Histological study on effect of mesenchymal stem cell therapy on experimental renal injury induced by ischemia/reperfusion in male albino rat

Muscle-Derived Stem/Progenitor Cells Ameliorate Acute Kidney Injury in Rats through the Anti-Apoptotic Pathway and Demonstrate Comparable Effects to Bone Marrow Mesenchymal Stem Cells

Background and Objectives: To date, the therapeutic potential of skeletal muscle-derived stem/progenitor cells (MDSPCs) for acute kidney injury (AKI) has only been evaluated by our research group. We aimed to compare MDSPCs with bone marrow mesenchymal stem cells (BM-MSCs) and evaluate their feasibility for the treatment of AKI. Materials and Methods: Rats were randomly assigned to four study groups: control, GM (gentamicin) group, GM+MDSPCs, and GM+BM-MSCs. AKI was induced by gentamicin (80 mg/kg/day; i.p.) for 7 consecutive days. MDSPCs and BM-MSCs were injected 24 h after the last gentamicin injection. Kidney parameters were determined on days 0, 8, 14, 21, and 35. Results: MDSPCs and BM-MSCs accelerated functional kidney recovery, as reflected by significantly lower serum creatinine levels and renal injury score, higher urinary creatinine and creatinine clearance levels (p < 0.05), lower TUNEL-positive cell number, and decreased KIM-1 and NGAL secretion in comparison to the non-treated AKI group. There was no significant difference in any parameters between the MDSPCs and BM-MSCs groups (p > 0.05). Conclusions: MDSPCs and BM-MSCs can migrate and incorporate into injured renal tissue, resulting in a beneficial impact on functional and morphological kidney recovery, which is likely mediated by the secretion of paracrine factors and an anti-apoptotic effect. MDSPCs were found to be non-inferior to BM-MSCs and therefore can be considered as a potential candidate strategy for the treatment of AKI.

Polyethylene glycol capped gold nanoparticles ameliorate renal ischemia-reperfusion injury in diabetic mice through AMPK-Nrf2 signaling pathway

The aim of this study is to investigate the protective effect of polyethylene glycol capped gold nanoparticles (PEG-AuNPs) on renal ischemia-reperfusion injury (I/R)-induced acute kidney injury (AKI) in diabetic mice via the activation of adenosine 5' monophosphate-activated protein kinase-nuclear factor erythroid-2-related factor-2 (AMPK-Nrf2) pathway. Diabetes was induced in male mice (12/group) by streptozotocin (50 mg/kg) for 5 consecutive days. After 4 weeks, the mice have intravenously received doses of PEG-AuNPs (40, 150, and 400 µg/kg body weight) for 3 consecutive days, and then animals were subjected to 30 min ischemia and 48 h reperfusion. Following the treatment with three different doses of PEG-AuNPs, the levels of blood urea nitrogen (BUN) and creatinine were reduced. Obvious reduction in renal tubular atrophy, glomerular damage, mitochondrial damage, and necrotic area were ultra-structurally detected, and renal interstitial inflammation and apoptosis were diminished. Moreover, PEG-AuNPs increased the recovering of damaged renal cells, suppressed significantly levels of malondialdehyde (MDA), downregulated significantly the level of inflammatory cytokines (TNF-α and IL-1β), and upregulated the AMPK-Nrf2 pathway. PEG-AuNPs exhibited a promising alternative therapeutic target for diabetic renal I/R-induced AKI through upregulation of AMPK/PI3K/AKT path which additionally stimulated Nrf2-regulated antioxidant enzymes in a dose-dependent manner.

Therapeutic Effects of Stem Cells From Different Source on Renal Ischemia- Reperfusion Injury: A Systematic Review and Network Meta-analysis of Animal Studies

Objective: Although stem cell therapy for renal ischemia-reperfusion injury (RIRI) has made immense progress in animal studies, conflicting results have been reported by the investigators. Therefore, we aimed to systematically evaluate the effects of different stem cells on renal function of animals with ischemia-reperfusion injury and to compare the efficacies of stem cells from various sources. Methods: PubMed, Web of Science, Embase, Cochrane, CNKI, VIP, CBM, and WanFang Data were searched for records until April 2021. Two researchers independently conducted literature screening, data extraction, and literature quality evaluation. Results and conclusion: Seventy-two animal studies were included for data analysis. Different stem cells significantly reduced serum creatinine and blood urea nitrogen levels in the early and middle stages (1 and 7 days) compared to the negative control group, however there was no significant difference in the late stage among all groups (14 days); In the early stage (1 day), the renal histopathological score in the stem cell group was significantly lower than that in the negative control group, and there was no significant difference among these stem cells. In addition, there was no significant difference between stem cell and negative control in proliferation of resident cells, however, significantly less apoptosis of resident cells than negative control. In conclusion, the results showed that stem cells from diverse sources could improve the renal function of RIRI animals. ADMSCs and MDMSCs were the most-researched stem cells, and they possibly hold the highest therapeutic potential. However, the quality of evidence included in this study is low, and there are many risks of bias. The exact efficacy of the stem cells and the requirement for further clinical studies remain unclear.

