SARS-CoV-2 receptor networks in diabetic and COVID-19-associated kidney disease

Revealing the therapeutic targets and molecular mechanisms of emodin-treated coronavirus disease 2019 via a systematic study of network pharmacology

Emodin has shown pharmacological effects in the treatment of infection with severe acute respiratory syndrome coronavirus-2, which leads to coronavirus disease 2019 (COVID-19). Thus, we speculated that emodin may possess anti-COVID-19 activity. In this study, using bioinformatics databases, we screened and harvested the candidate genes or targets of emodin and COVID-19 prior to the determination of pharmacological targets and molecular mechanisms of emodin against COVID-19. We discovered core targets for the treatment of COVID-19, including mitogen-activated protein kinase 1 (MAPK1), tumor protein (TP53), tumor necrosis factor (TNF), caspase-3 (CASP3), epidermal growth factor receptor (EGFR), vascular endothelial growth factor A (VEGFA), interleukin 1B (IL1B), mitogen-activated protein kinase 14 (MAPK14), prostaglandin-endoperoxide synthase 2 (PTGS2), B-cell lymphoma-2-like protein 1 (BCL2L1), interleukin-8 (CXCL8), myeloid cell leukemia-1 (MCL1), and colony stimulating factor 2 (CSF2). The GO analysis of emodin against COVID-19 mainly included cytokine-mediated signaling pathway, response to lipopolysaccharide, response to molecule of bacterial origin, developmental process involved in reproduction, and reproductive structure development. The KEGG results exhibited that the molecular pathways mainly included IL-17 signaling pathway, AGE-RAGE signaling pathway in diabetic complications, TNF signaling pathway, pertussis, proteoglycans in cancer, pathways in cancer, MAPK signaling pathway, NOD-like receptor signaling pathway, NF-kappa B signaling pathway, etc. Also, molecular docking results revealed the docking capability between emodin and COVID-19 and the potential pharmacological activity of emodin against COVID-19. Taken together, these findings uncovered the targets and pharmacological mechanisms of emodin for treating COVID-19 and suggested that the vital targets might be used as biomarkers against COVID-19.

The evolution and future of diabetic kidney disease research: a bibliometric analysis

BACKGROUND

Diabetic kidney disease (DKD) is one of the most important complications of diabetic mellitus. It is essential for nephrologists to understand the evolution and development trends of DKD.

METHODS

Based on the total cited numbers in the Web of Science Core Collection, which was searched through September 28th, 2020, we performed a bibliometric analysis of the top 100 most cited full-length original articles on the subject of DKD. The timespans, authors, contributions, subcategories, and topics of those 100 articles were analysed. In addition, the evolution of topics in DKD research was investigated.

RESULTS

There were 23,968 items under the subject of DKD in the Web of Science Core Collection. The top 100 cited articles, published from 1999 to 2017, were cited 38,855 times in total. Researchers from the USA contributed the most publications. The number of articles included in 'Experimental studies (EG)', 'Clinical studies (CS)', 'Epidemiological studies (ES)', and 'Pathological and pathophysiological studies (PP)' were 65, 26, 7, and 2, respectively. Among the 15 topics, the most popular topic is the renin-angiotensin-aldosterone system (RAAS), occurring in 26 articles, including 6 of the top 10 most cited articles. The evolution of topics reveals that the role of RAAS inhibitor is a continuous hotspot, and sodium-glucose cotransporter 2 (SGLT-2) inhibitor and glucagon-like peptide 1 (GLP-1) agonist are two renoprotective agents which represent novel therapeutic methods in DKD. In addition, the 26 clinical studies among the top 100 most cited articles were highlighted, as they help guide clinical practice to better serve patients.

CONCLUSIONS

This bibliometric analysis of the top 100 most cited articles revealed important studies, popular topics, and trends in DKD research to assist researchers in further understanding the subject.

