The pathogenesis of obesity is complex, and dysfunction of brown adipose tissue (BAT) is increasingly recognized as a key contributor. The role and underlying mechanisms of adipokine asprosin (ASP) in obesity remain to be fully elucidated. This study aimed to investigate the specific effect of adipose-derived ASP on systemic metabolism and BAT function and to elucidate the underlying molecular mechanisms involving ferroptosis. We generated adipose tissue–specific ASP deficiency (ASP−/−) mice and evaluated gluco-lipid metabolism, BAT thermogenesis, ferroptotic markers, and downstream signaling components through biochemical assays, histology, and molecular profiling. ASP−/− markedly improves systemic gluco-lipid metabolism in mice. This beneficial effect is associated with enhanced BAT function and a significant suppression of ferroptosis in brown adipocytes. Mechanistically, ASP directly binds to Notch3, which impedes the proteolytic cleavage and subsequent nuclear translocation of Notch3 intracellular domain (NICD). This interaction inhibits the formation of the NICD/RBP-Jκ transcriptional complex, ultimately leading to reduced transcription of the downstream target gene voltage-dependent anion channel 3 (VDAC3). Our findings demonstrate that ASP provokes BAT dysfunction and obesity by inducing ferroptosis through inhibiting Notch3/RBP-Jκ/VDAC3 signaling. This study reveals a novel mechanistic insight into obesity pathogenesis and suggests that targeting ASP could be a promising therapeutic strategy for metabolic disorders. Not applicable.
Real-time quantitative PCR (qPCR) is the gold standard for pathogen detection, but it relies on professional laboratory conditions and is difficult to meet the on-site application requirements of point-of-care testing (POCT). CRISPR/Cas12a technology offers high specificity, yet its sensitivity alone is limited, necessitating preamplification with recombinase polymerase amplification (RPA). The conventional two‑step recombinase polymerase amplification-clustered regularly interspaced short palindromic repeats (RPA‑CRISPR) method is prone to aerosol contamination, whereas one‑step systems (e.g., SHERLOCKv2) suffer from template competition, leading to a 10‑ to 100‑fold reduction in sensitivity. To address these issues, this study constructed the ChronoGate RPA‑CRISPR platform, which employs a thermosensitive poloxamer to achieve temporal separation of amplification and detection, thereby, establishing a rapid and sensitive point‑of‑care testing method. Poloxamer encapsulates the CRISPR-associated protein 12a (Cas12a)/CRISPR RNA (crRNA) complex at temperatures below 25 °C and releases it at 37 °C with a delay of approximately 8 min, enabling an ordered “amplification‑first, detection‑later” reaction. The optimal reaction conditions were determined to be 15
Vacuolar protein sorting 35 (VPS35) is a core component of the retromer complex. Dysfunction of VPS35 has been linked to the pathogenesis of Parkinson’s disease (PD), with the D620N point mutation identified as a causative factor in familial PD. However, the role of VPS35 in cancer progression and its post-translational modifications remains poorly understood. In this study, we demonstrate that the ubiquitin E3 ligase ubiquitin conjugation factor E4 B (UBE4B) mediates the ubiquitination of VPS35, catalyzing the formation of K48-linked polyubiquitin chains, which target VPS35 for degradation. We show that the VPS35 D620N mutant, along with most non-small cell lung cancer (NSCLC)-associated mutants, is similarly degraded by UBE4B, mirroring wild-type VPS35. Analysis of the Clinical Proteomic Tumor Analysis Consortium (CPTAC) and International Cancer Proteogenome Consortium (ICPC) databases revealed that UBE4B is upregulated in many cancers—particularly in lung and breast cancers—while VPS35 expression is correspondingly downregulated, suggesting an inverse correlation between the two proteins in these malignancies. Notably, the D620N mutation is absent in patients with NSCLC, underscoring distinct molecular mechanisms in lung cancer and PD. Further experiments indicated that UBE4B promotes proliferation and migration in H1299 and H125 cells, whereas VPS35 (including the D620N mutant) suppresses these processes. Intriguingly, UBE4B enhances apoptosis in a p53-dependent manner, while VPS35 has minimal impact on cancer cell apoptosis. In neuroblastoma cells, however, the UBE4B–VPS35 axis exhibits opposing roles: UBE4B inhibits, while VPS35 promotes, proliferation and migration. Our findings highlight UBE4B-mediated ubiquitination of VPS35 as a novel regulatory mechanism in cancer progression, providing new insights into the context-dependent roles of the UBE4B–VPS35 axis across different cancer types.
S-palmitoylation, a reversible post-translational modification, regulates critical biological processes and represents a promising therapeutic target for diverse human diseases. Over the past decade, human α/β hydrolase domain (ABHD) proteins have emerged as key regulators of the dynamic S-palmitoylation/depalmitoylation cycle, yet a systematic overview of their roles in this modification remains lacking. This review provides a comprehensive summary of the functions of emerging ABHD proteins—including ABHD17A/B/C, ABHD16A, ABHD10, ABHD7, and ABHD8—in the dynamics of S-palmitoylation and depalmitoylation cycle, along with their molecular mechanisms, structural features, and substrate specificities. Associations between dysregulated ABHD protein-mediated S-palmitoylation and various diseases, including cancers, neurological disorders, degenerative diseases, viral infectious diseases, metabolic diseases, and reproductive disorders are discussed. Predictive criteria for uncharacterized ABHD proteins and prospective targeted therapeutic strategies are also proposed. This review provides mechanistic insights into emerging ABHD proteins in S-palmitoylation/depalmitoylation, and lays a foundation for developing novel diagnostic markers and precision therapies for S-palmitoylation-related diseases.
Selenium is a nonmetal element incorporated into a small subset of proteins as selenocysteine, the 21st amino acid. In humans, the so-called selenoproteins represent a unique and physiologically important family of proteins, some of which are essential to life, primarily through the maintenance of redox balance. Other selenoprotein functions include defense against various forms of oxidative stress, thyroid hormone metabolism, muscular homeostasis and integrity, as well as immune regulation, inflammatory responses, and protection against oxidative stress-mediated cell deaths. Increasing evidence shows that inhibiting global selenoprotein expression or targeting individual selenoproteins, such as glutathione peroxidase 4 and thioredoxin reductase 1, can greatly affect cellular redox status in different tissues and organs and trigger cell death through apoptosis, pyroptosis, ferroptosis, or even cuproptosis. This is particularly true in hematopoietic cells, where oxidative stress and reactive oxygen species production may profoundly alter differentiation of stem and lineage-committed progenitor cells and thus contribute to the progression and treatment resistance of hematopoietic malignancies. Thus, inhibition of selenoprotein synthesis or activity by genetic or pharmacological approaches has been shown to trigger apoptosis and/or ferroptosis, leading to the elimination of leukemic cells. Of note, glutathione peroxidases 1 and 4, SELENOM, SELENOO, and SELENOW are overexpressed in some subtypes of acute myeloid leukemia, often conferring a pejorative prognosis. Thus, targeting selenoproteins, either alone or in combination with conventional or targeted therapies, might represent an attractive strategy for the management of patients suffering leukemia.
