Latest ArticlesOvarian tumor (OT) is the most lethal form of gynecologic malignancy, with minimal improvements in patient outcomes over the past several decades. Metastasis is the leading cause of ovarian cancer-related deaths, yet the underlying mechanisms remain poorly understood. Psychological stress is known to activate the glucocorticoid receptor (NR3C1), a factor associated with poor prognosis in OT patients. However, the precise mechanisms linking NR3C1 signaling and metastasis have yet to be fully elucidated. In this study, we demonstrate that chronic restraint stress accelerates epithelial–mesenchymal transition (EMT) and metastasis in OT through an NR3C1-dependent mechanism involving nuclear protein 1 (NUPR1). Mechanistically, NR3C1 directly regulates the transcription of NUPR1, which in turn increases the expression of snail family transcriptional repressor 2 (SNAI2), a key driver of EMT. Clinically, elevated NR3C1 positively correlates with NUPR1 expression in OT patients, and both are positively associated with poorer prognosis. Overall, our study identified the NR3C1/NUPR1 axis as a critical regulatory pathway in psychological stress-induced OT metastasis, suggesting a potential therapeutic target for intervention in OT metastasis.
The pathogenesis of pulmonary fibrosis (PF) is complex. It is characterized by myofibroblast hyperplasia and deposition of collagen protein. Indoleamine 2,3-dioxygenase 1 (IDO1) is expressed in lung fibroblasts and epithelial cells, but its functions in lung homeostasis and diseases remain elusive. Here, we characterize the critical role of IDO1 in PF patients and bleomycin (BLM)-induced PF mouse models. We find that IDO1 is significantly upregulated in the fibrotic lungs of patients and mice, showing a positive correlation with genes characteristic of fibrosis. Functionally, IDO1 knockout inhibits lung fibroblast proliferation, differentiation, mitochondrial biogenesis, and mitochondrial oxidative phosphorylation. Conversely, IDO1 overexpression and accumulation of kynurenine (Kyn) exacerbate progressive lung fibrosis. Mechanistically, IDO1-deletion activated profound mitochondrial fusion-enhanced potentially the capacity for fatty acid oxidation, along with activation of de novo glycolytic serine/glycine synthesis pathways and mitochondrial one-carbon metabolism. Wedelolactone (WEL), a small molecule IKK inhibitor, is found to strongly bind to IDO1 and effectively protect mice from PF in an IDO1-dependent manner. Collectively, this study characterizes a promotor role for IDO1 in PF and suggests a potential avenue of targeting IDO1 to treat lung diseases.
Ergopeptines or their derivatives are widely used for treating neurodegenerative and cerebrovascular diseases. The nonribosomal peptide synthetase—d-lysergyl peptide synthetase A (LPSA) determines ergopeptine formation but the detailed mechanism remains to be elucidated. Here, we characterized two LPSAs from Claviceps purpurea Cp-1 strain through heterologous expression in Aspergillus nidulans feeding with d-lysergic acid. We proved that Cp-LPSA1 catalyzed the formation of ergocornine, α-ergocryptine, and β-ergocryptine, precisely controlled by the substrate specificity of its three modules. Cp-LPSA2 was initially inactive but could be restored to catalyze α-ergosine formation. Using this platform, we validated that P1-LPSA1 and P1-LPSA2 from the reported C. purpurea P1 strain catalyzed ergotamine and α-ergocryptine formation, respectively. Typically, the non-ribosomal peptide codes implicated in every module of the LPSAs were defined and elucidated, in which certain key residues could play a switched role for substrate specificity and product interconversion. By constructing chimeric LPSAs through module assembly, the production of the desired ergopeptines was achieved. Notably, 1.46 mg/L of α-ergocryptine and 1.09 mg/L of ergotamine were produced respectively by mixed-culture of C. paspali No. 24 (fermentation supernatant) and the recombinants of A. nidulans. Our findings provide insights into the biosynthetic mechanism of ergopeptines and lay a foundation for directed ergopeptine biosynthesis.
