Discovery medicine最新文献

Background: Primary open-angle glaucoma (POAG) is one of the common types of glaucoma, an eye disease that causes irreversible blindness. Fibrosis of the trabecular meshwork (TM) caused by the accumulation of extracellular matrix (ECM) induced by transform growth factor-β (TGF-β) is closely related to high intraocular pressure (IOP). Deacetylase Sirtuin1 (Sirt1) plays an anti-oxidation and anti-fibrosis role in many diseases, including glaucoma; however, its mechanisms have not been fully revealed. In this study, we analyzed the anti-fibrotic role of Sirt1 in TM fibrosis induced by TGF-β to investigate potential mechanisms.

Methods: Transcriptome sequencing of trabecular meshwork cells (TMCs) was performed after transfection with the adenovirus-Sirt1-green fluorescent protein (Adv-Sirt1-GFP). Then, 5 ng/mL TGF-β was used to induce overexpression of ECM in TMCs in vitro. The expression of target proteins was detected by Western blot and immunofluorescence, and cytokine expression was detected by enzyme-linked immunosorbent serologic assay (ELISA). At the same time, we detected the functional changes in cell proliferation, adhesion, and migration.

Results: After treatment with TGF-β, we found that the accumulation of ECM was increased (fibronectin (FN), collagen I (COL I), laminin (LN), p < 0.05), and the phosphorylation (activation) of Smad2/3 and the expression of Smad4 were increased (p < 0.001). The results of transcriptome sequencing suggested that Sirt1 inhibits the expression of ECM by regulating the functions of co-Smad and co-COL binding proteins, thus participating in the regulation of cell adhesion. Finally, we confirmed that: (1) Sirt1 reduced the accumulation of ECM in TMCs by inhibiting the phosphorylation of Smad2/3 (p < 0.05) and the expression of Smad4 (p < 0.05), and (2) Sirt1 decreased the adhesive ability of TMCs by reducing the secretion of integrins (integrin-α3 (ITGα3), p < 0.01; integrin-β1 (ITGβ1), p < 0.001) and cadherins (E-cadherin, p < 0.01; N-cadherin, p < 0.01), and promoted cell migration (p < 0.05).

Conclusion: Sirt1 promotes the migration of cells and reduces the accumulation of ECM in TMCs induced by TGF-β by inhibiting the activation of Smad2/3 and the expression of Smad4.

Background: Chordoma is a rare, primary malignant bone tumor arising from remnants of embryonic notochord tissue. While the long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has been implicated in various cancers, its role in chordoma remains to be elucidated. This study aims to elucidate the mechanisms by which lncRNA NEAT1 influences chordoma growth and apoptosis.

Method: lncRNA NEAT1 expression was assessed in chordoma using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Two chordoma cell lines with high lncRNA NEAT1 expression were selected for lncRNA NEAT1 knockdown and inhibitor of apoptosis-stimulating protein of p53 (iASPP) overexpression experiments. Cell survival was assessed using Cell Counting Kit-8 (CCK-8) and colony formation assays, while apoptosis and iASPP expression levels were analyzed by flow cytometry, Western blotting (WB), and RT-qPCR. In vivo, treated U-CH1 cell lines were subcutaneously injected into nude mice to establish a chordoma model. Tumor apoptosis was evaluated through hematoxylin-eosin (HE) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay and WB was used to measure the levels of apoptosis-related proteins and iASPP in the tissues.

Results: The lncRNA NEAT1 was highly expressed in chordoma. Silencing lncRNA NEAT1 inhibited the survival and proliferation of chordoma cell lines MUG-Chor1 and U-CH1, and promoted apoptosis (p < 0.05). Overexpression of iASPP counteracted these effects, enhanced cell growth and inhibited apoptosis in the si-lncRNA NEAT1 group (p < 0.05). HE and TUNEL staining results indicated that silencing lncRNA NEAT1 reduced cell proliferation and division in chordoma tissues, and led to a marked increase in apoptosis (p < 0.05). These effects were reversed by overexpression of iASPP (p < 0.05).

Conclusion: In chordoma, lncRNA NEAT1 is highly expressed, and silencing lncRNA NEAT1 inhibits the proliferation and induces apoptosis of chordoma cells while decreasing the expression of iASPP. These findings offer new insights into the involvement of the lncRNA NEAT1/iASPP pathway in chordoma development.

