Hyperpolarization-activated cyclic nucleotide-gated cation channel 3 promotes HCC development in a female-biased manner

Hepatic immune environment differences among common mouse strains in models of MASH and liver cancer

Background & Aims

Inbred mouse strains are critical tools for studying immune regulation of metabolic dysfunction-associated steatohepatitis (MASH) and hepatocellular carcinoma (HCC). Here, we profiled mouse strain-associated hepatic immune differences, and performed mice-human cross-species immune comparisons.

Methods

Immune landscapes of C57BL/6, BALB/c, and FVB/N mice were compared under healthy, MASH, or HCC state using high-dimensional spectral flow cytometry (n = 4 per condition). MASH was induced by feeding methionine- and choline-deficient or Western diet + carbon tetrachloride. HCC was caused by hydrodynamic plasmid injection of MYC/sg-p53. Public mouse and human scRNA-seq datasets were used for validation and cross-species comparisons.

Results

In healthy mice, liver CD4+ T (24% vs. 14% vs. 34%, p <0.05) and B cells (36.5% vs. 35% vs.18%, p <0.05) varied the most among three strains. C57BL/6 mice showed TH1 dominance, whereas BALB/c and FVB/N mice had TH2 dominance (log[TH1:TH2] = 0.17, -0.31, -0.17). In MASH mice, expansion of liver myeloid cells and innate lymphocytes were commonly found, but changes of B cells (log(fold-change) = -0.38, -0.28, -0.58, p <0.05) and T subsets (e.g. CD4+ T log(fold-change) = -0.21, -0.07, -0.15, p <0.05) varied greatly among strains. MYC/sg-p53 HCC induced a consistent expansion of liver Tregs and CD8+ T cells (p <0.05), but differential shifts of liver immune landscape were seen among strains. The flow cytometry data was supported by public scRNA-seq datasets matching C57BL/6 background. Further cross-species comparison in MASH condition confirmed shared changes of adaptive lymphocytes between mice and humans. In two MASH models, BALB/c or C57BL/6 mice were more consistent to recapture loss of CD4+ T or B cells, respectively (p <0.05).

Conclusions

Substantial liver immune differences exist among common mouse strains. Mice can recapitulate certain human liver immune changes with strain variations.

Impact and implications

Our immune cell profiling study revealed that the liver immune environment can be quite different among common mouse strains both under healthy and pathologic states, such as steatohepatitis or neoplastic processes. Our results serve as a data resource for studies investigating liver immunology and provide valuable insights for the design of studies on various immune cells in the livers of mice.

Transcriptomic landscape of Hras12V oncogene-induced hepatocarcinogenesis with gender disparity

The genesis of hepatocellular carcinoma (HCC) is closely related to male factors and hyper-activated Ras signals. A transcriptomic database was established via RNA-Seq of HCC (T) and the adjacent precancerous liver tissue (P) of Hras12V transgenic mice (Ras-Tg, HCC model) and the normal liver tissue of wild-type mice (W) of both sexes. Comparative analysis within W, P, and T and correlation expression pattern analysis revealed common/unique cluster-enriched items towards HCC between the sexes. Specifically, the numbers of differentially expressed genes (DEGs) were much higher in females than in males, and tumor suppressor genes, such as p21Waf1/Cip1 and C6, were significantly higher in the female P. This finding denotes the higher sensitivity of female hepatocytes to the Ras oncogene and, therefore, the difficulty in developing HCC. Moreover, convergence in HCC between the sexes suggests the underlying mechanisms for the ineffectiveness of sex hormone therapies. Additionally, expression pattern analysis revealed that the DEGs and their relevant pathways were either positively or negatively associated with the HCC/Ras oncogene. Among them, the vital role of glutathione metabolism in HCC was established. This work provides a basis for future research on elucidating the underlying mechanisms, selecting the diagnostic biomarker, and planning the clinical therapy in HCC.

