated glomerular fibroblast growth factor-2 expression. In contrast, antagonism of PDGF-C in glomerulonephritis specifically reduced glomerular endothelial cell area and proliferation and increased mesangiolysis. Similarly, PDGF-C antagonism in murine thrombotic microangiopathy aggravated the disease and reduced glomerular endothelial area. In conditionally immortalized glomerular endothelial cells, PDGF-C was mitogenic and induced a 27-fold up-regulation of fibroblast growth factor-2 mRNA. PDGF-C also exerted indirect pro-angiogenic effects, since it induced endothelial cell mitogens and pro-angiogenic factors in mesangial cells and macrophages. These results identify PDGF-C as a novel, potent pro-angiogenic factor in the kidney that can accelerate capillary healing in experimental glomerulonephritis and thrombotic microangiopathy.
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http://dx.doi.org/10.2353/ajpath.2010.091008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2893651PMC
July 2010

[The dark side of the (half) moon].

Authors:
Luigi Villa

G Ital Nefrol 2009 May-Jun;26(3):294

Struttura Complessa di Nefrologia, Dialisi e Trapianto, Fondazione IRCCS, Policlinico San Matteo, Pavia, Italy.

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October 2009

The antifibrogenic effect of hepatocyte growth factor (HGF) on renal tubular (HK-2) cells is dependent on cell growth.

Growth Factors 2009 Jun;27(3):173-80

Unit of Nephrology, Dialysis and Transplantation, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy.

Although several reports suggest an antifibrogenic effect of hepatocyte growth factor (HGF), an increased deposition of matrix induced by HGF has also been reported. These conflicting effects could result from a diverse proliferative state of the target cells. Aim of the present study was to evaluate HGF effects on growth arrested (quiescent) and actively proliferating renal tubular epithelial (HK-2) cells. HK-2 cells were cultured in RPMI medium either on agarose gel or on plastic surface in order to inhibit or to allow cell proliferation. Cells were incubated with RPMI containing HGF (50 ng/ml) for 24 h at 37 degrees C. Untreated HK-2 were used as control. After 24 h of incubation, cells were counted by Coulter counter. (alpha2)IV collagen, transforming growth factor-beta (TGF-beta), Tissue inhibitor of metalloproteases (TIMP1 and 2) mRNA levels were determined by RT-PCR. The production of type IV collagen, c-met, proliferating cell nuclear antigen (PCNA), and SnoN, a transcriptional Smad corepressor and thus a TGF-beta inhibitor, was evaluated by ELISA or western blotting. MMP-9 and 2 gelatinolytic activity was studied by zymography. Treatment with HGF did not increase HK-2 cell number and PCNA synthesis when the cells were grown on agarose as it did for cells grown on plastic surface. HGF increased (alpha2)IV collagen in proliferating cells whereas it reduced (alpha2)IV collagen and c-met synthesis in growth arrested cells. HGF treatment increased TGF-beta and TIMP-2 in proliferating cells while reduced TIMP-1 mRNA levels of quiescent cells. Furthermore, production of the co repressor SnoN was significantly decreased by HGF in proliferating cells. Quiescent and proliferating HK-2 showed a different pattern of metalloproteases activity with a prevalence of MMP2 in quiescent and MMP9 in proliferating cells. In summary, HGF showed opposite effects on growth arrested and proliferating HK-2 cells favouring matrix deposition in the latter with increasing expression of collagen, TIMP-1 and TGF-beta. Our results demonstrate that the proliferative state of target cells may influence the effects of HGF on extracellular matrix turnover in HK-2 cells.
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http://dx.doi.org/10.1080/08977190902834077DOI Listing
June 2009

[spACE, the last frontier? Renin inhibition in hypertension].

Authors:
Luigi Villa

G Ital Nefrol 2008 May-Jun;25(3):274

Struttura Complessa di Nefrologia, Dialisi e Trapianto, Fondazione IRCCS-Policlinico San Matteo, Pavia, Italy.

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August 2008

Mesenchymal stem cells prevent progressive experimental renal failure but maldifferentiate into glomerular adipocytes.

