Roxadustat alleviates metabolic traits in letrozole-induced PCOS mice.

Polycystic ovary syndrome (PCOS) is a highly prevalent disorder in women that is commonly accompanied by metabolic syndrome. Activation of the hypoxia-inducible factor (HIF) pathway is known to alleviate metabolic defects. Hence, this study utilized a preclinical PCOS mouse model to investigate the effects of chemically induced HIF activation on the metabolic traits of PCOS. Prepubertal letrozole treatment was used to generate a PCOS mouse model in the C57Bl6/J strain, and PCOS mice were orally treated with vehicle or roxadustat for six weeks from age 12 weeks onwards to induce HIF activation. Although the PCOS mice showed impaired glucose tolerance, increased insulin resistance, elevated blood lipids, and reduced muscle glycogen content, there was no difference in histological evaluations of white adipose tissue (WAT) or liver or in organ weights. Roxadustat treatment resulted in significant improvement in glucose tolerance (27 % reduction in area under the curve (AUC) values, p < 0.0001), fasting glucose levels (4.59 ± 0.83 mmol/l vs 3.05 ± 0.62 mmol/l, p < 0.0001) and insulin resistance (46 % reduction in homeostasis model assessment-insulin resistance (HOMA-IR) values, 6.76 ± 3.72 vs 3.64 ± 2.44, p = 0.019) compared to vehicle-treated mice without altering the body weight. Gene expression analyses with real-time quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing revealed significant differences in gene expression in the tissues of PCOS mice compared to control mice, whereas the transcriptomic effects of roxadustat were mainly transient. However, immunohistochemistry revealed increased uncoupling protein 1 (UCP1) expression in WAT, which may indicate WAT browning related to HIF pathway activation.

Metabolic characteristics of transmembrane prolyl 4-hydroxylase (P4H-TM) deficient mice.

Transmembrane prolyl 4-hydroxylase (P4H-TM) is an enigmatic enzyme whose cellular function and primary substrate remain to be identified. Its loss-of-function mutations cause a severe neurological HIDEA syndrome with hypotonia, intellectual disability, dysautonomia and hypoventilation. Previously, P4H-TM deficiency in mice was associated with reduced atherogenesis and lower serum triglyceride levels. Here, we characterized the glucose and lipid metabolism of P4h-tm-/- mice in physiological and tissue analyses. P4h-tm-/- mice showed variations in 24-h oscillations of energy expenditure, VO2 and VCO2 and locomotor activity compared to wild-type (WT) mice. Their rearing activity was reduced, and they showed significant muscle weakness and compromised coordination. Sedated P4h-tm-/- mice had better glucose tolerance, lower fasting insulin levels, higher fasting lactate levels and lower fasting free fatty acid levels compared to WT. These alterations were not present in conscious P4h-tm-/- mice. Fasted P4h-tm-/- mice presented with faster hepatic glycogenolysis. The respiratory rate of conscious P4h-tm-/- mice was significantly lower compared to the WT, the decrease being further exacerbated by sedation and associated with acidosis and a reduced ventilatory response to both hypoxia and hypercapnia. P4H-TM deficiency in mice is associated with alterations in whole-body energy metabolism, day-night rhythm of activity, glucose homeostasis and neuromuscular and respiratory functions. Although the underlying mechanism(s) are not yet fully understood, the phenotype appears to have neurological origins, controlled by brain and central nervous system circuits. The phenotype of P4h-tm-/- mice recapitulates some of the symptoms of HIDEA patients, making this mouse model a valuable tool to study and develop tailored therapies.

Astragaloside IV restrains pyroptosis and fibrotic development of pulmonary artery smooth muscle cells to ameliorate pulmonary artery hypertension through the PHD2/HIF1α signaling pathway.