Molecular, Immunomodulatory, and Histopathological Role of Mesenchymal Stem Cells and Beetroot Extract on Cisplatin Induced Testicular Damage in Albino Rats

Simple Summary

The chemotherapeutic agent Cisplatin (Cis) has testicular damage as a side effect. Therefore, efforts are being done by scientists to get over this effect. The current experiment was done to utilize bone marrow-derived stem cells (BM-MSCs) and beetroot extract (BRE) in reducing the Cis testicular damage in rats. In the current study, Cis reduced the sperm count, plasma testosterone level, the testicular activity of alkaline phosphatase beside a marked inhabitation of succinate dehydrogenase activity. Also, it significantly increased malondialdehyde and along with a marked decrease in testis reduced glutathione content and total antioxidant capacity. At the same time, Cis administration resulted in a marked elevation in interleukine-6 and the iNOS and caspase-3 genes, however it decreased the expression of steroidogenic acute regulatory protein (StAR). Stem cell therapy (BM-MSCs) was accompanied with the use of herbal therapy (BRE) resulted in great improvement of all previous parameters. These results were confirmed by histopathological and immunohistochemical examination. In conclusion the current study recommends the use of beetroot as natural food in combination with stem cell therapy for the patient suffering from the testicular side effect of cisplatin chemotherapy.

Abstract

Cisplatin (Cis) a drug commonly used as a chemotherapeutic agent to treat various types of cancer, inducing testicular damage. The present study aimed to investigate the inhibitory potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) and beetroot extract (BRE) in albino rats after testicular toxicity induced by cisplatin. Thirty adult male albino rats were grouped into: the control group, Cis group receiving a single dose of 7 mg/kg i.p. (intraperitoneal) to induce testicular toxicity, Cis plus BM-MSCs injected Cis followed by 2 × 10⁶ of BM-MSCs; Cis plus BRE group receiving Cis followed by 300 mg/kg body weight/day of BRE, and Cis plus BM-MSCs and BRE group. In the current study, Cis reduced sperm count, serum testosterone level, and testicular activity of alkaline phosphatase (AKP), besides a marked inhibition of succinate dehydrogenase (SDH) activity. In addition, it significantly increased malondialdehyde (MDA) and along with a marked decrease in testis reduced glutathione content and total antioxidant capacity (TAC). At the same time, Cis administration resulted in a marked elevation in interleukine-6 and the iNOS and caspase-3 genes; however, it decreased the expression of steroidogenic acute regulatory protein (StAR). Combined treatment with BM-MSCs and BRE resulted in great improvement of all previous parameters. These results were also confirmed by histopathological and immunohistochemical examination. In conclusion, both MSCs and BRE were found to have potent potentials to inhibit testicular damage induced by cisplatin.

Combination of mesenchymal stromal cells and machine perfusion is a novel strategy for organ preservation in solid organ transplantation

Organ preservation is a prerequisite for an urgent increase in the availability of organs for solid organ transplantation (SOT). An increasing amount of expanded criteria donor (ECD) organs are used clinically. Currently, the paradigm of organ preservation is shifting from simple reduction of cellular metabolic activity to maximal simulation of an ex vivo physiological microenvironment. An ideal organ preservation technique should not only preserve isolated organs but also offer the possibility of rehabilitation and evaluation of organ function prior to transplantation. Based on the fact that mesenchymal stromal cells (MSCs) possess strong regeneration properties, the combination of MSCs with machine perfusion (MP) is expected to be superior to conventional preservation methods. In recent years, several studies have attempted to use this strategy for SOT showing promising outcomes. With better organ function during ex vivo preservation and the potential of utilization of organs previously deemed untransplantable, this strategy is meaningful for patients with organ failure to help overcome organ shortage in the field of SOT.

Effects of Methylene Blue on Ovarian Torsion-Detorsion Injury in a Rat Model

STUDY OBJECTIVES

Methylene blue (MB) is an antioxidant that ameliorates ischemia-reperfusion injury in several tissues. We analyzed the effects of MB as an inhibitor of torsion-detorsion injury in rat ovaries.