J Am Soc Nephrol 2007 Jun 25;18(6):1754-64. Epub 2007 Apr 25.

Division of Nephrology, University Hospital RWTH Aachen, Pauwelsstrasse 30, D-52057 Aachen, Germany.

Glomerulonephritis (GN) is a major cause of renal failure. This study sought to determine whether intrarenal injection of rat mesenchymal stem cells (MSC) can preserve renal function in a progressive rat model of GN. Early in GN (day 10), fluorescently labeled rat MSC localized to more than 70% of glomeruli, ameliorated acute renal failure, and reduced glomerular adhesions. Fifty days later, proteinuria had progressed in controls to 40 +/- 25 mg/d but stayed low in MSC-treated rats (13 +/- 4 mg/d; P < 0.01). Renal function on day 60 in the MSC group was better than in medium controls. Kidneys of the MSC group as compared with controls on day 60 contained 11% more glomeruli per 1-mm(2) section of cortex but also significantly more collagen types I, III, and IV and alpha-smooth muscle actin. Approximately 20% of the glomeruli of MSC-treated rats contained single or clusters of large adipocytes with pronounced surrounding fibrosis. Adipocytes exhibited fluorescence in their cytoplasm and/or intracellular lipid droplets. Lipid composition in these adipocytes in vivo mirrored that of MSC that underwent adipogenic differentiation in vitro. Thus, in this GN model, the early beneficial effect of MSC of preserving damaged glomeruli and maintaining renal function was offset by a long-term partial maldifferentiation of intraglomerular MSC into adipocytes accompanied by glomerular sclerosis. These data suggest that MSC treatment can be a valuable therapeutic approach only if adipogenic maldifferentiation is prevented.
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http://dx.doi.org/10.1681/ASN.2007010044DOI Listing
June 2007

Complement C5 mediates experimental tubulointerstitial fibrosis.

J Am Soc Nephrol 2007 May 27;18(5):1508-15. Epub 2007 Mar 27.

Division of Nephrology, Rheinische-Westfälische Technische Hochschule, University of Aachen, Aachen, Germany.

Renal fibrosis is the final common pathway of most progressive renal diseases. C5 was recently identified as a risk factor for liver fibrosis. This study investigated the role of C5 in the development of renal tubulointerstitial fibrosis by (1) induction of renal fibrosis in wild-type and C5(-/-) mice by unilateral ureteral ligation (UUO) and (2) investigation of the effects of a C5a receptor antagonist (C5aRA) in UUO. In C5(-/-) mice, when compared with wild-type controls, markers of renal fibrosis (Sirius Red, type I collagen, fibronectin, alpha-smooth muscle actin, vimentin, and infiltrating macrophages) were significantly reduced on day 5 of UUO. On day 10, fibronectin mRNA and protein expression were still reduced in the C5(-/-) mice. Cortical mRNA of all PDGF isoforms and of TGF-beta(1) (i.e., central mediators of renal disease) were significantly reduced in C5(-/-) mice when compared with controls. Renal tubular cell expression of the C5aR was sparse in normal cortex but markedly upregulated after UUO. Treatment of wild-type UUO mice with C5aRA also led to a significant reduction of cortical Sirius Red staining, fibronectin protein expression, and PDGF-B mRNA expression on day 5. Neither genetic C5 deficiency nor C5aRA treatment caused any histologic changes in the nonobstructed kidneys. In cultured murine cortical tubular cells, C5a stimulated production of TGF-beta(1), and this was inhibited by C5aRA. Using a combined genetic and pharmacologic approach, C5, in particular C5a, is identified as a novel profibrotic factor in renal disease and as a potential new therapeutic target.
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http://dx.doi.org/10.1681/ASN.2006121343DOI Listing
May 2007

PDGF-D inhibition by CR002 ameliorates tubulointerstitial fibrosis following experimental glomerulonephritis.

Nephrol Dial Transplant 2007 May 17;22(5):1323-31. Epub 2007 Feb 17.

Division of Nephrology, University Hospital Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany.

