Modulation of renal ischemia/reperfusion in rats by a combination of ischemic preconditioning and adipose-derived mesenchymal stem cells (ADMSCs)

Impact of folic acid supplementation on ischemia‒reperfusion-induced kidney injury in rats: folic acid prophylactic role revisited

Folic acid (FA), with its anti-inflammatory and antioxidant properties, may offer protection against ischemia-reperfusion (IR) injury. This study investigated whether FA safeguards rat kidneys from IR by targeting high mobility group box-1 (HMGB1), a key inflammatory mediator. Fifty adult male Wistar rats were randomly allocated into four groups: control, IR, IR + FA pretreatment, and FA alone. Compared to controls, IR significantly impaired renal function and elevated levels of malondialdehyde, HMGB1, NF-κB, and caspase 3. FA pretreatment effectively reversed these detrimental changes, protecting renal function and minimizing tissue damage. The FA-alone group showed no significant differences compared to the control group, indicating no adverse effects of FA treatment. Mechanistically, FA inhibited HMGB1 expression and its downstream activation of NF-κB and caspase 3, thereby quelling inflammation and cell death. FA shields rat kidneys from IR-induced injury by suppressing HMGB1-mediated inflammation and apoptosis, suggesting a potential therapeutic avenue for IR-associated kidney damage.

Prospects of new targeted nanotherapy combining liponiosomes with berberine to combat colorectal cancer development: An in vivo experimental model

Colorectal cancer (CRC) is one of the most identified and deadly malignancies worldwide. It presents a serious challenge due to its quick growth, which finally culminates in severe malignancy. It is critical to improve the efficacy of berberine (BR) as an anticancer agent to overcome its limited bioavailability. Implementation of a novel, effective nanocarrier system of liponiosomes for BR (LipoNio.BR) can support mechanistic actions associated with its anti-CRC role. Following CRC induction in rats using 1,2 Dimethylhydrazine (40 mg DMH/kg/week), the potency and mechanistic actions of LipoNio.BR were assessed by evaluating the lesion severity and molecular mechanisms controlling oxidative stress, apoptosis, autophagy, and inflammatory responses, and conducting histopathological and immunohistochemistry examinations of colonic tissues. The results indicated that the severity of clinical signs comprising weight gain loss, increased diarrhea and rectal bleeding, and reduced survivability were greatly restored in the LipoNio.BR-treated group. LipoNio.BR remarkably reduced CRC development compared to FBR (free berberine), as it induced apoptosis via upregulating apoptotic genes (Bax and caspase3, increased up to 7.89 and 6.25-fold, respectively) and downregulating the anti-apoptotic gene Bcl-2 by 2.25-fold. LipoNio.BR mitigated the oxidative stress associated with CRC and maintained redox homeostasis. Notably, the excessive inflammatory response associated with CRC was prominently reduced following administration of LipoNio.BR [which decreased iterleukin (IL-B, IL-6), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), proliferating cell nuclear antigen (PCNA), follistatin, and activin BA (beta-A) expression]. LipoNio.BR modulated the expression of nuclear factor kappa B (NF-κB) and mammalian target of rapamycin (mTOR), which impacted tumor vascularity (decreased Vascular endothelial growth factor (VEGF) expression by 2.36-fold). The severity of the histopathological alterations in the colonic tissues, including the development of neoplastic epithelium and the invasion of some neoplastic masses, was greatly reduced in the LipoNio.BR group compared to the FBR-(free berberine) administrated group. Following CRC induction, immunohistochemical staining revealed that the overexpression of cyclin and COX-2 in colonic tissues were suppressed in the LipoNio.BR group. Taken together, these findings suggest that LipoNio.BR has a potential role in reducing CRC progression to a greater extent compared to free BR and could be considered a promising and potent therapy against CRC.

Hepatoprotective Effects of Hyaluronic Acid-Preconditioned Bone Marrow Mesenchymal Stem Cells against Liver Toxicity via the Inhibition of Apoptosis and the Wnt/β-Catenin Signaling Pathway

BACKGROUND

Doxorubicin (DOX) is widely used to treat a variety of malignancies in both adults and children, including those of the bladder, breast, stomach, and ovaries. Despite this, it has been reported to cause hepatotoxicity. The recent discovery of bone marrow-derived mesenchymal stem cells' (BMSCs) therapeutic effects in the context of liver diseases suggests that their administration plays a part in the mitigation and rehabilitation of drug-induced toxicities.

