Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening complication characterized by high morbidity and mortality. However, effective pharmacological therapies are currently unavailable. Ferroptosis, an iron-dependent form of regulated cell death, plays a pivotal role in the pathogenesis of SA-AKI. Coptisine, a natural isoquinoline alkaloid derived from Coptis chinensis, has demonstrated anti-inflammatory and antioxidant effects, but its specific role in SA-AKI remains to be elucidated. In this study, we investigated the protective effects of Coptisine against SA-AKI and the underlying mechanisms involved. Using a cecal ligation and puncture (CLP) mouse model, our study revealed that administering Coptisine significantly alleviated renal injury and inflammation, decreased oxidative stress, and inhibited ferroptosis in kidney tissues. In vitro studies showed that Coptisine suppressed LPS-induced ferroptotic injury in HK2 cells. Nevertheless, this protective effect was reversed by Nrf2 knockdown or iron supplementation. Mechanistically, Coptisine upregulated the levels of Nrf2 and GPX4, resulting in reduced ROS, MDA, and Fe²⁺ levels, while enhancing GSH content. Collectively, our findings indicate that Coptisine alleviates sepsis-induced AKI by inhibiting ferroptosis through the activation of the Nrf2 signaling pathway, highlighting its potential as a therapeutic agent for SA-AKI.

To investigate the effects of reduced food intake on the serum and tissue levels of alkaline phosphatase (ALP) isoenzymes in rats, ALP1, ALP2, ALP3, and ALP5 were analyzed in serum, liver, bone, and small intestine of male and female Sprague-Dawley rats reared under a diet-restricted condition (fed 65% or 45% of the amount of the free-feeding group) for 4 weeks from six-week-old. In addition, to examine the effect of sex hormonal, each ALP isoenzyme level was also analyzed in free-feeding female rats with ovariectomy or testosterone administration. Food restriction was associated with the following changes: an increase of the serum ALP5 level in the females, mainly caused by an increase derived from the small intestine; increases in the liver ALP1 and small intestinal ALP5 levels in both sexes, which represented a compensatory increase of these ALP isoenzyme levels to enhance lipid absorption under the low nutritional condition; a decrease of the bone ALP3 level in females, which was considered reflective of suppressed bone formation. Regarding the sex differences, serum ALP2 and liver ALP1 levels were higher in the males than in the females; the levels in ovariectomized or testosterone-treated females shifted closer to those in the males. These results indicate that food restriction and sex hormonal intervention influenced the serum and tissue ALP isoenzyme levels in rats. These findings provide helpful information for understanding the effects of reduced food intake, often observed in toxicity studies, and sex differences in rats on ALP and help to properly evaluate the effects of test compounds.

Our study evaluated whether lenvatinib induces the disease process of diarrhea by facilitating intestinal epithelial barrier damage. Sprague-Dawley rats were orally administrated with 0.2 or 2 mg/kg lenvatinib for six consecutive days to induce diarrhea models. The diarrhea rate was monitored every day, and rats were sacrificed on day 6. We found that rats began to develop diarrhea on day 3 after lenvatinib treatment. Almost all rats treated with lenvatinib (2 mg/kg) developed grade 3 diarrhea. Intestinal villi structure damage and obvious inflammatory cell infiltration were observed in the colon tissues of lenvatinib-administrated rats. Lenvatinib significantly upregulated serum contents of intestinal injury biomarkers (D-lactate and DAO) but downregulated colon levels of tight junction proteins (ZO-1, Occludin, and Claudin-1) in rats. In vitro results showed that lenvatinib higher than 5 μM significantly attenuated the viability of human intestinal epithelial cell line Caco-2. Lenvatinib suppressed ZO-1, Occludin, and Claudin-1 levels, decreased the transepithelial electrical resistance value, and elevated paracellular permeability in Caco-2 cells. Mechanically, lenvatinib targeted AQP4 and inhibited its expression. Overexpressing AQP4 reversed lenvatinib-induced intestinal epithelial barrier injury in Caco-2 cells by inhibiting the MLCK/p-MLC2 signaling pathway. Collectively, lenvatinib triggers diarrhea by disrupting the intestinal barrier through downregulating AQP4 and activating the MLCK/p-MLC2 signaling pathway.

