Renal Regeneration Research Articles

The Review of Current Knowledge on Neutrophil Gelatinase-Associated Lipocalin (NGAL).

Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein that is secreted mostly by immune cells such as neutrophils, macrophages, and dendritic cells. Its production is stimulated in response to inflammation. The concentrations of NGAL can be measured in plasma, urine, and biological fluids such as peritoneal effluent. NGAL is known mainly as a biomarker of acute kidney injury and is released after tubular damage and during renal regeneration processes. NGAL is also elevated in chronic kidney disease and dialysis patients. It may play a role as a predictor of the progression of renal function decreases with complications and mortality due to kidney failure. NGAL is also useful in the diagnostic processes of cardiovascular diseases. It is highly expressed in injured heart tissue and atherosclerostic plaque; its serum concentrations correlate with the severity of heart failure and coronary artery disease. NGAL increases inflammatory states and its levels rise in arterial hypertension, obesity, diabetes, and metabolic complications such as insulin resistance, and is also involved in carcinogenesis. In this review, we present the current knowledge on NGAL and its involvement in different pathologies, especially its role in renal and cardiovascular diseases.

#4158 URINE DERIVED STEM CELL AMELIORATES RENAL FIBROSIS VIA KLOTHO ACTIVATION

Abstract Background and Aims After renal IRI, regeneration and recovery of the renal tubular cell occurs. However, if the renal repair process is maladaptive, it progresses to renal fibrosis. The role of stem cells in kidney regeneration or fibrosis has not been fully elucidated. we evaluated the urine drived stem cells (UDSC) for renal inflammation and fibrosis after renal ischemia reperfusion (IR). Method 10 week old balb/c nude male mice were used. sham, sham with UDSC, IR, IR with UDSC. UDSC were infused 3 times via tail vain at 6, 7, 8th day after renal IR. Urine NGAL/creatinine (Cr) were checked. The kidneys tissue were harvested at day 14 day. In vitro, TGF-β treated HK2 cell were co-cultured with UDSC. Klotho siRNA silencing was performed in UDSC. Results Urinary NGAL/Cr were significantly increased in IR mice after 14 day IR, compared to sham mice. Urinary NGAL/Cr significantly decreased in UDSC treated IR mice, compared to IR mice. In H&E stain, renal tubulo-interstitial injury were significantly decreased in UDSC treated IR mice, compared to IR mice. In masson trichrom stain, renal fibrosis area were were significantly decreased in UDSC treated IR mice, compared to IR mice. The renal expression of TGF-β, α-SMA, and collagne IV were significantly decreased in UDSC treated IR mice, compared to IR mice. The renal expression of Klotho were increased in UDSC treated IR mice, compared to IR mice. in vitro, UDSCs were stem cells that expressed Klotho protein more strongly than other mesenchymal stem cells (MSCs). UDSCs also suppressed fibrosis by inhibiting transforming growth factor (TGF)-β in HK-2 human renal proximal tubule cells in an in vitro model. Klotho siRNA silencing reduced the TGF-β-inhibiting ability of UDSCs. Conclusion UDSC attenuate renal fibrosis after renal IR. Klotho-secretion of UDSC play a role in these anti- fibrotic effects.

Downregulation of KLF10 contributes to the regeneration of survived renal tubular cells in cisplatin-induced acute kidney injury via ZBTB7A-KLF10-PTEN axis

Acute kidney injury (AKI) is a common clinical dysfunction with complicated pathophysiology and limited therapeutic methods. Renal tubular injury and the following regeneration process play a vital role in the course of AKI, but the underlining molecular mechanism remains unclear. In this study, network-based analysis of online transcriptional data of human kidney found that KLF10 was closely related to renal function, tubular injury and regeneration in various renal diseases. Three classical mouse models confirmed the downregulation of KLF10 in AKI and its correlation with tubular regeneration and AKI outcome. The 3D renal tubular model in vitro and fluorescent visualization system of cellular proliferation were constructed to show that KLF10 declined in survived cells but increased during tubular formation or conquering proliferative impediment. Furthermore, overexpression of KLF10 significantly inhibited, whereas knockdown of KLF10 extremely promoted the capacity of proliferation, injury repairing and lumen-formation of renal tubular cells. In mechanism, PTEN/AKT pathway were validated as the downstream of KLF10 and participated in its regulation of tubular regeneration. By adopting proteomic mass spectrum and dual-luciferase reporter assay, ZBTB7A were found to be the upstream transcription factor of KLF10. Our findings suggest that downregulation of KLF10 positively contributed to tubular regeneration in cisplatin induced acute kidney injury via ZBTB7A-KLF10-PTEN axis, which gives insight into the novel therapeutic and diagnostical target of AKI.