Background: Arresting or regressing kidney scarring is of major clinical relevance. Platelet-derived growth factor D (PDGF-D) is widely expressed in fibrotic kidneys. Administration of the PDGF-D neutralizing fully human monoclonal antibody CR002 in the acute phase of progressive anti-Thy 1.1 glomerulonephritis reduced glomerular and secondary tubulointerstitial damage.

Methods: Using this model, we now assessed the effects of CR002 (n=15) vs irrelevant control IgG (n=17) administered on days 17, 28 and 35 after disease induction, i.e. after acute glomerular damage had subsided.

Results: In vitro, CR002 inhibited the PDGF-D- but not the PDGF-B-induced proliferation of rat renal fibroblasts. Following the first CR002 injection on day 17, exposure to therapeutic levels was maintained until day 49. Proteinuria in the CR002-treated group was transiently reduced between days 49 and 77 (-19 to -23% in comparison with the controls; P<0.05). On day 100, CR002 treatment reduced the number of rats that had doubled their serum creatinine (CR002: 40 vs controls: 71%; P<0.05). Compared with controls, the CR002 animals, on day 100, significantly lowered glomerular expression of vimentin and collagens as well as tubulointerstitial damage scores, interstitial fibrosis, vimentin and cortical PDGF-D mRNA levels.

Conclusions: PDGF-D antagonism, even after the phase of acute glomerular damage, exerts beneficial effects on the course of tubulointerstitial damage, i.e. the final common pathway of most renal diseases.
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http://dx.doi.org/10.1093/ndt/gfl691DOI Listing
May 2007

Uremic serum induces proatherogenic changes in human endothelial cells.

J Nephrol 2006 Sep-Oct;19(5):599-604

Unit of Nephrology, Dialysis and Transplantation, IRCCS Policlinico San Matteo, University of Pavia, Pavia-Italy.

Background: Cardiovascular complications are the main cause of death in uremic patients. Uremic angiopathy has been regarded as an accelerated form of atherosclerosis. However the mechanism leading to vessel wall injury is still unknown. We hypothesized that uremic serum affects endothelium inducing a proatherogenic state.

Methods: We studied the effects of uremic serum on human endothelial cells (HECs). Cell proliferation and adhesion of mononuclear cells to HEC monolayers were evaluated by cell counting, apoptosis and collagen production by ELISA, and nitric oxide (NO) by measuring the concentration of nitrite/nitrate in the cell supernatant. (alfa2)IV collagen, tissue inhibitor of metalloproteases-1 (TIMP-1) and transforming growth factor-beta (TGF-beta) mRNA levels were measured by reverse transcriptase polymerase chain reaction (RT-PCR). In some experiments cells were preincubated with anti-receptor for advanced glycation end product (anti-RAGE) blocking antibodies.

Results: Uremic serum did not modify HEC proliferation but induced apoptosis after 72 hours of incubation. Adhesion of mononuclear cells to HEC monolayers was significantly increased by uremic serum. In addition, uremic serum increased (alfa2)IV collagen, TIMP-1 and TGF-beta mRNA levels. There was no increase in nitric oxide concentration in ure-mic serum-treated endothelial cells, and the expression of TGF-beta was neither modified by L-NAME nor by anti-RAGE antibodies.

Conclusions: Our results indicate that uremic serum affects HEC inducing a proatherogenic state that may be responsible for the accelerated atherosclerosis of uremic patients. Apparently uremic serum effect is not mediated by NO or by AGEs.
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June 2008

Solvent constraints on the property space of acetylcholine. 2. Ordered media.

J Med Chem 2005 Nov;48(22):6926-35

Istituto di Chimica Farmaceutica, Facoltà di Farmacia, Università di Milano, Viale Abruzzi 42, I-20131 Milan, Italy.

