Biochimica et biophysica acta. Molecular basis of disease最新文献

Currently, the molecular mechanisms underlying bladder cancer progression remain unclear. Immune checkpoint inhibitors (ICIs) have been used to treat bladder cancer, but their efficacy is limited. Exosomes, which play a critical role in cell communication, can alter the tumor microenvironment. Therefore, it is essential to investigate the impact of bladder cancer exosomes on the tumor microenvironment. Our research demonstrates a significant up-regulation of miR-184 in exosomes derived from bladder cancer cells. miR-184 promotes bladder cancer cell proliferation in vitro and facilitates tumor growth in mice by targeting the 3' UTR of AKR1C3 mRNA. Additionally, miR-184 targets IRF2 mRNA, reducing its transcriptional inhibition on CXCL10. This process induces the expression of CXCL10, which promotes the infiltration of CD8+ T cells into the tumor. However, these infiltrating T cells become exhausted. In summary, our study reveals that bladder cancer-derived exosomes deliver miR-184, which targets AKR1C3, contributing to bladder carcinogenesis and development. We also investigate how the IRF2-CXCL10 pathway induces T cell exhaustion and leads to immune escape. This research provides new insights into the immunotherapy of bladder cancer, highlighting potential molecular targets for more effective treatment strategies.

The integrity of the endothelial monolayer is critical for preventing life-threatening hemorrhaging and thrombosis. However, how severe endothelium-denuded injury is rapidly repaired remains unknown. Given the common biological properties between endothelial cells and circulating monocytes, we aimed to examine whether blood monocytes are involved in endothelium wound healing. The in vivo common carotid artery endothelium-denuded (CCAED) model was established through a wire-induced injury. Monocyte adhesion was assessed using immunofluorescence and a parallel plate flow chamber. We initially observed that the circulating monocyte-mediated endothelialization was better downstream of kinase 3 deficient mice (DOK3^-/-) than that of wild-type (WT) mice following induction of the CCAED model. Rapid endothelialization increased endothelial integrity, prevented coagulation, and decreased thrombosis. Mechanistically, following endothelium-denuded injury, monocyte chemoattractant protein 1 (MCP1) disassociated from DOK3 and C-C chemokine receptor type 2B (CCR2B), increased the intracellular Ca²⁺ concentration, and promoted adhesion in circulating monocytes. However, this process was inhibited by the CCR2B inhibitor INCB3344. Moreover, the adhesive functions of circulating monocytes isolated from DOK3^-/- mice were stronger than those from WT mice. Furthermore, adhered monocytes expressed endothelial-specific markers and compensated for endothelium-dependent vasorelaxation in WT mice. Similarly, these effects were enhanced in DOK3^-/- mice. Bindarit, a selective MCP1 inhibitor, suppressed endothelialization following CCAED surgery in WT mice but not in DOK3^-/- mice. In conclusion, endothelialization mediated by circulating monocytes repairs endothelium-denuded injury to compensate for endothelial functions through MCP1/DOK3/CCR2B/Ca²⁺ signaling. Our findings indicate that circulating monocyte adhesion is an important endothelial wound healing mechanism.

Targeted therapies persist as the conventional method of treatment of kidney clear cell carcinoma (KIRC). However, resistance to these drugs emerges as a significant impediment to the management of renal cancer. MICAL-L2 plays a pivotal role in cytoskeleton rearrangement. This study sought to elucidate the clinical relevance of MICAL-L2 in KIRC and its regulatory mechanism driving cancer progression and resistance to therapy. TCGA data mining was utilized to assess the expression of MICAL-L2 in samples from patients with KIRC. Kaplan-Meier analysis and immunohistochemistry were employed to explore the clinical significance of MICAL-L2. In vitro experiments, including assays for wound healing and Transwell migration, CCK-8, EDU staining, RT-PCR, flow cytometry, and co-immunoprecipitation analysis were conducted to investigate the effects of MICAL-L2 on the drug sensitivity of KIRC cells and to elucidate the molecular mechanisms involved. The results showed that MICAL-L2 was overexpressed in KIRC tissues. High levels of MICAL-L2 were associated with poor survival and a poor response to drug therapy among patients with KIRC. Overexpression of MICAL-L2 stimulated cell migration, proliferation, and rendered KIRC cells insensitive to sunitinib and everolimus, two traditional therapies for KIRC. Furthermore, MICAL-L2 overexpression accelerated cancer progression and resistance to therapy in KIRC cells by interacting with its downstream regulator α-actinin-4 (ACTN4) in a Rab13-dependent manner, which reduced the degradation of ACTN4, leading to increased Vimentin expression. All these findings indicate that MICAL-L2 plays a crucial role in the progression of KIRC and suggest that MICAL-L2 may serve as a potential therapeutic target for KIRC treatment.

