Ulcerative colitis (UC) is primarily characterized by inflammation-induced tissue damage, but impaired tissue repair also drives disease progression. This study demonstrates group 2 innate lymphoid cells (ILC2s), key players in tissue repair, are dysfunctional in UC and experimental colitis due to disrupted endoplasmic reticulum protein processing. We show that the pro-repair function of gut ILC2s depends on the IRE1α-Xbp1 branch of unfolded protein response (UPR), supported by IL-25 and suppressed by interferon-γ (IFN-γ). During colitis, loss of IL-25 and rise of IFN-γ hinder Xbp1 mRNA splicing, weakening ILC2s' ability to mediate tissue repair. Mechanistically, spliced Xbp1 drives folate-dependent one-carbon (1C) metabolism by promoting dihydrofolate reductase expression. Translationally, the 1C metabolite adenosine 5'-monophosphate alleviated colitis in both ILC2-specific Xbp1 knockout and wild-type mice. Our findings highlight the UPR's role in sensing gut environment to regulate ILC2 function and suggest folate-mediated 1C metabolism as a potential target for UC therapy.

Patients with sepsis-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) commonly suffer from severe pulmonary thrombosis, but clinical trials of anticoagulant therapies in patients with sepsis and ARDS have failed. Patients with ARDS plus thrombocytopenia also exhibit increased mortality, and widespread pulmonary thrombosis is often seen in patients with COVID-19 ARDS. Different amounts of microbeads were administered intravenously to adult mice to induce various levels of pulmonary thrombosis. ALI was induced by either intraperitoneal lipopolysaccharide or cecal ligation and puncture. Endothelial cell (EC)-targeted nanoparticles were used to deliver plasmid DNA expressing the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) system for EC-specific gene knockout of Alox15 (arachidonate 15-lipoxygenase) or plasmid DNA expressing Alox15 for EC-specific overexpression. Lipidomic profiling and in vivo rescue studies with the identified Alox15-regulated lipids were performed. In addition, thrombocytopenia was induced by genetic depletion of platelets using DTRPf4Cre mice, and the effects of restoration of pulmonary thrombosis were assessed. We show that although severe pulmonary thrombosis or thrombocytopenia augments sepsis-induced ALI, the induction of mild pulmonary thrombosis conversely reduces EC apoptosis, ALI, and mortality via sustained expression of endothelial Alox15. Endothelial Alox15 knockout in adult mice abolished the protective impact of mild lung thrombosis. Conversely, overexpression of endothelial Alox15 inhibited the increases in ALI caused by severe pulmonary thrombosis. Treatment of the endothelial Alox15 knockout mice with 1-palmitoyl-2-oleoyl-3-arachidonoyl-rac-glycerol (C57H100O6), a top candidate of the 32 Alox15-regulated lipids identified by lipidomic profiling, markedly reversed the defective phenotype, suggesting that Alox15 protects from lung injury via protective lipids. The clinical relevance of the findings was supported by the observation of reduced ALOX15-expressing ECs in lung autopsy samples of patients with ARDS. In addition, restoration of pulmonary thrombosis in thrombocytopenic mice normalized endotoxemia-induced ALI. We have demonstrated that moderate levels of lung thrombosis protect against sepsis-induced inflammatory lung injury via endothelial Alox15. Overexpression of endothelial Alox15 inhibits severe pulmonary thrombosis-induced increases in ALI. Thus, upregulation of ALOX15 expression or treatment with ALOX15-dependent protective lipid(s) represents a promising therapeutic strategy for treatment of ARDS, especially in subpopulations of patients with thrombocytopenia or widespread pulmonary thrombosis.

Cardiac hypertrophy is one of the major causes of heart failure and sudden cardiac death. OTUD7a (OTU domain-containing protein 7a) is identified as a deubiquitinizing enzyme and a possible tumor suppressor. The present study is aimed at exploring the potential role and key downstream effectors of OTUD7a in cardiac hypertrophy. The expression level of OTUD7a was detected in the cardiomyocytes with phenylephrine stimuli and the hearts subjected to transverse aortic constriction surgery. Then, the potential effects of OTUD7a on cardiac hypertrophy were evaluated in vivo by using cardiac-specific OTUD7a knockout mice and adeno-associated virus serotype 9-OTUD7a-infected mice. To further explore the direct modulation of OTUD7a on cardiomyocytes, hypertrophic parameters were detected in phenylephrine-stimulated cardiomyocytes with adenovirus system-induced OTUD7a overexpression or depletion. Furthermore, RNA-sequencing and interactome analysis, which were followed by multiple molecular biological methodologies, were combined to identify the direct target and corresponding molecular events contributing to OTUD7a function. Cardiac hypertrophy stimulates expression of OTUD7a in vitro and in vivo. Our data clearly showed that OTUD7a deficiency alleviates pathological cardiac hypertrophy in the transverse aortic constriction mouse model as well as in phenylephrine-treated cardiomyocytes, whereas overexpression of OTUD7a aggravated hypertrophic heart in vivo and enhanced cardiomyocyte enlargement in vitro. Mechanistically, TAK1 (transforming growth factor-β-activated kinase 1) was identified as a direct and essential target of OTUD7a in cardiac hypertrophy. To be more specific, OTUD7a directly interacts with TAK1 to inhibit the ubiquitination degradation of TAK1 and subsequently increase the phosphorylation levels of TAK1 and its downstream JNK (c-Jun N-terminal kinase)/P38. 5Z-7-oxozeaenol, a TAK1 inhibitor, blocked the detrimental effects of OTUD7a. Moreover, overexpression of TAK1 abolished the protection of OTUD7a depletion. Our findings, for the first time, provide evidence supporting OTUD7a as a novel promoter of pathological cardiac hypertrophy and indicate that targeting the OTUD7a-TAK1 axis represents a promising therapeutic strategy for cardiac hypertrophy and related heart failure.