The objective of this study was to investigate the conformational and property spaces of acetylcholine in hydrated octanol and in a membrane model. Molecular dynamics simulations of long duration (15 ns) were carried out, yielding 3000 conformers. For each, we calculated N(+)-C8 distance, solvent-accessible surface area (SAS), polar surface area (PSA), dipole moment, and lipophilicity (virtual logP). Their variations as a function of the dihedral angles tau(2) and tau(3) remained unexpectedly broad and comparable to those seen previously in a vacuum, in water, and in chloroform.(12) Thus, each of the seven conformational clusters was able to access a marked proportion of the lipophilicity space accessible to acetylcholine (0.40 in the logP scale). Histograms of logP distributions revealed two overlapping populations, namely more lipophilic and more hydrophilic. Their deconvolution into two Gaussian curves demonstrated solvent-mediated constraints on the lipophilicity space of acetylcholine, clearly showing how a polar medium favors polar conformers, whereas the opposite is true for media of low polarity.
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http://dx.doi.org/10.1021/jm0580306DOI Listing
November 2005

Range and sensitivity as descriptors of molecular property spaces in dynamic QSAR analyses.

J Med Chem 2005 Jul;48(15):4947-52

Istituto di Chimica Farmaceutica, Facoltà di Farmacia, Università di Milano, Viale Abruzzi 42, I-20131 Milano, Italy.

In this paper, we report the first study aimed at correlating pharmacological properties with molecular parameters derived from the physicochemical property space of bioactive molecules. A dataset of 36 ligands of the alpha(1a)-, alpha(1b)-, and alpha(1d)-adrenoceptors as published by Bremner et al. (Bioorg. Med. Chem. 2000, 8, 201-214) was used. One thousand conformers were generated for each ligand by Monte Carlo conformational analysis, and four 3D-dependent physicochemical properties were computed for each conformer of each ligand, namely virtual lipophilicity (log P), dipole moment, polar surface area (PSA), and solvent-accessible surface area (SAS). Thus, a space of four physicochemical properties was obtained for each ligand. These spaces were assessed by two descriptors, namely their range and their sensitivity (i.e., the variation amplitude of a given physicochemical property for a given variation in molecular geometric properties). Little or no correlation was found to exist between the physicochemical properties and their range or sensitivity, indicating that the latter descriptors do not encode the same molecular information as the former properties. As expected, neither the range nor the sensitivity of any of the four physicochemical properties correlated with receptor affinities. In contrast, range and sensitivity showed promising correlations with deltapK(a-b) (i.e., the alpha(1a)/alpha(1b) selectivity) for the complete dataset. The correlations were lower for deltapK(a-d) (i.e., the alpha(1a)/alpha(1d) selectivity), whereas there was no correlation at all with deltapK(b-d). These results are consistent with the results of Bremner et al., which indicate that the alpha(1a)-AR ligands bind in an extended geometry, whereas the alpha(1b)-AR and alpha(1d)-AR ligands assume more folded conformations. Since the property space descriptors presented here take structural variability into account, their correlation with deltapK(a-b) and deltapK(a-d) indicates that these selectivities are indeed driven by differences in conformational behavior and hence in property spaces.
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http://dx.doi.org/10.1021/jm0408969DOI Listing
July 2005

Solvent constraints on the property space of acetylcholine. I. Isotropic solvents.

J Med Chem 2005 Mar;48(6):1759-67

Istituto di Chimica Farmaceutica, Facoltà di Farmacia, Università di Milano, Viale Abruzzi 42, I-20131 Milano, Italy.

The objective of this study was, first, to examine the property space of a test molecule and, second, to assess solvent constraints. Acetylcholine was chosen as the object of study given its interesting molecular structure and major biological significance. Molecular dynamics simulations of long duration (30 ns) were carried out with acetylcholine in a vacuum or in a box of solvent (chloroform, water, water plus one chloride counterion). For each of the 6000 conformers stored during each run, various geometric and physicochemical properties were calculated, namely, N(+)-C8 distance, solvent-accessible surface area (SAS), polar surface area (PSA), dipole moment, and lipophilicity (virtual log P). The variations of these properties as a function of the dihedral angles tau(2) and tau(3) were unexpectedly broad for such a small molecule. Dipole moment and virtual log P were well correlated, and they varied in a complex manner with the dihedral angles. For example, each of the seven conformational clusters was able to access much of the lipophilicity space of acetylcholine. Solvent constraints on the property space clearly indicate that a polar medium tends to favor polar conformers, whereas the opposite is true for a solvent of low polarity.
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http://dx.doi.org/10.1021/jm040823pDOI Listing
March 2005

QSAR study for a novel series of ortho monosubstituted phenoxy analogues of alpha1-adrenoceptor antagonist WB4101.

