Frontiers in bioscience (Landmark edition)最新文献

Background: Infection is the leading cause of acute lung injury (ALI). Macrophages, which are pivotal innate immune cells, play a critical role in mediating inflammatory processes. Intracellular lipopolysaccharide (LPS) from invasive Gram-negative bacteria can activate the caspase-11 inflammasome, leading to the induction of pyroptosis in macrophages. This process subsequently triggers the release of inflammatory cytokines and damage-associated molecular patterns from pyroptotic macrophages, thereby exacerbating inflammatory progression in ALI. However, the precise regulatory mechanisms governing caspase-11 activation is still unclear. Sentrin-specific proteases (SENPs) have been identified as notable targets for their anti-inflammatory properties. Nevertheless, the specific role of SENPs in macrophage pyroptosis during the pathogenesis of ALI remains unknown.

Methods: We used LPS as an endotoxin to induce ALI. We analyzed the expression and location of sentrin-specific protease 1 (SENP1), pulmonary impairment, macrophage infiltration, caspase-11 inflammasome expression and activation, caspase-11 SUMOylation, and inflammatory cytokine secretion.

Results: Upregulated expression of SENP1 in lung tissue and macrophages was observed following LPS stimulation. SENP1 mediates de-SUMOylation and activation of caspase-11 inflammasome in macrophages. Moreover, pharmacological inhibition or genetic deficiency of SENP1 in macrophages significantly improved ALI-related histological damage by reducing the secretion of inflammatory cytokines and suppressing caspase-11-dependent pyroptosis.

Conclusions: Collectively, our findings highlight the involvement of SENP1 in caspase-11 activation and inflammatory progression in macrophages, thereby establishing a scientific foundation for the exploration of novel therapeutic strategies aimed at treating ALI.

Background: The associations of high-density lipoprotein (HDL) level and functionality with lipid metabolism, inflammation, and innate immunity in coronary artery disease (CAD) remain controversial. The differential expression of a set of genes related to HDL metabolism (24 genes) and atherogenesis (41 genes) in peripheral blood mononuclear cells (PBMC) from CAD and control patients with varied HDL cholesterol (HDL-C) levels was compared.

Methods: 76 male patients 40-60 years old with CAD diagnosed by angiography and 63 control patients were divided into three groups with low, normal (1.0-1.4 mM), and increased HDL-C levels. Transcript levels were measured by real-time PCR. The differentially expressed genes (DEGs) and associated metabolic pathways were analyzed for three groups, with prevalent CAD as an outcome.

Results: The common feature was the increased odds ratio values for liver X receptor (LXR) gene expression for three patient groups. CAD patients with low HDL-C possessed 24 DEGs with lower expression of genes involved in cholesterol efflux, and down-regulated SREBF1 and ABCG1 are suggested as gene signatures. CAD patients with normal HDL-C possessed nine DEGs with down-regulated ITGAM and ALB as gene signatures. CAD patients with increased HDL-C possessed 19 DEGs with down-regulated APOA1 and HMGCR as gene signatures. With gene expression signatures, one standard deviation higher average gene expressions were associated with 5.1-, 48.8-, and 38.9-fold fewer CAD cases for three patient groups. As HDL-C increased in CAD patients, the expression of ABCG1, CUBN, and HDLBP genes increased, while the expression of HMGCR and NPC2 genes, involved in cholesterol synthesis and trafficking, decreased. The expression of CD14, CD36, S100A8, S100A9, S100A12, TLR5, TLR8, and VEGFA genes, involved in angiogenesis and inflammation mainly via nuclear factor-κB (NF-κB), decreased.

Conclusions: The increased accumulation of cholesteryl ester in PBMC from patients with low HDL-C was suggested. This assumption contrasts with the suggested accumulation of free cholesterol in PBMC from patients with increased HDL-C, concomitant with suppression of cholesterol synthesis and traffic to the plasma membrane, and with an inflammatory state controlled by depressed CD36-mediated and upregulated apoE-mediated immunometabolic signaling. Gene signatures may be used for the diagnosis, prognosis, and treatment of CAD in dependence on HDL-C levels.

Background: Vitamin D receptor (VDR) can prevent myocardial ischemia reperfusion injury (MIRI). Hence, we aimed to illuminate the effect of VDR on cerebral ischemia/reperfusion injury (CIRI).

Methods: C57BL/6 mice and SK-N-SH cells were utilized to establish CIRI and cellular oxygen deprivation/reoxygenation (OGD/R) models. Mice were injected with 1 μg/kg Calcitriol or 1 μg/kg Paricalcitol (PC) and adenovirus-mediated VDR overexpression or knockdown plasmids. 2,3,5-triphenyl-tetrazolium chloride (TTC) and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to measure the brain infarct volume and the apoptosis of cerebral cells. SK-N-SH cells were treated with 5 mM N-acetyl-L-cysteine (NAC) and transfected with VDR knockdown plasmid. Flow cytometry and Cell Counting Kit-8 (CCK-8) assays were employed to assess the apoptosis and cell viability. Enzyme-Linked Immunosorbent Assay (ELISA), quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and Western blot were exploited to quantify the levels of reactive species oxygen (ROS), other oxidative stress-related factors, VDR and apoptosis-related factors.