OBJECTIVES

This study investigated whether bone BMSCs could reduce DOX-induced liver damage by blocking the Wnt/β-catenin pathway that causes fibrotic liver.

MATERIALS AND METHODS

BMSCs were isolated and treated with hyaluronic acid (HA) for 14 days before injection. Thirty-five mature male SD rats were categorized into four groups; group one (control) rats were supplemented with saline 0.9% for 28 days, group two (DOX) rats were injected with DOX (20 mg/kg), group three (DOX + BMSCs) rats were injected with 2 × 106 BMSCs after 4 days of DOX injection, group four (DOX + BMSCs + HA) rats were injected with 0.1 mL BMSCs pretreated with HA after 4 days of DOX. After 28 days the rats were sacrificed, and blood and liver tissue samples were subjected to biochemical and molecular analysis. Morphological and immunohistochemical observations were also carried out.

RESULTS

In terms of liver function and antioxidant findings, cells treated with HA showed considerable improvement compared to the DOX group (p < 0.05). Moreover, the expression of inflammatory markers (TGFβ1, iNos), apoptotic markers (Bax, Bcl2), cell tracking markers (SDF1α), fibrotic markers (β-catenin, Wnt7b, FN1, VEGF, and Col-1), and ROS markers (Nrf2, HO-1) was improved in BMSCs conditioned with HA in contrast to BMSCs alone (p < 0.05).

CONCLUSION

Our findings proved that BMSCs treated with HA exert their paracrine therapeutic effects via their secretome, suggesting that cell-based regenerative therapies conditioned with HA may be a viable alternative to reduce hepatotoxicity.

Renoprotective anti-CD45RB antibody induces B cell production in systemic lupus erythematosus based on single-cell RNA-seq analysis

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that commonly affects the kidney. Single-cell RNA sequencing (scRNA-seq) technology is a powerful tool for characterizing individual cells and elucidating biological mechanisms at the cellular level. The purpose of this study was to identify the mechanism underlying kidney injury in SLE using scRNA-seq technology.

METHODS

scRNA-seq data of peripheral blood mononuclear cells (PBMCs) in SLE were retrieved from the GEO database, followed by batch effect elimination, dimensionality reduction, cluster analysis, cell annotation and enrichment analysis. A model of SLE was developed in NZB/WF1 mice. Effects of anti-CD45RB antibody on the SLE-induced kidney injury were evaluated, and we measured the distribution of regulatory T cells and B cells in mouse spleen and kidney tissues, levels of kidney function-related indexes, deposition of IgG and C3 in the glomeruli, and the levels of inflammatory cytokines.

RESULTS

CD45RB was a specific marker gene of B cell clusters and had influence on the B cells. anti-CD45RB antibody treatment induced regulatory B cells and consequently arrested the kidney injury caused by SLE. In addition, depletion of regulatory T cells was found to partially undermine the alleviatory effect of anti-CD45RB antibody on SLE-induced kidney injury.

CONCLUSION

Collectively, our data suggest that anti-CD45RB antibody can prevent the SLE-induced kidney injury, pointing to anti-CD45RB antibody as a potential therapeutic strategy in kidney injury-related disease.

Possible Underlying Mechanisms for the Renoprotective Effect of Retinoic Acid-Pretreated Wharton's Jelly Mesenchymal Stem Cells against Renal Ischemia/Reperfusion Injury

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.

Rapamycin Improves Adipose-Derived Mesenchymal Stem Cells (ADMSCs) Renoprotective Effect against Cisplatin-Induced Acute Nephrotoxicity in Rats by Inhibiting the mTOR/AKT Signaling Pathway

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.

Renoprotective effect of bone marrow mesenchymal stem cells with hyaluronic acid against adriamycin- induced kidney fibrosis via inhibition of Wnt/β-catenin pathway

AIM

The current study aimed to explore the pretreatment of bone marrow mesenchymal stem cells (BMSCs) with hyaluronic acid (HA) on renal fibrosis in Adriamycin- induced CKD in rats.

MATERIAL AND METHODS

Sixty male SD rats were alienated into 4 equal groups; The control group: rats received two saline injections at 1 and 14 days, adriamycin (ADR) group: rats were injected i.v. twice via tail vein at day one and after 2 weeks, BMSCs group; rats were injected i.v. twice after 5 days of each ADR injection, and HA+BMSCs; rats were i.v. injected twice with BMSCs pretreated with 1 mg/ml HA after 5 days of each ADR injection. Protective role of BMSCs on renal function and morphology was detected using biochemical analysis, molecular studies, histopathological, and immunohistohemical investigations.