Stem Cells in Kidney Ischemia: From Inflammation and Fibrosis to Renal Tissue Regeneration

Ischemic nephropathy consists of progressive renal function loss due to renal hypoxia, inflammation, microvascular rarefaction, and fibrosis. We provide a literature review focused on kidney hypoperfusion-dependent inflammation and its influence on renal tissue's ability to self-regenerate. Moreover, an overview of the advances in regenerative therapy with mesenchymal stem cell (MSC) infusion is provided. Based on our search, we can point out the following conclusions: 1. endovascular reperfusion is the gold-standard therapy for RAS, but its success mostly depends on treatment timeliness and a preserved downstream vascular bed; 2. anti-RAAS drugs, SGLT2 inhibitors, and/or anti-endothelin agents are especially recommended for patients with renal ischemia who are not eligible for endovascular reperfusion for slowing renal damage progression; 3. TGF-β, MCP-1, VEGF, and NGAL assays, along with BOLD MRI, should be extended in clinical practice and applied to a pre- and post-revascularization protocols; 4. MSC infusion appears effective in renal regeneration and could represent a revolutionary treatment for patients with fibrotic evolution of renal ischemia.

Rapamycin Does Not Act as a Dietary Restriction Mimetic in the Protection against Ischemia Reperfusion Injury

Introduction: Short-term fasting protects against renal ischemia reperfusion injury (IRI). mTOR signaling is downregulated and may be involved in its protective effect. Rapamycin is considered a possible mimetic as it inhibits the mTOR pathway. This study examines the effect of rapamycin on renal IRI. Material and Methods: Mice were divided into four groups: ad libitum (AL), fasted (F), AL treated with rapamycin (AL+R), and F treated with rapamycin (F+R). Rapamycin was administered intraperitoneally 24 h before bilateral renal IRI was induced. Survival was monitored for 7 days. Renal cell death, regeneration, and mTOR activity were determined 48 h after reperfusion. Oxidative stress resistance of human renal proximal tubular and human primary tubular epithelial cells after rapamycin treatment was determined. Results: All F and F+R mice survived the experiment. Although rapamycin substantially downregulated mTOR activity, survival in the AL+R group was similar to AL (10%). Renal regeneration was significantly reduced in AL+R but not in F+R. After IRI (48 h), pS6K/S6K ratio was lower in F, F+R, and AL+R groups compared to AL fed animals (p = 0.02). In vitro, rapamycin also significantly downregulated mTOR activity (p < 0.001) but did not protect against oxidative stress. Conclusion: Rapamycin pretreatment does not protect against renal IRI. Thus, protection against renal IRI by fasting is not exclusively mediated through inhibition of mTOR activity but may involve preservation of regenerative mechanisms despite mTOR downregulation. Therefore, rapamycin cannot be used as a dietary mimetic to protect against renal IRI.

WT1+ glomerular parietal epithelial progenitors promote renal proximal tubule regeneration after severe acute kidney injury.

