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Abstract Background Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disorder associated with pregnancy and is usually diagnosed based on high serum bile acid. However, the pathogenesis of ICP is unclear. Ferroptosis has been reported as an iron-dependent mechanism of cell death. Although the role of Ferritin Heavy Chain 1 (FTH1) in ferroptosis has been extensively studied in various diseases, its mechanism in ICP through ferroptosis is yet to be analyzed. Methods Placental tissues from patients with ICP and healthy controls were employed to verify the expression of FTH1. Taurocholic acid (TCA)-induced HTR-8/SVneo cells were established as an in vitro model for ICP, and ferroptosis-related experiments were performed. In particular, HTR-8/SVneo cells with or without overexpressing FTH1 and HTR-8/SVneo cells with or without TCA induction were investigated to explore the relationship between FTH1 and ferroptosis during ICP in vitro, respectively. Results FTH1 was significantly downregulated in the ICP group compared with the control group. Furthermore, FTH1 and ferroptosis-related protein levels were downregulated, while the intracellular iron, reactive oxygen species, and lipid peroxidation levels were upregulated in the TCA-induced HTR-8/SVneo cells. In contrast, ferroptosis was inhibited by overexpression of FTH1 in TCA-induced HTR-8/SVneo cells. Conclusions A high concentration of TCA in HTR-8/SVneo cells decreased the expression of FTH1. Overexpression of FTH1 could prevent cell death from ferroptosis induced by TCA. Thus, inhibiting the downregulation of FTH1 could be a potential therapeutic target for ICP treatment.

Human pancreatic lipase (hPL) is a crucial digestive enzyme responsible for the digestion of dietary lipids in humans, and inhibition of hPL is effective in reducing triglyceride intake, thereby preventing and treating obesity. In this study, a series of fatty acids with different carbon chain lengths were constructed to the fluorophore resorufin based on the substrate preference of hPL. Among them, RLE was found to have the best combination of stability, specificity, sensitivity and reactivity towards hPL. Under physiological conditions, RLE can be rapidly hydrolyzed by hPL and released to resorufin, which triggered approximately 100-fold fluorescence enhancement at 590 nm. RLE was successfully applied for sensing and imaging of endogenous PL in living systems with low cytotoxicity and high imaging resolution. Moreover, a visual high-throughput screening platform was established using RLE, and the inhibitory effects of hundreds of drugs and natural products toward hPL were evaluated. Collectively, this study reports a novel and highly specific enzyme-activatable fluorogenic substrate for hPL that could serve as a powerful tool for monitoring hPL activity in complex biological systems and showcases the potential to explore physiological functions and rapid screening of inhibitors.

Claudin 5 is one of the major proteins of tight junctions and is responsible for cerebrovascular integrity and BBB function. Muscone and (+)-borneol is the major ingredient of moschus and borneolum, respectively, with antioxidative and anti-inflammatory activities. This study investigated whether muscone and (+)-borneol combination protected claudin 5 by targeting ROS-mediated IL-1β accumulation. Muscone and (+)-borneol reduced cerebral infarct volume and cerebrovascular leakage with claudin 5 protection in mice after stroke, largely due to inhibiting ROS accumulation and inflammatory infiltrate of microglia. Muscone reduced ROS and then blocked the CaN/Erk1/2 pathway to decrease IL-1β release, while (+)-borneol removed mitochondrial ROS and attenuated the SDH/Hif-1α pathway to inhibit IL-1β transcription, thereby jointly reducing IL-1β production. Accumulated IL-1β disrupted cAMP/CREB activation and attenuated transcriptional regulation of claudin 5. Muscone and (+)-borneol combination cooperatively protected BBB function by blocking IL-1β-mediated cAMP/CREB/claudin 5 cascades. Mutation of Ser133 site of CREB or knockdown of claudin 5 weakened the effects of muscone and (+)-borneol on upregulation of TEER value and downregulation of FITC-dextran permeability, suggesting that targeting CREB/claudin 5 was an important strategy to protect vascular integrity. This study provided ideas for the studies of synergistic protection against ischemic brain injury about the active ingredients of traditional Chinese medicines (TCMs).

