Group II muscarinic acetylcholine receptors attenuate hepatic injury via Nrf2/ARE pathway.

Parasympathetic nervous system dysfunction is common in patients with liver disease. We have previously shown that muscarinic acetylcholine receptors (mAchRs) play an important role in the regulation of hepatic fibrosis and that the receptor agonists and antagonists affect hepatocyte proliferation. However, little is known about the impact of the different mAchR subtypes and associated signaling pathways on liver injury. Here, we treated the human liver cell line HL7702 with 10 mmol/L carbon tetrachloride (CCL4) to induce hepatocyte damage. We found that CCL4 treatment increased the protein levels of group I mAchRs (M1, M3, M5) but reduced the expression of group II mAchRs (M2, M4) and activated the Nrf2/ARE and MAPK signaling pathways. Although overexpression of M1, M3, or M5 led to hepatocyte damage with an intact Nrf2/ARE pathway, overexpression of M2 or M4 increased, and siRNA-mediated knockdown of either M2 or M4 decreased the protein levels of Nrf2 and its downstream target genes. Moreover, CCL4 treatment increased serum ALT levels more significantly, but only induced slight changes in the expression of mAchRs, NQO1 and HO1, while reducing the expression of M2 and M4 in liver tissues of Nrf2-/- mice compared to wild type mice. Our findings suggest that group II mAchRs, M2 and M4, activate the Nrf2/ARE signaling pathway, which regulates the expression of M2 and M4, to protect the liver from CCL4-induced injury.

Enhancing immobilized Chlorella vulgaris growth with novel buoyant barium alginate bubble beads.

Microalgae immobilization in alginate beads shows promise for biomass production and water pollution control. However, carrier instability and mass transfer limitations are challenges. This study introduces buoyant barium alginate bubble beads (BABB), which offer exceptional stability and enhance Chlorella vulgaris growth. In just 12 days, compared to traditional calcium alginate beads, BABB achieved a 20 % biomass increase while minimizing cell leakage and simplifying harvesting. BABB optimization involved co-immobilization with BG-11 medium, enrichment of CO2 in internal bubbles, and the integration of Fe nanoparticles (FeNPs). In the open raceway pond reactor, these optimizations resulted in a 39 % increase in biomass over 7 days compared to the unoptimized setup in closed flasks. Furthermore, enhancements in pigment and organic matter production were observed, along with improved removal of ammonia nitrogen and phosphate. These results highlight the overall advantages of BABB for microalgae immobilization, offering a scientific foundation for their effective utilization.

Allyl-isothiocyanate against colorectal cancer via the mutual dependent regulation of p21 and Nrf2.

Allyl-isothiocyanate (AITC) is a common Isothiocyanates (ITC) and its chemo-preventive and anti-tumor effects are believed to be related to the activation of NF-E2 p45-related Factor 2 (Nrf2). However, its anti-tumor effects on colorectal cancer (CRC) are not well elucidated. Here, we investigated the therapeutic in vitro and/or in vivo effects and mechanisms of action (MOA) for AITC on CRC cell line HCT116 (human) and MC38 (mouse). AITC treatment in a low concentration range (1 mg/kg in vivo) significantly inhibited the tumor cell growth and increased the expression of p21 and Nrf2. The AITC-mediated induction of p21 was dependent on Nrf2 but independent on p53 in vitro and in vivo at low dose. In contrast, the high dose of AITC (5 mg/kg in vivo) failed to increase substantial levels of p21/MdmX, and impaired the total antioxidant capacity of tumors and subsequent anti-tumor effect in vivo. These results suggest that an optimal dose of AITC is important and required for the proper Nrf2 activation and its anti-CRC effects and thus, providing insights into the potential applications of AITC for the prevention and treatment of CRC.

Muscarinic receptor mediated signaling pathways in hepatocytes from CCL4 - induced liver fibrotic rat.

The pathological changes of parasympathetic nerves are considered as an independent prognostic factor of the survival rate for patients with chronic liver disease. The non-selective muscarinic acetylcholine receptors (mAchR) agonists and antagonists can affect the proliferation of hepatocytes, but little is known about the role of mAChR in hepatocytes and hepatic fibrosis and the signaling pathway of this receptor in regulation of hepatocytes remains elusive. Here, 3ml/kg 40% carbon tetrachloride (CCL4) was given to induce hepatic fibrosis in rats and the hepatocytes were isolated to investigate the expression of mAchR and the cell signaling pathways which were involved in. Compared with the normal state, the expression levels of m1, 3, 5 in fibrotic hepatocytes (FHC) and the cells treated with 10µM pilocarpine (Pi) were obviously increased, while decreased in m2,4. Pi could increase the value of alanine aminotransferase (ALT), hydroxyproline (Hyp), decrease albumin (ALB) and cell viability, while atropine could ameliorate fibrotic hepatocytes fuction. The p-AKT, p-ERK, p- JNK and p-P38 increased in Pi group or FHC group, but the inhibitors of PI3K, MAPK and PKC could reverse the Pi action and improve the FHC fuction. In this study we found that mAchR played an important role in the regulation of hepatic fibrosis process and the PKC, ERK, P38 and PI3K/AKT signaling pathways involved in the parasympathetic excitation mediated by mAchR.