Bioorg Med Chem 2005 Apr;13(7):2547-59

Istituto di Chimica Farmaceutica e Tossicologica, Università di Milano, viale Abruzzi 42, I-20131 Milano, Italy.

A number of (S)- and (R)-2-[(2-phenoxyethyl)aminomethyl]-1,4-benzodioxanes unsubstituted or ortho monosubstituted at the phenoxy moiety were synthesized and tested in binding assays on the alpha(1a)-AR, alpha(1b)-AR, alpha(1d)-AR and the 5-HT(1A) receptor. The affinity values of the new compounds 1-16 were compared with those of the enantiomers of the 2,6-dimethoxyphenoxy analogue, the well-known alpha(1) antagonist WB4101, finding that the unsubstituted derivative (S)-1 and the o-methyl, the o-t-butyl, the o-fluoro and the o-methoxy derivatives, (S)-2, (S)-4, (S)-8 and (S)-16, respectively, display a significantly specific 5-HT(1A) affinity, very close, with the exception of (S)-4, to the almost nanomolar one of (S)-WB4101. Otherwise, sensible affinity decreases were recorded for the three alpha(1)-AR subtypes. A classical quantitative structure-activity relationship (Hansch) analysis was successfully applied to compounds (S)-1 to (S)-16 and (S)-WB4101 to rationalize such binding data.
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http://dx.doi.org/10.1016/j.bmc.2005.01.034DOI Listing
April 2005

Synthesis and alpha4beta2 nicotinic affinity of 2-pyrrolidinylmethoxyimines and prolinal oxime ethers.

Bioorg Med Chem Lett 2004 Dec;14(23):5827-30

Istituto di Chimica Farmaceutica e Tossicologica, Università di Milano, viale Abruzzi 42, I-20131 Milano, Italy.

Homochiral E and Z isomers of N-methylprolinal O-isopropyloxime and (1-methyl-2-pyrrolidinyl)methoxyimines were synthesized as candidate bioisosteres of nicotine and its isoxazolic analogue ABT 418. Two of them, namely (S)-2-isopropylideneaminooxymethyl- and (Z)-(S)-2-ethylideneaminooxymethyl-1-methylpyrrolidine, proved to bind at alpha4beta2 nicotinic acetylcholine receptor with submicromolar affinity and remarkable selectivity over alpha7 and muscarinic receptors thus supporting the hypothesized bioisosteric relationship between their methyloxyimino group and the aromatic heterocycles of the reference ligands.
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http://dx.doi.org/10.1016/j.bmcl.2004.09.044DOI Listing
December 2004

VEGA--an open platform to develop chemo-bio-informatics applications, using plug-in architecture and script programming.

J Comput Aided Mol Des 2004 Mar;18(3):167-73

Istituto di Chimica Farmaceutica, University of Milan, Viale Abruzzi, 42, I-20131 Milan, Italy.

In this paper we present the expandability and flexibility features of the VEGA program (downloadable free of charge at http://www.ddl.unimi.it), for the development of custom applications, using it as a multipurpose graphical environment. VEGA can be customized using both plug-in architecture and script programming. The first is useful to add new features and functions, using homemade routines, written with the VEGA Plug-in Development Kit (SDK). With the second approach it is possible to design scripts in VEGA, using the REBOL language, in order to (1) add new functions or customize existing ones; (2) automate common procedures; and (3) allow network communications, by creating a bridge between VEGA and other applications (or other PCs) through the TCP/IP protocol.
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http://dx.doi.org/10.1023/b:jcam.0000035186.90683.f2DOI Listing
March 2004

Structure-affinity studies for a novel series of homochiral naphtho and tetrahydronaphtho analogues of alpha 1 antagonist WB-4101.

Bioorg Med Chem 2004 Sep;12(18):4937-51

Istituto di Chimica Farmaceutica e Tossicologica, Universitá degli Studi di Milano, viale Abruzzi 42, I-20131 Milano, Italy.