METHODS

Rats were randomly divided into 5 groups. Group 1 was the sham group, in which only laparotomy was performed. Group 2 was the torsion group, with 3 hours of ischemia. Group 3 was the torsion + MB group, with 3 hours of ischemia after MB administration. Group 4 was the torsion-detorsion group, with 3 hours of ischemia and reperfusion. Finally, group 5 was the torsion-detorsion + MB group, with 3 hours of ischemia and MB administration before detorsion/reperfusion. Ovary injuries were histopathologically scored. Malondialdehyde (MDA) and total protein levels in ovarian tissues were determined, and long pentraxin-3 (PTX3) levels were measured in ovarian tissue using an enzyme-linked immunosorbent assay.

RESULTS

In comparing group 4 with group 5 and group 2 with 3, histopathological parameters reflecting injury were significantly increased in groups 4 and 2. Group 3 generated increased MDA levels when compared with group 2 (P < .05). However, there was no significant difference between groups 2 and 3 in terms of plasma PTX3 levels. MDA and PTX3 levels decreased in group 5 in comparison with group 4 for MDA (P < .000) and PTX3 levels (P < .01).

CONCLUSIONS

MB alleviated ischemia-reperfusion ovary injury in our experimental model.

Therapeutic effects of bone marrow mesenchymal stem cells via modulation of TLR2 and TLR4 on renal ischemia-reperfusion injury in male Sprague-Dawley rats

Introduction: Acute kidney injury (AKI) induced by renal ischemia-reperfusion (I/R) injury is a pro-inflammatory process that activates toll-like receptors (TLRs). Stem cell therapy holds a great promise for kidney repair. Therefore, we investigated the immunomodulatory role of bone marrow stromal cells (BMSCs) on TLR2 and TLR4 expression in AKI in male Sprague-Dawley rats. Methods: BMSCs were isolated from the bone marrow of male rats, cultured in DMEM, and characterized using appropriate markers before transplantation. Renal I/R was induced by 45 minutes bilateral ischemia followed by 24 hours of reperfusion. Rats received intraperitoneal injections of BMSCs (1.5 × 10⁶ cells, i.p, per rat) immediately after termination of renal ischemia. Serum samples were collected pre-and post-stem cells injection for assessment of blood urea nitrogen (BUN) and creatinine (Cr) levels. The kidneys were harvested after 24 hours of reperfusion for structural and molecular analysis. Results: Renal I/R caused severe tissue injuries and increased the level of BUN (166.5 ± 12.9 vs. 18.25 ± 1.75) and Cr (3.7 ± 0.22 vs. 0.87 ± 0.06) compared to the sham group. In addition, mRNA expression of TLR2 and TLR4 elevated in the renal I/R group. Administration of BMSCs improved the functional and structural state of the kidney induced by I/R and down-regulated TLR2 and TLR4 gene expression. Conclusion: The results showed a highly significant renoprotection by BMSCs that indicates their therapeutic potential in I/R injures. These effects are most likely associated with the TLR2/4 signaling pathway via modulation of the inflammatory response cascades.

The Efficacy of Mesenchymal Stem Cells in Therapy of Acute Kidney Injury Induced by Ischemia-Reperfusion in Animal Models

Mesenchymal stem cells (MSCs), discovered and isolated from the bone marrow in the 1960s and with self-renewal capacity and multilineage differentiation potential, have valuable immunomodulatory abilities. Acute kidney injury (AKI) refers to rapid renal failure, which exhibits as quickly progressive decreasing excretion in few hours or days. This study was performed to assess the efficacy of MSCs in the treatment of AKI induced by ischemia-reperfusion using a meta-analysis method. A literature search using corresponding terms was performed in the following databases: Embase, Cochrane Library, PubMed, and ISI Web of Science databases up to Dec 31, 2019. Data for outcomes were identified, and the efficacy of MSCs for AKI was assessed using Cochrane Review Manager Version 5.3. Nineteen studies were eligible and recruited for this meta-analysis. MSC treatment can reduce the Scr levels at 1 day, 2 days, 3 days, 5 days, and >7 days (1 day: WMD = -0.56, 95% CI: -0.78, -0.34, P < 0.00001; 2 days: WMD = -0.58, 95% CI: -0.89, -0.28, P = 0.0002; 3 days: WMD = -0.65, 95% CI: -0.84, -0.45, P < 0.00001; 5 days: WMD = -0.35, 95% CI: -0.54, -0.16, P = 0.0003; and >7 days: WMD = -0.22, 95% CI: -0.36, -0.08, P = 0.002) and can reduce the levels of BUN at 1 day, 2 days, 3 days, and 5 days (1 day: WMD = -11.72, 95% CI: -18.80, -4.64, P = 0.001; 2 days: WMD = -33.60, 95% CI: -40.15, -27.05, P < 0.00001; 3 days: WMD = -21.14, 95% CI: -26.15, -16.14, P < 0.00001; and 5 days: WMD = -8.88, 95% CI: -11.06, -6.69, P < 0.00001), and it also can reduce the levels of proteinuria at 3 days and >7 days and alleviate the renal damage in animal models of AKI. In conclusion, MSCs might be a promising therapeutic agent for AKI induced by ischemia-reperfusion.