RESULTS

Pretreatment of BMSCs with HA showed significant decrease in KIM-1, and increase in serum albumin compared to CKD group (p <0.05). Moreover, it reduced the expression of the apoptotic marker Caspase-3, the inflammatory markers TNF and IL-6, and the fibrotic markers Wnt7a, β-catenin, and fibronectin1 than the CKD group (p < 0.05).

CONCLUSION

The current outcomes suggested that BMSCs preconditioned with HA could attenuate the renal fibrosis in adriamycin- induced CKD.

Impact of preconditioning stem cells with all-trans retinoic acid signaling pathway on cisplatin-induced nephrotoxicity by down-regulation of TGFβ1, IL-6, and caspase-3 and up-regulation of HIF1α and VEGF

The survival reduction after transplantation limited the clinical uses of stem cells so the current study explored preconditioning adipose-derived stem cells (ADMSCs) and all-trans retinoic acid (ATRA) effects on cisplatin that caused acute kidney injury (AKI). One hundred and fifty Sprague–Dawley male rats were distributed into five groups: control group; Cisplatin (CIS) group; CIS and ATRA group; CIS and ADMSC group, and CIS, ATRA, and ADMSCs group. Ten rats were euthanized after 3rd, 7th, and 11th days from CIS injection. Renal function, molecular studies, and histopathological analysis were studied. The preconditioning of ADMSCs with ATRA increased the viability of the cells which was reflected in the amelioration of kidney functions after CIS injection by the significant reduction of serum creatinine, microalbuminuria, as well as NO, and the significant rise of creatinine clearance, as well as SOD compared to the group of cisplatin. ATRA also supported ADMSCs by a significant down-regulation of caspase-3, il-6 and TGFβ1, and a significant up-regulation of HIF1, VEGF and CD31 compared to group of cisplatin which reversed the cisplatin effect. ATRA increased renoprotective properties of ADMSCs against cisplatin- induced AKI by reducing the apoptosis, inflammation, and stimulating angiogenesis.

Adipose-Derived Stem/Stromal Cells in Kidney Transplantation: Status Quo and Future Perspectives

Kidney transplantation (KT) is the gold standard treatment of end-stage renal disease. Despite progressive advances in organ preservation, surgical technique, intensive care, and immunosuppression, long-term allograft survival has not significantly improved. Among the many peri-operative complications that can jeopardize transplant outcomes, ischemia–reperfusion injury (IRI) deserves special consideration as it is associated with delayed graft function, acute rejection, and premature transplant loss. Over the years, several strategies have been proposed to mitigate the impact of IRI and favor tolerance, with rather disappointing results. There is mounting evidence that adipose stem/stromal cells (ASCs) possess specific characteristics that could help prevent, reduce, or reverse IRI. Immunomodulating and tolerogenic properties have also been suggested, thus leading to the development of ASC-based prophylactic and therapeutic strategies in pre-clinical and clinical models of renal IRI and allograft rejection. ASCs are copious, easy to harvest, and readily expandable in culture. Furthermore, ASCs can secrete extracellular vesicles (EV) which may act as powerful mediators of tissue repair and tolerance. In the present review, we discuss the current knowledge on the mechanisms of action and therapeutic opportunities offered by ASCs and ASC-derived EVs in the KT setting. Most relevant pre-clinical and clinical studies as well as actual limitations and future perspective are highlighted.

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.

Hydrogen-rich saline reduces tissue injury and improves skin flap survival on a rat hindlimb degloving injury model

BACKGROUND

Degloving injuries represent a challenge in plastic surgery. The aim of this study is to acknowledge the protective effects of hydrogen-rich saline (HRS) solution on a rat hindlimb degloved skin flap.

METHODS

Twenty-one Sprague-Dawley rats were divided into three groups (control, saline and HRS). Degloving injury model was established, and flaps were sutured back following 5 min of ischemia. The control group did not receive any treatment. The saline group received intraperitoneal physiological saline (10 ml/kg) and the HRS group received intraperitoneal HRS solution (10 ml/kg) postoperatively and daily for 5 days after the operation. Skin samples were obtained for histological, immunohistochemical and biochemical evaluations.