BACKGROUND: Astragaloside (AS)-IV, extracted from traditional Chinese medicine Astragalus mongholicus, has been widely used in the anti-inflammatory treatment for cardiovascular disease. However, the mechanism by which AS-IV affects pulmonary artery hypertension (PAH) development remains largely unknown. METHODS: Monocrotaline (MCT)-induced PAH model rats were administered with AS-IV, and hematoxylin-eosin staining and Masson staining were performed to evaluate the histological change in pulmonary tissues of rats. Pulmonary artery smooth muscle cells (PASMCs) were treated by hypoxia and AS-IV. Pyroptosis and fibrosis were assessed by immunofluorescence, western blot and enzyme-linked immunosorbent assay. RESULTS: AS-IV treatment alleviated pulmonary artery structural remodeling and pulmonary hypertension progression induced by MCT in rats. AS-IV suppressed the expression of pyroptosis-related markers, the release of pro-inflammatory cytokine interleukin (IL)-1ß and IL-18 and fibrosis development in pulmonary tissues of PAH rats and in hypoxic PAMSCs. Interestingly, the expression of prolyl-4-hydroxylase 2 (PHD2) was restored by AS-IV administration in PAH model in vivo and in vitro, while hypoxia inducible factor 1α (HIF1α) was restrained by AS-IV. Mechanistically, silencing PHD2 reversed the inhibitory effect of AS-IV on pyroptosis, fibrosis trend and pyroptotic necrosis in hypoxia-cultured PASMCs, while the HIF1α inhibitor could prevent these PAH-like phenomena. CONCLUSION: Collectively, AS-IV elevates PHD2 expression to alleviate pyroptosis and fibrosis development during PAH through downregulating HIF1α. These findings may provide a better understanding of AS-IV preventing PAH, and the PHD2/HIF1α axis may be a potential anti-pyroptosis target during PAH.

Comprehensive In silico analysis of chaperones identifies CRYAB and P4HA2 as potential therapeutic targets and their small-molecule inhibitors for the treatment of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a subtype of liver cancer with increasing incidence, poor prognosis, and limited treatment modalities. It is, therefore, imperative to identify novel therapeutic targets for better management of the disease. Chaperones are known to be significant regulators of carcinogenesis, however, their role in CCA remains unclear. This study aims to screen chaperones involved in CCA pathogenesis and identify drugs targeting key chaperones to improve the therapeutic response to the disease. To achieve this, first we mined the literature to create an atlas of human chaperone proteins. Next, their expression in CCA was determined by publicly available datasets of patients at mRNA and protein levels. In addition, our analysis involving protein-protein interaction and pathway analysis of eight key dysregulated chaperones revealed that they control crucial cancer-related pathways. Furthermore, topology analysis of the CCA network identified crystallin alpha-B protein (CRYAB) and prolyl-4-hydroxylase subunit 2 (P4HA2) as novel therapeutic targets for the disease. Finally, drug repurposing of 286 clinically approved anti-cancer drugs against these two chaperones performed by molecular docking and molecular dynamics simulations showed that tucatinib and regorafenib had a modulatory effect on them and could be potential inhibitors of CRYAB and P4HA2, respectively. Overall, our study, for the first time, provides insights into the pan-chaperone expression in CCA and explains the pathways that might drive CCA pathogenesis. Further, our identification of potential therapeutic targets and their inhibitors could provide new and complementary approaches to CCA treatment.

Emerging roles for diguanylate cyclase during the evolution of soma in dictyostelia.

