Emodin ameliorates cisplatin-induced apoptosis of rat renal tubular cells in vitro by activating autophagy

Autophagy: A new treatment strategy for MSC-based therapy in acute kidney injury (Review)

Acute kidney injury (AKI) is a common and serious medical condition associated with poor health outcomes. Autophagy is a conserved multistep pathway that serves a major role in many biological processes and diseases. Recent studies have demonstrated that autophagy is induced in proximal tubular cells during AKI. Autophagy serves a pro‑survival or pro‑death role under certain conditions. Furthermore, mesenchymal stem cells (MSCs) have therapeutic potential in the repair of renal injury. This review summarizes the recent progress on the role of autophagy in AKI and MSCs‑based therapy for AKI. Further research is expected to prevent and treat acute kidney injury.

HucMSC exosomes-delivered 14-3-3ζ enhanced autophagy via modulation of ATG16L in preventing cisplatin-induced acute kidney injury

The clinical application of cisplatin is restricted by its side effects of nephrotoxicity. Human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-ex) have an important effect in tissue injury repair. Our previous work discovered that pretreatment with human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-ex) alleviated cisplatin-induced acute kidney injury (AKI) by activating autophagy both in vitro and in vivo. In this study, we further explored the mechanisms of hucMSC-ex in autophagy for preventing cisplatin-induced nephrotoxicity. We discovered that 14-3-3ζ was contained in hucMSC-ex, and knockdown and overexpression 14-3-3ζ reduced and enhanced the autophagic activity respectively. Furthermore, Knockdown of 14-3-3ζ alleviated the preventive effect of hucMSC-ex. In contrast, overexpression of 14-3-3ζ enhanced the effect. Further results confirmed that hucMSC-ex increased ATG16L expression and that 14-3-3ζ interacted with ATG16L, promoting the localization of ATG16L at autophagosome precursors. In this study, we revealed that hucMSC-ex-delivered 14-3-3ζ interacted with ATG16L to activate autophagy. Our findings suggest that 14-3-3ζ is a novel mechanism for MSC-exosomes-activated autophagy and provides a new strategy for the prevention of cisplatin-induced nephrotoxicity.

Protective Effect of Rheum turkestanicum against Cisplatin by Reducing Oxidative Stress in Kidney Tissue

Background:

Cisplatin is used as chemotherapeutic drug in the treatment of some solid tumors. It causes different side effects such as nephrotoxicity because of increasing oxidative stress and reactive oxygen species production. This study was designed to investigate the effect of Rheum turkestanicum on cisplatin-induced nephrotoxicity in rat.

Materials and Methods:

Animals were randomly divided into four groups (six each). Group I received normal saline (1mL/day, intraperitoneally [i.p.]). Group II received a single dose of cisplatin (8mg/kg, i.p.). Groups III and IV received extract at doses of 100mg/kg and 200mg/kg, i.p., respectively, for 3 consecutive days, 1h before a single dose of cisplatin only at the first day. Blood samples were taken for measuring the level of urea and creatinine. Furthermore, 24-h urinary factors such as glucose and protein were measured. Histopathological observation was carried out on kidney sections. Statistical analysis was performed using one-way analysis of variance followed by Tukey–Kramer post hoc test for multiple comparisons.

Results:

Cisplatin increased the lipid peroxidation, serum creatinine, serum urea, urinary glucose, and urinary protein, whereas decreased the content of thiol in kidney. The extract reduced serum creatinine, serum urea, urinary glucose, urinary protein, lipid peroxidation, and increased thiol following cisplatin administration. Histological studies revealed lower lesions in kidney in the extract-treated groups compared to cisplatin-treated one.

Conclusion:

This research showed the extract has protective effect against cisplatin-induced nephrotoxicity. This observation may be related to antioxidant properties of the extract.

Protective effect of Rheum turkestanicum root against mercuric chloride-induced hepatorenal toxicity in rats

OBJECTIVE

The present study was designed to investigate the protective effects of hydroalcoholic extract of Rheum turkestanicum against HgCl₂ hepatorenal toxicity in rats.

MATERIALS AND METHODS

Animals were randomly divided into five groups (n= 6 in each group) and received HgCl₂ and plant's extract, intraperitoneally. Group1 received saline (1 mL/kg/day), group 2 received extract (200 mg/kg/day), group 3 was treated with HgCl₂ (5 mg/kg/day,) and groups 4 and 5 received the extract (100 and 200 mg/kg/day, respectively), 1 hr before HgCl₂ administration. All injections last for 3 days. Blood samples and specimens of the liver and kidney were collected 24 hr after the last injection.

RESULTS

Data showed that HgCl₂ significantly increases liver malondialdehyde (MDA) level, reduces total sulfhydryl content and increases serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, compared to control group. The histopathological changes such as inflammatory cells infiltration was observed in HgCl₂-treated group while plant's extract partially improved histological changes. The extract (100 and 200 mg/kg/day) improved the liver functions as reflected by significant reductions in AST and ALT levels in serum, MDA decreased and the content of total sulfhydryl elevated. Also, the extract improved necrosis and atrophy of the kidney induced byHgCl₂. Pretreatment with the extract reduced creatinine and urea in serum, and glucose and protein concentrations in urine, compared to HgCl₂- treated group (group III). The extract significantly reversed HgCl₂-induced depletion in thiol content and elevation in MDA content.

