The FAcilitates Chromatin Transcription complex regulates the ratio of glycolysis to oxidative phosphorylation in neural stem cells.

Defects in the FAcilitates Chromatin Transcription (FACT) complex, a histone chaperone composed of SSRP1 and SUPT16H, are implicated in intellectual disability. Here, we reveal that the FACT complex promotes glycolysis and sustains the correct cell fate of neural stem cells/neuroblasts in the Drosophila 3rd instar larval central brain. We show that the FACT complex binds to the promoter region of the estrogen-related receptor (ERR) gene and positively regulates ERR expression. ERR is known to act as an aerobic glycolytic switch by upregulating the enzymes required for glycolysis. Dysfunction of the FACT complex leads to the downregulation of ERR transcription, resulting in a decreased ratio of glycolysis to oxidative phosphorylation (G/O) in neuroblasts. Consequently, neuroblasts exhibit smaller cell sizes, lower proliferation potential, and altered cell fates. Overexpression of ERR or suppression of mitochondrial oxidative phosphorylation in neuroblasts increases the relative G/O ratio and rescues defective phenotypes caused by dysfunction of the FACT complex. Thus, the G/O ratio, mediated by the FACT complex, plays a crucial role in neuroblast cell fate maintenance. Our study may shed light on the mechanism by which mutations in the FACT complex lead to intellectual disability in humans.

Regulation of m6Am RNA modification and its implications in human diseases.

N 6,2'-O-dimethyladenosine (m6Am) is a prevalent modification frequently found at the 5' cap-adjacent adenosine of mRNAs and snRNAs and the internal adenosine of snRNAs. This dynamic and reversible modification is under the regulation of methyltransferases PCIF1 and METTL4, along with the demethylase FTO. m6Am RNA modification plays a crucial role in the regulation of pre-mRNA splicing, mRNA stability, and translation, thereby influencing gene expression. In recent years, there has been growing interest in exploring the functions of m6Am and its relevance to human diseases. In this review, we provide a comprehensive overview of the current knowledge concerning m6Am, with a focus on m6Am-modifying enzymes, sequencing approaches for its detection, and its impacts on pre-mRNA splicing, mRNA stability, and translation regulation. Furthermore, we highlight the roles of m6Am in the context of obesity, viral infections, and cancers, unravelling its underlying regulatory mechanisms.

Design and biological evaluation of dual tubulin/HDAC inhibitors based on millepachine for treatment of prostate cancer.

In this work, a novel of dual tubulin/HDAC inhibitors were designed and synthesized based on the structure of natural product millepachine, which has been identified as a tubulin polymerization inhibitor. Biological evaluation revealed that compound 9n exhibited an impressive potency against PC-3 cells with the IC50 value of 16 nM and effectively inhibited both microtubule polymerization and HDAC activity. Furthermore, compound 9n not only induced cell cycle arrest at G2/M phase, but also induced PC- 3 cells apoptosis. Further study revealed that the induction of cell apoptosis by 9n was accompanied by a decrease in mitochondrial membrane potential and an elevation in reactive oxygen species levels in PC-3 cells. Additionally, 9n exhibited inhibitory effects on tumor cell migration and angiogenesis. In PC-3 xenograft model, 9n achieved a remarkable tumor inhibition rate of 90.07%@20 mg/kg, significantly surpassing to that of CA-4 (55.62%@20 mg/kg). Meanwhile, 9n exhibited the favorable drug metabolism characteristics in vivo. All the results indicate that 9n is a promising dual tubulin/HDAC inhibitor for chemotherapy of prostate cancer, deserving the further investigation.

Discovery of Novel Isoquinoline Analogues as Dual Tubulin Polymerization/V-ATPase Inhibitors with Immunogenic Cell Death Induction.