Sulf1 is an extracellular sulfatase that regulates cell signaling by removing 6-O-sulfates from heparan sulfate. Although the roles of Sulf1 in neural development have been studied extensively, its functions in the adult brain remain largely unknown. Here, we report the effects of Sulf1 disruption on the neuronal properties of the medium spiny neurons (MSNs) in the nucleus accumbens (NAc) shell, one of the regions highly expressing Sulf1. We separately labeled MSNs expressing dopamine D1 receptors (D1-MSNs) or D2 receptors (D2-MSNs) by injecting adult male Drd1-Cre and Drd2-Cre mice with a Cre-dependent AAV vector expressing a red fluorescent protein, mCherry, and examined their electrophysiological properties by means of whole-cell patch–clamp recording. In the D2-MSNs, Sulf1 disruption led to drastic changes in neural firing responses to depolarizing current injections: in the Sulf1 knock-out mice, the rheobase was smaller than in the wild-type mice, but the number of action potentials elicited by depolarization did not increase at larger current injections. In the D1-MSNs, Sulf1 disruption resulted in more depolarized resting membrane potentials and increase in the AMPA/NMDA ratio. These results suggest that Sulf1 is essential for regulation of neuronal excitability and glutamatergic transmission of NAc MSNs in adult mice and implicate the potential roles of Sulf1 in NAc circuit activity, reward-aversion behaviors, and psychiatric disorders such as schizophrenia and drug addiction.

A high-fat diet disrupts neural tracts in apolipoprotein E mouse models.

The mitochondrial protein TMEM177 fine-tunes mammalian cytochrome c oxidase assembly.

Focused ultrasound delivery of enzyme replacement therapy to the brain of Gaa-/- Pompe disease mice.

Epithelial cell-specific Atg5 knockout in mice aggravates DSS-induced colitis and activates nuclear factor-kappaB signaling pathway.

Sex-dependent behavioral responses and phenotypic traits of Pcsk9 knockout mice in anxiety- and depression-like paradigms.

Rationale: Liver regeneration is regulated by both metabolic processes and immune responses. Nonetheless, there is limited comprehension of the mechanisms involved. PINK1/Parkin-mediated mitophagy has been well documented, the role and underlying alternative mechanism of PINK1/Parkin in regulating mitochondrial metabolism during liver regeneration remains unclear.Methods: Liver tissues from mice undergoing hepatectomy were utilized to evaluate the expression levels of PINK1/Parkin. Hepatocyte-specific PINK1 knockout and transgenic mouse models were generated to investigate the impact of PINK1 on regeneration. Mass spectrometry, co-immunoprecipitation, and ubiquitination assays were performed to explore the underlying molecular mechanisms.Results: We observed PINK1/Parkin expression was markedly upregulated in hepatic tissue following liver resection. PINK1 depletion in hepatocytes caused impaired liver regeneration. Moreover, mitochondrial calcium overload was found be responsible for restricted TCA by inhibiting succinate dehydrogenase activity in PINK1 deficient hepatocytes. Interestingly, PINK1 deficiency leads to succinate accumulation and release from hepatocytes, which impairs liver regeneration by restricting macrophage pro-repair phenotypes. This effect was further confirmed by enhanced regeneration in myeloid SUCNR1 knockout mice. Mechanistically, Sigma-1 is a molecular chaperone of the endoplasmic reticulum calcium channel IP3R, which helps maintain its normal functional conformation. Parkin was able to bind Sigma-1 through its UBL domain, facilitating its k48-linked ubiquitination, which promotes Sigma-1 degradation and subsequently suppressing calcium transfer from the ER to mitochondria at the mitochondrial-associated ER membrane.Conclusions: Collectively, PINK1/Parkin signaling regulates hepatocellular mitochondrial ATP and succinate production by modulating ER-mitochondria calcium transfer to promote liver regeneration, revealing a promising therapeutic target for liver regeneration.

The protective role of intestinal alkaline phosphatase in inflammatory bowel disease-associated non-alcoholic fatty liver disease.

