NAM protects against cisplatin-induced acute kidney injury by suppressing the PARP1/p53 pathway

Cytosine-phosphate-guanine oligodeoxynucleotides alleviate radiation-induced kidney injury in cervical cancer by inhibiting DNA damage and oxidative stress through blockade of PARP1/XRCC1 axis

BACKGROUND

Radiotherapy can cause kidney injury in patients with cervical cancer. This study aims to investigate the possible molecular mechanisms by which CpG-ODNs (Cytosine phosphate guanine-oligodeoxynucleotides) regulate the PARP1 (poly (ADP-ribose) polymerase 1)/XRCC1 (X-ray repair cross-complementing 1) signaling axis and its impact on radiation kidney injury (RKI) in cervical cancer radiotherapy.

METHODS

The GSE90627 dataset related to cervical cancer RKI was obtained from the Gene Expression Omnibus (GEO) database. Bioinformatics databases and R software packages were used to analyze the target genes regulated by CpG-ODNs. A mouse model of RKI was established by subjecting C57BL/6JNifdc mice to X-ray irradiation. Serum blood urea nitrogen (BUN) and creatinine levels were measured using an automated biochemical analyzer. Renal tissue morphology was observed through HE staining, while TUNEL staining was performed to detect apoptosis in renal tubular cells. ELISA was conducted to measure levels of oxidative stress-related factors in mouse serum and cell supernatant. An in vitro cell model of RKI was established using X-ray irradiation on HK-2 cells for mechanism validation. RT-qPCR was performed to determine the relative expression of PARP1 mRNA. Cell proliferation activity was assessed using the CCK-8 assay, and Caspase 3 activity was measured in HK-2 cells. Immunofluorescence was used to determine γH2AX expression.

RESULTS

Bioinformatics analysis revealed that the downstream targets regulated by CpG-ODNs in cervical cancer RKI were primarily PARP1 and XRCC1. CpG-ODNs may alleviate RKI by inhibiting DNA damage and oxidative stress levels. This resulted in significantly decreased levels of BUN and creatinine in RKI mice, as well as reduced renal tubular and glomerular damage, lower apoptosis rate, decreased DNA damage index (8-OHdG), and increased levels of antioxidant factors associated with oxidative stress (SOD, CAT, GSH, GPx). Among the CpG-ODNs, CpG-ODN2006 had a more pronounced effect. CpG-ODNs mediated the inhibition of PARP1, thereby suppressing DNA damage and oxidative stress response in vitro in HK-2 cells. Additionally, PARP1 promoted the formation of the PARP1 and XRCC1 complex by recruiting XRCC1, which in turn facilitated DNA damage and oxidative stress response in renal tubular cells. Overexpression of either PARP1 or XRCC1 reversed the inhibitory effects of CpG-ODN2006 on DNA damage and oxidative stress in the HK-2 cell model and RKI mouse model.

CONCLUSION

CpG-ODNs may mitigate cervical cancer RKI by blocking the activation of the PARP1/XRCC1 signaling axis, inhibiting DNA damage and oxidative stress response in renal tubule epithelial cells.

Dihydromyricetin attenuates cisplatin-induced acute kidney injury by reducing oxidative stress, inflammation and ferroptosis

BACKGROUND

Cisplatin is effective against various types of cancers. However, its clinical application is limited owing to its adverse effects, especially acute kidney injury (AKI). Dihydromyricetin (DHM), a flavonoid derived from Ampelopsis grossedentata, has varied pharmacological activities. This research aimed to determine the molecular mechanism for cisplatin-induced AKI.

METHODS

A murine model of cisplatin-induced AKI (22 mg/kg, I.P.) and a HK-2 cell model of cisplatin-induced damage (30 μM) were established to evaluate the protective function of DHM. Renal dysfunction markers, renal morphology and potential signaling pathways were investigated.

RESULTS

DHM decreased the levels of renal function biomarkers (blood urea nitrogen and serum creatinine), mitigated renal morphological damage, and downregulated the protein levels of kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin. It upregulated the expression levels of antioxidant enzymes (superoxide dismutase and catalase expression), nuclear factor-erythroid-2-related factor 2 (Nrf2) and its downstream proteins, including heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunits, thus eventually reducing cisplatin-induced reactive oxygen species (ROS) production. Moreover, DHM partially inhibited the phosphorylation of the active fragments of caspase-8 and -3 and mitogen-activated protein kinase and restored glutathione peroxidase 4 expression, which attenuated renal apoptosis and ferroptosis in cisplatin-treated animals. DHM also mitigated the activation of NLRP3 inflammasome and nuclear factor (NF)-κB, attenuating the inflammatory response. In addition, it reduced cisplatin-induced HK-2 cell apoptosis and ROS production, both of which were blocked by the Nrf2 inhibitor ML385.