Therapeutic Properties of Mesenchymal Stem Cell on Organ Ischemia-Reperfusion Injury

The shortage of donor organs is a major global concern. Organ failure requires the transplantation of functional organs. Donor’s organs are preserved for variable periods of warm and cold ischemia time, which requires placing them into a preservation device. Ischemia and reperfusion damage the organs, due to the lack of oxygen during the ischemia step, as well as the oxidative stress during the reperfusion step. Different methodologies are developed to prevent or to diminish the level of injuries. Preservation solutions were first developed to maximize cold static preservation, which includes the addition of several chemical compounds. The next chapter of organ preservation comes with the perfusion machine, where mechanical devices provide continuous flow and oxygenation ex vivo to the organs being preserved. In the addition of inhibitors of mitogen-activated protein kinase and inhibitors of the proteasome, mesenchymal stem cells began being used 13 years ago to prevent or diminish the organ’s injuries. Mesenchymal stem cells (e.g., bone marrow stem cells, adipose derived stem cells and umbilical cord stem cells) have proven to be powerful tools in repairing damaged organs. This review will focus upon the use of some bone marrow stem cells, adipose-derived stem cells and umbilical cord stem cells on preventing or decreasing the injuries due to ischemia-reperfusion.

Protective effect of bone marrow mesenchymal stem cells modified with klotho on renal ischemia-reperfusion injury

Objective: To detect the combination protective effect of bone marrow mesenchymal stem cells (BMSCs) and Klotho gene on the renal ischemia-reperfusion injury (RIRI).

Methods: BMSCs isolated from rats were transfected with Klotho gene to form BMSC^Kl. We injected BMSC^Kl to allogenic rat RIRI model. After 24 h and 72 h, we detected the serum creatinine (SCr), malondialdehyde (MDA), and superoxide dismutase (SOD) in renal tissue, Hematoxylin-eosin (HE) staining, and TUNEL of renal pathology. The expression of FoxO1 and p-FoxO1 in post-hypoxia tubular epithelial cells of normal rat kidney (NRK-52E) were detected by Western blot after cocultured with BMSC^Kl.

Results: Comparing with BMSC^Con group, Rats in BMSC^Kl group had lower SCr and MDA but higher SOD. Both HE and TUNEL score of renal tissue in BMSC^Kl group were lower than that of BMSC^Con group. Western blot indicated that FoxO1 was upregulated, while p-FoxO1 was downregulated in post-hypoxia NRK-52E cells.

Conclusions: BMSCs transfected with Klotho gene can further ameliorate RIRI. The possible mechanism may be attributed to the upregulation of SOD in NRK-52E caused by Klotho-FoxO1 axis.

Diacerein protects against glycerol-induced acute kidney injury: Modulating oxidative stress, inflammation, apoptosis and necroptosis

Necroptosis is suggested to have an important role in the pathogenesis of rhabdomyolysis induced acute kidney injury (AKI). In this study, the renoprotective effect of diacerein on glycerol-induced AKI was investigated. Twenty four male albino rats were included in this study and divided into four groups: (group I) saline control group, (group II) glycerol-treated group, (groups III&IV) diacerein + glycerol -treated groups (25 and 50 mg/kg/day) respectively. Renal malondialdehyde (MDA) level in addition to catalase and heme oxygenase (HO) activities were estimated. Comet assay and histopathological changes were evaluated. The levels of pro-apoptotic Bcl-2-associated X (Bax) protein, tumor necrosis factor alpha (TNF-α) and receptor-interacting serine/threonine-protein kinases 3 (RIPK3) were measured by ELISA. RIPK3 and mixed lineage kinase domain-like pseudokinase (MLKL) mRNA expression were assessed by real time PCR. Glycerol treatment caused significant renal histological abnormalities and functional impairment (increased urea and creatinine). Increased levels of renal MDA with concomitant decrease in renal catalase activity and significant DNA damage in comet assay were observed. High expression of RIPK3 and MLKL in the glycerol-treated group with marked elevation of Bax, TNF-α and RIPK3 levels and HO-1 activity were also documented. Diacerein treatment dependently attenuated glycerol induced structural and functional changes in kidney and significantly elicit reduction of renal tissue oxidative damage whereas it decreased renal expression of RIPK3 and MLKL, and decreased Bax, TNF-α and RIPK3 levels and HO-1 activity. CONCLUSION: These results demonstrated that diacerein might have potential application in the amelioration of AKI via its anti-oxidant, anti-inflammatory, anti-apoptotic and anti-necroptotic effects.