Brain delivery of a neurotrophic peptide derived from secreted amyloid precursor protein APPsα as a therapeutic strategy for Alzheimer's disease.

Osteocytic FSH inhibition rescues bone mass and boosts fracture healing in ovariectomized mice.

Uncoupling protein 1 (UCP1), a mitochondrial protein traditionally regarded as exclusive to thermogenic adipocytes, and Ucp1-promoter-driven Cre is widely used in gene manipulation in thermogenic adipocytes. However, new evidence suggests that Ucp1-promoter-driven Cre is also active in nonadipocyte types. The presence and role of UCP1 in nonadipose tissues during development, and its potential nonthermogenic functions, remain under debate. This study systematically investigated UCP1 expression patterns from embryogenesis to adulthood using Ucp1GFP/+ (knock-in), Ucp1CreERT2/+ (knock-in), and Ucp1Cre/+ (transgenic) mice crossed with Ai9-tdTomato-Red mice, complemented by single-cell RNA sequencing and immunostaining analyses. Ucp1CreERT2/CreERT2 knockout mice were used to evaluate the developmental consequences of UCP1 deficiency. Significantly, UCP1 expression initiated in nonthermogenic tissues by embryonic day 10.5, before adipose tissue formation, notably in the brain, eye, ear, mammary gland, kidney, and reproductive systems. UCP1 was more broadly expressed in nonadipose tissues during embryonic stages compared to adulthood, particularly in the epithelial cells of these nonadipose tissues. UCP1 knockout mice exhibited retinal developmental defects, suggesting physiological roles for UCP1 beyond thermogenesis in nonadipose tissues. This study highlights that using Ucp1-promoter-driven tamoxifen-inducible Cre can minimize off-target effects in gene manipulation of thermogenic adipocytes compared with the traditional transgenic Cre strategy.NEW & NOTEWORTHY Our findings reveal UCP1 expression begins from E10.5, particularly in the brain, kidney, ear, eye, mammary gland, and reproductive system. During embryonic development, UCP1 expression is more prevalent in nonadipose tissues, compared to adulthood, especially in epithelial cells. Notably, UCP1-knockout mice exhibit developmental defects in retinas, suggesting UCP1 has physiological functions beyond thermogenesis. Our study highlights using Ucp1-promoter-driven tamoxifen-inducible Cre can minimize off-target effects in gene manipulation within thermogenic adipocytes compared to traditional Cre methods.

Contribution of transmembrane channel-like (TMC) proteins 3, 5 and 7 to pain and itch processing.

Rationale: The single nucleotide polymorphism (SNP) rs11830157 within the scaffold protein kinase suppressor of Ras 2 (KSR2) locus is strongly associated with the incidence of coronary artery disease (CAD), yet its functional role remains undefined. This study aimed to investigate the potential impact of rs11830157 polymorphism on atherosclerosis and to elucidate the underlying molecular mechanisms.Methods: Dual-luciferase reporter assays, chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assays (EMSA), and CRISPR/Cas9 gene-editing techniques were used to investigate the regulatory role of the SNP rs11830157. To assess the role of KSR2 in atherosclerosis, we utilized global KSR2 knockout mice fed a high-fat diet ad libitum, pair-fed global KSR2 and Apoe (Apolipoprotein E) double knockout mice, and mice with endothelial-specific KSR2 overexpression mediated by AAV9-ICAM2.Results: Genetic analyses identified SNP rs12822146, in linkage disequilibrium with rs11830157 and located within an endothelial enhancer, as a regulator of KSR2 expression via differential binding of the transcriptional repressor XBP1s. KSR2 expression was significantly reduced in endothelial cells within atherosclerotic plaques in both humans and mice. Using multiple KSR2 gene-edited mouse models, we demonstrated that endothelial KSR2 protects against atherosclerosis by suppressing inflammation and apoptosis. Mechanistic studies revealed that KSR2 competes with CRBN for binding to the K52 site of AMPKα1, inhibiting CRL4ACRBN E3 ubiquitin ligase complex-mediated K48-linked polyubiquitination and proteasomal degradation of AMPKα1. The subsequently activated AMPK signaling pathway maintains glycolytic balance in endothelial cells, ultimately exerting anti-inflammatory and anti-apoptotic effects.Conclusions: Our findings provide the first comprehensive molecular explanation of the rs12822146-KSR2-atherosclerosis axis, with important implications for both primary prevention and secondary treatment of CAD.

Sex-specific aggressive and emotional behavior in myostatin-deficient mice: Ratio of acylated versus unacylated ghrelin is reduced, but not correlated with butyrylcholinesterase activity level, however parvalbumin expression is lost in the habenular complex.

Angiopoietin-like protein 8 mediates inflammation and fibrosis of tubular cells in diabetic kidney disease progression by interacting with Akt2.

SARM1 deficiency promotes depressive-like behavior and neuroinflammation through JNK/STING/TBK1 signaling.

Mode of action analysis for induction of mouse lung tumors by permethrin: Involvement of CYP2F2 enzyme and human relevancy.