Fibrate treatment of eEOCs in murine AKI

Immunomagnetic Delivery of Adipose-Derived Endothelial Progenitor Cells for the Repair of Renal Ischemia-Reperfusion Injury in a Rat Model

Renal ischemia-reperfusion injury (IRI) is a significant cause of acute kidney injury (AKI) and usually brings severe public health consequences. Adipose-derived endothelial progenitor cell (AdEPCs) transplantation is beneficial for AKI but suffers from low delivery efficiency. This study was conducted to explore the protective effects of magnetically delivered AdEPCs on the repair of renal IRI. Two types of magnetic delivery methods, namely the endocytosis magnetization (EM) method and the immunomagnetic (IM) method were fabricated using PEG@Fe₃O₄ and CD133@Fe₃O₄, and their cytotoxicities in AdEPCs were assessed. In the renal IRI rat model, magnetic AdEPCs were injected via the tail vein and a magnet was placed beside the injured kidney for magnetic guidance. The distribution of transplanted AdEPCs, renal function, and tubular damage were evaluated. Our results suggested that CD133@Fe₃O₄ had the minimum negative effects on the proliferation, apoptosis, angiogenesis, and migration of AdEPCs compared with PEG@Fe₃O₄. Renal magnetic guidance could significantly enhance the transplantation efficiency and the therapeutic outcomes of AdEPCs-PEG@Fe₃O₄ and AdEPCs-CD133@Fe₃O₄ in the injured kidneys. However, under renal magnetic guidance, AdEPCs-CD133@Fe₃O₄ had stronger therapeutic effects than PEG@Fe₃O₄ after renal IRI. The immunomagnetic delivery of AdEPCs with CD133@Fe₃O₄ could be a promising therapeutic strategy for renal IRI.

Long Noncoding RNA ZFAS1 Protects HK-2 Cells against Sepsis-Induced Injury through Targeting the miR3723p/PPARα Axis

In septic acute kidney injury, one of the main purposes of long noncoding RNA (lncRNA) ZFAS1 is still unclear. This study is intended to analyze the effects of lncRNA ZFAS1 on the septic AKI in the HK-2 cell line. Materials and Methods. In order to construct an in vitro model of septic AKI, HK-2 cells have been treated with lipopolysaccharides. CCK-8 assay has been utilized to check the viability of HK-2 cells. The contents of inflammatory cytokines (that includes IL-1β, TNF-α, and IL-6) have been marked with enzyme-linked immune sorbent assay (ELISA). Cell apoptosis was assessed by TUNEL staining. To detect the expression of lncRNA ZFAS1 and microRNA-372-3p, quantitative reverse-transcription PCR has been used. And to confirm the connection among genes, luciferase reporter assay has been applied. Results. Overexpression of ZFAS1 alleviated LPS-induced HK-2 cell injury. ZFAS1 positively regulated expression of α receptor activated by peroxisome proliferation (PPARα) through competitive linkage with miR-372-3p. In addition, over expression of miR-372-3p counteracted the protective effect of upward regulation of ZFAS1 on LPS-induced HK-2 cell damage, which could be reversed by over expression of PPARα. Conclusion. It is concluded that, in LPS-induced HK-2 cell injury, ZFAS1 has a protective role via modulating the miR-372-3p/PPARα axis, suggesting the potential of ZFAS1 as a protective target for septic AKI.

Ligliptin for treatment of type 2 diabetes mellitus with early renal injury: Efficacy and impact on endogenous hydrogen sulfide and endothelial function

BACKGROUND

Diabetes is a clinically common chronic disease, and its incidence has been increasing in recent years. Diabetes is believed to accelerate the process of atherosclerosis in patients, and abnormal endothelial function is an important factor leading to diabetic kidney damage.

AIM

To investigate the efficacy of ligliptin in the treatment of type 2 diabetes mellitus (T2DM) with early renal injury and its effect on serum endogenous hydrogen sulfide (H₂S), endothelial cell particles, and endothelial function.

METHODS

From January 2018 to April 2019, 110 patients with T2DM and early kidney injury treated at our hospital were divided into an observation group (receiving ligliptin treatment, n = 54) and a control group (receiving gliquidone therapy, n = 56). Blood glucose and renal function before and after treatment were compared between the two groups.

RESULTS

The differences in fasting blood glucose, 2 h blood glucose, and glycated hemoglobin were not statistically significant between the two groups after treatment. The urinary albumin excretion rate after treatment in the ligliptin group was 70.32 ± 11.21 µg/min, which was significantly lower than that of the gliquidone group (P = 0.000). Serum endogenous H₂S and endothelial cell microparticles of the ligliptin treatment group were 40.04 ± 8.82 mol/L and 133.40 ± 34.39, respectively, which were significantly lower than those of the gliquidone treatment group (P = 0.000 for both); endothelin-dependent diastolic function and nitric oxide after treatment in the ligliptin group were 7.98% ± 1.22% and 190.78 ± 30.32 mol/L, significantly higher than those of the gliquidone treatment group (P = 0.000 for both).

CONCLUSION

Ligliptin treatment of T2DM with early renal injury has the same glucose-lowering effect as gliquidone treatment. Ligliptin treatment has a better effect and it can significantly improve the renal function and vascular endothelial function of patients, and reduce serum endogenous H₂S and endothelial cell particle levels.