Potential therapeutic roles of stem cells in ischemia-reperfusion injury

Ischemia-reperfusion injury (I/RI), produced by an initial interruption of organ blood flow and its subsequent restoration, contributes significantly to the pathophysiologies of stroke, myocardial infarction, renal I/RI, intestinal I/RI and liver I/RI, which are major causes of disability (including transplant failure) and even mortality. While the restoration of blood flow is required to restore oxygen and nutrient requirements, reperfusion often triggers local and systemic inflammatory responses and subsequently elevate the ischemic insult where the duration of ischemia determines the magnitude of I/RI damage. I/RI increases vascular leakage, changes transcriptional and cell death programs, drives leukocyte entrapment and inflammation and oxidative stress in tissues. Therapeutic approaches which reduce complications associated with I/RI are desperately needed to address the clinical and economic burden created by I/RI. Stem cells (SC) represent ubiquitous and uncommitted cell populations with the ability to self-renew and differentiate into one or more developmental 'fates'. Like immune cells, stem cells can home to and penetrate I/R-injured tissues, where they can differentiate into target tissues and induce trophic paracrine signaling which suppress injury and maintain tissue functions perturbed by ischemia-reperfusion. This review article summarizes the present use and possible protective mechanisms underlying stem cell protection in diverse forms of ischemia-reperfusion.

Enhanced proliferation and differentiation of HO-1 gene-modified bone marrow-derived mesenchymal stem cells in the acute injured kidney

The aim of the present study was to investigate the effect of heme oxygenase-1 (HO-1) overexpression on the survival and differentiation ability of bone marrow‑derived mesenchymal stem cells (BMSCs) in the acute kidney injury (AKI) microenvironment. HO-1-BMSCs and enhanced green fluorescent protein (eGFP)-BMSCs were constructed. Rat ischemia/reperfusion (I/R)‑AKI-kidney homogenate supernatant was prep-ared to treat the BMSCs, eGFP-BMSCs and HO-1-BMSCs in vitro. In the AKI microenvironment, the HO-1-BMSCs exhibited a smaller proportion of cells at the G0/G1 phase, and a larger proportion of cells expressing proliferating cell nuclear antigen (PCNA) and cytokeratin 18 (CK18). Phosphorylated protein kinase B (Akt) and extracellular signal‑regulated kinase (ERK) protein levels were observed to be increased in the HO-1-BMSCs compared with the BMSCs. LY294002 and PD98059 each inhibited the above effects. BMSCs, eGFP-BMSCs and HO-1-BMSCs were implanted into an I/R-AKI rat model. The proportions of PCNA+ BMSCs and CK18+ BMSCs were higher in the HO-1-BMSCs group compared with the BMSCs group, which resulted in a decreased acute tubular necrosis score and improved renal function for the AKI rats. In conclusion, the enhanced proliferation and differentiation of HO-1-BMSCs suggest the beneficial effects of such cells in the BMSC-based therapy of AKI. The mechanism underlying these effects may involve the stimulation of Akt and ERK signaling.

Troxerutin down-regulates KIM-1, modulates p38 MAPK signaling, and enhances renal regenerative capacity in a rat model of gentamycin-induced acute kidney injury

Troxerutin enhances renal tissue regeneration, improves renal function, and decreases renal tissue injury in gentamycin-treated rats.

Stem Cell Therapies in Peripheral Vascular Diseases — Current Status

Peripheral artery diseases include all arterial diseases with the exception of coronary and aortic involvement, more specifically diseases of the extracranial carotids, upper limb arteries, mesenteric and renal vessels, and last but not least, lower limb arteries. Mononuclear stem cells, harvested from various sites (bone marrow, peripheral blood, mesenchymal cells, adipose-derived stem cells) have been studied as a treatment option for alleviating symptoms in peripheral artery disease, as potential stimulators for therapeutic angiogenesis, thus improving vascularization of the ischemic tissue. The aim of this manuscript was to review current medical literature on a novel treatment method — cell therapy, in patients with various peripheral vascular diseases, including carotid, renal, mesenteric artery disease, thromboangiitis obliterans, as well as upper and lower limb artery disease.

Therapeutic efficacy of bone marrow derived mesenchymal stromal cells versus losartan on adriamycin-induced renal cortical injury in adult albino rats

BACKGROUND

Renal disease is a major health problem. Recent studies have reported the efficacy of stem cell therapy in nephropathy animal models.

AIM OF THE WORK

This study was designed to investigate the therapeutic effectiveness of bone marrow-derived mesenchymal stromal cells (MSCs) versus losartan in the treatment of renal alterations induced by adriamycin (ADR).

