Hepatic regulator of G protein signaling 14 ameliorates NAFLD through activating cAMP-AMPK signaling by targeting Giα1/3

RGS14 promotes the progression of hepatocellular carcinoma by activating the cAMP/PKA/CREB signaling pathway

BACKGROUND

G protein-coupled receptors (GPCRs) mediate the intracellular signals that drive tumor development. Regulator of G protein signaling 14 (RGS14), a key negative regulator of GPCR signaling, influences liver injury, fat metabolism, and inflammation. However, the role of RGS14 in hepatocellular carcinoma (HCC) progression and its underlying mechanisms remain unclear.

METHODS

In this study, we compared three pairs of HCC tissues and matched portal vein tumor thrombus (PVTT) samples using 4D-FastDIA proteomics to identify differentially expressed proteins. The clinical significance of RGS14 expression was further evaluated in HCC patient cohorts. Stable RGS14-overexpressing/knockdown cell models were established for functional assays (CCK-8, colony formation, Transwell, and wound healing assays). Additionally, tumor proliferation was evaluated through in vivo studies using a subcutaneous xenograft mouse model. RNA sequencing and western blot analysis were subsequently applied to validate the potential downstream signaling pathways.

RESULTS

The results revealed that RGS14 was overexpressed in HCC tissues, which was correlated with adverse clinical outcomes. We also confirmed that RGS14 increased the proliferation, colony formation, migration, and invasion and promoted the epithelial‒mesenchymal transition (EMT) of HCC cells both in vitro and in vivo. Mechanistically, RGS14 elevated intracellular cAMP levels, activating the PKA/CREB axis to drive HCC progression.

CONCLUSION

Our findings suggest that RGS14 plays a critical oncogenic role in HCC by regulating cAMP/PKA/CREB pathway activation, underscoring its potential as both a prognostic marker and therapeutic target for HCC patients.

Single-Cell Proteomics Uncovers Dual Traits of Dermal Sheath Cells in Wound Repair

Wound healing is a dynamic process involving multiple cell types and signaling pathways. Dermal sheath cells (DSCs), residing surrounding hair follicles, play a critical role in tissue repair, yet their regulatory mechanisms remain unclear. This study used single-cell proteomics with the AcanCreER;R26LSL-tdTomato-DTR mouse model to explore DSC function across different healing stages. All animal procedures were conducted in accordance with the Animal Research: Reporting of In Vivo Experiments guidelines. Gene set enrichment analysis (GSEA) and temporal clustering (Mfuzz) were employed to reveal dynamic functional shifts. GSEA identified enriched gene sets related to interferon-gamma response, inflammatory response, ultraviolet response, myogenesis, and xenobiotic metabolism. Temporal clustering revealed eight distinct clusters: clusters associated with the early contracting and proliferative phases were linked to metabolic activation and oxidative stress, while clusters from the later remodeling phase emphasized extracellular matrix remodeling and structural reorganization. The dynamic expression of epithelial-mesenchymal transition-related genes and keratins supported DSCs' dual epithelial and mesenchymal traits. Additionally, keratins, collagens, integrins, and actin proteins emerged as promising markers or signature molecules for DSCs. This study reveals DSCs' dual traits during wound repair, providing a basis for therapies to enhance healing.

Polyribonucleotide nucleotidyltransferase 1 participates in metabolic-associated fatty liver disease pathogenesis by affecting lipid metabolism and mitochondrial homeostasis

OBJECTIVE

Metabolic-associated fatty liver disease (MAFLD) represents one of the most prevalent chronic liver conditions worldwide, but its precise pathogenesis remains unclear. This research endeavors to elucidate the involvement and molecular mechanisms of polyribonucleotide nucleotidyltransferase 1 (PNPT1) in the progression of MAFLD.

METHODS

The study employed western blot and qRT-PCR to evaluate PNPT1 levels in liver specimens from individuals diagnosed with MAFLD and in mouse models subjected to a high-fat diet. Cellular studies investigated the effects of PNPT1 on lipid metabolism, apoptosis, and mitochondrial stability in hepatocytes. Immunofluorescence was utilized to track the subcellular movement of PNPT1 under high lipid conditions. RNA immunoprecipitation and functional assays were conducted to identify interactions between PNPT1 and Mcl-1 mRNA. The role of PPARα as an upstream transcriptional regulator of PNPT1 was investigated. Recombinant adenoviral vectors were utilized to modulate PNPT1 expression in vivo.

RESULTS

PNPT1 was found to be markedly reduced in liver tissues from MAFLD patients and HFD mice. In vitro, PNPT1 directly regulated hepatic lipid metabolism, apoptosis, and mitochondrial stability. Under conditions of elevated lipids, PNPT1 relocated from mitochondria to cytoplasm, modifying its physiological functions. RNA immunoprecipitation revealed that the KH and S1 domains of PNPT1 bind to and degrade Mcl-1 mRNA, which in turn affects mitochondrial permeability. The transcriptional regulator PPARα was identified as a significant influencer of PNPT1, impacting both its expression and subsequent cellular functions. Alterations in PNPT1 expression were directly correlated with the progression of MAFLD in mice.

CONCLUSIONS

The study confirms the pivotal function of PNPT1 in the development of MAFLD through its interactions with Mcl-1 and its regulatory effects on lipid metabolism and mitochondrial stability. These insights highlight the intricate association between PNPT1 and MAFLD, shedding light on its molecular pathways and presenting a potential new therapeutic avenue for MAFLD management.

Unveiling the Genetic Mechanism of Meat Color in Pigs through GWAS, Multi-Tissue, and Single-Cell Transcriptome Signatures Exploration

Meat color traits directly influence consumer acceptability and purchasing decisions. Nevertheless, there is a paucity of comprehensive investigation into the genetic mechanisms underlying meat color traits in pigs. Utilizing genome-wide association studies (GWAS) on five meat color traits and the detection of selection signatures in pig breeds exhibiting distinct meat color characteristics, we identified a promising candidate SNP, 6_69103754, exhibiting varying allele frequencies among pigs with different meat color characteristics. This SNP has the potential to affect the redness and chroma index values of pork. Moreover, transcriptome-wide association studies (TWAS) analysis revealed the expression of candidate genes associated with meat color traits in specific tissues. Notably, the largest number of candidate genes were observed from transcripts derived from adipose, liver, lung, spleen tissues, and macrophage cell type, indicating their crucial role in meat color development. Several shared genes associated with redness, yellowness, and chroma indices traits were identified, including RINL in adipose tissue, ENSSSCG00000034844 and ITIH1 in liver tissue, TPX2 and MFAP2 in lung tissue, and ZBTB17, FAM131C, KIFC3, NTPCR, and ENGSSSCG00000045605 in spleen tissue. Furthermore, single-cell enrichment analysis revealed a significant association between the immune system and meat color. This finding underscores the significance of the immune system associated with meat color. Overall, our study provides a comprehensive analysis of the genetic mechanisms underlying meat color traits, offering valuable insights for future breeding efforts aimed at improving meat quality.