Autophagy activation in circulating proangiogenic cells aggravates AKI in type I diabetes mellitus

Acute kidney injury (AKI) occurs frequently in hospitals worldwide, but the therapeutic options are limited. Diabetes mellitus (DM) affects more and more people around the globe. The disease worsens the prognosis of AKI even further. In recent years, cell-based therapies have increasingly been applied in experimental AKI. The aim of the study was to utilize two established autophagy inducers for pharmacological preconditioning of so-called proangiogenic cells (PACs) in PAC treatment of diabetic AKI. Insulin-dependent DM was induced in male C57/Bl6N mice by intraperitoneal injections of streptozotocine. Six weeks later, animals underwent bilateral renal ischemia for 45 min, followed by intravenous injections of either native or zVAD (benzyloxycarbonyl-Val-Ala-Asp-fluoro-methylketone)- or Z-Leu-Leu-Leu-al (MG132)-pretreated syngeneic murine PACs. Mice were analyzed 48 h (short term) and 6 wk (long term) later, respectively. DM worsened postischemic AKI, and PAC preconditioning with zVAD and MG132 resulted in a further decline of excretory kidney function. Injection of native PACs reduced fibrosis in nondiabetic mice, but cell preconditioning promoted interstitial matrix accumulation significantly. Both substances aggravated endothelial-to-mesenchymal transition (EndoMT) under diabetic conditions; these effects occurred either exclusively in the short (zVAD) or in the short and long term (MG132). Preconditioned cells stimulated the autophagocytic flux in intrarenal endothelial cells, and all experimental groups displayed increased endothelial abundances of senescence-associated β-galactosidase, a marker of premature cell senescence. Pharmacological autophagy activation may not serve as an effective strategy for improving PAC competence in diabetic AKI in general. On the contrary, several outcome parameters (excretory function, fibrosis, EndoMT) may even be worsened.

The endothelial-to-mesenchymal transition and endothelial cilia in EPC-mediated postischemic kidney protection

Renal ischemia induces peritubular capillary rarefication and fibrosis, with the latter partly resulting from the endothelial-to-mesenchymal transition (EndoMT). Endothelial cilia transmit blood flow-associated forces into the cell. Early endothelial progenitor cells (eEPCs) have been shown to protect mice from acute kidney injury in the short term. The aim of the present study was to analyze midterm consequences of eEPC treatment in the context of endothelial cilia and the EndoMT. Male C57/Bl6N mice were subjected to unilateral renal ischemia postuninephrectomy. Syngeneic murine eEPCs were systemically injected at the time of reperfusion. Animals were investigated 1, 4, and 6 wk later. Cultured mature endothelial cells were exposed to a variable flow with versus without eEPC supernatant incubation. Systemically injected eEPCs reduced serum creatinine levels at week 1 (35 and 45 min) and week 4 (45 min). Interstitial fibrosis was significantly diminished by cell treatment at all time points as well. The EndoMT was less pronounced at week 4 (35 min) and week 6 (45 min). eEPC supernatant reduced α-smooth muscle actin expression and α-tubulin abundance in flow-treated cultured mature endothelial cells, and percentages of cilium-positive cells increased. The loss of peritubular capillaries was prevented by eEPCs. Intrarenal endothelial α-tubulin decreased postischemia and was further reduced by eEPC administration. We conclude that eEPCs are capable of reorganizing the endothelial cytoskeleton in an indirect manner, ultimately resulting in stabilization of the endothelial ciliome. The investigation indicates an antimesenchymal role of endothelial cilia in the process of postischemic tissue fibrosis/EndoMT.

Endothelial autophagy and Endothelial-to-Mesenchymal Transition (EndoMT) in eEPC treatment of ischemic AKI

BACKGROUND

Autophagy enables cells to digest endogenous/exogenous waste products, thus potentially prolonging the cellular lifespan. Early endothelial progenitor cells (eEPCs) protect mice from ischemic acute kidney injury (AKI). The mid-term prognosis in AKI critically depends on vascular rarefication and interstitial fibrosis with the latter partly being induced by mesenchymal transdifferentiation of endothelial cells (EndoMT). This study aimed to determine the impact of eEPC preconditioning with different autophagy inducing agents [suberoylanilide hydroxamic acid (SAHA)/temsirolimus] in ischemic AKI.

METHODS

Male C57/Bl6 N mice were subjected to bilateral renal ischemia (40 min). Animals were injected with either untreated, or SAHA- or temsirolimus-pretreated syngeneic murine eEPCs at the time of reperfusion. Mice were analyzed 48 h and 4 weeks later. In addition, cultured eEPCs were treated with transforming growth factor (TGF)-β ± SAHA, autophagy (perinuclear LC3-II), and stress-induced premature senescence (SIPS-senescence-associated β-galactosidase, SA-β-Gal), and were evaluated 96 h later.

RESULTS

Cultured eEPCs showed reduced perinuclear density of LC3-II + vesicles and elevated levels of SA-β-Gal after treatment with TGF-β alone, indicating impaired autophagy and aggravated SIPS. These effects were completely abrogated by SAHA. Systemic administration of either SAHA or tems pretreated eEPCs resulted in elevated intrarenal endothelial p62 at 48 h and 4 weeks, indicating stimulated endothelial autophagy. This effect was most pronounced after injection of SAHA-treated eEPCs. At 4 weeks endothelial expression of mesenchymal alpha-smooth muscle actin (αSMA) was reduced in animals receiving untreated and SAHA-pretreated cells. In addition, SAHA-treated cells reduced fibrosis at week 4. Tems in contrast aggravated EndoMT. Postischemic renal function declined after renal ischemia and remained unaffected in all experimental cell treatment groups.

CONCLUSION

In ischemic AKI, intrarenal endothelial autophagy may be stabilized by systemic administration of pharmacologically preconditioned eEPCs. Early EPCs can reduce postischemic EndoMT and fibrosis in the mid-term. Autophagy induction in eEPCs either increases or decreases the mesenchymal properties of intrarenal endothelial cells, depending on the substance being used. Thus, endothelial autophagy induction in ischemic AKI, mediated by eEPCs is not a renoprotective event per se.