Brown adipose tissue (BAT) plays a role in energy expenditure and is involved in nutrient metabolism. C-X-C chemokine ligand 12 (CXCL12)-CXCR4 pathway regulates the immune, nervous, and cardiovascular systems and affects the adipose tissue. Here, we investigated the role of this pathway as an activator of BAT. Uncoupling protein 1 mRNA and protein levels and oxygen consumption increased in the brown adipocytes treated with 100 nM CXCL12 peptide. CXCL12-mediated upregulation in P38 and extracellular signal-regulated kinase (ERK) levels was reduced by each inhibitor. Thus, the CXCL12-CXCR4 pathway activated the brown adipocytes through P38 and ERK that acted downstream of this pathway. Mice with CXCR4 defects only in the brown adipocytes were generated and fed with high-fat diet (HFD). Body weight and blood glucose after glucose injection increased in these mice. Long-term exposure to HFD deteriorated blood glucose level after glucose injection. Insulin sensitivity was exacerbated in the knockout mice fed with HFD. Serum lipid parameters and CXCL12 level in knockout mice were similar to those in control mice. These results suggest that the CXCL12-CXCR4 pathway induces brown adipocyte activity and affects nutrient metabolism under HFD load.

Cuproptosis-related genes (CRGs) are associated with lung adenocarcinoma. However, the links between CRGs and non-small-cell lung cancer (NSCLC) are not clear. In this study, we aimed to develop two cuproptosis models and investigate their correlation with NSCLC in terms of clinical features and tumor microenvironment.

Mitochondria are essential for energy production and although they have their own genome, many nuclear-encoded mitochondrial ribosomal proteins (MRPs) are required for proper function of the organelle. Although mutations in MRPs have been associated with human diseases, little is known about their role during development. Presented here are the null phenotypes for 21 nuclear-encoded mitochondrial proteins and in-depth characterization of mouse embryos mutant for the Mrp genes Mrpl3, Mrpl22, Mrpl44, Mrps18c and Mrps22 Loss of each MRP results in successful implantation and egg-cylinder formation, followed by severe developmental delay and failure to initiate gastrulation by embryonic day 7.5. The robust and similar single knockout phenotypes are somewhat surprising given there are over 70 MRPs and suggest little functional redundancy. Metabolic analysis reveals that Mrp knockout embryos produce significantly less ATP than controls, indicating compromised mitochondrial function. Histological and immunofluorescence analyses indicate abnormal organelle morphology and stalling at the G2/M checkpoint in Mrp null cells. The nearly identical pre-gastrulation phenotype observed for many different nuclear-encoded mitochondrial protein knockouts hints that distinct energy systems are crucial at specific time points during mammalian development.

Human endothelial cells (ECs) are widely used to study mechanisms of angiogenesis, inflammation, and endothelial permeability. Targeted gene disruption induced by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-Associated Protein 9 (Cas9) nuclease gene editing is potentially an important tool for definitively establishing the functional roles of individual genes in ECs. We showed that co-delivery of adenovirus encoding EGFP-tagged Cas9 and lentivirus encoding a single guide RNA (sgRNA) in primary human lung microvascular ECs (HLMVECs) disrupted the expression of the Tie2 gene and protein. Tie2 disruption increased basal endothelial permeability and prevented permeability recovery following injury induced by the inflammatory stimulus thrombin. Thus, gene deletion via viral co-delivery of CRISPR-Cas9 in primary human ECs provides a novel platform to investigate signaling mechanisms of normal and perturbed EC function without the need for clonal expansion.