Objectives: The current work investigated the effect of Wharton jelly mesenchymal stem cells (WJ-MSCs) pretreated with all-trans-retinoic acid (ATRA) on renal ischemia in rats and the possible role of oxidative stress, apoptotic and Wnt/β-Catenin signaling pathways, and inflammatory cytokines in their effects. Methods: The study included 90 male Sprague Dawley rats that were allocated to five groups (n = 18 rats): (I) Sham-operated group (right nephrectomy was performed); (II) Ischemia/reperfusion injury (IRI) group, a sham group with 45-min renal ischemia on the left kidney; (III) ATRA group, an ischemic group with an intravenous (i.v.) administration of ATRA 10 µM, 10 min post-surgery); (IV) WJ-MSCs group, an IRI group with an i.v. administration of 150 µL containing 7 × 10⁶ WJ-MSCs, 10 min post-surgery; (V) WJ-MSCs + ATRA group, an IRI group with an i.v. administration of 150 µL of 7 × 10⁶ WJ-MSCs pretreated with 10 µM ATRA. At the end of the experiments, serum creatinine, BUN micro-albuminuria (MAU), urinary protein, markers of redox state in the left kidney (MDA, CAT, SOD, and GSH), and the expression of Bax, IL-6, HIF-1α, Wnt7B, and β-catenin genes at the level of mRNA as well as for immunohistochemistry for NFkB and β-Catenin markers were analyzed. Results: The current study found that 45-min of renal ischemia resulted in significant impairment of kidney function (evidenced by the increase in serum creatinine, BUN, and urinary proteins) and deterioration of the kidney morphology, which was associated with a significant increase in redox state (evidenced by an increase in MDA and a decrease in GSH, SOD, and CAT), and a significant increase in inflammatory and apoptotic processes (evidenced by an increase in Bax and IL-6, NFkB, Wnt7B, β-catenin and HIF-1α) in kidney tissues (p < 0.05). On the other hand, treatment with ATRA, WJ-MSCs, or a combination of both, caused significant improvement in kidney function and morphology, which was associated with significant attenuation of oxidative stress, apoptotic markers, and inflammatory cytokines (IL6 and NFkB) with the upregulation of HIF-1α and β-catenin in kidney tissues (p < 0.05). Moreover, the renoprotective effect of WJ-MSCs pretreated with ATRA was more potent than WJ-MSCs alone. Conclusions: It is concluded that preconditioning of WJ-MSCs with ATRA may enhance their renoprotective effect. This effect could be due to the upregulation of the beta-catenin/Wnt pathway and attenuation of apoptosis, inflammation, and oxidative stress.

Objective: Because the poor survival of transplanted cells in a hostile microenvironment limits stem cell therapy, in the current study, we investigated the effect of rapamycin (Rapa)-preactivated autophagy on the survival and homing of transplanted adipose mesenchymal stem cells (ADMSCs) in a rat model of cisplatin (Cis)-induced nephrotoxicity, as well as the possible role of the mTOR/AKT signaling pathway. Materials and methods: In vitro, ADMSCs isolated from rats were treated with 50 nmol/L rapamycin for 2 h, after which the cytoprotective and autophagy-inducing effects of Rapa were investigated. The cis-induced acute nephrotoxicity rat model was constructed in vivo. ADMSCs and Rapa-ADMSCs were administered into the tail vein before Cis therapy. At 3, 7, and 10 days after Cis injection, all animals were euthanized. The renal functions and morphology as well as autophagy response were assessed. Results: The pretreatment of cultured ADMSCs with Rapa caused a significant increase in autophagic activities and lysosome production of the cells, with a significant increase in the secretion of SDF-1, IL-10 and autophagy promoter LC3 and Beclin from these cells, while mTOR/AKT pathways were inhibited. In addition, the transplantation of Rapa-pretreated ADMSCs restored the kidney functions and morphology dramatically. Renal expression of SDF-1 and HIF1 was upregulated, while expression of IL-6, NF-kB and TGF-β1 was downregulated. Conclusions: We concluded that the preactivation of autophagy with Rapa improves the survival and differentiation of the transplanted ADMSCs by inhibiting the mTOR/AKT signaling pathway, which in turn could significantly attenuate the Cis-induced acute renal injury.

