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1.
Non-conventional in English | NTIS, Grey literature | ID: grc-753749

ABSTRACT

In Year Three of the funded grant, we have substantial progress in the following critical areas: 1). As noted in the project narrative, we generated four different lines of mice to directly test the hypothesis that RAGE and DIAPH1 contribute to the pathogenesis of diabetes-associated nephropathy in the podocytes and/or in myeloid cells/macrophages. All of the mouse lines are now generated and largely completed (mice sacrificed) and samples being evaluation by Dr DAgati. There are no new pending mice to generate all are generated and on time course. 2). We have determined that the small molecule RAGE/DIAPH1 antagonist is best administered orally and that the RAGE antagonist survives the medicated chow pelleting, heating and irradiation. Our first data on treated vs. untreated male and female diabetic mice illustrates reduction in mesangial sclerosis, reduced thickening of the glomerular basement membrane and reduction in podocyte effacement in diabetic mice receiving RAGE229 medicated chow (vs vehicle). Additional mice are on study and time course at this time to complete the indicated enrollment.3). For transcriptomics and metabolomics/lipidomics assay, Dr. Ramasamy will be testing the macrophages from the mice through the time course and he has verified all of his experimental systems for the performance of the outlined studies. Dr. Ramasamy identifies substantial progress in the development and validation of metabolomics and lipidomics assays here at NYU and in transcriptomic data (all on macrophages) in order to understand detailed mechanisms of the role of these molecules in the diabetic kidney. Taken together, despite the >3 month shutdown due to COVID19 our work in Year 3 has been productive and we await tissue and other analyses, as above, to render final conclusions.

2.
Kidney Int ; 2022 Feb 01.
Article in English | MEDLINE | ID: covidwho-1665244

ABSTRACT

Risk variants of the apolipoprotein-L1 (APOL1) gene are associated with severe kidney disease, putting homozygous carriers at risk. Since APOL1 lacks orthologs in all major model organisms, a wide range of mechanisms frequently in conflict have been described for APOL1-associated nephropathies. The genetic toolkit in Drosophila allows unique in vivo insights into disrupted cellular homeostasis. To perform a mechanistic analysis, we expressed human APOL1 control and gain-of-function kidney risk variants in the podocyte-like garland cells of Drosophila nephrocytes and a wing precursor tissue. Expression of APOL1 risk variants was found to elevate endocytic function of garland cell nephrocytes that simultaneously showed early signs of cell death. Wild-type APOL1 had a significantly milder effect, while a control transgene with deletion of the short BH3 domain showed no overt phenotype. Nephrocyte endo-lysosomal function and slit diaphragm architecture remained unaffected by APOL1 risk variants, but endoplasmic reticulum (ER) swelling, chaperone induction, and expression of the reporter Xbp1-EGFP suggested an ER stress response. Pharmacological inhibition of ER stress diminished APOL1-mediated cell death and direct ER stress induction enhanced nephrocyte endocytic function similar to expression of APOL1 risk variants. We confirmed APOL1-dependent ER stress in the Drosophila wing precursor where silencing the IRE1-dependent branch of ER stress signaling by inhibition with Xbp1-RNAi abrogated cell death, representing the first rescue of APOL1-associated cytotoxicity in vivo. Thus, we uncovered ER stress as an essential consequence of APOL1 risk variant expression in vivo in Drosophila, suggesting a central role of this pathway in the pathogenesis of APOL1-associated nephropathies.

3.
Front Immunol ; 12: 800074, 2021.
Article in English | MEDLINE | ID: covidwho-1662584

ABSTRACT

Collapsing glomerulopathy represents a special variant of the proteinuric kidney disease focal segmental glomerulosclerosis (FSGS). Histologically, the collapsing form of FSGS (cFSGS) is characterized by segmental or global condensation and obliteration of glomerular capillaries, the appearance of hyperplastic and hypertrophic podocytes and severe tubulointerstitial damage. Clinically, cFSGS patients present with acute kidney injury, nephrotic-range proteinuria and are at a high risk of rapid progression to irreversible kidney failure. cFSGS can be attributed to numerous etiologies, namely, viral infections like HIV, cytomegalovirus, Epstein-Barr-Virus, and parvovirus B19 and also drugs and severe ischemia. Risk variants of the APOL1 gene, predominantly found in people of African descent, increase the risk of developing cFSGS. Patients infected with the new Corona-Virus SARS-CoV-2 display an increased rate of acute kidney injury (AKI) in severe cases of COVID-19. Besides hemodynamic instability, cytokine mediated injury and direct viral entry and infection of renal epithelial cells contributing to AKI, there are emerging reports of cFSGS associated with SARS-CoV-2 infection in patients of mainly African ethnicity. The pathogenesis of cFSGS is proposed to be linked with direct viral infection of podocytes, as described for HIV-associated glomerulopathy. Nevertheless, there is growing evidence that the systemic inflammatory cascade, activated in acute viral infections like COVID-19, is a major contributor to the impairment of basic cellular functions in podocytes. This mini review will summarize the current knowledge on cFSGS associated with viral infections with a special focus on the influence of systemic immune responses and potential mechanisms propagating the development of cFSGS.