Results: The level of VDR in mouse cerebral tissue was elevated by CIRI (p < 0.001). CIRI-induced cerebral infarction (p < 0.001) and the apoptosis of cerebral cells (p < 0.001) in mice were mitigated by the activation of VDR. VDR overexpression abrogated while VDR silencing enhanced CIRI-induced infarction, oxidative stress and apoptosis of cerebral cells (p < 0.05). Furthermore, VDR silencing aggravated the oxidative stress and apoptosis in OGD/R-treated SK-N-SH cells (p < 0.05). NAC, a scavenger of oxidative stress, could reverse the effects of VDR silencing on apoptosis and oxidative stress in OGD/R-treated SK-N-SH cells (p < 0.01).

Conclusion: VDR alleviates the oxidative stress to protect against CIRI.

Background: Clear cell renal cell carcinoma (ccRCC) represents the most prevalent form of renal cell carcinoma. The management of early-stage ccRCC has a better prognosis, while patients with metastatic ccRCC have a lower five-year survival rate. Angiogenesis serves as the fundamental process underlying tumor metastasis. Therefore, it is crucial to discover new targets for angiogenesis to improve patient survival rates.

Methods: The Cancer Genome Atlas database, International Cancer Genome Consortium database, Clinical Proteomic Tumor Analysis Consortium database, and a gene set of the vascular endothelial growth factor (VEGF) signaling pathway were utilized to identify differentially expressed genes. Western blot (WB), quantitative real-time polymerase chain reaction, and immunohistochemistry were employed to validate the downregulation of phospholipase C gamma 2 (PLCG2) in ccRCC tissues and cells. Cell Counting Kit-8 (CCK-8) assays, transwell assays, tube formation assays, and oil-red staining were performed to elucidate the biological functions of PLCG2 in tumor cells. Gene set enrichment analysis was applied to explore the downstream pathway. Subcutaneous tumor models and live small animal fluorescent imaging assay were utilized for in vivo investigation of the roles played by PLCG2.

Results: Our study has identified a novel biomarker, PLCG2, for ccRCC. PLCG2 is a central gene in regulating angiogenesis in ccRCC, as validated by bioinformatics analysis. The findings revealed a diminished expression of PLCG2 in both ccRCC tissues and cells. Further experiments in vivo and in vitro have demonstrated the significant roles of PLCG2 in tumor proliferation, invasion, migration, and lipid accumulation. Results of tube formation assays and WB support the role of PLCG2 in regulating VEGFA expression and angiogenesis.

Conclusions: Our results show that PLCG2 functions as a potential biomarker and an independent prognostic indicator for ccRCC. PLCG2 may modulate angiogenesis by influencing the expression of VEGFA. Therefore, targeting PLCG2 could potentially lead to drug discovery and improved cancer treatment strategies.

Lysosomes are essential intracellular catabolic organelles that contain digestive enzymes involved in the degradation and recycle of damaged proteins, organelles, etc. Thus, they play an important role in various biological processes, including autophagy regulation, ion homeostasis, cell death, cell senescence. A myriad of studies has shown that the dysfunction of lysosome is implicated in human aging and various age-related diseases, including cancer. However, what is noteworthy is that the modulation of lysosome-based signaling and degradation has both the cancer-suppressive and cancer-promotive functions in diverse cancers depending on stage, biology, or tumor microenvironment. This dual role limits their application as targets in cancer therapy. In this review, we provide an overview of lysosome and autophagy-lysosomal pathway and outline their critical roles in many cellular processes, including cell death. We highlight the different functions of autophagy-lysosomal pathway in cancer development and progression, underscoring its potential as a target for effective cancer therapies.

Background: The goal of this study was to investigate the effects of dexamethasone on human lens epithelial cells (HLECs) and the potential mechanisms.

Methods: HLECs (HLE-B3) were cultured in vitro to assess the effects of dexamethasone on cell size at different concentrations. Immunofluorescence staining was used to detect specific protein expression in HLE-B3 cells. The cell size was observed using phase-contrast microscopy, and the length and area were quantitatively measured with ImageJ software for statistical analysis. Flow cytometry was used to verify these outcomes. The means of three groups were statistically analyzed using one-way analysis of variance, whereas the means of two groups were statistically analyzed with the parametric Student's t-test. Additionally, high-throughput transcriptome sequencing was performed to compare messenger RNA (mRNA) expression levels between different concentrations of dexamethasone treatment groups and the control group, to identify potential signaling pathways. Subsequently, we performed quantitative Polymerase Chain Reaction (qPCR), immunofluorescence staining, and molecular docking experiments on the key differentially expressed genes.

