Expression of HIV transgene aggravates kidney injury in diabetic mice

With the widespread use of combination antiretroviral agents, the incidence of HIV-associated nephropathy has decreased. Currently, HIV-infected patients live much longer and often suffer from comorbidities such as diabetes mellitus. Recent epidemiological studies suggest that concurrent HIV infection and diabetes mellitus may have a synergistic effect on the incidence of chronic kidney disease. To address this, we determined whether HIV-1 transgene expression accelerates diabetic kidney injury using a diabetic HIV-1 transgenic (Tg26) murine model. Diabetes was initially induced with low-dose streptozotocin in both Tg26 and wild-type mice on a C57BL/6 background, which is resistant to classic HIV-associated nephropathy. Although diabetic nephropathy is minimally observed on the C57BL/6 background, diabetic Tg26 mice exhibited a significant increase in glomerular injury compared with nondiabetic Tg26 mice and diabetic wild-type mice. Validation of microarray gene expression analysis from isolated glomeruli showed a significant upregulation of proinflammatory pathways in diabetic Tg26 mice. Thus, our study found that expression of HIV-1 genes aggravates diabetic kidney disease

Single-Cell Spatial MIST for Versatile, Scalable Detection of Protein Markers

High-multiplex detection of protein biomarkers across tissue regions has been an attractive spatial biology approach due to significant advantages over traditional immunohistochemistry (IHC) methods. Different from most methods, spatial multiplex in situ tagging (MIST) transfers the spatial protein expression information to an ultrahigh-density, large-scale MIST array. This technique has been optimized to reach single-cell resolution by adoption of smaller array units and 30% 8-arm PEG polymer as transfer medium. Tissue cell nuclei stained with lamin B have been clearly visualized on the MIST arrays and are colocalized with detection of nine mouse brain markers. Pseudocells defined at 10 μm in size have been used to fully profile tissue regions including cells and the intercellular space. We showcased the versatility of our technology by successfully detecting 20 marker proteins in kidney samples with the addition of five minutes atop the duration of standard immunohistochemistry protocols. Spatial MIST is amenable to iterative staining and detection on the same tissue samples. When 25 proteins were co-detected on 1 mouse brain section for each round and 5 rounds were executed, an ultrahigh multiplexity of 125 proteins was obtained for each pseudocell. With its unique abilities, this single-cell spatial MIST technology has the potential to become an important method in advanced diagnosis of complex diseases

Safety, tolerability, and outcomes of losartan use in patients hospitalized with SARS-CoV-2 infection: A feasibility study

BACKGROUND: Retrospective studies on the use of Renin-Angiotensin-Aldosterone System blockade in patients with Coronavirus Disease 2019 (COVID-19) have been informative but conflicting, and prospective studies are required to demonstrate the safety, tolerability, and outcomes of initiating these agents in hospitalized patients with COVID-19 and hypertension. METHODS AND FINDINGS: This is a single center feasibility study encompassing two cohorts: (1) prospective cohort (April 21, 2020 to May 29, 2020) and (2) retrospective cohort (March 7, 2020 to April 1, 2020) of hospitalized patients with real-time polymerase chain reaction (PCR) positive SARS-CoV-2 by nasopharyngeal swab. Key inclusion criteria include BP > 130/80 and a requirement of supplemental oxygen with FiO2 of 25% or higher to maintain SpO2 > 92%. Key exclusion criteria included hyperkalemia and acute kidney injury (AKI) at the time of enrollment. Prospective cohort consisted of de novo initiation of losartan and continuation for a minimum of 7 days and assessed for adverse events (AKI, hyperkalemia, transaminitis, hypotension) and clinical outcomes (change in SpO2/FiO2 and inflammatory markers, need for ICU admission and mechanical ventilation). Retrospective cohort consisted of continuation of losartan (prior-to-hospitalization) and assessment of similar outcomes. In the prospective cohort, a total of 250 hospitalized patients were screened and inclusion/exclusion criteria were met in 16/250 patients and in the retrospective cohort, a total of 317 hospitalized patients were screened and inclusion/exclusion criteria were met in 14/317 patients. Most common adverse event was hypotension, leading to discontinuation in 3/16 (19%) and 2/14 (14%) patients in the prospective and retrospective cohort. No patients developed AKI in the prospective cohort as compared to 1/14 (7%) patients in the retrospective cohort, requiring discontinuation of losartan. Hyperkalemia occurred in 1/16 (6%) and 0/14 patients in the prospective and retrospective cohorts, respectively. In the prospective cohort, 3/16 (19%) and 2/16 (13%) patients required ICU admission and mechanical ventilation. In comparison, 3/14 (21%) required ICU admission and mechanical ventilation in the retrospective cohort. A majority of patients in both cohorts (14/16 (88%) and 13/14 (93%) patients from the prospective and retrospective cohort) were discharged alive from the hospital. A total of 9/16 (prospective) and 5/14 (retrospective) patients completed a minimum 7 days of losartan. In these 9 patients in the prospective cohort, a significant improvement in SpO2/FiO2 ratio was observed from day 1 to 7. No significant changes in inflammatory markers (initiation, peak, and day 7) were observed in either cohort. CONCLUSION: In this pilot study we demonstrate that losartan was well-tolerated among hospitalized patients with COVID-19 and hypertension. We also demonstrate the feasibility of patient recruitment and the appropriate parameters to assess the outcomes and safety of losartan initiation or continuation, which provides a framework for future randomized clinical trials

Kruppel-like factor 15 (KLF15) is a key regulator of podocyte differentiation

Podocyte injury resulting from a loss of differentiation is the hallmark of many glomerular diseases. We previously showed that retinoic acid (RA) induces podocyte differentiation via stimulation of the cAMP pathway. However, many podocyte maturity markers lack binding sites for RA-response element or cAMP-response element (CREB) in their promoter regions. We hypothesized that transcription factors induced by RA and downstream of CREB mediate podocyte differentiation. We performed microarray gene expression studies in human podocytes treated with and without RA to identify differentially regulated genes. In comparison with known CREB target genes, we identified Krüppel-like factor 15 (KLF15), a kidney-enriched nuclear transcription factor, that has been previously shown to mediate cell differentiation. We confirmed that RA increased KLF15 expression in both murine and human podocytes. Overexpression of KLF15 stimulated expression of differentiation markers in both wild-type and HIV-1-infected podocytes. Also, KLF15 binding to the promoter regions of nephrin and podocin was increased in RA-treated podocytes. Although KLF15(−/−) mice at base line had minimal phenotype, lipopolysaccharide- or adriamycin-treated KLF15(−/−) mice had a significant increase in proteinuria and podocyte foot process effacement with a reduction in the expression of podocyte differentiation markers as compared with the wild-type treated mice. Finally, KLF15 expression was reduced in glomeruli isolated from HIV transgenic mice as well as in kidney biopsies from patients with HIV-associated nephropathy and idiopathic focal segmental glomerulosclerosis. These results indicate a critical role of KLF15 in mediating podocyte differentiation and in protecting podocytes against injury