Subject(s)
COVID-19/complications , Glomerulosclerosis, Focal Segmental/etiology , Kidney Glomerulus/virology , Animals , COVID-19/immunology , COVID-19/virology , Epithelial Cells/immunology , Epithelial Cells/virology , Glomerulosclerosis, Focal Segmental/immunology , Glomerulosclerosis, Focal Segmental/virology , Humans , Immunity/immunology , Kidney Glomerulus/immunology , Podocytes/immunology , Podocytes/virology , Proteinuria/etiology , Proteinuria/immunology , Proteinuria/virology , SARS-CoV-2/immunology
4.
Swiss Medical Weekly ; 151(SUPPL 256):35S, 2021.
Article in English | EMBASE | ID: covidwho-1623103

ABSTRACT

Background: Post vaccination minimal change disease with nephrotic syndrome and acute kidney injury has been reported after influenza and Pfizer-BioNTech vaccine. Further research is needed to prove a correlation. Methods: Clinical case, renal biopsy, dialysis Results: We present a case of a 65 years old patient, who developed minimal change disease 8 days following first injection with Moderna COVID-19 vaccine. In his medical history the patient has collagenous colitis and was on treatment with budenofalk. He presented with full blown nephrotic syndrome and developed dialysis dependent acute kidney injury for two weeks. Renal biopsy showed minimal change disease with 90% loss of podocyte processes in electron microscopy. Two weeks of dialysis and immunosupressive therapy over three months after the event lead to recovery of renal function to baseline. The patient received the second COVID-19 vaccination without developing complications or relapse. Conclusions: We present one of the first patients with minimal change disease after Moderna COVID-19 vaccine. There was an association between the timing of the vaccination and clinical manifestation of ne-phrotic syndrome. A definite causal relation still needs to be elucidated. A possible pathomechanism would be, that mRNA vaccines initiate T-cell mediated injury. However further studies are needed to find the im-munological mechanism of action after COVID-19 vaccination. Out of many millions of mRNA vaccines administered so far, to our knowledge, 7 cases of de novo minimal change disease have been described as well as up to 17 other glomerular diseases de novo and relapsing after COVID-19 vaccination.

5.
Clin J Am Soc Nephrol ; 16(11): 1755-1765, 2021 11.
Article in English | MEDLINE | ID: covidwho-1526737

ABSTRACT

Despite evidence of multiorgan tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with coronavirus disease 2019 (COVID-19), direct viral kidney invasion has been difficult to demonstrate. The question of whether SARS-CoV2 can directly infect the kidney is relevant to the understanding of pathogenesis of AKI and collapsing glomerulopathy in patients with COVID-19. Methodologies to document SARS-CoV-2 infection that have been used include immunohistochemistry, immunofluorescence, RT-PCR, in situ hybridization, and electron microscopy. In our review of studies to date, we found that SARS-CoV-2 in the kidneys of patients with COVID-19 was detected in 18 of 94 (19%) by immunohistochemistry, 71 of 144 (49%) by RT-PCR, and 11 of 84 (13%) by in situ hybridization. In a smaller number of patients with COVID-19 examined by immunofluorescence, SARS-CoV-2 was detected in 10 of 13 (77%). In total, in kidneys from 102 of 235 patients (43%), the presence of SARS-CoV-2 was suggested by at least one of the methods used. Despite these positive findings, caution is needed because many other studies have been negative for SARS-CoV-2 and it should be noted that when detected, it was only in kidneys obtained at autopsy. There is a clear need for studies from kidney biopsies, including those performed at early stages of the COVID-19-associated kidney disease. Development of tests to detect kidney viral infection in urine samples would be more practical as a noninvasive way to evaluate SARS-CoV-2 infection during the evolution of COVID-19-associated kidney disease.