Rationale: Mammalian renal proximal tubules can partially regenerate after acute kidney injury (AKI). However, cells participating in the renal proximal tubule regeneration remain to be elucidated. Wilms' tumor 1 (WT1) expresses in a subtype of glomeruli parietal epithelial cells (PECs) in adult kidneys, it remains unclear whether these WT1+ PECs play a role in renal regeneration/repair after AKI. Methods: Ischemia-reperfusion injury (IRI) mouse model was used to investigate the expression pattern of WT1 in the kidney after severe AKI. Conditional deletion of WT1 gene mice were generated using Pax8CreERT2 and WT1fl/fl mice to examine the function of WT1. Then, genetic cell lineage tracing and single-cell RNA sequencing were performed to illustrate that WT1+ PECs develop into WT1+ proximal tubular epithelial cells (PTECs). Furthermore, in vitro clonogenicity, direct differentiation analysis and in vivo transplantation were used to reveal the stem cell-like properties of these WT1+ PECs. Results: The expression of WT1 protein in PECs and PTECs was increased after severe AKI. Conditional deletion of WT1 gene in PTECs and PECs aggravated renal tubular injury after severe AKI. WT1+ PECs develop into WT1+ PTECs via the transient scattered tubular cell stage, and these WT1+ PECs possess specific stem cell-like properties. Conclusions: We discovered a group of WT1+ PECs that promote renal proximal tubule regeneration/repair after severe AKI, and the expression of WT1 in PECs and PTECs is essential for renal proximal tubule regeneration after severe kidney injury.

GDF11 Improves Ischemia-Reperfusion-Induced Acute Kidney Injury via Regulating Macrophage M1/M2 Polarization

Introduction: Acute kidney injury (AKI) is a clinical emergency caused by the rapid decline of renal function caused by various etiologies. Growth differentiation factor 11 (GDF11) can promote renal tubular regeneration and improve kidney function in AKI, but the specific mechanism remains unclear. Herein, we investigated the effect and mechanisms of GDF11 in ameliorating AKI induced by ischemia-reperfusion (I/R). Methods: An animal model of AKI was established by I/R method, and the changes of serum urea nitrogen and creatinine were measured to evaluate the AKI. Enzyme-linked immunosorbent assay (ELISA) was used to measure cytokines, malondialdehyde, superoxide dismutase, nitric oxide synthase, and arginase 1 levels. Flow cytometry was used to count the M1/M2 macrophages. IHC, WB, and q-PCR experiments were used to evaluate the expression of GDF11. Results: The changes in serum levels of urea nitrogen and creatinine after I/R suggest that an animal model of AKI induced by I/R was successfully established. AKI caused by I/R significantly changed the M1/M2 macrophage polarization balance, with an increase in M2 being significantly higher than M1 as well as increased oxidative stress. Treatment with GDF11 after I/R significantly increased the differentiation of M2 cells and inhibited the differentiation of M1 macrophages, as well as decreased oxidative stress. Conclusion: GDF11 can promote the repair of AKI caused by I/R by regulating the balance of M1/M2 polarization in macrophages and oxidative stress.

Kidney tissue engineering in preclinical models of renal failure: a systematic review and meta-analysis.

Aim: This study aims to compare the efficacy of tissue engineering for kidney reconstruction. Materials & methods: We searched MEDLINE, EMBASE (May 2021), and reference lists of review articles. Results: 19articles matched our inclusion criteria. A range of natural, synthetic and hybrid scaffolds with or without incorporating cells/growth factors was investigated in 937 animals. More favorable results were observed with a combination of two or more biomaterials, addition of bioactive moieties, and cell seeding. Creatinine concentration, PAX2, collagen type-1, α-SMA, vimentin, IL-1, IL-6 and TNF-α gene expressions were significantly increased compared with native control. Conclusion: Tissue engineering can improve renal function and regeneration; however, further research could benefit from using hybrid scaffolds, stem cells and large animal models.

Locally transplanted human urine-induced nephron progenitor cells contribute to renal repair in mice kidney with diabetic nephropathy

Chronic Kidney Disease (CKD) is increasingly recognized as a global public health issue. Diabetic nephropathy (DN), also known as diabetic kidney disease, is a leading cause of CKD. Regenerative medicine strategy employing nephron progenitor cells (NPCs) is worthy of consideration as an alternative to shortage of donor organs for kidney transplantation. In previous study, we successfully generated induced NPCs (iNPCs) from human urine-derived cells that resembled human embryonic stem cell-derived NPCs. Here, we aimed to investigate the therapeutic potential of iNPCs in DN animal model. The results revealed the therapeutic effect of iNPCs as follows: (1) diminished glomerular hypertrophy, (2) reduced tubulointerstitial fibrosis, (3) low blood urea nitrogen, serum creatinine and albuminuria value, (4) decreased inflammation/fibrosis, (5) enhanced renal regeneration and (6) confirmed safety. This study demonstrates that human iNPCs have a therapeutic potential as a cell source for transplantation in patients with kidney diseases.