Background: The heat shock response (HSR) is a highly conserved mechanism that maintains intracellular homeostasis in response to various environmental and physiological stresses. Heat shock proteins (HSPs), particularly HSP70, play a pivotal role in this process as molecular chaperones. Although HSP70 inhibitors have demonstrated anti-cancer activity, their therapeutic potential has been limited by the negative feedback mechanism between HSP70 and heat shock factor 1 (HSF1). The combination of HSP70 inhibitors with HSF1 inhibitors has been proposed to overcome this limitation and enhance anti-cancer effects.

Methods: We combined HSP70 inhibitors (VER-155008 and YK-5) with an HSF1 inhibitor (DTHIB) in CRC cells and evaluated their effects on cell survival, apoptosis, and protein homeostasis.

Results: Strong synergistic effects were observed (combination index <0.5, ZIP score > 10) with the combination treatment, leading to decreased cell survival and increased apoptosis in CRC cells. Mechanistic studies revealed that HSP70 inhibitors activated the phosphorylation of HSF1, inducing HSP70 expression, and that the combination therapy resulted in more pronounced HSR inhibition and protein homeostasis disturbances.

Conclusion: The combination therapy of HSP 70 and HSF 1 inhibitors showed significant synergistic antitumor activity.

General significance: Combining HSP70 and HSF1 inhibitors may be a promising anti-cancer strategy, offering a potential solution to overcome the negative feedback mechanism and enhance anti-cancer effects.

Mitochondria are pivotal in cellular energy metabolism, the oxidative stress response and apoptosis. Recent research has focused on harnessing their functions to enhance the efficacy of radiation therapy (RT). This review focuses on the critical functions and applications of mitochondria in radiation therapy, including the targeting of mitochondrial metabolism and the modulation of mitochondria-mediated cell death and immune responses. While these strategies have demonstrated considerable potential in preclinical studies to improve radiotherapy outcomes, challenges remain, such as optimizing drug delivery systems, ensuring safety and overcoming resistance to therapy.

Cyclin-dependent kinase 8 (CDK8) is a transcription-related CDK family member implicated in the regulation of bone homeostasis, and we recently demonstrated that our internally developed CDK8 inhibitor KY-065 can prevent postmenopausal osteoporosis in a mouse model. Achondroplasia (ACH), the most common form of genetic dwarfism in humans, is caused by a gain-of-function mutation in fibroblast growth factor receptor 3 (FGFR3), a receptor tyrosine kinase that activates downstream mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT) signaling pathways. The first precision drug approved for the treatment of ACH in children, the C-type natriuretic peptide analog vosoritide, antagonizes the MAPK pathway, while there are currently no effective and safe medications targeting the STAT1 pathway. Here, we demonstrate that KY-065 rescues impaired chondrogenesis and stunted long bone growth in the Fgfr3^Ach mouse model of ACH. KY-065 inhibited CDK8 with high affinity in vitro by competing with ATP. The CDK8 expression and STAT1^Ser727 phosphorylation were upregulated in chondrocytes isolated from ACH model mice, and KY-065 repressed its phosphorylation and restored normal chondrogenic differentiation without affecting MAPK activation. Moreover, daily administration of 10 mg/kg KY-065 to Fgfr3^Ach mice (yielding a peak concentration of 22.0 ± 1.47 μM in plasma) resulted in significant elongation of long bone and improved growth plate cytoarchitecture. Collectively, these findings identify the CDK8 in chondrocytes as a potential therapeutic target for ACH and KY-065 as a promising candidate drug treatment for this debilitating skeletal disease.