Subject(s)
COVID-19/virology , Kidney Diseases/virology , Kidney/virology , SARS-CoV-2/pathogenicity , Animals , Biopsy , COVID-19/complications , COVID-19/diagnosis , COVID-19/mortality , COVID-19 Testing , Host-Pathogen Interactions , Humans , Kidney Diseases/diagnosis , Kidney Diseases/mortality , Predictive Value of Tests , Prognosis , Risk Assessment , Risk Factors
6.
J Am Soc Nephrol ; 32(2): 357-374, 2021 02.
Article in English | MEDLINE | ID: covidwho-1496662

ABSTRACT

BACKGROUND: Injury to kidney podocytes often results in chronic glomerular disease and consecutive nephron malfunction. For most glomerular diseases, targeted therapies are lacking. Thus, it is important to identify novel signaling pathways contributing to glomerular disease. Neurotrophic tyrosine kinase receptor 3 (TrkC) is expressed in podocytes and the protein transmits signals to the podocyte actin cytoskeleton. METHODS: Nephron-specific TrkC knockout (TrkC-KO) and nephron-specific TrkC-overexpressing (TrkC-OE) mice were generated to dissect the role of TrkC in nephron development and maintenance. RESULTS: Both TrkC-KO and TrkC-OE mice exhibited enlarged glomeruli, mesangial proliferation, basement membrane thickening, albuminuria, podocyte loss, and aspects of FSGS during aging. Igf1 receptor (Igf1R)-associated gene expression was dysregulated in TrkC-KO mouse glomeruli. Phosphoproteins associated with insulin, erb-b2 receptor tyrosine kinase (Erbb), and Toll-like receptor signaling were enriched in lysates of podocytes treated with the TrkC ligand neurotrophin-3 (Nt-3). Activation of TrkC by Nt-3 resulted in phosphorylation of the Igf1R on activating tyrosine residues in podocytes. Igf1R phosphorylation was increased in TrkC-OE mouse kidneys while it was decreased in TrkC-KO kidneys. Furthermore, TrkC expression was elevated in glomerular tissue of patients with diabetic kidney disease compared with control glomerular tissue. CONCLUSIONS: Our results show that TrkC is essential for maintaining glomerular integrity. Furthermore, TrkC modulates Igf-related signaling in podocytes.


Subject(s)
Kidney Diseases/metabolism , Nephrons/metabolism , Receptor, IGF Type 1/metabolism , Receptor, trkC/metabolism , Animals , Case-Control Studies , Disease Models, Animal , Humans , Kidney Diseases/etiology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Phosphoproteins/metabolism , Podocytes/metabolism , Signal Transduction/physiology
7.
Clin J Am Soc Nephrol ; 16(11): 1755-1765, 2021 11.
Article in English | MEDLINE | ID: covidwho-1269953

ABSTRACT

Despite evidence of multiorgan tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with coronavirus disease 2019 (COVID-19), direct viral kidney invasion has been difficult to demonstrate. The question of whether SARS-CoV2 can directly infect the kidney is relevant to the understanding of pathogenesis of AKI and collapsing glomerulopathy in patients with COVID-19. Methodologies to document SARS-CoV-2 infection that have been used include immunohistochemistry, immunofluorescence, RT-PCR, in situ hybridization, and electron microscopy. In our review of studies to date, we found that SARS-CoV-2 in the kidneys of patients with COVID-19 was detected in 18 of 94 (19%) by immunohistochemistry, 71 of 144 (49%) by RT-PCR, and 11 of 84 (13%) by in situ hybridization. In a smaller number of patients with COVID-19 examined by immunofluorescence, SARS-CoV-2 was detected in 10 of 13 (77%). In total, in kidneys from 102 of 235 patients (43%), the presence of SARS-CoV-2 was suggested by at least one of the methods used. Despite these positive findings, caution is needed because many other studies have been negative for SARS-CoV-2 and it should be noted that when detected, it was only in kidneys obtained at autopsy. There is a clear need for studies from kidney biopsies, including those performed at early stages of the COVID-19-associated kidney disease. Development of tests to detect kidney viral infection in urine samples would be more practical as a noninvasive way to evaluate SARS-CoV-2 infection during the evolution of COVID-19-associated kidney disease.


Subject(s)
COVID-19/virology , Kidney Diseases/virology , Kidney/virology , SARS-CoV-2/pathogenicity , Animals , Biopsy , COVID-19/complications , COVID-19/diagnosis , COVID-19/mortality , COVID-19 Testing , Host-Pathogen Interactions , Humans , Kidney Diseases/diagnosis , Kidney Diseases/mortality , Predictive Value of Tests , Prognosis , Risk Assessment , Risk Factors
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