Coconut Water - Healthy Beverage with Multiple Therapeutic Potentials

Abstract: Cocos Nucifera (L.) is a tree that offers multiple advantages to the food and health industry. The most useful natural resource in the world, coconut water, has a long history of use in medicine and healthcare due to its ability to maintain hydration. It has been shown to have anti-inflammatory, hepatoprotective, antipyretic, wound curing, antihypertensive, antithrombotic, hypoglycaemic, hypolipidaemic, diuretic, antioxidant, and renal regeneration properties. Over the last few decades, numerous studies describing its nutritional and medicinal properties have been published in reputable scientific journals. Information related to the therapeutic benefits of coconut is available in traditional Ayurvedic writings, and it is consistent with recent scientific findings.

Update on Renal Sympathetic Denervation for the Treatment of Hypertension.

Hypertension is a leading risk factor for all-cause mortality in adults; however, medication non-adherence and intolerance present an enormous treatment challenge. Given the critical role of renal sympathetic nerves in neurogenic control of blood pressure and pathophysiology of hypertension, renal sympathetic denervation (RDN) has been explored as a therapeutic strategy in hypertension treatment over the last 15years. In this review, we will discuss the role of renal sympathetic nerves in the pathophysiology of hypertension, provide an update on the available evidence regarding the short- and long-term safety and effectiveness of RDN in the treatment of hypertension, and consider its future perspectives. RDN is a percutaneous endovascular catheter-based neuromodulation approach that enables ablation of renal sympathetic nerve fibers within the adventitial layer of the renal arteries using radiofrequency (most extensively studied), ultrasound energy, or neurolytics (e.g., alcohol). In the last decade, advancements in procedural techniques and well-designed sham-controlled trials utilizing 24-h ambulatory blood pressure measurements have demonstrated that RDN has an excellent safety profile and results in a modest reduction of blood pressure, in a wide range of hypertensive phenotypes (mild to resistant), irrespective of antihypertensive drug use and this effect is sustained over a 3-year period. Superiority of a particular RDN modality has not been yet established. Despite strong evidence demonstrating efficacy and safety of RDN, current data does not support its use as a primary approach in the treatment of hypertension due to its modest treatment effect and concerns around long-term sustainability. Perhaps the best utility of RDN is in hypertensives intolerant to antihypertensive medications or as an adjunct to aldosterone antagonists in the management of resistant hypertension. Patient selection will be critical to demonstrate a meaningful benefit of RDN. Future well-designed studies are necessary to determine predictors and measures of response to RDN, long-term efficacy given question of renal nerve regeneration, comparison of available technologies, safety in patients with advanced kidney disease, and improvement in patient quality of life measures.

A Comprehensive Analysis of HAVCR1 as a Prognostic and Diagnostic Marker for Pan-Cancer.