Bardoxolone methyl, also known as CDDO-Me or RTA 402, was a new investigational drug that improves the estimated glomerular filtration rate by activating the Keap1-Nrf2 pathway. Bardoxolone methyl is a synthetic triterpenoid compound derived from oleanolic acid (OA). OA-mediated cholestasis has not been reported in the clinical treatment of treat liver disorders but has been reported in mice. Cholestasis can be transient (e.g., during pregnancy) but can also be chronic and is a risk factor for hepatobiliary carcinoma. Therefore, it is important to evaluate and understand the risk of drug-induced cholestasis and its mechanisms, including species differences. We evaluated the effects of bardoxolone methyl on the in vivo hepatobiliary systems in rats and monkeys, as well as sandwich-cultured hepatocytes. Bardoxolone methyl was administered daily to rats and monkeys for 26 or 52 weeks, respectively. As a result, bardoxolone methyl was associated with the development of cholestasis and cholangioma in rats but not in monkeys. In an in vitro evaluation using sandwich-cultured hepatocytes treated with bardoxolone methyl, cholestasis was observed in rat hepatocytes, but not in monkey or human hepatocytes. A gene expression analysis showed that rat-specific cholestasis was caused by the reduction of the bile salt export pump gene expression after treatment with bardoxolone methyl. These results strongly suggest that the effects of bardoxolone methyl on the hepatobiliary system differ among animal species, especially between rodents and non-rodents. In conclusion, the risk of cholestasis and cholestasis-derived carcinogenicity associated with bardoxolone methyl are expected to be quite low in humans.

Asthma attacks during pregnancy can cause inadequate oxygen supply to the fetus because the mother cannot get enough oxygen into her bloodstream. Even during pregnancy, medication such as theophylline is needed to avoid asthma seizure. Theophylline is metabolized by (Cytochrome P450) CYP1A2 in the maternal liver. On the other hand, whether theophylline transferred from the mother to the fetus is metabolized in its liver depends on the degree of CYP1A2 expression, but no such information is available. In the adult liver, CYP1A2 forms zonation structures to efficiently metabolize drugs and foreign substances. In this study, we quantitatively analyzed the expression levels of mCyp1a2 mRNA and protein in the liver throughout development, from fetal and neonatal stages to adulthood, while distinguishing between males and females. In addition, to determine the timing of the mCyp1a2 zonation, analysis was performed in fetal and neonatal livers. We found that mCyp1a2 males and females express very little mCyp1a2 in the fetal liver. One week after birth, mCyp1a2 protein expression was 24% and 14% of adult expression in males and females, respectively. Furthermore, the expression level of mCyp1a2 in both sexes was almost the same as that of adults after 28 days of age. In addition, they found that the zonation of mCyp1a2 begins to form 5 days after birth. It was found that mCyp1a2 expression is very low in the fetal liver, while the liver of a 14-day-old (P14) has approximately half the drug-metabolizing capacity compared to that of an adult liver.

Cadmium (Cd) is a toxic heavy metal that induces proximal tubular cell damage. Previously, we identified that retinoic acid receptor (RAR) activity was suppressed in the kidney of Cd-exposed mice. In addition, peroxisome proliferator-activated receptor δ, PPARδ, contributed to the modification of Cd toxicity in HK-2 human proximal tubular cells. In this study, we investigated the protective effects of retinoic acid (RA) and its precursor, retinol, against Cd-induced cytotoxicity in HK-2 cells. Pretreatment with RA or retinol significantly reduced Cd toxicity. Knockdown of RARA, RARG, or PPARD did not alter the protective effects of RA; moreover, the double knockdown of RARA and RARG partly suppressed the RA-reduced Cd toxicity. This suggested that RA may reduce Cd toxicity by a receptor-independent mechanism. Furthermore, RA did not affect the expression of metallothionein genes (MT-1X and MT-2A) or the intracellular accumulation of Cd after Cd treatment. RA pretreatment suppressed Cd-induced apoptosis, partly by inhibiting caspase-3 activation. These findings suggest that RA prevents Cd toxicity via a novel, receptor-independent mechanism involving the suppression of apoptosis.

Excessive fructose intake has been reported to increase the risks of obesity, diabetes and kidney diseases, including diabetic nephropathy. We investigated the effects of a high-fructose diet on nephropathy in both male and female Spontaneously Diabetic Torii-Lepr^fa (SDT fatty) rats, a model for obese type 2 diabetes. 11-week-old male and female Sprague-Dawley (SD) and SDT fatty rats that developed diabetes were each divided into 2 groups receiving either a high-fructose diet (60% fructose) or a basal diet. The diets were fed ad libitum for 7 weeks. Body weights, food consumption, clinical chemistry, urinalysis, kidney weights and histopathology of the kidneys were evaluated. In the SDT fatty rats, fructose intake increased the urinary excretion of calcium and inorganic phosphate in both sexes. Histopathological examination revealed that fructose intake worsened nephropathy (mineralization, inflammatory cell infiltration, and increased mesangial matrix in the glomeruli) in the female SDT fatty rats. In conclusion, a 7-week high-fructose diet induced several renal changes in SDT fatty rats, including urinary electrolyte imbalances and associated mineral deposition in the kidney, suggestive of urinary stone formation. It suggests that the SDT fatty rat is a useful model to investigate type 2 diabetes and diabetic nephropathy and that excessive fructose intake can be a risk factor for the development and progression of urinary stone formation and diabetes- related kidney injury.