A number of enantiomeric pairs of naphthodioxane, tetrahydronaphthodioxane and naphthoxy analogues of WB-4101 (1) were designed and synthesized in order to improve the selectivity profile of the parent compound, hopefully in favour of the alpha(1a)-AR with respect to the other two alpha(1) subtypes and the 5-HT(1A) receptor. The new compounds 2-8 and, in addition, the two enantiomers of 1 were tested in binding assays on the alpha(1a)-AR, alpha(1b)-AR, alpha(1d)-AR, and the 5-HT(1A) receptor. Two of them, namely the naphtho- and tetrahydronaphthodioxane derivatives (S)-2 and (S)-3, showed lower, but significantly more specific alpha(1a) affinity than (S)-1, while the two enantiomers of the 2-methoxy-1-naphthoxy analogue 6 maintained most of the very high alpha(1a) affinity of (S)-1 and its alpha(1a) versus alpha(1b) selectivity slightly increasing the alpha(1a)/alpha(1d) and alpha(1a)/5HT(1A) affinity ratios. The SAR data were evaluated in the light of known alpha(1) subtype pharmacophores and of the alpha(1a)-AR binding mode of WB-4101 resultant from literature mutagenesis studies disclosing some interesting consonances with these models.
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http://dx.doi.org/10.1016/j.bmc.2004.06.040DOI Listing
September 2004

Binding site analysis of full-length alpha1a adrenergic receptor using homology modeling and molecular docking.

Biochem Biophys Res Commun 2004 Jun;319(2):493-500

Istituto di Chimica Farmaceutica, Faculty of Pharmacy, Viale Abruzzi, 42 University of Milan, 20131 Milan, Italy.

The recent availability of crystal structure of bovine rhodopsin offers new opportunities in order to approach the construction of G protein coupled receptors. This study focuses the attention on the modeling of full-length alpha(1a) adrenergic receptor (alpha(1a)-AR) due to its biological role and significant implications in pharmacological treatment of benign prostate hyperplasia. This work could be considered made up by two main steps: (a) the construction of full structure of alpha(1a)-AR, through homology modeling methods; (b) the automated docking of an endogenous agonist, norepinephrine, and of an antagonist, WB-4101, using BioDock program. The obtained results highlight the key residues involved in binding sites of both agonists and antagonists, confirming the mutagenesis data and giving new suggestions for the rational design of selective ligands.
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http://dx.doi.org/10.1016/j.bbrc.2004.04.149DOI Listing
June 2004

Analysis of the full-length integrase-DNA complex by a modified approach for DNA docking.

Biochem Biophys Res Commun 2003 Oct;310(4):1083-8

Dipartimento Farmaco-Chimico, Università di Messina,Viale Annunziata, I-98168 Messina, Italy.

A model of the full-length HIV-1 integrase dimer was constructed assembling the experimentally determined structures of the single domains. Subsequently, the three-domain protein-viral DNA complex was generated for the first time through an automated docking algorithm, obtained modifying the ESCHER program, a well-known method for protein-protein docking. A detailed study of the contacts established with DNA by the enzyme revealed that the predicted model reproduced the results of mutagenesis and cross-linking experiments, confirming the validity of our docking approach in predicting the base specificity in the DNA-protein interaction.
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http://dx.doi.org/10.1016/j.bbrc.2003.09.120DOI Listing
October 2003

VEGA: a versatile program to convert, handle and visualize molecular structure on Windows-based PCs.

J Mol Graph Model 2002 Aug;21(1):47-9

Istituto di Chimica Farmaceutica e Tossicologica, University of Milan, Italy.

We here propose the program VEGA, that was developed to create a bridge between the most popular molecular software packages. In this tool some features are implemented some features to analyze, display and manage the three dimensional (3D) structure of the molecules. The most important features are (1) file format conversion (with assignment of the atom types and atomic charges), (2) surface calculation and (3) trajectory analysis. The executable and the source code can be free downloaded from [URL: see text].
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http://dx.doi.org/10.1016/s1093-3263(02)00123-7DOI Listing
August 2002
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