Hepatitis A virus cellular receptor (HAVCR1) is a type-1 integral membrane glycoprotein that plays a key role in immunity and renal regeneration and is abnormally expressed in various tumor types. Nonetheless, the function of HAVCR1 in pan-cancer remains unknown. In this study, we comprehensively analyzed the expression and promoter methylation level of HAVCR1 and assessed the immune cell infiltration, correlation between stromal and immune cell admixture, CD (Cluster of Differentiation) and HAVCR1 expression and prognostic value of HAVCR1 mRNA expression in Liver hepatocellular carcinoma (LIHC) and Pancreatic adenocarcinoma (PAAD). Our results showed that HAVCR1 was overexpressed while the promoter methylation of HAVCR1 was decreased in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. HAVCR1 was associated with increased infiltration of B cells, CD8 cells, macrophages, neutrophils and Dendritic cells in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. HAVCR1 expression was positively correlated with the immune, stromal and estimate scores of Pancreatic adenocarcinoma and the stromal and estimate scores of Liver hepatocellular carcinoma. Furthermore, HAVCR1 expression was correlated with other immune molecules such as HHLA2 (Human endogenous retrovirus-H long terminal repeat-associating protein 2), CD44 and TNFRSF4 (TNF Receptor Superfamily Member 4) in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. During Kaplan-Meier analysis, high HAVCR1 expression in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma correlated with poor survival. A marginally significant p-value (p = 0.051) was obtained when the relationship between HAVCR1 expression in Liver hepatocellular carcinoma and prognosis was analyzed, attributed to the small sample size. Overall, we provided compelling evidence that HAVCR1 could be a prognostic and diagnostic marker for Liver hepatocellular carcinoma and Pancreatic adenocarcinoma.

Arginase-1 Is Required for Macrophage-Mediated Renal Tubule Regeneration.

After kidney injury, macrophages transition from initial proinflammatory activation to a proreparative phenotype characterized by expression of arginase-1 (Arg1), mannose receptor 1 (Mrc1), and macrophage scavenger receptor 1 (Msr1). The mechanism by which these alternatively activated macrophages promote repair is unknown. We characterized the macrophage and renal responses after ischemia-reperfusion injury with contralateral nephrectomy in LysM-Cre;Arg1fl/fl mice and littermate controls and used in vitro coculture of macrophages and tubular cells to determine how macrophage-expressed arginase-1 promotes kidney repair. After ischemia-reperfusion injury with contralateral nephrectomy, Arg1-expressing macrophages were almost exclusively located in the outer stripe of the medulla adjacent to injured S3 tubule segments containing luminal debris or casts. Macrophage Arg1 expression was reduced by more than 90% in injured LysM-Cre;Arg1fl/fl mice, resulting in decreased mouse survival, decreased renal tubular cell proliferation and decreased renal repair compared with littermate controls. In vitro studies demonstrate that tubular cells exposed apically to dead cell debris secrete high levels of GM-CSF and induce reparative macrophage activation, with those macrophages in turn secreting Arg1-dependent factor(s) that directly stimulate tubular cell proliferation. GM-CSF-induced, proreparative macrophages express arginase-1, which is required for the S3 tubular cell proliferative response that promotes renal repair after ischemia-reperfusion injury.

Mesenchymal Stem Cells-Derived Exosomes Ameliorate Ischemia/Reperfusion Induced Acute Kidney Injury in a Porcine Model.

Exosomes are membrane-enclosed vesicles secreted by cells, containing a variety of biologically active ingredients including proteins, nucleic acids and lipids. In this study, we investigated the therapeutic effects of the exosomes and underlying mechanisms in a miniature pig model of ischemia/reperfusion-induced acute kidney injury (I/R-AKI). The exosomes were extracted from cultured human umbilical cord derived mesenchymal stem cells (hUC-MSCs) and infused into a miniature pig model of I/R AKI. Our results showed that 120 min of unilateral ischemia followed by reperfusion and contralateral nephrectomy resulted in renal dysfunction, severe kidney damage, apoptosis and necroptosis. Intravenous infusion of one dose of exosomes collected from about 4 × 108 hUC-MSCs significantly improved renal function and reduced apoptosis and necroptosis. Administration of hUC-MSC exosomes also reduced the expression of some pro-inflammatory cytokines/chemokines, decreased infiltration of macrophages to the injured kidneys and suppressed the phosphorylation of nuclear factor-κB and signal transducer and activator of transcription 3, two transcriptional factors related to inflammatory regulation. Moreover, hUC-MSC exosomes could promote proliferation of renal tubular cells, angiogenesis and upregulation of Klotho and Bone Morphogenetic Protein 7, two renoprotective molecules and vascular endothelial growth factor A and its receptor. Collectively, our results suggest that injection of hUC-MSC exosomes could ameliorate I/R-AKI and accelerate renal tubular cell repair and regeneration, and that hUC-MSC exosomes may be used as a potential biological therapy for Acute kidney injury patients.