MATERIALS AND METHODS

Thirty-five adult male albino rats were divided into four groups. Group I was the control group. Group II (adriamycin-treated group),which included ten rats that were injected with a single dose of adriamycin (15 mg/kg) intraperitoneally, was subdivided into subgroup IIa and IIb and they were sacrificed 1 week and 5 weeks after adriamycin injection, respectively. Group III was the adriamycin + losartan-treated group and 1 week after adriamycin injection five rats received 10 mg/kg of losartan orally and daily for 4 weeks. Group IV was the adriamycin + MSC-treated group); five rats were injected with adriamycin as group II then supplied with MSCs at a dose of 1 × 10(6) cells suspended in 0.5 mL of phosphate-buffered saline (PBS) per rat in the tail vein 1 week after adriamycin injection. Rats of this group were sacrificed 4 weeks after the stem cell injection. Blood urea nitrogen and serum creatinine were measured. Samples from renal cortex were processed for light and electron microscope examination. As regards light microscope, sections were stained with hematoxylin and eosin (H-E), periodic acid-Schiff (PAS), masson trichrome, proliferating cell nuclear antigen (PCNA) and Caspase-3 immunohistochemical stains. Morphometrical and statistical analyses were also conducted.

RESULTS

Examination of adriamycin-treated group revealed deterioration of renal functions and various degrees of renal structural alterations as vacuolated cytoplasm, dark nuclei and detached epithelial lining. Administration of losartan partially improved ADR-induced kidney dysfunction, whereas MSCs denoted a more ameliorative role evidenced by structural and functional recovery.

CONCLUSION

MSCs have a relevant therapeutic potential against ADR-induced renal damage. MSCs may accomplish this role by decreasing caspase-3 expression and increasing proliferating cell nuclear antigen staining which influence the regeneration of the kidney.

Mesenchymal stem cells correct haemodynamic dysfunction associated with liver injury after extended resection in a pig model

In patients, acute kidney injury (AKI) is often due to haemodynamic impairment associated with hepatic decompensation following extended liver surgery. Mesenchymal stem cells (MSCs) supported tissue protection in a variety of acute and chronic diseases, and might hence ameliorate AKI induced by extended liver resection. Here, 70% liver resection was performed in male pigs. MSCs were infused through a central venous catheter and haemodynamic parameters as well as markers of acute kidney damage were monitored under intensive care conditions for 24 h post-surgery. Cytokine profiles were established to anticipate the MSCs’ potential mode of action. After extended liver resection, hyperdynamic circulation, associated with hyponatraemia, hyperkalaemia, an increase in serum aldosterone and low urine production developed. These signs of hepatorenal dysfunction and haemodynamic impairment were corrected by MSC treatment. MSCs elevated PDGF levels in the serum, possibly contributing to circulatory homeostasis. Another 14 cytokines were increased in the kidney, most of which are known to support tissue regeneration. In conclusion, MSCs supported kidney and liver function after extended liver resection. They probably acted through paracrine mechanisms improving haemodynamics and tissue homeostasis. They might thus provide a promising strategy to prevent acute kidney injury in the context of post-surgery acute liver failure.

Deficiency of cold-inducible ribonucleic acid-binding protein reduces renal injury after ischemia-reperfusion

BACKGROUND

Renal ischemia-reperfusion injury, commonly caused by major operation and shock, leads to acute kidney injury and is associated with high morbidity and mortality. Cold-inducible ribonucleic acid-binding protein, a cold shock protein, has recently been identified as a damage-associated molecular pattern. We hypothesized that cold-inducible ribonucleic acid-binding protein exacerbates severity of injury in renal ischemia-reperfusion.

METHODS

Renal ischemia was induced in an 8-week-old male C57BL/6 wild-type mice and Cirp(-/-) mice via bilateral clamping of renal pedicles for 30 minutes, followed by reperfusion for 5 or 24 hours and harvest of blood and renal tissue for analysis. Anti-cold-inducible ribonucleic acid-binding protein antibody or non-immunized immunoglobulin G (IgG) was injected intravenously (10 mg/kg body weight) at time of reperfusion.

RESULTS

After renal ischemia-reperfusion, Cirp(-/-) mice demonstrated a reduction of blood urea nitrogen and creatinine of 53% and 60%, respectively, compared with wild-type mice. Serum IL-6 levels were reduced significantly: 70% in Cirp(-/-) mice compared with wild-type mice after renal ischemia-reperfusion. Levels of nitrotyrosine, an oxidatively modified protein marker, and cyclooxygenase-2, an inflammatory mediator, also were significantly decreased in the kidneys of the Cirp(-/-) mice compared with wild-type mice after renal ischemia-reperfusion. Renal caspase-3 activity was decreased in Cirp(-/-) mice compared with wild-type mice after renal ischemia-reperfusion, which corresponded to the reduction of apoptotic cells determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Injection of neutralizing anti-cold-inducible ribonucleic acid-binding protein antibody into wild-type mice led to an 82% reduction in blood urea nitrogen compared with the vehicle after renal ischemia-reperfusion.