Immune checkpoint inhibitors are one of the most promising areas in oncoimmunology research. T cell immunoglobulin and mucin domain-3 (TIM-3) expression has been linked to the advanced stages with reduced survival in several types of cancer, primarily due to its association with the dysfunction in T cells. Thus, TIM-3 is an interesting target in designing advanced therapy for cancer. TIM-3 has been implicated in resistance to immunotherapy on account of its involvement in T cell exhaustion. Identifying small molecule inhibitors targeting TIM-3 with high affinity, either alone or in combination with either chemotherapy or other types of immunotherapies could significantly enhance the life span, overcoming the resistance and overall immune response in therapy. TIM-3 pathway is multidimensional in terms of canonical signaling with varied expression of immune cells and diverse ligands and modulates the immune response. This may include restoration of the functioning of killer T lymphocytes and natural killer cells (NK cells) and likely promise better results in cancer immunotherapy. In this review, we will discuss the immunomodulatory role of TIM-3 in cancer, with special emphasis on lymphoma and solid tumors, and their role in diverse immune cells in tumorigenesis and inflammation.

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Advanced CRC has a poor prognosis, with treatment primarily relying on chemotherapy combined with targeted therapies. Currently, immunotherapy based on immune checkpoint inhibitors is reserved exclusively for mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) tumors, which represent less than 10% of advanced CRC cases. Chimeric antigen receptor (CAR)-T cell therapy is a type of adoptive cell therapy involving modified T-lymphocytes engineered to express chimeric antigen receptors, enabling them to recognize surface antigens expressed by tumor cells. CAR-T cell therapy has demonstrated efficacy in treating hematological malignancies such as lymphoma, myeloma, and leukemia. However, its efficacy in solid tumors remains limited due to several limitations such as antigen heterogeneity, restricted CAR-T cell trafficking into the tumor area, and the presence of an immunosuppressive tumor microenvironment. Developing novel CAR-T cell therapies for solid tumors represents an unmet need, particularly for cases where immune checkpoint blockade is ineffective, such as CRC. Preclinical studies have shown the efficacy of various CAR-T cell models targeting a wide range of tumor-associated antigens in CRC, both in vitro and in vivo. Despite these promising results, the clinical efficacy of CAR-T cell therapy for CRC has been limited in early-phase clinical trials. Factors such as trial design or tumor characteristics, including antigen heterogeneity and the immunosuppressive microenvironment, should be considered. The development of innovative CAR-T cell models and the identification of novel antigens may improve the effectiveness of CAR-T cell therapy for CRC patients.

The central nervous system (CNS) and the immune system might cooperate with each other on various levels in a body. Interestingly, signaling pathways linked to several G protein-coupled receptors (GPCRs) have been shown to be involved in the pathology both of CNS disorders including neurodegenerative diseases and/or immune-related diseases. Oxidative stress and inflammation are likely to contribute to cell damage and death in these disorders, which in turn could cause mitochondrial injury. Interestingly, it has been revealed that gut microbiota could play a significant role in changing the phenotype of various neuron and/or immune-related disorders. Remarkably, GPCR signaling has been recognized as a key upstream regulator for autophagy/mitophagy via the action of the mammalian/mechanistic target of rapamycin (mTOR) signaling. In addition, adjusting the composition of gut microbiota could be applied to modulate the autophagy/mitophagy by the alteration of GPCR signaling to ameliorate the mitochondrial injury. Collectively, this approach may contribute to the innovative development of promising therapeutics for neurodegenerative diseases and/or immune-related diseases. This review describes that concept, highlighting the intracellular mTOR signaling from the cell surface GPCRs within cells of Gut-brain-immune axis.

Background: Celastrol has been shown to inhibit hepatocellular carcinoma (HCC) progression, but the underlying mechanism is unknown. Fanconi anemia complementation group D2 (FANCD2), a ferroptosis inhibitor, promotes HCC proliferation and invasion. This study aims to investigate whether Celastrol exerts its effects by targeting FANCD2.

Methods: Using data from The Cancer Genome Atlas (TCGA), we identified differentially expressed genes in HCC utilizing Gene Expression Profiling Interactive Analysis 2 (GEPIA 2). FANCD2 and Celastrol were analyzed for molecular docking using Autodock, which was based on geometric matching and energy matching. The correlation between FANCD2 and survival rate was analyzed using Kaplan-Meier's estimates by log-rank (Mantel-Cox) test. HCC cell lines (SNU-423 and SNU-387) were overexpressed or silenced with FANCD2 and treated with Celastrol. Autophagy and ferroptosis were evaluated by measuring oxidative stress and related markers, and cell function experiments were performed.

