BioFactors最新文献

Inflammation of adipose tissue is a contributing factor to many chronic diseases associated with obesity. We previously showed that micronutrients such as vitamin D (VD) limited this metabolic inflammation by decreasing inflammatory markers expression including miR-155 (microRNA-155) or miR-146a in different in vitro and in vivo models. These miRNAs could be incorporated into extracellular vesicles (EVs) in order to modulate the activity of target cells. Nevertheless, the role of VD on the miRNAs contained in EVs from adipose tissue in inflammatory conditions remains unclear. In this study, we used a human model of SGBS (Simpson-Golabi-Behmel syndrome) adipocytes preincubated with 1,25(OH)₂D (the active form of VD) before an inflammatory stress with tumor necrosis factor α (TNFα). First, we confirmed by quantitative PCR that the expression of classical inflammatory factors (TNFα and chemokine ligand 2 [CCL2/MCP1]), miR-146a, and miR-155 was increased significantly under inflammatory conditions in SGBS cells and that VD prevented this up-regulation. Secondly, transmission electron microscope imaging of EVs preparations in supernatant allowed visualization of small and large vesicles under these conditions. Then, EVs were obtained with isolation kit and the expression of miR-155 and miR-146a were measured. The expression of miR-155 under TNFα effect was increased in EVs while miR-146a was not detected. Moreover, we also showed that the TNFα-mediated expression of miR-155 in EVs was significantly reduced by a VD pre-incubation of cells. Using miRNA PCR array, we also identified 33 miRNAs, organized in 5 clusters that were differentially regulated by TNFα and VD. Bioinformatic analysis of biological pathways revealed that the different miRNAs targeting genes that are involved in important cell process such as the regulation of transcription or protein phosphorylation. In conclusion, these results support for the first time that VD modulated the expression of miRNAs in EVs from adipocytes, which could represent a new mechanism of regulation of inflammation by micronutrients.

Stereocaulon alpinum has been found to have potential pharmaceutical properties due to the presence of secondary metabolites such as usnic acid, atranorin, and lobaric acid (LA) which have anticancer activity. On the other hand, the effect of LA on the stemness potential of colorectal cancer (CRC) cells remains unexplored, and has not yet been thoroughly investigated. In this study, we examined the inhibitory activity of LA from Stereocaulon alpinum against the stemness potential of CRC cells and investigated the possible underlying mechanisms. The results demonstrated that LA did not inhibit the cell viability of CSC221 and DLD1. In addition, LA significantly decreased the spheroid formation of CSC221 and DLD1. Moreover, LA treatment suppressed cancer stem cell (CSC) markers; aldehyde dehydrogenase 1 (ALDH1), B-cell-specific Moloney leukemia virus insertion site 1 (BMI1), musashi1 (MSI1), and leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), along with the sonic hedgehog (Shh) and mTOR/AKT pathways that contribute significantly to maintaining the stemness of CRC cells. Therefore, LA may be a new therapeutic approach for reducing the stemness of CRC cells.

SARS-CoV-2-related proteins, ACE2 and TMPRSS2, are determinants of SARS-CoV-2 infection. Although these proteins are expressed in oral-related tissues, their expression patterns and modulatory mechanisms in the salivary glands remain unknown. We herein showed that full-length ACE2, which has both a fully functional enzyme catalytic site and high-affinity SARS-CoV-2 spike S1-binding sites, was more highly expressed in salivary glands than in oral mucosal epithelial cells and the lungs. Regarding TMPRSS2, zymogen and the cleaved form were both expressed in the salivary glands, whereas only zymogen was expressed in murine lacrimal glands and the lungs. Metformin, an AMPK activator, increased stimulated saliva secretion and full-length ACE2 expression and decreased cleaved TMPRSS2 expression in the salivary glands, and exerted the same effects on soluble ACE2 (sACE2) and sTMPRSS2 in saliva. Moreover, metformin decreased the expression of beta-galactosidase, a senescence marker, and ADAM17, a sheddase of ACE2 to sACE2, in the salivary glands. In aged mice, the expression of ACE2 was decreased in the salivary glands, whereas that of sACE2 was increased in saliva, presumably by the up-regulated expression of ADAM17. The expression of TMPRSS2 in the salivary glands and sTMPRSS2 in saliva were both increased. Collectively, these results suggest that the protein expression patterns of ACE2 and TMPRSS2 in the salivary glands differ from those in other oral-related cells and tissues, and also that metformin and aging affect the salivary expression of ACE2 and TMPRSS2, which have the potential as targets for preventing the transmission of SARS-CoV-2.