Extracellular Vesicles and Acute Kidney Injury: Potential Therapeutic Avenue for Renal Repair and Regeneration.

Acute kidney injury (AKI) is a sudden decline of renal function and represents a global clinical problem due to an elevated morbidity and mortality. Despite many efforts, currently there are no treatments to halt this devastating condition. Extracellular vesicles (EVs) are nanoparticles secreted by various cell types in both physiological and pathological conditions. EVs can arise from distinct parts of the kidney and can mediate intercellular communication between various cell types along the nephron. Besides their potential as diagnostic tools, EVs have been proposed as powerful new tools for regenerative medicine and have been broadly studied as therapeutic mediators in different models of experimental AKI. In this review, we present an overview of the basic features and biological relevance of EVs, with an emphasis on their functional role in cell-to-cell communication in the kidney. We explore versatile roles of EVs in crucial pathophysiological mechanisms contributing to AKI and give a detailed description of the renoprotective effects of EVs from different origins in AKI. Finally, we explain known mechanisms of action of EVs in AKI and provide an outlook on the potential clinical translation of EVs in the setting of AKI.

Therapeutic role of uterine-derived stem cells in acute kidney injury

BackgroundAcute kidney injury (AKI) causes abrupt deterioration in kidney function that disrupts metabolic, electrolyte and fluid homeostasis. Although the prevalence of AKI is steadily increasing, no definitive treatment options are available, leading to severe morbidity and mortality. We evaluated the role of uterine-derived multipotent stem cells in kidney regeneration after ischemic AKI.MethodsFemale C57BL/6J mice were hysterectomized and subsequently subject to AKI by either unilateral or bilateral renal ischemia–reperfusion injury. Uterine-derived cells (UDCs), containing a population of uterine stem cells, were isolated from the uteri of female transgenic DsRed mice and injected intravenously to AKI mice. Engraftment of DsRed cells was analyzed by flow cytometry while serum creatinine levels were determined colorimetrically. Expression of UDC markers and cytokine markers were analyzed by immunohistochemical and qRT-PCR methods, respectively. The Kaplan–Meier method was used to analyze survival time while unpaired t test with Welch’s correction used for data analysis between two groups.ResultsMice with an intact uterus, and hence an endogenous source of UDCs, had a higher survival rate after bilateral ischemic AKI compared to hysterectomized mice. Mice treated with infusion of exogenous UDCs after hysterectomy/AKI had lower serum creatinine levels and higher survival rates compared to controls that did not receive UDCs. Engraftment of labeled UDCs was significantly higher in kidneys of bilateral ischemic AKI mice compared to those that underwent a sham surgery. When unilateral ischemic AKI was induced, higher numbers of UDCs were found in the injured than non-injured kidney. Immunofluorescence staining demonstrated double-positive DsRed/Lotus tetragonolobus agglutinin (LTA) positive cells and DsRed/CD31 positive cells indicating contribution of UDCs in renal tubular and vascular regeneration. Expression of Cxcl12, Bmp2, Bmp4, and Ctnf in renal tissue was significantly higher in the UDCs injection group than the control group.ConclusionsUDCs engrafted injured kidneys, contributed to proximal tubule and vascular regeneration, improved kidney function and increased survival in AKI mice. UDC administration is a promising new therapy for AKI. Endogenous uterine stem cells likely also preserve kidney function, suggesting a novel interaction between the uterus and kidney. We suggest that hysterectomy may have a detrimental effect on response to renal injury.

Association between engulfment and cell motility 1-gene polymorphisms and diabetic nephropathy in an Egyptian population with type 2 diabetes.