BACKGROUND: Cyclic di-guanylate (c-di-GMP), synthesized by diguanylate cyclase, is a major second messenger in prokaryotes, where it triggers biofilm formation. The dictyostelid social amoebas acquired diguanylate cyclase (dgcA) by horizontal gene transfer. Dictyostelium discoideum (Ddis) in taxon group 4 uses c-di-GMP as a secreted signal to induce differentiation of stalk cells, the ancestral somatic cell type that supports the propagating spores. We here investigated how this role for c-di-GMP evolved in Dictyostelia by exploring dgcA function in the group 2 species Polysphondylium pallidum (Ppal) and in Polysphondylium violaceum (Pvio), which resides in a small sister clade to group 4. RESULTS: Similar to Ddis, dgcA is upregulated after aggregation in Ppal and Pvio and predominantly expressed in the anterior region and stalks of emerging fruiting bodies. DgcA null mutants in Ppal and Pvio made fruiting bodies with very long and thin stalks and only few spores and showed delayed aggregation and larger aggregates, respectively. Ddis dgcA- cells cannot form stalks at all, but showed no aggregation defects. The long, thin stalks of Ppal and Pvio dgcA- mutants were also observed in acaA- mutants in these species. AcaA encodes adenylate cyclase A, which mediates the effects of c-di-GMP on stalk induction in Ddis. Other factors that promote stalk formation in Ddis are DIF-1, produced by the polyketide synthase StlB, low ammonia, facilitated by the ammonia transporter AmtC, and high oxygen, detected by the oxygen sensor PhyA (prolyl 4-hydroxylase). We deleted the single stlB, amtC and phyA genes in Pvio wild-type and dgcA- cells. Neither of these interventions affected stalk formation in Pvio wild-type and not or very mildly exacerbated the long thin stalk phenotype of Pvio dgcA- cells. CONCLUSIONS: The study reveals a novel role for c-di-GMP in aggregation, while the reduced spore number in Pvio and Ppal dgcA- is likely an indirect effect, due to depletion of the cell pool by the extended stalk formation. The results indicate that in addition to c-di-GMP, Dictyostelia ancestrally used an as yet unknown factor for induction of stalk formation. The activation of AcaA by c-di-GMP is likely conserved throughout Dictyostelia.

Prolyl 4-hydroxylase subunit beta (P4HB) could serve as a prognostic and radiosensitivity biomarker for prostate cancer patients.

BACKGROUND: Prolyl 4-hydroxylase subunit beta (P4HB) has been reported as a suppressor in ferroptosis. However, no known empirical research has focused on exploring relationships between P4HB and prostate cancer (PCa). In this research, we initially examine the function of P4HB in PCa by thorough analysis of numerous databases and proliferation experiment. METHODS: We analyzed the correlations of P4HB expression with prognosis, clinical features, mutation genes, tumor heterogeneity, stemness, tumor immune microenvironment and PCa cells using multiple databases and in vitro experiment with R 3.6.3 software and its suitable packages. RESULTS: P4HB was significantly upregulated in tumor tissues compared to normal tissues and was closely related to biochemical recurrence-free survival. In terms of clinical correlations, we found that higher P4HB expression was significantly related to older age, higher Gleason score, advanced T stage and residual tumor. Surprisingly, P4HB had highly diagnostic accuracy of radiotherapy resistance (AUC 0.938). TGF beta signaling pathway and dorso ventral axis formation were upregulated in the group of low-expression P4HB. For tumor stemness, P4HB expression was positively related to EREG.EXPss and RNAss, but was negatively associated with ENHss and DNAss with statistical significance. For tumor heterogeneity, P4HB expression was positively related to MATH, but was negatively associated with tumor ploidy and microsatellite instability. For the overall assessment of TME, we observed that P4HB expression was negatively associated with all parameters, including B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score and ESTIMATE score. Spearman analysis showed that P4HB expression was negatively related to TIDE score with statistical significance. In vitro experiment, RT-qPCR and western blot showed that three siRNAs of P4HB were effective on the knockdown of P4HB expression. Furthermore, we observed that the downregulation of P4HB had significant influence on the cell proliferation of six PCa cell lines, including LNCap, C4-2, C4-2B, PC3, DU145 and 22RV1 cells. CONCLUSIONS: In this study, we found that P4HB might serve as a prognostic biomarker and predict radiotherapy resistance for PCa patients. Downregulation of P4HB expression could inhibit the cell proliferation of PCa cells.

Corrigendum: Systematic pan-cancer analysis of the potential tumor diagnosis and prognosis biomarker P4HA3.

[This corrects the article DOI: 10.3389/fgene.2023.1045061.].