Results: High expression of FANCD2 was correlated with poor survival in HCC patients. Celastrol targeted FANCD2, reducing its level in SNU-423 and SNU-387 cells. FANCD2 overexpression resulted in increased SNU-423 cell viability, migration, invasion, and tube formation ability, as well as attenuated autophagy and ferroptosis, while FANCD2 knockdown in SNU-387 cells showed opposite effects. Additionally, FANCD2 overexpression reversed the ability of Celastrol to induce autophagy and ferroptosis and to inhibit SNU-423 cell survival in vitro, while FANCD2 knockdown enhanced the effects of Celastrol in SNU-387 cells.

Conclusion: Celastrol inhibits malignant behavior in HCC cells by targeting FANCD2 to induce autophagy-dependent ferroptosis.

Background: Common cognitive impairment in the elderly may be aggravated by the anesthetic propofol, whereas the mammalian target of rapamycin protein (mTOR)-brain-derived neurotrophic factor (BDNF) pathway and autophagy regulation play a key role in neuroprotection. In this study, we investigated whether esketamine can improve propofol-induced cognitive impairment in aged rats by affecting these mechanisms and revealed potential new therapeutic strategies.

Methods: A propofol-induced age-related cognitive dysfunction model was used in the experiments. Behaviours were evaluated by the sugar-water preference test and the water maze, neuronal damage by Nissl staining, and neuronal apoptosis was detected by flow cytometry. Neuronal autophagy-related proteins phospho-mammalian target of rapamycin (p-mTOR), mTOR, BDNF, phospho-Unc-51 like autophagy activating kinase 1 (p-ULK1), Unc-51 like autophagy activating kinase 1 (ULK1), autophagy related 5 (ATG-5), and microtubule-associated protein 1 light chain 3-I/microtubule-associated protein 1 light chain 3-II (LC3-II/LC3-Ⅰ) were detected by western blotting (WB); immunohistochemistry was used to detect the deposition of β-amyloid (amyloid-beta, Aβ) in the hippocampal region and the positivity rate of caspase-3; postsynaptic density protein 95 (PSD95) and synapsin I (SYN1) levels were detected by WB.

Results: Water maze and sugar-water preference tests showed that the propofol group had longer escape latency, more platform crossings, lower platform quadrant time ratio, and reduced sugar-water preference, all improved by esketamine (p < 0.05). Nissl staining and immunohistochemistry revealed sparser neurons, darker staining, wrinkled morphology, and increased Aβ in the propofol group, all improved by esketamine (p < 0.05). WB showed increased phosphorylated Tau (p-Tau) and Aβ, higher apoptosis and caspase-3 positivity, and decreased BDNF, and ATG-5 in the propofol group, all reversed by esketamine. Propofol increased inflammatory markers and decreased SYN1, PSD95, and SYN expression, all of which were improved by esketamine (p < 0.05).

Conclusion: By inhibiting the mTOR-BDNF pathway with esketamine, the inhibition of neuronal autophagy ultimately improves the cognitive dysfunction induced by propofol.

Background: The management of temporomandibular disorders (TMD) remains challenging, with its underlying pathological mechanisms requiring further investigation. This study aimed to explore the effects of Botulinum Toxin A (Botox A) on the lateral pterygoid (LP) muscle and its impact on condylar subchondral bone mass.

Methods: Rats were randomly assigned to either an experimental group (injected with Botox A) or a control group (injected with an equal volume of 0.9% normal saline). All rats were sacrificed at 2-, 4-, 8-, or 12-weeks post-injection. The right condyles were harvested and analyzed using Micro-computed tomography (CT) scanning and hematoxylin-eosin staining to evaluate changes in the condylar subchondral bone. Osteoclast activity in the subchondral bone was assessed via tartrate-resistant acid phosphatase (TRAP) staining. The activities of osteoclasts and osteoblasts in subchondral bone were detected by western blotting.