Septic cardiomyopathy is characterized by impaired contractive function with mitochondrial dysregulation. Songorine is a typical active C20-diterpene alkaloid from the lateral root of Aconitum carmichaelii, which has been used for the treatment of heart failure. This study investigated the protective role of songorine in septic heart injury from the aspect of mitochondrial biogenesis. Songorine (10, 50 mg/kg) protected cardiac contractive function against endotoxin insult in mice with Nrf2 induction. In cardiomyocytes, lipopolysaccharide (LPS) evoked mitochondrial reactive oxygen species (ROS) production and redistributed STIM1 to interact with Orai1 for the formation of calcium release-activated calcium (CRAC) channels, mediating calcium influx, which were prevented by songorine, likely due to ROS suppression. Songorine activated Nrf2 by promoting Keap1 degradation, having a contribution to enhancing antioxidant defenses. When LPS shifted metabolism away from mitochondrial oxidative phosphorylation (OXPHOS) in cardiomyocytes, songorine upregulated mitochondrial genes involved in fatty acid β-oxidation, tricarboxylic acid (TCA) cycle and electron transport chain in a manner dependent on Nrf2, resultantly protecting the capability of OXPHOS. Songorine increased luciferase report gene activities of nuclear respiratory factor-1 (Nrf1) and mitochondrial transcription factor A (Tfam) dependently on Nrf2, indicative of the regulation of Nrf2/ARE and NRF1 signaling cascades. Songorine promoted PGC-1α binding to Nrf2, and the cooperation was required for songorine to activate Nrf2/ARE and NRF1 for the control of mitochondrial quality and quantity. In support, the beneficial effects of songorine on cardioprotection and mitochondrial biogenesis were diminished by cardiac Nrf2 deficiency in mice subjected to LPS challenge. Taken together, these results showed that Nrf2 transcriptionally promoted mitochondrial biogenesis in cooperation with PGC-1α. Songorine activated Nrf2/ARE and NRF1 signaling cascades to rescue cardiomyocytes from endotoxin insult, suggesting that protection of mitochondrial biogenesis was a way for pharmacological intervention to prevent septic heart injury.

Zonula occludens-1 (ZO-1) is a tight junction protein in the cerebrovascular endothelium, responsible for blood–brain barrier function. Hydroxysafflor yellow A (HSYA) is a major ingredient of safflower (Carthamus tinctorius L.) with antioxidative activity. This study investigated whether HSYA protected ZO-1 by targeting ROS-generating NADPH oxidases (NOXs). HSYA administration reduced cerebral vascular leakage with ZO-1 protection in mice after photothrombotic stroke, largely due to suppression of ROS-associated inflammation. In LPS-stimulated brain microvascular endothelial cells, HSYA increased the ratio of NAD+/NADH to restore Sirt1 induction, which bound to Von Hippel–Lindau to promote HIF-1αdegradation. NOX2 was the predominant isoform of NOXs in endothelial cells and HIF-1α transcriptionally upregulated p47phox and Nox2 subunits for the assembly of the NOX2 complex, but the signaling cascades were blocked by HSYA via HIF-1α inactivation. When oxidate stress impaired ZO-1 protein, HSYA attenuated carbonyl modification and prevented ZO-1 protein from 20S proteasomal degradation, eventually protecting endothelial integrity. In microvascular ZO-1 deficient mice, we further confirmed that HSYA protected cerebrovascular integrity and attenuated ischemic injury in a manner that was dependent on ZO-1 protection. HSYA blocked HIF-1α/NOX2 signaling cascades to protect ZO-1 stability, suggestive of a potential therapeutic strategy against ischemic brain injury.

Background: Formaldehyde can induce misfolding and aggregation of Tau protein and β amyloid protein, which are characteristic pathological features of Alzheimer's disease (AD). An increase in endogenous formaldehyde concentration in the brain is closely related to dementia in aging people. Therefore, the discovery of effective drugs to counteract the adverse impact of formaldehyde on neuronal cells is beneficial for the development of appropriate treatments for age-associated cognitive decline. Methods: In this study, we assessed the neuroprotective properties of TongLuoJiuNao (TLJN), a traditional Chinese medicine preparation, against formaldehyde stress in human neuroblastoma cells (SH-SY5Y cell line). The effect of TLJN and its main ingredients (geniposide and ginsenoside Rg1) on cell viability, apoptosis, intracellular antioxidant activity and the expression of apoptotic-related genes in the presence of formaldehyde were monitored. Results: Cell counting studies showed that in the presence of TLJN, the viability of formaldehyde-treated SH-SY5Y cells significantly recovered. Laser scanning confocal microscopy revealed that the morphology of formaldehyde-injured cells was rescued by TLJN and geniposide, an effective ingredient of TLJN. Moreover, the inhibitory effect of geniposide on formaldehyde-induced apoptosis was dose-dependent. The activity of intracellular antioxidants (superoxide dismutase and glutathione peroxidase) increased, as did mRNA and protein levels of the antiapoptotic gene Bcl-2 after the addition of geniposide. In contrast, the expression of the apoptotic-related gene--P53, apoptotic executer--caspase 3 and apoptotic initiator--caspase 9 were downregulated after geniposide treatment. Conclusions: Our results indicate that geniposide can protect SH-SY5Y cells against formaldehyde stress through modulating the expression of Bcl-2, P53, caspase 3 and caspase 9, and by increasing the activity of intracellular superoxide dismutase and glutathione peroxidase. [ABSTRACT FROM AUTHOR]