RESULTS

Inflammation was lower in the HRS compared with saline (p = 0.02) and control (p = 0.004) groups. Edema was lower in the HRS compared with saline (p = 0.02) and control (p = 0.001) groups. Malondialdehyde (MDA) level was lower in the HRS than the control group (p = 0.01). Total antioxidant level was higher in the HRS compared with saline (p = 0.009) and control (p = 0.03) groups. Total oxidant level was lower in the HRS than the control group (p = 0.02). Oxidative stress index was lower in the HRS compared with saline (p = 0.001) and control (p = 0.0001) groups`. Vascular proliferation was higher in the HRS compared with the control group (p = 0.01).

CONCLUSION

Repeated HRS injections after trauma increased the viability of skin flap in rat degloving injury model by decreasing local tissue injury, due to its antioxidant, anti-inflammatory and angiogenic effects.

Effect of zinc oxide nanoparticles and ferulic acid on renal ischemia/reperfusion injury: possible underlying mechanisms

OBJECTIVES

The present study examined the effects of ferulic acid (FA) and Zinc oxide nanoparticles (ZnO-NPs) and a combination of both on renal ischemia/reperfusion injury (IRI) in rats and their possible underlying mechanisms.

METHODS

two-hundreds male Sprague Dawley rats were randomly allocated into the 5 groups; i) sham group, ii) control (IRI) group (occlusion of the left renal pedicle for 45 min), iii) FA group as IRI group with FA (100 mg/Kg oral 24 hrs before ischemia), iv) ZnO-NPs group as IRI group with ZnO-NPs single 5 mg/Kg i.p. 2 hrs before ischemia and v) FA + ZnO-NPs group as IRI group with both FA and ZnO-NPs in the same previous doses. According to the reperfusion times, each group was further subdivided into 4 hr, 24 hr, 48 hr and 7 days reperfusion subgroups.

RESULTS

administration of either FA or ZnO-NPs caused significant improvement in the elevated serum creatinine and BUN and malondialdehyde (MDA) concentrations and expression of TNF-α, Bax, caspase-3 in kidney tissues with significant rise in the creatinine clearance, the activities of catalase (CAT) and superoxide dismutase (SOD) and the expression of HO-1, HIF-1α genes and proliferation marker (ki67) in kidney tissues compared to IRI group (p < 0.05). Moreover, a combination of both agents produced more significant improvement in the studied parameters than each agent did alone (p < 0.05).

CONCLUSIONS

Both FA and ZnO-NPs exerted cytoprotective effects against ischemic kidney injury and a combination of both exhibited more powerful renoprotective effect. This renoprotective effect might be due to suppression of oxidative stress, enhancement of cell proliferation (ki67), upregulation of antioxidant genes (Nrf2, HO-1 and HIF-1α) and downregulation of inflammatory cytokine (TNF-α) and apoptotic genes (caspase-3 and Bax).

The Role of CXCL12 in Kidney Diseases: A Friend or Foe?

Background

Chemokines are a family of proteins mainly mediating the homing and migration of various cells. The CXC chemokine CXCL12 is a member of low-weight-molecular chemokines. In the kidney, CXCL12 is pivotal for renal development and exerts a modulatory effect in kidney diseases under different etiologic settings by binding with CXC chemokine receptor 4 (CXCR4) or CXC chemokine receptor 7 (CXCR7). Besides, CXCL12 also exerts homeostasis influence in diverse physical conditions and various pathological situations. Thus, we conclude the complicated relationship between CXCL12 and kidney diseases in this review.

Summary

In renal development, CXCL12 contributes a lot to nephrogenesis and the formation of renal vasculature via correlating with CXCR4. CXCL12 also plays an essential role in renal recovery from acute kidney injury. However, the CXCL12/CXCR4 axis plays a dual regulatory role in the initiation and development of diabetic kidney disease as well as chronic allogeneic nephropathy after kidney transplantation through dialectical consideration. Additionally, the CXCL12/CXCR4 link is considered as a new risk factor for lupus nephritis and renal cell carcinoma.

Key Messages

Plenty of studies have presented the influence of CXCL12 and the relation with corresponding receptors in diverse biological and pathological statuses. Simultaneously, some drugs and antagonists targeting CXCL12/CXCR4 axis effectively treat various kidney diseases. However, more researches are needed to explore thorough influence and mechanisms, providing more cues for clinical treatments.