Intracellular proteins take part in almost every body function; thus, protein homeostasis is of utmost importance. The ubiquitin proteasome system (UPS) has a fundamental role in protein homeostasis. Its main role is to selectively eradicate impaired or misfolded proteins, thus halting any damage that could arise from the accumulation of these malfunctioning proteins. Proteasomes have a critical role in controlling protein homeostasis in all cell types, including stem cells. We will discuss the role of UPS enzymes as well as the 26S proteasome complex in stem cell biology from several angles. First, we shall overview common trends of proteasomal activity and gene expression of different proteasomal subunits and UPS enzymes upon passaging and differentiation of stem cells toward various cell lineages. Second, we shall explore the effect of modulating proteasomal activity in stem cells and navigate through the interrelation between proteasomes' activity and various proteasome-related transcription factors. Third, we will shed light on curated microRNAs and long non-coding RNAs using various bioinformatics tools that might have a possible role in regulating UPS in stem cells and possibly, upon manipulation, can enhance the differentiation process into different lineages and/or delay senescence upon cell passaging. This will help to decipher the role played by individual UPS enzymes and subunits as well as various interrelated molecular mediators in stem cells' maintenance and/or differentiation and open new avenues in stem cell research. This can ultimately provide a leap toward developing novel therapeutic interventions related to proteasome dysregulation.

Current lifestyles include calorie-dense diets and late-night food intake, which can lead to circadian misalignment. Our group recently demonstrated that sweet treats before bedtime alter the clock system in healthy rats, increasing metabolic risk factors. Therefore, we aimed to assess the impact of the sweet treat consumption time on the clock system in rats fed a cafeteria diet (CAF). Moreover, since flavanols have demonstrated beneficial effects in metabolic disorders and clock gene modulation, we also investigated whether these phenolic compounds can restore the circadian disruption caused by these altered dietary patterns. For this, 64 Fisher rats were fed CAF for 9 weeks. In the last 4 weeks, animals were daily administered a low dose of sugar (160 mg/kg) as a sweet treat at 8 a.m. (ZT0) or 8 p.m. (ZT12). Two other groups received 25 mg/kg of grape seed flavanols in addition to sweet treats. Finally, the animals were sacrificed at different time points (9 a.m., 3 p.m., 9 p.m., and 3 a.m.). The results showed that metabolic and circadian disturbances by CAF may be influenced by the time of sugar administration, slightly reinforcing the alterations in diurnal rhythmicity of serum biochemical parameters, hormones, and hypothalamic genes with bedtime snacking. Flavanols improved metabolic health and restored the oscillation of biochemical parameters, hormones, and clock and appetite-signaling genes, showing greater effects at ZT12. These results highlight the importance of meal timing in influencing physiological and metabolic outcomes, even under calorie-dense diets. Moreover, they also suggest the zeitgeber role of flavanols, modulating the clock system and contributing to an improved metabolic profile under different feeding pattern conditions.

Curcumin, a compound from Curcuma longa L., has significant anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory activity in dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) remain inadequately understood. This study aimed to further elucidate the molecular mechanisms of curcumin DSS-induced UC mice. Our data showed that curcumin alleviated DSS-induced colitis by reducing intestinal damage and inflammation, increasing goblet cells in colon tissues. Enzyme-linked immunosorbent assay revealed that curcumin reduced the expression of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1β, and interleukin-8) in serum and myeloperoxidase in colon tissues. A comprehensive analysis integrating network pharmacology and RNA sequencing (RNA-seq) revealed significant enrichment of the nuclear factor kappa B (NF-κB) signaling pathways. Notably, RNA-seq analysis demonstrated that curcumin significantly downregulated the mRNA expression of sphingosine kinase 1 (SphK1). Furthermore, molecular docking analysis showed that curcumin can bind to SphK1 and NF-κB. Additionally, curcumin was found to inhibit the activation of the SphK1/NF-κB signaling pathway in DSS-induced UC colon tissue. This study addresses pharmacologic and mechanistic perspectives of curcumin that ameliorates DSS-induced UC and inflammatory response.

Breast cancer continues to be a major health issue for women worldwide, with vimentin (VIM) identified as a crucial factor in its progression due to its role in cell migration and the epithelial-to-mesenchymal transition (EMT). This study focuses on elucidating VIM's regulatory mechanisms on the miR-615-3p/PICK1 axis. Utilizing the 4T1 breast cancer cell model, we first used RNA-seq and proteomics to investigate the changes in the APA of PICK1 following VIM knockout (KO). These high-throughput analyses aimed to uncover the underlying transcriptional and proteomic alterations associated with VIM's influence on breast cancer cells. RNA-seq and proteomic profiling revealed significant APA in PICK1 following VIM KO, suggesting a novel mechanism by which VIM regulates breast cancer progression. Validation experiments confirmed that VIM KO affects the miR-615-3p-PICK1 axis, with miR-615-3p's regulation of PICK1 being contingent upon the APA of PICK1. These findings highlight the complex interplay between VIM, miR-615-3p, and PICK1 in the regulation of breast cancer cell behavior. This study reveals that vimentin affects the miR-615-3p-PICK1 axis through APA, revealing the key role of VIM in cancer progression. Opened up new avenues for targeted cancer therapy, with a focus on regulating the interaction between APA and miR-615-3p-PICK1.