Assessing the Carcinogenicity of Vadadustat, an Oral Hypoxia-Inducible Factor Prolyl-4-Hydroxylase Inhibitor, in Rodents.

Vadadustat is an investigational oral hypoxia-inducible factor (HIF) prolyl-4-hydroxylase inhibitor to treat anemia due to chronic kidney disease (CKD). Some studies suggest that HIF activation promotes tumorigenesis by activating angiogenesis downstream of vascular endothelial growth factor, while other studies suggest that elevated HIF activity may produce an antitumor phenotype. To evaluate the potential carcinogenicity of vadadustat in mice and rats, we dosed CByB6F1/Tg.rasH2 hemizygous (transgenic) mice orally by gavage with 5 to 50 mg/kg/d of vadadustat for 6 months and dosed Sprague-Dawley rats orally by gavage with 2 to 20 mg/kg/d for approximately 85 weeks. Doses were selected based on the maximally tolerated dose established for each species in previous studies. The tumors that were identified in the studies were not considered to be treatment-related for statistical reasons or within the historical control range. There was no carcinogenic effect attributed to vadadustat in mice or rats.

P4HA1 Promotes Cell Migration and Colonization in Hypopharyngeal Squamous Cell Carcinoma.

BACKGROUND/AIM: This study aimed to identify key molecules associated with the survival of patients with hypopharyngeal squamous cell carcinoma (HpSCC) by combining in silico and in vitro analyses. MATERIALS AND METHODS: Differentially expressed genes (DEGs) were screened using the Gene Expression Omnibus database. For DEGs, we performed functional enrichment and protein-protein interaction network analyses to identify potential biological functions and hub genes. Functional analysis of HpSCC cell lines verified the critical roles of the hub genes. RESULTS: DEGs were associated with the extracellular matrix. Among the hub genes, high expression of prolyl 4-hydroxylase subunit alpha 1 (P4HA1) was significantly associated with shorter survival. In addition, P4HA1 knockdown inhibited cell migration and colonization. Suppression of cell proliferation was demonstrated using P4HA1-selective inhibitors. CONCLUSION: P4HA1 may be a useful therapeutic target for the treatment of HpSCC.

A meta-analysis and bioinformatics analysis of P4HB expression levels in the prognosis of cancer patients.

BACKGROUND: P4HB (prolyl 4-hydroxylase, beta polypeptide) is a human chromosomal gene that encodes an endoplasmic reticulum (ER) molecular chaperone protein with oxidoreductase, chaperone and isomerase activities. Recent studies indicated that P4HB may have clinical significance, with elevated P4HB expression reported in cancer patients, but its impact on tumor prognosis is not yet clear. To our knowledge, this is the first meta-analysis to show an association between P4HB expression and the prognosis of various cancers. METHODS: We conducted a systematic literature search in the PubMed, PubMed Central, Web of Science, Embase, CNKI, Wanfang and Weipu databases, followed by a quantitative meta-analysis using Stata SE14.0 and R statistics software 4.2.1. The hazard ratio (HR) and relative risk (RR) were analyzed to evaluate the relationships of P4HB expression levels with overall survival (OS), disease-free survival (DFS), and clinicopathological parameters of cancer patients. Subsequently, P4HB expression in various cancer types was validated using the Gene Expression Profiling Interactive Analysis (GEPIA) online database. RESULTS: Ten articles containing the data of 4121 cancer patients were included in the analysis, and a significant correlation of high P4HB expression with apparently shorter OS was found (HR, 1.90; 95% CI, 1.50-2.40; P < 0.01), while there was no significant correlation with gender (RR, 1.06; 95% CI, 0.91-1.22; P = 0.084), or age. Additionally, GEPIA online analysis revealed significant upregulation of P4HB in 13 types of cancer. Among them, P4HB overexpression was associated with shorter OS in 9 and worse DFS in 11 cancer types. CONCLUSIONS: Upregulation of P4HB is correlated with worse prognosis in various cancers, which could provide new ideas for the development of P4HB-related diagnostic biomarkers and new therapeutic targets.