The utilization of mesenchymal stem cell (MSC)-derived exosomes, which include numerous growth factors, cytokines, and microRNAs, is the primary aspect of the novel MSC activity models. The current research aims to: (i) identify the morphology of exosomes; (ii) determine exosomes secreted into MSCs conditioned cell culture medium; and (iii) perform a comprehensive characterization of isolated exosomes and elucidate their protective role in the diabetic nephropathy animal model. Ultracentrifugation was performed by utilizing the culture supernatant of MSCs. Transmission electron microscopy, nanoparticle tracking analysis, as well as Western blot, were utilized for isolated exosome characterization. The purified exosomes were used for in vivo implantation in a diabetic nephropathy animal model. The present research was carried out on 70 adult male albino rats weighing 180 to 200 grams. Rats were classified into seven groups: Group I: negative control group; Group II: diabetic nephropathy group; Group III: Balanites therapeutic group; Group IV: Balanites + MSCs therapeutic group; Group V: Balanites + exosome therapeutic group; Group VI: MSCs therapeutic group; and Group VII: exosome therapeutic group. By the end of the study period, total antioxidant capacity (TAC), malondialdehyde (MDA), and the histology of pancreatic tissue were assessed. Isolated exosomes with sizes ranging from 30 to 150 nm demonstrated the typical cup-shaped morphology. Additionally, exosome criteria were demonstrated by the exosome surface proteins CD81 and CD63, which were expressed by exosome marker proteins. Treatment with exosomes along with Balanites induced a significant reduction in pancreatic MDA with a substantial elevation in pancreatic TAC. Furthermore, treatment with exosomes and Balanites demonstrated normal pancreatic parenchyma and pancreatic lobules with normal pancreatic acini and acinar cells. These findings strongly suggest that ultracentrifugation is the most efficient tool for isolating exosomes. Also, these findings demonstrated that Balanites and exosomes had synergistic effects on one another, with more potent renoprotective activities in rats.

(1) Background: Hepatotoxicity is a common health problem, and oxidative stress plays a crucial role in its underlying mechanisms. We inspected the possible effect of retinoic acid (RA) in the potentiation of hepatoprotective effect of bone marrow mesenchymal stem cells (BM-MSCs) against Cisplatin (Cis)-induced hepatotoxicity. (2) Methods: 60 male Sprague Dawley rats (SD) were separated randomly and designated to six main equal groups as follows: (1) Control group, (2) Cis group (rats got Cis 7 mg/Kg i.p.), (3) Cis + vehicle group (as group 2, but rats received the (vehicle) culture media of BM-MSCs), (4) Cis as in group 2 + BM-MSCs (1x10⁶), (5) Cis as for group 2 + RA 1 mg/Kg i.p., and (6) Cis and BM-MSCs as for group 3 + RA as for group 4. Liver injury was assessed by measuring liver enzymes (ALT, AST), while liver toxicity was evaluated by histopathological examination. Apoptotic marker caspase-3 protein was detected immunohistochemically. Real time PCR was performed to detect NADPH oxidase and TNF-α at transcription levels. Oxidative stress was investigated by colorimetric measurement of MDA, GSH and catalase. (3) Results: Contrary to the Cis group (p < 0.05), BM-MSCs/RA supplementation resulted in a substantial decrease in serum levels of hepatic impairment indicators such as ALT, AST and oxidative stress markers such as MDA, as well as an increase in hepatic GSH, Catalase, and a decrease in expression of TNF-α and downregulation of NADPH oxidase. The improvement after therapy with BM-MSCs/RA was confirmed by histopathological examination. Moreover, the downregulation of caspase-3 in liver tissue after BM-MSCs/RA treatment was validated by immunohistochemistry investigation. (4) Conclusions: BM-MSCs and RA attenuated Cis induced hepatotoxicity through downregulation of oxidative stress resulted in modulation of anti-inflammatory TNF-α and apoptosis caspase-3 indicating a promising role in hepatotoxicity.

Objectives: To evaluate the urinary kidney injury molecule-1 (KIM-1) as a predictor for early detection of acute kidney injury in cases with obstructive nephropathy in an animal model and to correlate urinary KIM-1 with the progress of obstructive nephropathy on a histopathological basis. Materials and methods: Three models of obstruction were induced in 90 male rats: unilateral partial ureteral obstruction with a normal contra-lateral kidney, with nephrectomy of a contralateral kidney (solitary kidney), and bilateral partial ureteral obstruction. Each group was further divided into 2 subgroups; the sham-group (10 rats) and the disease group (20 rats). Serum creatinine, blood urea nitrogen, and urinary KIM-1 were collected on days 0, 7, and 14. Rats were sacrificed on the 7th and 14th day for histopathological examination of the obstructed kidney. Results: By the end of first week, there was a significant rise of all biomarker levels in all groups when compared with basal levels. Similarly, biomarker levels at the 14th day were significantly higher than those obtained at the 7th day. The urinary KIM-1 level was not detected in the baseline condition. Expression of urinary KIM-1 showed a significant rise in all models ranging from 22 to 85 fold at the 7th day and even higher levels at the 14th day. Histopathological examination confirmed the presence of different forms of tubular injury. Conclusions: Urinary KIM-1 is significantly elevated in obstructive uropathy. Such an elevation might be advantageous in the early diagnosis and subsequent early intervention of cases with partial ureteral obstruction.