Colorectal cancer (CRC) ranks as the third most prevalent cancer globally and is the second leading cause of cancer mortality. FAM49B, a member of the FAM49 gene family, is a recently identified, evolutionarily conserved gene. Emerging studies indicate that FAM49B plays a role in various cancers, though its specific mechanism in CRC remains largely unexplored. In this study, we observed that FAM49B was abnormally expressed in CRC tissues and cell lines, with elevated expression correlating with poor patient prognosis. FAM49B knockdown markedly suppressed CRC cell proliferation by arresting the cell cycle and reducing cell migration and invasion. Single-cell RNA-seq (ScRNA-seq) analysis revealed that high FAM49B expression in malignant epithelial cell clusters was strongly linked to c-Myc oncogene activation. Further, FAM49B knockdown significantly reduced c-Myc expression by enhancing its K48 ubiquitination. We identified NEK9 as a direct interacting partner of FAM49B, with FAM49B knockdown inhibiting NEK9-Thr210 phosphorylation. Similarly, high NEK9 expression was linked to unfavorable prognosis in CRC. In FAM49B-overexpressing CRC cells, NEK9 knockdown significantly suppressed c-Myc expression, c-Myc-ser62 phosphorylation, and reduced cell proliferation, migration, and invasion. Thus, directly targeting the FAM49B/NEK9/c-Myc pathway presents a promising therapeutic approach for c-Myc positive CRC patients.

Ultraviolet (UV) irradiation is a major factor contributing to skin photoaging, including the formation of reactive oxygen species (ROS), collagen breakdown, and overall skin damage. Insulin-like growth factor-I (IGF-1) is a polypeptide hormone that regulates dermal survival and collagen synthesis. Echinacoside (Ech), a natural phenylethanoid glycoside, is the most abundant active compound in Cistanches. However, its potential benefits for the skin and the underlying molecular mechanisms remain unclear. The objective of this research is to investigate the protective effect of Ech on human dermal fibroblast cells (HDFs) against UVB-induced skin photodamage. In this study, we demonstrated that Ech promotes IGF-1/IGF-1R/ERK-mediated collagen synthesis and IGF-1/IGF-1R/PI3K-mediated survival pathways, as well as induces IGF-1 secretion to counteract UVB-induced aging in HDFs. Furthermore, UVB-induced accumulation of SA-β-gal-positive cells, ROS, and impaired collagen synthesis were attenuated following Ech treatment. However, the protective effects of Ech were significantly diminished when IGF-1 and IGF-1R expression was silenced using small interfering RNA, indicating that Ech exerts its antiaging effects primarily by activating the IGF-1/IGF-1R signaling pathway. Our findings provide evidence of the antiaging effects of Ech on UVB-induced skin photodamage and suggest its potential development as a supplement in cosmetic dermal protective products.

Endometrial cancer (EC) is a prevalent gynecological malignancy with a rising incidence and poor prognosis in advanced cases. Long non-coding RNAs (lncRNAs) have been implicated in various cancers, including EC. This study explores the role of lncRNA Linc01224 in EC. Analyzing TCGA data, we found Linc01224 expression significantly elevated in EC tissues, correlating with poor prognosis. Clinical samples validated these findings, showing higher Linc01224 levels in tumor tissues. Knockdown of Linc01224 in EC cell lines (Hec-1-B and Ishikawa) inhibited proliferation, migration, and promoted apoptosis, alongside increased Bax and decreased BCL2 expression. Furthermore, Linc01224 knockdown notably reduced Wnt2/β-catenin pathway activation. We identified TPX2 as a target of miR-4673, which is regulated by Linc01224 through a competing endogenous RNA (ceRNA) mechanism. Dual-luciferase reporter assays confirmed miR-4673 binding to Linc01224 and TPX2. Rescue experiments revealed that TPX2 knockdown reversed Linc01224-induced proliferation and migration, highlighting TPX2's pivotal role in Linc01224's oncogenic function. In vivo, Linc01224 knockdown significantly impeded tumor growth and metastasis in a xenograft model, with decreased expression of c-Myc, Cyclin D1, and β-catenin. These findings reveal a novel ceRNA regulatory axis involving Linc01224, miR-4673, and TPX2, elucidating Linc01224's role in EC progression through the Wnt2/β-catenin pathway. Linc01224 emerges as a potential biomarker and therapeutic target for EC prognosis and treatment.