CONCLUSION

Therefore, oxidative stress may play an important role in HgCl₂-induced hepatorenal injury and R. turkestanicum extract may be regarded as a useful to protect the kidney and liver against HgCl₂-induced oxidative damage.

Rhein Inhibits Autophagy in Rat Renal Tubular Cells by Regulation of AMPK/mTOR Signaling

Rhubarb and its bioactive component rhein are frequently used for the treatment of chronic kidney diseases (CKD) in eastern Asia countries. However, the potential therapeutic mechanism remains unclear. Autophagy plays an important role in CKD. However, there were some important related issues that remained unresolved in the role of autophagy in CKD and treatment by rhubarb and rhein. We designed a number of experiments to examine whether rhubarb may reduce renal fibrosis and autophagy in rats with adenine (Ade)-induced renal tubular injury, and whether rhein could affect autophagic pathways in rat renal tubular cells. We found that, autophagic activation accompanied with renal fibrosis in rats with Ade-induced renal tubular injury, and both autophagy and renal fibrosis were attenuated by rhubarb. In addition, we observed that rhein could inhibit autophagy through regulating the key molecules in the AMPK-dependent mTOR signaling pathways, as well as the Erk and p38 MAPKs signaling pathways. These findings may partly explain the therapeutic mechanisms of rhubarb and rhein in treating CKD patients in clinic, and further suggest that targeting autophagy and related signaling pathways may provide new strategies for the treatment of renal fibrosis in CKD.

Protocatechuic Aldehyde Attenuates Cisplatin-Induced Acute Kidney Injury by Suppressing Nox-Mediated Oxidative Stress and Renal Inflammation

Cisplatin is a classic chemotherapeutic agent widely used to treat different types of cancers including ovarian, head and neck, testicular and uterine cervical carcinomas. However, cisplatin induces acute kidney injury by directly triggering an excessive inflammatory response, oxidative stress, and programmed cell death of renal tubular epithelial cells, all of which lead to high mortality rates in patients. In this study, we examined the protective effect of protocatechuic aldehyde (PA) in vitro in cisplatin-treated tubular epithelial cells and in vivo in cisplatin nephropathy. PA is a monomer of Traditional Chinese Medicine isolated from the root of S. miltiorrhiza (Lamiaceae). Results show that PA prevented cisplatin-induced decline of renal function and histological damage, which was confirmed by attenuation of KIM1 in both mRNA and protein levels. Moreover, PA reduced renal inflammation by suppressing oxidative stress and programmed cell death in response to cisplatin, which was further evidenced by in vitro data. Of note, PA suppressed NAPDH oxidases, including Nox2 and Nox4, in a dosage-dependent manner. Moreover, silencing Nox4, but not Nox2, removed the inhibitory effect of PA on cisplatin-induced renal injury, indicating that Nox4 may play a pivotal role in mediating the protective effect of PA in cisplatin-induced acute kidney injury. Collectively, our data indicate that PA blocks cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation without compromising anti-tumor activity of cisplatin. These findings suggest that PA and its derivatives may serve as potential protective agents for cancer patients receiving cisplatin treatment.

Plant-Derived Agents for Counteracting Cisplatin-Induced Nephrotoxicity

Cisplatin (CSP) is a chemotherapeutic agent commonly used to treat a variety of malignancies. The major setback with CSP treatment is that its clinical efficacy is compromised by its induction of organ toxicity, particular to the kidneys and ears. Despite the significant strides that have been made in understanding the mechanisms underlying CSP-induced renal toxicity, advances in developing renoprotective strategies are still lacking. In addition, the renoprotective approaches described in the literature reveal partial amelioration of CSP-induced renal toxicity, stressing the need to develop potent combinatorial/synergistic agents for the mitigation of renal toxicity. However, the ideal renoprotective adjuvant should not interfere with the anticancer efficacy of CSP. In this review, we have discussed the progress made in utilizing plant-derived agents (phytochemicals) to combat CSP-induced nephrotoxicity in preclinical studies. Furthermore, we have also presented strategies to utilize phytochemicals as prototypes for the development of novel renoprotective agents for counteracting chemotherapy-induced renal damage.

Emodin Inhibits Migration and Invasion of Human Endometrial Stromal Cells by Facilitating the Mesenchymal-Epithelial Transition Through Targeting ILK

OBJECTIVE

To determine whether emodin facilitates the mesenchymal-epithelial transition (MET) of endometrial stromal cells (ESCs) as well as to explore the mechanism through which emodin favored the MET of ESCs.

METHODS

Cell viability was tested by methyl thiazolyl tetrazolium assay. Cell migration and invasion abilities were detected by transwell assays. Levels of integrin-linked kinase (ILK) and epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot.

RESULTS

Upregulated ILK and increased abilities of migration and invasion were confirmed in the eutopic and ectopic ESCs (EuSCs and EcSCs), especially in the EcSCs. After treated with emodin, the expression of ILK was statistically downregulated in EcSCs, resulting in the MET and decreased migration and invasion abilities of EcSCs. Additionally, silencing of the ILK gene in EcSCs also achieved the above-mentioned effects, which were strengthened by emodin. Furthermore, exogenous expression of ILK in control ESCs (CSCs) resulted in the EMT and increased abilities of migration and invasion of CSCs, which can be abrogated by emodin. Besides, exogenous expression of ILK also abrogated the effects of emodin on CSCs.

CONCLUSION

Emodin inhibits the migration and invasion abilities of human ESCs by facilitating the MET through targeting ILK.