ACE2 protein expression within isogenic cell lines is heterogeneous and associated with distinct transcriptomes

The membrane protein angiotensin-converting enzyme 2 (ACE2) is a physiologic regulator of the renin-angiotensin system and the cellular receptor for the SARS-CoV-2 virus. Prior studies of ACE2 expression have primarily focused on mRNA abundance, with investigation at the protein level limited by uncertain specificity of commercial ACE2 antibodies. Here, we report our development of a sensitive and specific flow cytometry-based assay for cellular ACE2 protein abundance. Application of this approach to multiple cell lines revealed an unexpected degree of cellular heterogeneity, with detectable ACE2 protein in only a subset of cells in each isogenic population. This heterogeneity was mediated at the mRNA level by transcripts predominantly initiated from the ACE2 proximal promoter. ACE2 expression was heritable but not fixed over multiple generations of daughter cells, with gradual drift toward the original heterogeneous background. RNA-seq profiling identified distinct transcriptomes of ACE2-expressing relative cells to non-expressing cells, with enrichment in functionally related genes and transcription factor target sets. Our findings provide a validated approach for the specific detection of ACE2 protein at the surface of single cells, support an epigenetic mechanism ACE2 gene regulation, and identify specific pathways associated with ACE2 expression in HuH7 cells.

Sodium-glucose co-transporter 2 inhibitors in COVID-19: meeting at the crossroads between heart, diabetes and infectious diseases

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are a new class of glucose-lowering agents which have changed the landscape of diabetes therapy, due to their remarkable cardiorenal protective properties. The attack of severe acute respiratory syndrome coronavirus 2 on the heart and kidneys shares similarities with diabetes; therefore, the notion that SGLT2i might have a role in the future management of Coronavirus Disease 2019 (COVID-19) is based on a solid pathophysiological hypothesis. SGLT2i have been proved to decrease the expression of proinflammatory cytokines, ameliorate oxidative stress and reduce sympathetic activity, thus resulting in downregulation of both systemic and adipose tissue inflammation. On the other hand, they have been linked to an increased risk of euglycemic diabetic ketoacidosis. Therefore, the efficacy and safety of SGLT2i in COVID-19 are still debatable and remain to be clarified by ongoing randomized trials, to assess whether the benefits of treatment with these drugs outweigh the potential risks.

Balzer M, Park J, Zhou T, Ma Z, Sullivan KM, Hu H, Sheng X, Liu H, Wei Y, Boustany-Kari CM, Patel U, Almaani S, Palmer M, Townsend R, Blady S, Hogan J, Morton L, Susztak K. Urinary Single-Cell Profiling Captures the Cellular Diversity of the Kidney

BACKGROUND

Microscopic analysis of urine sediment is probably the most commonly used diagnostic procedure in nephrology. The urinary cells, however, have not yet undergone careful unbiased characterization.

METHODS

Single-cell transcriptomic analysis was performed on 17 urine samples obtained from five subjects at two different occasions, using both spot and 24-hour urine collection. A pooled urine sample from multiple healthy individuals served as a reference control. In total 23,082 cells were analyzed. Urinary cells were compared with human kidney and human bladder datasets to understand similarities and differences among the observed cell types.

RESULTS

Almost all kidney cell types can be identified in urine, such as podocyte, proximal tubule, loop of Henle, and collecting duct, in addition to macrophages, lymphocytes, and bladder cells. The urinary cell-type composition was subject specific and reasonably stable using different collection methods and over time. Urinary cells clustered with kidney and bladder cells, such as urinary podocytes with kidney podocytes, and principal cells of the kidney and urine, indicating their similarities in gene expression.

CONCLUSIONS

A reference dataset for cells in human urine was generated. Single-cell transcriptomics enables detection and quantification of almost all types of cells in the kidney and urinary tract.

Angiotensin-converting enzyme 2: from a vasoactive peptide to the gatekeeper of a global pandemic

PURPOSE OF REVIEW

We provide a comprehensive overview of angiotensin-converting enzyme 2 (ACE2) as a possible candidate for pharmacological approaches to halt inflammatory processes in different pathogenic conditions.

RECENT FINDINGS

ACE2 has quickly gained prominence in basic research as it has been identified as the main entry receptor for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This novel pathogen causes Coronavirus Disease 2019 (COVID-19), a pathogenic condition that reached pandemic proportion and is associated with unprecedented morbidity and mortality.