CONCLUSION

Deficiency of cold-inducible ribonucleic acid-binding protein results in less renal injury after renal ischemia-reperfusion by attenuating inflammation and oxidative stress. Furthermore, blockade of cold-inducible ribonucleic acid-binding protein shows a protective effect, indicating cold-inducible ribonucleic acid-binding protein as a target in the treatment of renal ischemia-reperfusion.

Regenerative pharmacology for the treatment of acute kidney injury: Skeletal muscle stem/progenitor cells for renal regeneration?

Regenerative pharmacology and advanced therapy medicinal products is a relatively new and challenging field in drug development. Acute kidney injury (AKI) is a common clinical condition in nephrology with increasing incidence and high mortality rate. During the last few decades, researchers have been eagerly trying to find novel therapeutic strategies for AKI treatment, including advanced pharmacological therapies using mesenchymal stem cells (MSCs). Several types of MSCs have been thoroughly investigated, including bone marrow, adipose derived and umbilical cord blood MSCs and shown promising results in kidney repair. Research has demonstrated, that MSCs exert their effect through reduction of apoptosis, increased production of growth factors, suppression of oxidative stress and inflammatory processes, promotion of renal tubular cell proliferation, as well as by migration and direct incorporation into the renal tissue. Skeletal muscle-derived stem/progenitor cells (MDSPCs) are mesenchymal stem cell lineage of multipotent cells, demonstrating long-term proliferation, high self-renewal capacities, and ability to enhance endogenous tissue repair. The capacity of MDSPCs to regenerate a variety of different tissues following acute injury or destructive tissue diseases have been demonstrated in preclinical and clinical studies. MDSPCs were also reported to promote endogenous tissue repair via paracrine pathway. Considering advantageous properties of MDSPCs, the administration of these cells might be considered as a potential strategy for the treatment of AKI. However, to date, the therapeutic effect of MDSPCs for renal regeneration has not been investigated. This review reflects the current development in AKI treatment using different types of MSCs and the pilot results of the experimental study in vivo using a novel type of stem cells - MDSPCs for the treatment of gentamicin-induced AKI.

Skeletal Muscle-Derived Stem/Progenitor Cells: A Potential Strategy for the Treatment of Acute Kidney Injury

Skeletal muscle-derived stem/progenitor cells (MDSPCs) have been thoroughly investigated and already used in preclinical studies. However, therapeutic potential of MDSPCs isolated using preplate isolation technique for acute kidney injury (AKI) has not been evaluated. We aimed to characterize rat MDSPCs, compare them with bone marrow mesenchymal stem cells (BM-MSCs), and evaluate the feasibility of MDSPCs therapy for gentamicin-induced AKI in rats. We have isolated and characterized rat MDSPCs and BM-MSCs. Characteristics of rat BM-MSCs and MDSPCs were assessed by population doubling time, flow cytometry, immunofluorescence staining, RT-PCR, and multipotent differentiation capacity. Gentamicin-induced AKI model in rat was used to examine MDSPCs therapeutic effect. Physiological and histological kidney parameters were determined. MDSPCs exhibited similar immunophenotype, stem cell gene expression, and multilineage differentiation capacities as BM-MSCs, but they demonstrated higher proliferation rate. Single intravenous MDSPCs injection accelerated functional and morphological kidney recovery, as reflected by significantly lower serum creatinine levels, renal injury score, higher urinary creatinine, and GFR levels. PKH-26-labeled MDSPCs were identified within renal cortex 1 and 2 weeks after cell administration, indicating MDSPCs capacity to migrate and populate renal tissue. In conclusion, MDSPCs are capable of mediating functional and histological kidney recovery and can be considered as potential strategy for AKI treatment.