Possible mechanisms for the renoprotective action of adipose-derived mesenchymal stem cells with CD44-targeted hyaluronic acid against renal ischemia

The present study aimed to investigate the invitro preconditioning of adipose-derived mesenchymal stem cells (ADMSCs) with CD44-targeted hyalournic acid (HA) on ischemic kidney injury in rats. Ninety male Sprague Dawley rats were randomly allocated into the following groups; i) sham group, ii) control group: rats exposed to 45 min left renal ischemia with saline treatment, iii) HA group as control group but rats treated with HA, iv) ADMSCs group as control but rats treated with ADMSCs v) HA + ADMSCs group as ADMSCs but rats treated with ADMSCs preconditioned with CD44-tageted HA for 14 days. We found that treattment with either ADMSCs or HA + ADMSCs caused significant decrease in the elevated serum creatinine and BUN and malondialdehyde (MDA) concentrations and expression of TGF-β1, fibronectin, collagen type I, inducible nitric oxide synthease (iNOS) and microRNAs (miR-21, miR-17-5p, miR-10a) in kidney and significant increase in creatinine clearance, superoxide dismutase (SOD), reduced glutathione (GSH) and the expression of Bcl2, vascular endothelial growth factor (VEGF), Wnt/β-catenin pathway genes in kidney compared to control group (p < 0.05). Moreover, HA + ADMSCs group caused more significant improvement in these parameters than ADMSCs group (p < 0.05), while HA group did not cause any significant improvement in these parameters compared to control group. These results suggest that preconditioning of ADMSCs preconditioned with CD44-targted HA enhanced their cytoprotective effect against ischemic kidney injury. This renoprotective effect might be due to activation of angiogenesis, Wnt/β-catenin pathway proteins, and suppression of oxidative stress, apoptosis, inflammation and fibrosis.

Possible mechanisms for the renoprotective effects of date palm fruits and seeds extracts against renal ischemia/reperfusion injury in rats

PURPOSE

This work investigates the possible renoprotective effects of date palm fruits and seeds extract against renal ischemia and their underlying mechanisms.

METHODS

108-Sprague Dawle male rats were randomly allocated into 6 equal groups differently receiving aqueous or methanolic fruit and seed extracts. Assay of serum creatinine, BUN and TNF-α, morphological examination of the left kidney, markers of the redox state (MDA, CAT, and GSH), the expression of TNFα and Nrf2 genes at the level of mRNA, the expression of caspase-3 and TGF-β proteins by immunohistochemistry were performed.

RESULTS

45-min renal I/R caused significant deterioration of kidney functions (increase in serum creatinine and BUN) and morphology (P < 0.001) and significant reduction in CAT activity and GSH levels with significant increase in serum TNF-α and MDA concentration and the expression of Nrf2, caspase-3, TNF-α, and TGF-β in kidney tissues. Pre-treatment with either date palm fruit or seed extracts significantly improved kidney functions and morphology (P ≤ 0.001) with a significant increase in the expression of Nrf2 and CAT activity, and GSH concentration and a reduction in serum TNF-α and expression of caspase-3, TNF-α, and TGF-β (P < 0.001).

CONCLUSIONS

Administration of date palm extracts exhibited a renoprotective effect against renal I/R injury.This renoprotective action might be due to their antioxidants, anti-apoptotic and anti-inflammatory actions. Moreover, aqueous fruit extracts offered powerful renoprotective effect than aqueous seed extracts, and aqueous fruit and seed extracts were generally more effective than methanolic extracts.

New insights in the mechanisms of impaired redox signaling and its interplay with inflammation and immunity in multiple sclerosis

Multiple sclerosis (MS) is an autoimmune neurological disease characterized by chronic inflammation of the central nervous system (CNS), leading to demyelination and axonal damage and resulting in a range of physical, mental or even psychiatric symptoms. Key role of oxidative stress (OS) in the pathogenesis of MS has been suggested, as indicated by the biochemical analysis of cerebrospinal fluid and blood samples, tissue homogenates, and animal models of multiple sclerosis. OS causes demyelination and neurodegeneration directly, by oxidation of lipids, proteins and DNA but also indirectly, by inducing a dysregulation of the immunity and favoring the state of pro-inflammatory response. In this review, we discuss the interrelated mechanisms of the impaired redox signaling, of which the most important are inflammation-induced production of free radicals by activated immune cells and growth factors, release of iron from myelin sheath during demyelination and mitochondrial dysfunction and consequent energy failure and impaired oxidative phosphorylation. Review also provides an overview of the interplay between inflammation, immunity and OS in MS. Finally, this review also points out new potential targets in MS regarding attenuation of OS and inflammatory response in MS.