Engulfment and cell motility 1 (ELMO1), is a candidate gene responsible for cell motility and phagocytosis. However, its role in the development and progression of nephropathy attributed to T2D is still unknown. Kidney injury molecule-1 (KIM-1) plays a significant role in renal regeneration processes. The current study aimed to evaluate the association between kidney injury molecule-1 levels, ELMO1 gene polymorphism (rs741301, and rs1345365) as well as DN in an Egyptian population with T2D. In this study, we enrolled 89 participants from the internal medicine outpatient clinic, 23 T2DM without DN, 22 with DN, and 44 control subjects. They were genotyped by real-time PCR. Serum level of KIM-1 was detected by ELISA. Serum KIM-1 level was correlated with DM duration, HbA1C, and UACR (P value <0.001) in T2D. There was no significant difference in the allelic and genotypic frequencies of rs741301 and rs1345365 between participants with DM who presented with albuminuria and those without. Results showed that rs1345365A/rs741301T and rs1345365G/rs741301C haplotypes were more common in patients with T2D than in HCs. However, the difference was not statistically significant (P = 0.262 and 0.414, respectively). KIM-1 can be a useful non-invasive biomarker for detecting early DN. The association between ELMO1 gene polymorphisms and the risk of DN in patients with T2D was not validated. Therefore, further studies with a larger sample size must be conducted.

POS-066 URINE-DRIVED STEM CELL ATTENUATE RENAL INFLAMMATION AND FIBROSIS AFTER RENAL ISCHEMIA REPERFUSION

After renal IRI, regeneration and recovery of the renal tubular cell occurs. However, if the renal repair process is maladaptive, it progresses to renal fibrosis. The role of stem cells in kidney regeneration or fibrosis has not been fully elucidated. we evaluated the urine drived stem cells(UDSC) for renal inflammation and fibrosis after renal ischemia reperfusion (IR).

POS-077 CD153-CD30 SIGNALING ACCELERATES AGE-DEPENDENT TERTIARY LYMPHOID TISSUE FORMATION AND KIDNEY INJURY

The elderly show a reduced capacity for renal regeneration after acute kidney injury (AKI). We previously showed that, after AKI, aged, but not young, kidneys exhibit tertiary lymphoid tissues (TLTs), which underlie maladaptive repair in aged injured kidneys. TLT is an unique microenvironment for lymphocyte activation and differentiation in situ and are involved in pathophysiology in various human diseases. However, the cells and signals responsible for age-dependent TLT formation in the kidneys are still undefined.

A biomimetic double network hydrogel ameliorates renal fibrosis and promotes renal regeneration.

Acute kidney injury (AKI) and chronic kidney disease (CKD) are serious global public health issues. Both interconnect closely, and AKI-CKD transition significantly increases the morbidity of CKD and inevitably progresses to end stage renal disease. However, with the current drug delivery system it is hard to achieve precise delivery and apply it to clinical practice due to the local fibrotic milieu of the AKI-CKD transition procedure. Consequently, new treatment options to halt or even reverse AKI-CKD transition are urgently needed. Curcumin and Ac-SDKP were proved to be capable of ameliorating renal injury and restoring renal biological function. However, due to the water-insolubility, poor absorption and ease of degradation features, their utilization based on traditional drug delivery systems was still confined to the laboratory. A new approach for the targeted delivery of curcumin and Ac-SDKP into kidneys is needed. Hydrogels, owing to their capability of targeted-drug delivery and bio-favorable nature, emerge as a promising resolution. Herein, we developed a bioinspired double network hydrogel scaffold loaded with curcumin and N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) to explore the feasibility of drug-loaded hydrogels for treatment of AKI-CKD transition. This double network hydrogel (GCS) was prepared based on gelatin and curcumin-zinc with polydopamine (DOPA) coating and then immobilized with Ac-SDKP on the surface. The prepared hydrogels possessed appropriate porosity, suitable mechanical properties, and excellent biocompatibility. In vitro, the GCS hydrogel was demonstrated to be pro-angiogenic, anti-oxidative and anti-fibrotic. In vivo, after the GCS hydrogel was implanted into partially nephrectomized rat kidneys, local renal fibrosis was observed to be improved significantly, and neo-blood vessels and neonatal renal tubules appeared around the implanted area. We speculated that the GCS hydrogel could ameliorate renal fibrosis and injury significantly and stimulate regeneration in situ. Taken together, this study demonstrated the promising potential of this bioinspired hydrogel scaffold for renal injury repair and renal regeneration.