Fetal Kidney Cells Can Ameliorate Ischemic Acute Renal Failure in Rats through Their Anti-Inflammatory, Anti-Apoptotic and Anti-Oxidative Effects

Fetal kidney cells may contain multiple populations of kidney stem cells and thus appear to be a suitable cellular therapy for the treatment of acute renal failure (ARF) but their biological characteristics and therapeutic potential have not been adequately explored. We have culture expanded fetal kidney cells derived from rat fetal kidneys, characterized them and evaluated their therapeutic effect in an ischemia reperfusion (IR) induced rat model of ARF. The fetal kidney cells grew in culture as adherent spindle shaped/polygonal cells and expressed CD29, CD44, CD73, CD90, CD105, CD24 and CD133 markers. Administration of PKH26 labeled fetal kidney cells in ARF rats resulted in a significant decrease in the levels of blood urea nitrogen, creatinine, and neutrophil gelatinase-associated lipocalin and decreased tubular necrosis in the kidney tissues (p<0.05 for all). The injected fetal kidney cells were observed to engraft around injured tubular cells, and there was increased proliferation and decreased apoptosis of tubular cells in the kidneys (p<0.05 for both). In addition, the kidney tissues of ARF rats treated with fetal kidney cells had a higher gene expression of renotropic growth factors (VEGF-A, IGF-1, BMP-7 and bFGF) and anti-inflammatory cytokine (IL10); up regulation of anti-oxidative markers (HO-1 and NQO-1); and a lower Bax/Bcl2 ratio as compared to saline treated rats (p<0.05 for all). Our data shows that culture expanded fetal kidney cells express mesenchymal and renal progenitor markers, and ameliorate ischemic ARF predominantly by their anti-apoptotic, anti-inflammatory and anti-oxidative effects.

Methylene blue attenuates renal ischemia-reperfusion injury in rats

BACKGROUND AND PURPOSE

In our study, we investigated the effects of methylene blue (MB) on histopathological changes in renal ischemia/reperfusion (I/R) injury rat model.

MATERIAL AND METHODS

Twenty-one Sprague-Dawley male rats were divided equally into three groups. Group 1 (control) was administered intraperitoneal saline solution. In Groups 2 (untreated group) and 3 (MB treatment), the renal arteries were clamped, and ischemia (for 1 hour) and then reperfusion (for 4 hours) were applied. Thirty minutes before ischemia, the untreated group received physiological saline, whereas the treatment group was administered 30 mg/kg MB through an intraperitoneal route. Blood samples were drawn, and renal specimens were harvested 5.5 hours after physiologic saline injection in the control and immediately after the reperfusion period in the other groups. The levels of tissue superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total oxidant status (TOS), total antioxidant status (TAS), plasma urea, creatinine and ischemia modified albumin (IMA) were measured. Moreover, the histopathological damage score of the renal tissue was determined.

RESULTS

MB significantly alleviated the severity of histopathological damage by increasing the levels of tissue SOD and TAS and decreasing TOS concentrations in the renal I/R model (p<0.05).

CONCLUSION

Administration of MB in renal I/R damage may play a protective role.

Local injection of mesenchymal stem cells protects testicular torsion-induced germ cell injury

Introduction

Testicular torsion is a urological emergency and infertility is a common complication due to ischemic injury. Surgical reduction and orchiopexy is indicated, but to date there is no effective method for restoration of spermatogenesis. The effects of mesenchymal stem cells (MSCs) on acute tissue injury have been demonstrated, and the abilities of paracrine support, differentiation and immune-modulation may benefit to testicular torsion-induced infertility. We investigate the therapeutic efficacy and the mechanisms of MSCs in testicular torsion-induced germ cell injury when injected locally.

Methods

Six to eight-week-old Sprague–Dawley rats received surgical 720 degree torsion for 3 hours, followed by detorsion on the left testis. 20 μl of phosphate-buffered saline (PBS) without or with 3 x 10⁴ MSCs from human orbital fat tissues (OFSCs) were given for 10 rats, respectively, via local injection into the left testis 30 minutes before detorsion. 20 μl of PBS injection for 6 rats with surgical exposure without torsion served as sham control. Histopathology with Johnsen’s score analysis, Western blot analysis for superoxide dismutase 2, Bax, Caspase-3, human insulin growth factor-1 and human stem cell factor, malondialdehyde (MDA) assay in testis and plasma, hormones level including testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by ELISA Kits, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and fluorescence staining for P450, Sox-9 and VASA were performed.

Results

Animals were sacrificed and bilateral orchiectomy was performed 7 days after torsion-detorsion. Local injections of OFSCs prevented torsion-induced infertility judging from Johnsen's score. TUNEL assay and Western blot analysis on caspase 3 and Bax demonstrated that OFSCs prevented ischemic/reperfusion induced intrinsic apoptosis. MDA assay revealed that OFSCs significantly reduced the oxidative stress in the damaged testicular tissues. After the OFSC injection, serum testosterone secretion was increased, while the elevation of FSH triggered by testicular injury was balanced. OFSCs also produced stem cell factor in the damaged testis. Immunofluorescence staining revealed that most transplanted cells surrounded the Leydig cells. Some of transplanted cells differentiated into p450 expressing cells within 7 days.

Conclusions

Local injection of allogenic MSCs before surgical detorsion is a simple, clinical friendly procedure to rescue torsion-induced infertility.