SUMMARY

The renin-angiotensin system is a complex, coordinated hormonal cascade that plays a pivotal role in controlling individual cell behaviour and multiple organ functions. ACE2 acts as an endogenous counter-regulator to the pro-inflammatory and pro-fibrotic pathways triggered by ACE through the conversion of Ang II into the vasodilatory peptide Ang 1-7. We discuss the structure, function and expression of ACE2 in different tissues. We also briefly describe the role of ACE2 as a pivotal driver across a wide spectrum of pathogenic conditions, such as cardiac and renal diseases. Furthermore, we provide the most recent data concerning the possible role of ACE2 in mediating SARS-CoV-2 infection and dictating COVID-19 severity.

Acute Kidney Injury in Pediatric Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common complication of type 1 and 2 diabetes and often presents during adolescence and young adulthood. Given the growing incidence of both type 1 and type 2 diabetes in children and adolescents, DKD represents a significant public health problem. Acute kidney injury (AKI) in youth with diabetes is strongly associated with risk of DKD development. This review will summarize the epidemiology and pathophysiology of AKI in children with diabetes, the relationship between AKI and DKD, and the potential therapeutic interventions. Finally, we will appraise the impact of the recent COVID-19 infection pandemic on AKI in children with diabetes.

Clinical Characteristics of COVID-19 Patients in a Regional Population With Diabetes Mellitus: The ACCREDIT Study

OBJECTIVE

To identify clinical and biochemical characteristics associated with 7- & 30-day mortality and intensive care admission amongst diabetes patients admitted with COVID-19.

RESEARCH DESIGN AND METHODS

We conducted a cohort study collecting data from medical notes of hospitalised people with diabetes and COVID-19 in 7 hospitals within the Mersey-Cheshire region from 1 January to 30 June 2020. We also explored the impact on inpatient diabetes team resources. Univariate and multivariate logistic regression analyses were performed and optimised by splitting the dataset into a training, test, and validation sets, developing a robust predictive model for the primary outcome.

RESULTS

We analyzed data from 1004 diabetes patients (mean age 74.1 (± 12.6) years, predominantly men 60.7%). 45% belonged to the most deprived population quintile in the UK. Median BMI was 27.6 (IQR 23.9-32.4) kg/m². The primary outcome (7-day mortality) occurred in 24%, increasing to 33% by day 30. Approximately one in ten patients required insulin infusion (9.8%). In univariate analyses, patients with type 2 diabetes had a higher risk of 7-day mortality [p < 0.05, OR 2.52 (1.06, 5.98)]. Patients requiring insulin infusion had a lower risk of death [p = 0.02, OR 0.5 (0.28, 0.9)]. CKD in younger patients (<70 years) had a greater risk of death [OR 2.74 (1.31-5.76)]. BMI, microvascular and macrovascular complications, HbA1c, and random non-fasting blood glucose on admission were not associated with mortality. On multivariate analysis, CRP and age remained associated with the primary outcome [OR 3.44 (2.17, 5.44)] allowing for a validated predictive model for death by day 7.

CONCLUSIONS

Higher CRP and advanced age were associated with and predictive of death by day 7. However, BMI, presence of diabetes complications, and glycaemic control were not. A high proportion of these patients required insulin infusion warranting increased input from the inpatient diabetes teams.

A Kidney International "journal of the COVID-19 year" in kidney transplantation

The global coronavirus disease 2019 pandemic’s impact on kidney transplant recipients and transplantation programs in the calamitous months of February to June 2020, spring to summer in the Northern Hemisphere, is represented in articles published in the December issue of Kidney International. Writing about another pandemic in the year of 1665 over 300 years ago, the author Daniel Defoe¹ describes the same period of time in London and gives a remarkably familiar description of how a pandemic affects populations, including the unproven treatments, epidemiology of infection, and human response to restrictions on freedom of city lockdowns that occurred during that time. The risks, outcomes, epidemiology, and potential treatments for the kidney transplant population worldwide during the past 12 months have been thankfully studied in detail by multiple investigators and form the subject of papers in KI this month.