Gut Microbiome and Hepatic Transcriptomic Determinants of HCC Development in Mice with Metabolic Dysfunction-Associated Steatohepatitis

Purpose

Hepatocellular carcinoma (HCC) related to metabolic dysfunction-associated steatotic liver disease (MASLD) is often diagnosed at a late stage, and its incidence is increasing. Predictive biomarkers are therefore needed to identify individuals at high risk of HCC. We aimed to characterize the gut microbiome and hepatic transcriptome associated with HCC development in female mice with hepatocyte-deletion of Pten (HepPten -). These mice present with large variations in HCC development, making them a powerful model for biomarker discovery.

Methods & Results

Sequencing of stool 16S and hepatic RNA was performed on a first set of mice. Among all liver histology parameters measured, the strongest association with microbiome composition changes was with the number of tumors detected at necropsy, followed by inflammation. The gut microbiome of mice with more than 2 tumors was enriched with Lachnospiraceae UCG and depleted of Palleniella intestinalis and Odoribacter. In contrast, hepatic transcriptomic changes were most strongly associated with tumor burden, followed by liver fibrosis. The 840 differentially expressed genes correlating with tumor burden were enriched in leukocyte extravasation and interleukin 10 receptor A (IL10RA) pathways. In addition, the abundance of Spp1-high epithelial cells is correlated with tumor burden. Association between tumor number and depletion of Palleniella intestinalis, and between tumor burden and circulating levels of C-X-C motif chemokine ligand 13 (CXCL13) and stem cell factor (SCF), was further validated in an independent set of mice.

Conclusion

We identified microbiome components contributing to liver carcinogenesis by inducing inflammation, and changes in hepatic gene expression and hepatic cells distribution that contribute to tumor growth. Such information can be highly valuable for the development of new prevention strategies as well as of new biomarkers for risk modeling in HCC.

Biochemical pharmacology of adenylyl cyclases in cancer

Globally, despite extensive research and pharmacological advancement, cancer remains one of the most common causes of mortality. Understanding the signaling pathways involved in cancer progression is essential for the discovery of new drug targets. The adenylyl cyclase (AC) superfamily comprises glycoproteins that regulate intracellular signaling and convert ATP into cyclic AMP, an important second messenger. The present review highlights the involvement of ACs in cancer progression and suppression, broken down for each specific mammalian AC isoform. The precise mechanisms by which ACs contribute to cancer cell proliferation and invasion are not well understood and are variable among cancer types; however, AC overactivation, along with that of downstream regulators, presents a potential target for novel anticancer therapies. The expression patterns of ACs in numerous cancers are discussed. In addition, we highlight inhibitors of AC-related signaling that are currently under investigation, with a focus on possible anti-cancer strategies. Recent discoveries with small molecules regarding more direct modulation AC activity are also discussed in detail. A more comprehensive understanding of different components in AC-related signaling could potentially lead to the development of novel therapeutic strategies for personalized oncology and might enhance the efficacy of chemoimmunotherapy in the treatment of various cancers.

Investigating TIP30-Mediated regulation of mTORC1 signaling as a therapeutic strategy for coxsackievirus B3-Induced viral myocarditis

This study aims to elucidate the role of TIP30 (30 KDa HIV-1 TAT-Interacting Protein) in the progression of coxsackievirus B3 (CVB3)-induced viral myocarditis. TIP30 knockout and wildtype mice were intraperitoneally infected with CVB3 and evaluated at day 7 post-infection. HeLa cells were transfected with TIP30 lentiviral particles and subsequently infected with CVB3 to evaluate viral replication, cellular pathogenesis, and mechanistic target of rapamycin complex 1 (mTORC1) signaling. Deletion of the TIP30 gene heightened heart virus titers and mortality rates in mice with CVB3-induced myocarditis, exacerbating cardiac damage and fibrosis, and elevating pro-inflammatory factors level. In vitro experiments demonstrated the modulation of mTORC1 signaling by TIP30 during CVB3 infection in HeLa cells. TIP30 overexpression mitigated CVB3-induced cellular pathogenesis and VP1 expression, with rapamycin, an mTOR1 inhibitor, reversing these effects. These findings suggest TIP30 plays a critical protective role against CVB3-induced myocarditis by regulating mTORC1 signaling.