CONCLUSIONS

DHM suppressed cisplatin-induced oxidative stress, inflammation and ferroptosis probably through regulating of Nrf2/HO-1, MAPK and NF-κB signaling pathways.

An herbal formulation "Shenshuaifu Granule" alleviates cisplatin-induced nephrotoxicity by suppressing inflammation and apoptosis through inhibition of the TLR4/MyD88/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Shenshuaifu Granule (SSF) is an in-hospital preparation approved by the Guangdong Food and Drug Administration of China. It has been clinically used against kidney diseases for more than 20 years with a definite curative effect.

AIM OF THE STUDY

Cisplatin (CDDP) is a first-line chemotherapeutic drug in clinical practice, primarily excreted by the kidney with nephrotoxicity as a common side effect. Approximately 5-20% of cancer patients develop acute kidney injury (AKI) after chemotherapy; however, prevention and control strategies are currently unavailable. Therefore, it is important to identify safe and effective drugs that can prevent the nephrotoxicity of CDDP. SSF is an herbal formulation with 8 herbs, and has been used to protect the kidney in China. Nonetheless, its mechanism in relieving CDDP nephrotoxicity remains unclear. Therefore, this work attempt to prove that SSF can alleviate CDDP nephrotoxicity. We also explore its mechanism.

MATERIALS AND METHODS

First, Thin Layer Chromatography (TLC) of a few herbs in SSF were performed for quality control. Several open-access databases were used to identify the active ingredients of SSF, their corresponding targets, and CDDP-induced nephrotoxicity targets. We performed Protein-Protein Interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Next, the results of network pharmacology were validated using CDDP-induced nephrotoxicity mouse models. Renal function in the mice was assessed by analyzing the levels of serum creatinine (Scr) and blood urea nitrogen (BUN). On the other hand, renal damage was assessed by determining the level of tubular injury and apoptotic cells using Periodic acid-Schiff (PAS) staining and Terminal Dutp Nick End-Labeling (TUNEL) staining, respectively. The expression of inflammatory and apoptotic-related targets including IL-1β, IL-6, TNF-α, Cox-2, Bax, Bcl-2, Cleaved-caspase 3, and Cleaved-caspase 9 was determined using Western Blot (WB) and Immunohistochemistry (IHC). Furthermore, WB was used to analyze the expression of proteins associated with the TLR4/MyD88/NF-κB pathway in the kidneys of mice with CDDP-induced nephrotoxicity. Finally, molecular docking simulations were performed to evaluate the binding abilities between major active ingredients of SSF and core targets.

RESULT

Through network pharmacology, we identified 127 active ingredients of SSF and their corresponding 134 targets. Additional screening identified 14 active ingredients and 17 targets for further analysis. In biological process (BP), the targets were enriched in inflammation and apoptosis, among others. In KEGG terms, they were enriched in apoptosis and NF-κB pathways. Animal experiments revealed that SSF significantly reduced the levels of Scr and BUN and prevented renal tubular damage in mice treated with CDDP. In addition, SSF inhibited inflammation and apoptosis by targeting the TLR4/MyD88/NF-κB pathway. Molecular docking revealed good binding capacities of active ingredients and core targets.

CONCLUSION

In summary, the experimental findings were consistent with the network pharmacological predictions. SSF can inhibit inflammation and apoptosis by targeting the TLR4/MyD88/NF-κB pathway. Taken together, our data suggest that SSF is an alternative agent for the treatment of CDDP-induced nephrotoxicity.

Therapeutic effect and underlying mechanism of Shenkang injection against cisplatin-induced acute kidney injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Shenkang injection (SKI), a Chinese patent medicine injection, has been approved for the treatment of chronic kidney disease (CKD) due to its definite clinical therapeutic efficacy. However, the effect and associated underlying mechanism of Shenkang injection against cisplatin (CDDP)-induced acute kidney injury (AKI) has not yet been well elucidated.

AIM OF THE STUDY

This study aims to investigate the therapeutic effect and associated underlying mechanism of Shenkang injection against CDDP-induced AKI.

MATERIALS AND METHODS

We established a CDDP-induced AKI mouse model to evaluate renal function by biochemical markers measurement and to observe histopathological alterations by haemotoxylin and eosin (HE)-staining sections of renal. In addition, the distribution of representative components of SKI in the kidneys of mice was evaluated by liquid chromatography tandem mass spectrometry (LC-MS/MS). Furthermore, the degree of oxidative stress and inflammation were assessed by detecting the levels of inflammatory cytokines and oxidants, while the related mechanisms were elucidated by network pharmacology.