Results: Dexamethasone affected the size of HLE-B3 cells. Both 0.25 and 0.5 μmol/L dexamethasone increased cell length and area, exhibiting no significant difference between the two treatment groups. Flow cytometry showed that dexamethasone increased cell size and granularity, with 0.25 μmol/L dexamethasone leading to larger cell areas and higher intracellular granularity. High-throughput transcriptome sequencing revealed significant upregulation of lysophosphatidic acid receptor 1 (LPAR1) and the pathways related to the glucocorticoid (GC) receptor.

Conclusions: Certain concentrations of dexamethasone impact the morphology and biological functions of HLECs. As a subtype of G protein-coupled receptors, LPAR1 on the cell membrane may interact with dexamethasone, affecting cell size and inhibiting autophagy via the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. These discoveries offer crucial biological insights into how dexamethasone influences the morphology and function of HLECs and the pathogenesis of GC-induced cataracts, offering potential molecular targets for future therapeutic strategies.

Cell-to-substrate adhesion sites, also known as focal adhesion sites (FAs), are complexes of different proteins on the cell surface. FAs play important roles in communication between cells and the extracellular matrix (ECM), leading to signal transduction involving different proteins that ultimately produce the cell response. This cell response involves cell adhesion, migration, motility, cell survival, and cell proliferation. The most important component of FAs are integrins. Integrins are transmembrane proteins that receive signals from the ECM and communicate them to the cytoplasm, thus activating several downstream proteins in a signaling cascade. Cellular Proto-oncogene tyrosine-protein kinase Src (c-Src) and focal adhesion kinase (FAK) are non-receptor tyrosine kinases that functionally interact to promote crucial roles in FAs. c-Src is a tyrosine kinase, activated by autophosphorylation and, in turn, activates another important protein, FAK. Activated FAK directly interacts with the cytoplasmic domain of integrin and activates other FA proteins by attaching to them. These proteins activated by FAK then activate other downstream pathways such as mitogen-activated protein kinase (MAPK) and Akt pathways involved in cell proliferation, migration, and cell survival. Src can induce detachment of FAK from the integrin to increase the focal adhesion turnover. As a result, the Src-FAK complex in FAs is critical for cell adhesion and survival mechanisms. Overexpression of FA proteins has been linked to a variety of pathological disorders, including cancers, growth retardation, and bone deformities. FAK and Src are overexpressed in various cancers. This review, which focuses on the roles of two important signaling proteins, c-Src and FAK, attempts to provide a thorough and up-to-date examination of the signal transduction mechanisms mediated by focal adhesions. The author also described that FAK and Src may serve as potential targets for future therapies against diseases associated with their overexpression, such as certain types of cancer.

Multiple sclerosis (MS) is a complex autoimmune disorder of the central nervous system (CNS) with an unknown etiology and pathophysiology that is not completely understood. Although great strides have been made in developing disease-modifying therapies (DMTs) that have significantly improved the quality of life for MS patients, these treatments do not entirely prevent disease progression or relapse. Identifying the unaddressed pathophysiological aspects of MS and developing targeted therapies to fill in these gaps are essential in providing long-term relief for patients. Recent research has uncovered some aspects of MS that remain outside the scope of available DMTs, and as such, yield only limited benefits. Despite most MS pathophysiology being targeted by DMTs, many patients still experience disease progression or relapse, indicating that a more detailed understanding is necessary. Thus, this literature review seeks to explore the known aspects of MS pathophysiology, identify the gaps in present DMTs, and explain why current treatments cannot entirely arrest MS progression.

Background: The biological activities of sulfated polysaccharides (SP) are well-documented, especially regarding wound healing. Sulfated galactan (SG), a type of SP extracted from the red seaweed Gracilaria fisheri, has been identified as having multiple therapeutic properties related to its wound healing capacity. Recent research indicates that degraded SG (DSG) from G. fisheri, when combined with octanoyl ester (DSGO), can improve wound healing in fibroblasts. However, the effectiveness of natural products in clinical settings often differs from in vitro results. This study aimed to develop and evaluate ointments containing DSG and DSGO for skin repair in an animal model.

Methods: Twenty-four Wistar rats were divided into four groups: (1) normal control, (2) ointment control, (3) DSG ointment, and (4) DSGO ointment. After inducing full-thickness excision wounds, these ointments were applied to the wounds. Wound contraction rate, histopathology, and protein related wound healing expression were then elucidated.

Results: Our findings showed that both DSG and DSGO ointments significantly enhanced wound closure compared to the control groups. Histopathological and biochemical analyses indicated increased extracellular matrix production and fibroblasts, marked by improved fibroblast activity, neovascularization, and collagen deposition. Furthermore, immunohistochemistry and immunoblot analysis revealed that the ointments altered the expression of Ki67, α-smooth muscle actin (α-SMA), E-cadherin, vimentin, collagen, and components of the Smad signaling pathway, all of which are crucial for wound healing. The results also suggested that the DSGO ointment was marginally more effective in promoting wound healing in this model.

Conclusions: These results indicate that ointment supplemented with DSG and DSGO have the potential to enhance skin repair by improving histopathology and altering wound healing-related proteins.