Results: At 2-weeks post-Botox A injection, the trabecular number (Tb.N) was significantly lower (p < 0.01). At 2- and 4-weeks, bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) were significantly lower (p < 0.05), while trabecular space (Tb.SP) and the ratio of bone surface area to bone volume (BS/BV) were significantly increased in the experimental group compared to control group (p < 0.05). At 8-weeks, BS/BV remained significantly elevated (p < 0.05), but no significant differences were observed in Tb.N, Tb.Th, BV/TV, or Tb.Sp at 8- and 12- weeks. Osteoclast numbers in the condylar subchondral bone were significantly higher in the Botox A group at 2-, 4-, and 8-weeks compared to the control group (p < 0.05). Additionally, protein expression levels of osteocalcin (OCN) and type I collagen (COL1A1) were markedly increased in the experimental group at 8- and 12-weeks (p < 0.05).

Conclusions: Botox A induces a significant reduction in condylar subchondral bone mass in rats during the early post-injection period, with subsequent time-dependent recovery.

Background: Obesity threatens human health, and interventions to reduce obesity may have important effects on the gut microbiota. This study investigated alterations in gut microbial composition in response to aerobic exercise (AE) and intermittent fasting (IF).

Methods: We randomly divided mice into four groups of seven mice each: normal, obesity, exercise, and fasting. The normal group was fed a Chow Diet, whereas the other three groups were fed a High Fat Diet (HFD). After 13 weeks, the exercise group was subjected to aerobic treadmill running, and the fasting group started IF for 8 weeks. We then analyzed the composition of the fecal microbiome in all mice at the end of 21 weeks.

Results: Our investigation revealed that the HFD significantly influenced species (s)_Romboutsia ilealis, genus (g)_Dubosiella, and g_Blautia. AE predominantly affected family (f)_Rhizobiaceae and g_Rikenella, indicating its impact on enhancing microbial taxa associated with improved metabolic health profiles. On the other hand, IF prominently altered the abundance of s_Lactobacillus johnsonii and g_Colidextribacter, which are known for their roles in enhancing glucolipid metabolism and anti-inflammatory activity. Furthermore, the exercise group displayed increased diversity within f_Rhizobiaceae, potentially associated with anti-inflammatory benefits. The IF intervention was particularly effective in enriching s_Lactobacillus johnsonii, suggesting its pivotal role in regulating metabolic responses influenced by fasting.

Conclusion: The results demonstrated significant beneficial alterations in microbial composition following AE and IF interventions, which supports the use of personalized approaches for obesity management and overall health.

Background: Polyubiquitin gene Ubb knockout (KO) mice exhibit early onset reactive astrogliosis and adult-onset hypothalamic neurodegeneration with obesity. However, it remains unknown why the obesity phenotype only manifests in adulthood and why mice are smaller at an early age. Therefore, this study aimed to identify the link between neuroinflammation at an early age and adult-onset leptin signaling dysfunction in Ubb KO mice.

Methods: To investigate neuroinflammatory marker expression in the hypothalamus of Ubb KO mice, RNA-seq analysis and quantitative reverse transcription-polymerase chain reaction were used. Moreover, astrocytes isolated from postnatal brains were cultured and pure astrocytes were obtained by magnetic-activated cell sorting. Furthermore, mice were challenged with lipopolysaccharide (LPS) to induce upregulation of neuroinflammatory markers, including lipocalin-2 (LCN2). Leptin signaling was examined through the administration of leptin via intraperitoneal or intracerebroventricular injection, followed by monitoring of relevant proteins using immunofluorescence and western blot analyses.

Results: In Ubb KO mice, reactive astrogliosis occurred at an early age and increased the expression of Lcn2 and other neuroinflammatory markers. Upon exposure to LPS, these levels showed upward trends; however, they were comparable with those in wild-type mice, suggesting that Ubb KO mice were under intrinsic inflammatory stress. In adulthood, leptin signaling dysfunction was observed owing to elevated levels of negative regulators, such as suppressor of cytokine signaling-3 (SOCS3) and forkhead box protein O1 (FOXO1), possibly as a result of chronic neuroinflammation.

Conclusion: This study demonstrates that Lcn2 expression is increased in young Ubb KO mice. Although leptin signaling is intact at an early age, high LCN2 levels may contribute to reduced daily food intake and lower body weight. Chronic neuroinflammation resulting from reactive astrogliosis persists into adulthood, leading to leptin signaling dysfunction. This is most likely a result of elevated levels of SOCS3 and FOXO1, both of which are negative regulators of leptin signaling.