Loss of RIP3 initiates annihilation of high-fat diet initialized nonalcoholic hepatosteatosis: A mechanism involving Toll-like receptor 4 and oxidative stress.

Non-alcoholic fatty liver disease (NAFLD) is a prevalent and complex disease that confers a high risk of severe liver disorders. Although such public and clinical health importance, very few effective therapies are presently available for NAFLD. Here, we showed that receptor-interacting kinase-3 (RIP3) was up-regulated in liver of mouse with hepatic steatosis induced by high fat diet (HFD). After 16 weeks on a HFD, obesity, insulin resistance, metabolic syndrome, hepatic steatosis, inflammatory response and oxidative stress were significantly alleviated in liver of mice with the loss of RIP3. We provided mechanistic evidence that RIP3 knockdown attenuated hepatic dyslipidemia through preventing the expression of lipogenesis-associated genes. Furthermore, in the absence of RIP3, the transcription factor of nuclear factor-κB (NF-κB) signaling pathway activated by HFD was blocked, accompanied with the inhibition of NLRP3 inflammasome. We also found that RIP3 knockdown-induced activation of nuclear factor-erythroid 2 related factor 2/heme oxygenase-1 (Nrf-2/HO-1) led to the inhibition of oxidative stress. The detrimental effects of RIP3 on hepatic steatosis and related pathologies were confirmed in palmitate (PAL)-treated mouse liver cells. Of note, lipopolysaccharide (LPS)- or PAL-activated TLR-4 resulted in the up-regulation of RIP3 that was accompanied by the elevated inflammation and lipid deposition, and these effects were reversed in TLR-4 knockdown cells. Furthermore, promoting Nrf-2 pathway activation effectively reduced reactive oxygen species (ROS) generation and RIP3 expression in PAL-stimulated cells, consequently leading to the suppression of cellular inflammation and lipid accumulation. In contrast, blocking Nrf-2/HO-1 signaling abrogated RIP3 knockdown-reduced reactive oxygen species (ROS), inflammatory response and lipid deposition in PAL-stimulated cells. Taken together, the present study helped to elucidate how HFD-induced hepatic steatosis was regulated by RIP3, via the TLR-4/NF-κB and Nrf-2/HO-1 signaling pathways.

iRhom2 loss alleviates renal injury in long-term PM2.5-exposed mice by suppression of inflammation and oxidative stress.

Particulate matter (PM2.5) is a risk factor for organ injury and disease progression, such as lung, brain and liver. However, its effects on renal injury and the underlying molecular mechanism have not been understood. The inactive rhomboid protein 2 (iRhom2), also known as rhomboid family member 2 (Rhbdf2), is a necessary modulator for shedding of tumor necrosis factor-α (TNF-α) in immune cells, and has been explored in the pathogenesis of chronic renal diseases. In the present study, we found that compared to the wild type (iRhom2+/+) mice, iRhom2 knockout (iRhom2-/-) protected PM2.5-exposed mice from developing severe renal injury, accompanied with improved renal pathological changes and functions. iRhom2-/- mice exhibited reduced inflammatory response, as evidenced by the reduction of interleukin 1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α) and IL-18 in kidney samples, which might be, at least partly, through inactivating TNF-α converting enzyme/TNF-α receptors (TACE/TNFRs) and inhibitor of α/nuclear factor κ B (IκBα/NF-κB) signaling pathways. In addition, oxidative stress was also restrained by iRhom2-/- in kidney of PM2.5-exposed mice by enhancing heme oxygenase/nuclear factor erythroid 2-related factor 2 (HO-1/Nrf-2) expressions, and reducing phosphorylated c-Jun N-terminal kinase (JNK). In vitro, blockage of HO-1 or Nrf-2 rescued the inflammatory response and oxidative stress that were reduced by iRhom2 knockdown in PM2.5-incubated RAW264.7 cells. Similar results were observed in JNK activator-treated cells. Taken together, our findings indicated that iRhom2 played an essential role in regulating PM2.5-induced chronic renal damage, thus revealing a potential target for preventing chronic kidney diseases development.

Metabolism of glycyrrhizin and glycyrrhetinic acid in the in situ vascularly perfused rat intestine-liver model / 中国药理学通报

Aim To study the biotransformation of gly-cyrrhizin in rat intestine-liver. Methods The in situ vascularly perfused rat intestine-liver model was estab-lished with a validated LC-MS/MS method for assay of the model perfusate glycyrrhizin and glycyrrhetinic acid. Results The steady state intestinal and liver ex-traction ratios in the once-through perfused rat intes-tine-liver model for glycyrrhizin were ( 4. 2 ± 0. 6 )%and (28. 0 ± 3. 0)%, respectively; the first-order ab-sorption rate constant for glycyrrhizin in the recircula-tion of perfusate to the intestine model was ( 0. 33 ± 0. 06 ) min-1;after intraduodenal administration of gly-cyrrhizin,the main active metabolite in was the perfu-sate glycyrrhetinic acid, which was also found in intes-tinal luminal fluids. Conclusions The first-pass effi-cacy of glycyrrhizin is obvious and there is only a small amount of metabolite in the intestinal mucosa cells;gly-cyrrhizin is metabolized by gut bacteria or liver cells af-ter oral administration;the in situ vascularly perfused rat intestine-liver model can be used in glycyrrhizin pharmacokinetic studies.

Clinical exploration of discriminant model of progressive ischemic stroke / 中国综合临床

Objective To explore the related risk factors of stroke in progression(SIP)and establish discriminant models to predict the incidence.Methods 31 possible related factors were compared between progressive group(n=110)and non-progressive group(n=336),and the related factors were analyzed in discriminant models.Results Discriminant models were established by 16 factors,including arterial stenosis,OCSP subtype,blood glucose,low density lipoprotion,creatinine,the sign of early cerebral infarction on CT,the temperature increasing and the rapidly decreasing of blood pressure in 48 hours after admittion.The evaluation to the models by interview data and prospective data showed a satisfied result.Conclusion Arterial stenosis,OCSP subtype and other significant factors selected by model will be helpful in prediction of SIP.

Studies on pharmacokinetics of guanfu base I,a metabolite of guanfu base A / 中国药理学通报

Aim To establish an analytical method for determination of guanfu base I (GFI) concentration in plasma and investigate its pharmacokinetics in rats. Methods Rats were given a 20 mg?kg~-1 dose intravenously. Blood samples were collected at various times after iv administration. The plasma concentration of GFI was determined by LC-MS. Pharmacokinetic parameters were calculated by 3p97 program.Results The method was linear in the 0.05～20 mg?L~-1 concentration range (r=~0.999 4 ). The recovery of guanfu base I was more than 80%.The intraday and interday precision, expressed as the relative standard deviation (RSD), was generally good (