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.

Zinc Supplementation and Ischemia Pre-conditioning in Renal Ischemia/Reperfusion Injury

Backgrounds

Renal ischemia/reperfusion (RIR) is a major cause of kidney dysfunction in clinic. The main objective of this study was to investigate the effect of pre-conditioning ischemia (IPC) and zinc (Zn) supplementation on renal RIR injury.

Methods

A total of 63 unilateral nephrectomised male and female Wistar rats were divided into five groups. Group 1 (ShOPR): Rats as sham-operated group were subjected to surgical procedure without RIR. Group 2 (Isch): Rats underwent RIR (left kidney ischemia for 30 min followed by 48 h reperfusion). Group 3 (Zn+Isch): Rats were treated as group 2 but they received Zn sulphate (30 mg/kg) 1 h before induction of RIR. Group 4 (IPC+Isch): Rats were treated as group 2 but they underwent 1 min of ischemia followed by 3 min reperfusion as IPC, which was repeated for three times before induction of RIR. Group 5 (Zn+IPC+Isch): Rats were subjected to receive both Zn sulphate and IPC before induction of RIR. Urine samples were collected in the last 6 h of reperfusion, and finally biochemical and histological measurements were performed.

Results

The serum level of creatinine (Cr), normalised kidney weight (KW) and kidney tissue damage score (KTDS) increased by RIR alone significantly (P < 0.05). These parameters were attenuated statistically by Zn supplementation (P < 0.05). However, IPC alone or co-treatment of Zn and IPC did not improve the biochemical and histological markers altered by RIR injury.

Conclusion

Zn supplementation had a protective role against RIR while such protective effect was not observed by IPC alone or by co-treatment of Zn and IPC.

Emerging therapeutic strategies for transplantation-induced acute kidney injury: protecting the organelles and the vascular bed

INTRODUCTION

Renal ischemia-reperfusion injury (IRI) is a significant clinical challenge faced by clinicians in a broad variety of clinical settings such as perioperative and intensive care. Renal IRI induced acute kidney injury (AKI) is a global public health concern associated with high morbidity, mortality, and health-care costs. Areas covered: This paper focuses on the pathophysiology of transplantation-related AKI and recent findings on cellular stress responses at the intersection of 1. The Unfolded protein response; 2. Mitochondrial dysfunction; 3. The benefits of mineralocorticoid receptor antagonists. Lastly, perspectives are offered to the readers. Expert opinion: Renal IRI is caused by a sudden and temporary impairment of blood flow to the organ. Defining the underlying cellular cascades involved in IRI will assist us in the identification of novel interventional targets to attenuate IRI with the potential to improve transplantation outcomes. Targeting mitochondrial function and cellular bioenergetics upstream of cellular damage may offer several advantages compared to targeting downstream inflammatory and fibrosis processes. An improved understanding of the cellular pathophysiological mechanisms leading to kidney injury will hopefully offer improved targeted therapies to prevent and treat the injury in the future.

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.

Barriers and Advances in Kidney Preservation

Despite the fact that a significant fraction of kidney graft dysfunctions observed after transplantation is due to ischemia-reperfusion injuries, there is still no clear consensus regarding optimal kidney preservation strategy. This stems directly from the fact that as of yet, the mechanisms underlying ischemia-reperfusion injury are poorly defined, and the role of each preservation parameter is not clearly outlined. In the meantime, as donor demography changes, organ quality is decreasing which directly increases the rate of poor outcome. This situation has an impact on clinical guidelines and impedes their possible harmonization in the transplant community, which has to move towards changing organ preservation paradigms: new concepts must emerge and the definition of a new range of adapted preservation method is of paramount importance. This review presents existing barriers in transplantation (e.g., temperature adjustment and adequate protocol, interest for oxygen addition during preservation, and clear procedure for organ perfusion during machine preservation), discusses the development of novel strategies to overcome them, and exposes the importance of identifying reliable biomarkers to monitor graft quality and predict short and long-term outcomes. Finally, perspectives in therapeutic strategies will also be presented, such as those based on stem cells and their derivatives and innovative models on which they would need to be properly tested.