Background: Type 2 diabetes mellitus (T2D) is a significant health concern. Research using non-human primates, which develop T2D with similar symptoms and pancreatic changes as humans, is crucial but limited by long timelines and low success rates.

Results: We targeted capture sequenced 61 normal and 81 T2D cynomolgus monkeys using a primer panel that captured 269 potential regulatory regions potentially associated with T2D in the cynomolgus monkey genome. 80 variants were identified to be associated with T2D and were used to construct a genetic prediction model. Among 8 machine learning algorithms tested, we found that the best prediction performance was achieve when the model using support vector machine with polynomial kernel as the machine learning algorithm (AUC = 0.933). Including age and sex in this model did not significantly improve the prediction performance. Using the genetic prediction model, we further screened 22 monkeys and found 13 were high risk while 9 were low risk. After feeding the 22 monkeys with high-energy food for 32 weeks, we found all the 9 low risk monkeys did not develop T2D while 4 out of 13 high risk monkeys (31 %) develop T2D.

Conclusions: This method greatly increased the success rate of establishing T2D monkey models while decreased the time needed compared to traditional methods. Therefore, we developed a new high-efficiency method to establish T2D monkey models by combining the genetic prediction model and high-energy diet, which will greatly contribute to the research on the clinical characteristics, pathogenesis, complications and potential new treatments.

Auditory neuropathy (AN) is an under-recognized form of hearing loss characterized by lesions in inner hair cells (IHCs), ribbon synapses and spiral ganglion neurons (SGNs). The lack of a targeted therapy for AN has increased the need for a better understanding of the pathogenic mechanism of AN. As mitogen-activated protein kinase (MAPK) signaling is ubiquitous in many biological processes, its alteration may facilitate the pathogenesis of multiple sites in AN. Here, we summaries the characteristics of AN under different molecular bases and first explore the mechanism of MAPK at different lesion sites. Alterations of extracellular signal-regulated kinase (ERK)/MAPK occur in IHCs and SGNs, whereas modulations of p38 and c-Jun NH2-terminal kinase (JNK) were found in ribbon synapses and SGNs. In conclusion, inductive MAPK alterations in the pathogenesis and development of AN are likely to represent a potential therapeutic target to guide the development of treatments.

This study investigates the involvement of fibrosis in primary inferior oblique overaction (PIOOA), a strabismus characterized by excessive upward eye rotation. First, we identified extensive fibrotic changes in inferior oblique (IO) muscles in PIOOA patients compared to normal controls. A strong positive correlation was clinically established between the severity of PIOOA and the expression of collagen type I alpha 1 chain (COL1A1). COL1A1 levels correlate with preoperative and postoperative clinical grading of PIOOA and the degree of fundus deviation, as measured by disk-foveal angle (DFA). Moreover, immunofluorescence in IO muscle sections of PIOOA patients confirmed activation of fibro/adipogenic progenitors (FAPs) and suggested increased activation of YAP. Interestingly, the TGFβ signaling pathway also exhibited activation, with a notable increase observed in the expression of TGFβ2 in the PIOOA group. Subsequently, we first isolated FAPs from human IO muscles and validated these findings. In vitro, YAP overexpression promoted the differentiation of FAPs into myofibroblasts, exacerbating fibrotic changes. However, knockdown of YAP inhibited the activation of FAPs and fibrogenesis induced by TGFβ2. More importantly, we found TGFβ2 treatment promoted the activation of YAP simultaneously, and the overexpression or inhibition of YAP also affected TGFβ2 production and Smad phosphorylation, indicating a close connection between the two. Remarkably, verteporfin was observed to block both pathways effectively. Taken together, these findings suggest that the YAP-TGFβ-SMAD signaling cascade plays a key role in the pathophysiology of PIOOA through FAP-mediated fibrosis. Targeting these pathways may therefore provide a potential therapeutic strategy for managing PIOOA by alleviating muscle fibrosis.