The coinfection of respiratory viruses and bacteria is a major cause of morbidity and mortality worldwide, despite the development of vaccines and powerful antibiotics. As a macromolecule that is difficult to absorb in the gastrointestinal tract, a homogeneous polysaccharide from Houttuynia cordata (HCPM) has been reported to exhibit anti-complement properties and alleviate influenza A virus (H1N1)-induced lung injury; however, the effects of HCPM without in vitro antiviral and antibacterial activities on more complicated pulmonary diseases resulting from viral-bacterial coinfection remains unclear. This study established a representative coinfection murine pneumonia model infected with H1N1 (0.2 LD50) and methicillin-resistant Staphylococcus aureus (MRSA, 107 CFU). HCPM significantly improved survival rate and weight loss, and ameliorated gut–lung damage and inflammatory cytokine production. Interestingly, the therapeutic effect of HCPM on intestinal damage preceded that in the lungs. Mechanistically, HCPM inhibited the overactivation of the intestinal complement (C3a and C5a) and suppressed the activation of the NLR family pyrin domain-containing 3 (NLRP3) pathway, which contributes to the regulation of the Treg/Th17 cell balance in the gut–lung axis. The results indicate the beneficial effects of an anti-complement polysaccharide against viral–bacterial coinfection pneumonia by modulating crosstalk between multiple immune regulatory networks.
Metastatic lung cancer continues to cause a high number of deaths due to high malignancy and poor prognosis, and the efficacy of typical chemotherapy or immunotherapy is less than ideal due to the low pulmonary accumulation and targeting of therapeutics. Here, a submicron-sized biomimetic liposome was formulated for the lung-targeted co-delivery of bacterial superantigen and paclitaxel. Recombinant staphylococcal enterotoxin C2 (rSEC2), a bacterial superantigen, was expressed with the Escherichia coli system and showed potent immunostimulatory activities to mediate tumor cell death. The submicron-sized (∼800 nm) biomimetic liposomes, namely 4T1 cell membrane-hybrid rSEC2 paclitaxel liposomes (TSPLs), exhibited high lung-accumulation efficiency and tumor homologous effect due to the suitable particle size and membrane hybridization of cancer cell membranes with phospholipids. Intravenous TSPLs remarkably inhibited metastatic lung cancer with limited systemic immune responses. TSPLs reversed the immunosuppressive state and increased the proportion of local CD4+ and CD8+ T cells in the lung; moreover, paclitaxel increased tumor cell apoptosis and reduced tumor burden. In summary, the high lung cancer targeting was achieved by particle size control and cell membrane hybridization, and the highly efficient anticancer effect was achieved by the co-delivery of superantigens and chemotherapeutic drugs.
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and pathological brain changes. While aging is the primary risk factor, circadian rhythm disruption (CRD) is increasingly recognized as a central driver of AD pathology. CRD exacerbates oxidative stress, systemic inflammation, and gut microbiome dysbiosis, impairing sleep-wake cycles, disrupting metabolic homeostasis, and promoting neuroinflammation, ultimately accelerating disease progression. Oxidative stress, a key factor in neuronal damage, is both a cause and consequence of circadian misalignment, while mitochondrial dysfunction further amplifies oxidative damage, impairing synaptic function and cognitive stability. Additionally, gut microbiome dysbiosis contributes to neuroinflammatory processes, worsening neurodegeneration. Given these complex interactions, this review aims to elucidate the role of CRD in AD pathology and explore potential therapeutic interventions targeting circadian dysfunction. Specifically, it examines the efficacy of time-restricted feeding (TRF), a dietary strategy that aligns food intake with circadian rhythms. TRF has shown promise in restoring circadian function, reducing oxidative stress, improving mitochondrial health, and promoting gut microbiome diversity. By addressing CRD, TRF may offer a novel approach to mitigating AD pathologies. This review also identifies current research gaps and future directions for developing circadian-based interventions in AD prevention and treatment.
Chronic kidney disease (CKD) affects 8%–15% of the population globally and can cause renal failure, partly due to lack of effective treatments and drug targets. Three novel cembrane diterpenoids papyifurans A‒C (1–3), in particular of 1 with an unprecedented trioxatetracyclo[10.2.1.12,5.16,9]heptadecane polyether scaffold, derived from Boswellia papyrifera resin, were found to effectively protect against renal fibrosis in vitro and in vivo. Their structures were fully characterized using a combination of spectroscopic, computational, modified Mosher’s, and X-ray crystallographic analysis. In particular, we performed chemical proteomic analyses and found that Elongation factor 2 (EEF2) is the key target of compound 1 for anti-renal fibrosis in vitro. Moreover, previous studies have linked EEF2 with lung fibrosis, while compound 1 was found to inhibit the hallmarks of organ fibrosis in vitro. Such effects were observed to decrease with the knock down of EEF2 in vitro, suggesting that EEF2 might be a universal drug target of organ fibrosis. Collectively, the present study demonstrated an example of identifying drug targets by using structurally novel natural products, which will be beneficial for developing therapeutic agents against organ fibrosis.