Citations

Abstract Background and Aims Autologous mesenchymal stem/stromal cells (MSCs) have emerged as a therapeutic option for many chronic diseases. Hypertensive kidney disease (HKD) might impair MSCs’ reparative ability by altering important biomolecular properties of the cell, but the characteristics of this impairment are unclear. In our previous pre-clinical studies, hypoxic preconditioning (HPC) enhanced MSC angiogenesis and reduced senescence through global gene and protein expression. Thus, we hypothesize that HPC would improve human MSCs by enhancing their functionality and angiogenesis, creating an anti-inflammatory and anti-senescence environment in MSCs from healthy control (HC), hypertensive patients (HTN), and hypertensive kidney disease patients (HKD). Method Human MSCs were collected from abdominal subcutaneous fat tissue biopsy of HC, HTN, and HKD patients (n=12 each). Samples were collected from healthy volunteers with no history of hypertension or kidney disease (HC), patients diagnosed with hypertension controlled with antihypertensive drugs (HTN), and hypertensive patients with eGFR<60 mL/min/1.73 m2 (HKD). MSCs were harvested and cultured in Normoxic (20% O2) or Hypoxic (1% O2) conditions for 24-48 hours. MSC functionality was measured by migration and proliferation. Angiogenic and inflammatory secretome in conditioned media was assessed along with MSC senescence by senescence-associated beta-galactosidase (SA-beta-gal) activity. In addition, transcriptome analysis using RNA-sequencing (n=3/group) and quantitative PCR (qPCR) were performed to evaluate gene expression. Results At baseline, Normoxic HTN-MSCs interestingly had higher proliferation compared to HC. HC-MSC subjected to HPC showed increased proliferation (Figure 1A). SA-β-gal activity tended to decrease after HPC, particularly in the HC group (P = .06). HPC did not affect the release of the pro-angiogenic protein VEGF from MSCs, but increased EGF in HC-MSC, and decreased HGF in HC and HKD MSCs. HPC upregulated the pro-angiogenetic genes, inflammatory gene, and a few senescence genes (Figure 1F). Conclusion HPC has a more favorable functional effect on HC- than on HKD-MSC, reflected in increased proliferation and EGF release, and tends to decrease senescence, whereas it has little effect on HTN or HKD MSCs. These observations may assist in developing novel therapeutic strategies to improve the regenerative capacity of MSCs in patients with hypertensive kidney disease.

Abstract Atherosclerotic renal artery stenosis (ARAS) is associated with irreversible parenchymal renal disease and regenerative stem cell therapies may improve renal outcomes. Hypoxia preconditioning (HPC) may improve the regenerative functions of adipose tissue-derived mesenchymal stem cells (AMSC) by affecting DNA 5-hydroxymethylcytosine (5hmC) marks in angiogenic genes. Here, we investigated using a porcine ARAS model, whether growth of ARAS AMSCs in hypoxia (Hx) versus normoxia (Nx) would enhance renal tissue repair, and comprehensively analyze how HPC modifies DNA hydroxymethylation compared to untreated ARAS and healthy/normal pigs (n=5 each). ARAS pigs exhibited elevated serum cholesterol, serum creatinine and renal artery stenosis, with a concomitant decrease in renal blood flow (RBF) and increased blood pressure (BP) compared to healthy pigs. Renal artery injection of either autologous Nx or Hx AMSCs improved diastolic BP, reduced kidney tissue fibrosis, and inflammation (CD3+ T-cells) in ARAS pigs. In addition, renal medullary hypoxia significantly lowered with Nx but not Hx AMSC treatment. Mechanistically, levels of epigenetic 5hmC marks (which reflect gene activation) estimated using DNA immunoprecipitation technique were elevated in profibrotic and inflammatory genes in ARAS compared with normal AMSCs. HPC significantly reduced 5hmC levels in cholesterol biosynthesis and oxidative stress response pathways in ARAS AMSCs. Thus, autologous AMSCs improve key renovascular parameters and inflammation in ARAS pigs, with HPC mitigating pathological molecular effects on inflammatory and profibrotic genes which may play a role in augmenting regenerative capacity of AMSCs.

Abstract Background and Aims While the percentage of women entering nephrology has increased over the years, women representation and sex disparities in the authorship of major nephrology Clinical practice guidelines (CPG) has not been examined. Our study evaluates current sex disparities and women representation, and the nationalities of women authors in nephrology CPGs developed by the Kidney Disease: Improving Global Outcomes (KDIGO), Kidney Disease Outcomes Quality Initiative (KDOQI), and the European Renal Best Practice (ERBP), the official guideline body of the ERA-EDTA. Method We examined the number of female versus male guideline workgroup members (panelists) for all available CPGs in each of the three organizations as of Dec. 2020, which are available on their respective websites. We discerned the sex of the panelists based on google search and their affiliated institutional websites. We obtained the nationalities of the workgroup members from the authorship information of the respective CPG. Results Of the total 488 panelists in all three organizations, 115 (23.6%) were females and 373 (76.4%) males. KDIGO had 184 panelists, of which 46 (25%) were females. The CPGs with the highest and the least women representation are ‘Diabetes in Chronic Kidney Disease (CKD)’ (41.2%) and ‘Anemia in CKD’ (11.8%), respectively. The countries with the highest number of women representations are the USA (20), followed by Canada (6), and China (4). In KDOQI, 39 (31%) of 127 panelists were female. While CPGs related to ‘Evaluation and management of CKD’ and ‘Nutrition in children with CKD’ each had 50% female panelists, ‘Blood pressure management in CKD’ CPG had 10% female panelists. 28 (72%) of the total 39 women were from the USA. The ERBP had 30 (17%) females of the total 177 panelists. ‘CKD in older patients’ CPG comprised 42.1% female panelists. CPGs for ‘Glycemic control in diabetes’ and ‘Glucose lowering drugs in diabetes’ had no female panelists. Belgium and UK each had six women representatives, while France and The Netherlands 4 women representatives each. Conclusion The guidelines developed by the most prominent organizations – KDIGO, KDOQI, and ERA-EDTA have less than 25% women representation. While it is encouraging to note that there is more women representation in some of the CPGs developed by KDIGO in 2020, evaluating the barriers contributing to the under-representation of women in major nephrology organizations is warranted. Also notable is a lack of women representation from developing countries.