RESULTS

CDDP could induce excessive inflammation and severe injury to the kidneys of mice. However, SKI significantly ameliorated the kidney damages and improved the renal function by reducing the levels of renal function markers (SCr, BUN and urine protein), and inhibiting the production of inflammatory cytokines IL-34, IL-6 and TNF-α. SKI repaired oxidative balance through up-regulation of antioxidants SOD and GSH and down-regulated oxidants MDA. Moreover, 4 components from SKI were detected in the kidney by LC-MS/MS quantification. In addition, pharmacology network indicated the PI3K/AKT, TNF, MAPK, and p53 were the possible signaling pathways for the therapeutic effect of SKI against CDDP-induced AKI, which were related to inflammation, oxidative stress and apoptosis.

CONCLUSION

In the present study, we for the first time demonstrated that SKI alleviates CDDP-induced nephrotoxicity by antioxidant and anti-inflammation via regulating PI3K/AKT, MAPK, TNF, and p53 signaling pathways. The study may provide a scientific rationale for the clinical indication of SKI.

Carbamazepine-induced renal toxicity may be associated with oxidative stress and apoptosis in male rat

Carbamazepine (CBZ) is the antiepileptic drug used in epilepsy and some psychiatric disorders. Besides its widely used, many adverse effects have been reported including hematotoxicity, hepatotoxicity, endocrine disorders, and testicular damages due to oxidative stress. However, the role of CBZ on renal toxicity is not fully known. In this study, we attempted to explain the connected mechanisms by focusing on the metabolism of CBZ-induced renal toxicity in rats. Twenty male Wistar-Albino rats were randomized into 2 groups (n = 10); control (1 mL/day distilled water, orally) and CBZ (25 mg/kg/day CBZ, orally) groups. After 60 days, TAS (total oxidant status) and TOS (total oxidant status) levels, histopathological features, some genes involved in apoptosis, 8-hydroxy-2-deoxyguanosine (8-OHdG) activity, and apoptotic cells were assessed of kidney tissue. The oxidative stress index (OSI) was measured from TAS and TOS levels. TOS levels and OSI significantly increased, while TAS levels decreased in the CBZ group relative to the control group. Histopathological observations, Caspase-3 (Casp3), Poly [ADP-ribose] polymerase-1 (PARP-1), 8-OHdG immunoreactivities, and apoptotic cells markedly raised in the CBZ group compared with the control group. Also, mRNA expression of Cytochrome c (Cytc) and CASP3 significantly increased in the CBZ group compared to the control group. In conclusion, long-term use of CBZ may promote renal damage in rats by inducing oxidative stress and apoptosis.

Compartmentalized regulation of NAD+ by Di (2-ethyl-hexyl) phthalate induces DNA damage in placental trophoblast

Di (2-ethyl-hexyl) phthalate (DEHP) is a wildly used plasticizer. Maternal exposure to DEHP during pregnancy blocks the placental cell cycle at the G2/M phase by reducing the efficiency of the DNA repair pathways and affects the health of offsprings. However, the mechanism by which DEHP inhibits the repair of DNA damage remains unclear. In this study, we demonstrated that DEHP inhibits DNA damage repair by reducing the activity of the DNA repair factor recruitment molecule PARP1. NAD+ and ATP are two substrates necessary for PARP1 activity. DEHP abated NAD+ in the nucleus by reducing the level of NAD+ synthase NMNAT1 and elevated NAD+ in the mitochondrial by promoting synthesis. Furthermore, DEHP destroyed the mitochondrial respiratory chain, affected the structure and quantity of mitochondria, and decreased ATP production. Therefore, DEHP inhibits PARP1 activity by reducing the amount of NAD+ and ATP, which hinders the DNA damage repair pathways. The supplement of NAD+ precursor NAM can partially rescue the DNA and mitochondria damage. It provides a new idea for the prevention of health problems of offsprings caused by DEHP injury to the placenta.

Unexpected Enhancement of Cytotoxicity of Cisplatin in a Rat Kidney Proximal Tubular Cell Line Overexpressing Mitochondrial Glutathione Transport Activity

In previous studies, we identified the two principal transporters that mediate the uptake of glutathione (GSH) from cytoplasm into the mitochondrial matrix of rat kidney proximal tubular cells. We hypothesized that genetic modulation of transporter expression could markedly alter susceptibility of renal proximal tubular cells to a broad array of oxidants and mitochondrial toxicants. Indeed, we previously showed that overexpression of either of these transporters resulted in diminished susceptibility to several chemicals. In the present work, we investigated the influence of overexpression of the mitochondrial 2-oxoglutarate carrier (OGC) in NRK-52E cells on the cytotoxicity of the antineoplastic drug cisplatin. In contrast to previous results showing that overexpression of the mitochondrial OGC provided substantial protection of NRK-52E cells from injury due to several toxicants, we found a remarkable enhancement of cellular injury from exposure to cisplatin as compared to wild-type NRK-52E cells. Despite the oxidative stress that cisplatin is known to cause in the renal proximal tubule, the increased concentrations of mitochondrial GSH associated with OGC overexpression likely resulted in increased delivery of cisplatin to molecular targets and increased cellular injury rather than the typical protection observed in the previous work.