Cholesterol gallstone disease is a worldwide common disease. Cholesterol supersaturation in gallbladder bile is the prerequisite for its pathogenesis, while the mechanism is not completely understood. In this study, we find enrichment of gut microbiota (especially Desulfovibrionales) in patients with gallstone disease. Fecal transplantation of gut microbiota from gallstone patients to gallstone-resistant strain of mice can induce gallstone formation. Carrying Desulfovibrionales is associated with enhanced cecal secondary bile acids production and increase of bile acid hydrophobicity facilitating intestinal cholesterol absorption. Meanwhile, the metabolic product of Desulfovibrionales, H₂S increase and is shown to induce hepatic FXR and inhibit CYP7A1 expression. Mice carrying Desulfovibrionales present induction of hepatic expression of cholesterol transporters Abcg5/g8 to promote biliary secretion of cholesterol as well. Our study demonstrates the role of gut microbiota, Desulfovibrionales, as an environmental regulator contributing to gallstone formation through its influence on bile acid and cholesterol metabolism.

Evidence suggests that fasting exerts extensive antitumor effects in various cancers, including colorectal cancer (CRC). However, the mechanism behind this response is unclear. We investigate the effect of fasting on glucose metabolism and malignancy in CRC. We find that fasting upregulates the expression of a cholesterogenic gene, Farnesyl-Diphosphate Farnesyltransferase 1 (FDFT1), during the inhibition of CRC cell aerobic glycolysis and proliferation. In addition, the downregulation of FDFT1 is correlated with malignant progression and poor prognosis in CRC. Moreover, FDFT1 acts as a critical tumor suppressor in CRC. Mechanistically, FDFT1 performs its tumor-inhibitory function by negatively regulating AKT/mTOR/HIF1α signaling. Furthermore, mTOR inhibitor can synergize with fasting in inhibiting the proliferation of CRC. These results indicate that FDFT1 is a key downstream target of the fasting response and may be involved in CRC cell glucose metabolism. Our results suggest therapeutic implications in CRC and potential crosstalk between a cholesterogenic gene and glycolysis.

Background/Aims: Micro-RNA (miR)-146b-5p is overexpressed in papillary thyroid carcinoma (PTC) and associated with extrathyroidal invasion and advanced tumor stage. In the present study, we showed that miR-146b-5p is upregulated in PTC with lymph node metastasis. Methods: A computational search and luciferase assay identified zinc RING finger 3 (ZNRF3), a negative regulator of Wnt/β-catenin signaling, as a direct target of miR-146b-5p in PTC. Results: MiR-146b-5p promoted migration and invasiveness and induced epithelial-mesenchymal transition (EMT) of PTC cells, whereas ZNRF3 overexpression reversed this effect. MiR-146b-5p increased the cell surface levels of the Wnt receptors Frizzled-6 and LRP6 and enhanced Wnt/β-catenin signaling by downregulating ZNRF3, whereas an inhibitor of Wnt/β-catenin suppressed the effect of miR-146b-5p on migration, invasiveness and EMT of PTC cells. Conclusion: These results indicate that miR-146b-5p induces EMT and may promote PTC metastasis through the regulation of Wnt/β-catenin signaling, and suggest novel potential therapeutic targets for the treatment of PTC.

The long noncoding RNA H19 is overexpressed in many cancers and acts as an oncogene. Here, we investigated the role of H19 in thyroid carcinogenesis and its relation to microRNA miR‐17‐5p and its target gene YES1. H19 expression was higher in tumor samples and in thyroid cancer cell lines than nontumor tissues and normal thyroid cells. H19 knockdown and ectopic expression in the TPC‐1 and NIM thyroid cancer cell lines showed that overexpression of H19 promoted proliferation, migration, and invasion, whereas H19 knockdown reduced cell viability and invasion and induced growth arrest in vitro and in vivo. H19 was identified as a target of miR‐17‐5p, by Dual‐Luciferase Reporter assays and RNA‐binding protein immunoprecipitation assays. H19 antagonized the function of miR‐17‐5p on upregulation of its target YES1 and inhibited miR‐17‐5p‐induced cell cycle progression. Our results suggest that H19 functions as a competitive endogenous RNA (ceRNA) by acting as a sink for miR‐17‐5p, revealing a potential ceRNA regulatory network involving H19 and miR‐17‐5p with a role in the modulation of YES1 expression. This mechanism may contribute to a better understanding of thyroid cancer pathogenesis and provide new insights into the treatment of this disease.

Macroautophagy/autophagy, an evolutionarily conserved process, plays an important role in the regulation of immune inflammation and nervous system homeostasis. However, the exact role and mechanism of autophagy in pain is still unclear. Here, we showed that impaired autophagy flux mainly occurred in astrocytes during the maintenance of neuropathic pain. No matter the stage of neuropathic pain induction or maintenance, activation of autophagy relieved the level of pain, whereas inhibition of autophagy aggravated pain. Moreover, the levels of neuroinflammation and reactive oxygen species (ROS) were increased or decreased following autophagy inhibition or activation. Further study showed that inhibition of autophagy slowed the induction, but increased the maintenance of neuroinflammatory responses, which could be achieved by promoting the binding of TRAF6 (TNF receptor-associated factor 6) to K63 ubiquitinated protein, and increasing the levels of p-MAPK8/JNK (mitogen-activated protein kinase 8) and nuclear factor of kappa light polypeptide gene enhancer in B cells (NFKB/NF-κB). Impaired autophagy also reduced the protective effect of astrocytes on neurons against ROS stress because of the decrease in the level of glutathione released by astrocytes, which could be improved by activating the NFE2L2/NRF2 (nuclear factor, erythroid derived 2, like 2) pathway. We also demonstrated that simultaneous activation of autophagy and the NFE2L2 pathway further relieved pain, compared to activating autophagy alone. Our study provides an underlying mechanism by which autophagy participates in the regulation of neuropathic pain, and a combination of autophagy and NFE2L2 activation may be a new treatment approach for neuropathic pain. Abbreviation: 3-MA: 3-methyladenine; 8-OHdG: 8-hydroxydeoxy-guanosine; ACTB: actin, beta; AMPAR: alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor; ATG: autophagy-related; CAMK2/CaMKII: calcium/calmodulin-dependent protein kinase II; CCL7: chemokine (C-C motif) ligand 7; CGAS: cyclic GMP-AMP synthase; CQ: chloroquine; GABA: gamma-aminobutyrate; GCLC: glutamate-cysteine ligase, catalytic subunit; GFAP: glial fibrillary acidic protein; GSH: glutathione; HMOX1/HO-1: heme oxygenase 1; KEAP1: kelch-like ECH-associated protein 1; MAP1LC3/LC3-II: microtubule-associated protein 1 light chain 3 beta (phosphatidylethanolamine-conjugated form); MAPK: mitogen-activated protein kinase; MAPK1/ERK: mitogen-activated protein kinase 1; MMP2: matrix metallopeptidase 2; MAPK8/JNK: mitogen-activated protein kinase 8; MAPK14/p38: mitogen-activated protein kinase 14; NFE2L2/NRF2: nuclear factor, erythroid derived 2, like 2; NFKB/NF-κB: nuclear factor of kappa light polypeptide gene enhancer in B cells; ROS: reactive oxygen species; SLC12A5: solute carrier family 12, member 5; SNL: spinal nerve ligation; TLR4: toll-like receptor 4; TRAF6: TNF receptor-associated factor; TRP: transient receptor potential.