Cancer immunotherapy has revolutionized clinical advances in a variety of cancers. Due to the low immunogenicity of the tumor, only a few patients can benefit from it. Specific microtubule inhibitors can effectively induce immunogenic cell death and improve immunogenicity of the tumor. A series of isoquinoline derivatives based on the natural products podophyllotoxin and diphyllin were designed and synthesized. Among them, F10 showed robust antiproliferation activity against four human cancer cell lines, and it was verified that F10 exerted antiproliferative activity by inhibiting tubulin and V-ATPase. Further studies indicated that F10 is able to induce immunogenic cell death in addition to apoptosis. Meanwhile, F10 inhibited tumor growth in an RM-1 homograft model with enhanced T lymphocyte infiltration. These results suggest that F10 may be a promising lead compound for the development of a new generation of microtubule drugs.

Design, synthesis and biological evaluation of CDC20 inhibitors for treatment of triple-negative breast cancer.

The involvement of CDC20 in promoting tumor growth in different types of human cancers and it disturbs the process of cell division and impedes tumor proliferation. In this work, a novel of Apcin derivatives targeting CDC20 were designed and synthesized to evaluate for their biological activities. The inhibitory effect on the proliferation of four human tumor cell lines (MCF-7, MDA-MB-231, MDA-MB-468 and A549) was observed. Among them, compound E1 exhibited the strongest inhibitory effect on the proliferation of MDA-MB-231 cells with an IC50 value of 1.43 µM, which was significantly superior to that of Apcin. Further biological studies demonstrated that compound E1 inhibited cancer cell migration and colony formation. Furthermore, compound E1 specifically targeted CDC20 and exhibited a higher binding affinity to CDC20 compared to that of Apcin, thereby inducing cell cycle arrest in the G2/M phase of cancer cells. Moreover, it has been observed that compound E1 induces autophagy in cancer cells. In 4T1 Xenograft Models compound E1 exhibited the potential antitumor activity without obvious toxicity. These findings suggest that E1 could be regarded as a CDC20 inhibitor deserved further investigation.

Sodium carboxymethyl celluloses as a cryoprotectant for survival improvement of lactic acid bacterial strains subjected to freeze-drying.

This study investigated the possibility of sodium carboxymethyl celluloses (Na-CMC) in protecting the viability of lactic acid bacteria (LAB) against freeze-drying stress. 1 % concentration of Na-CMC with a 0.7 substitution degree and viscosity of 1500 to 3100 (MPa.s) was found to protect Lactobacillus delbrueckii subsp. bulgaricus CICC 6098 best, giving a high survival rate of 23.19 ± 0.88 %, high key enzymatic activities, and 28-day storage stability. Additionally, Na-CMC as cryoprotectant provided good protection for other 7 lactic acid bacterial strains subjected to freeze-drying. The highest survival rate was 48.79 ± 0.20 U/mg for ß-GAL, 2.75 ± 0.15 U/mg for Na+-K+-ATPase, and 2.73 ± 0.41 U/mg for Ca2+-Mg2+-ATPase as 48.48 ± 0.46 % for freeze-dried Pediococcus pentosaceus CICC 22228. It was Interesting to note that the presence of Na-CMC reduced the freezable water content of the lyophilized powders containing the tested strains through its hydroxyl group, and supplied micro-holes and fibers for protecting the integrated structure of LAB cell membrane and wall against the freezing damage. It is clear that addition of Na-CMC should be promising as a new cryoprotective agent available for processing the lyophilized stater cultures of LAB strains.

Mutational burden of XPNPEP3 leads to defects in mitochondrial complex I and cilia in NPHPL1.

Nephronophthisis-like nephropathy-1 (NPHPL1) is a rare ciliopathy, caused by mutations of XPNPEP3. Despite a well-described monogenic etiology, the pathogenesis of XPNPEP3 associated with mitochondrial and ciliary function remains elusive. Here, we identified novel compound heterozygous mutations in NPHPL1 patients with renal lesion only or with extra bone cysts together. Patient-derived lymphoblasts carrying c.634G>A and c.761G>T together exhibit elevated mitochondrial XPNPEP3 levels via the reduction of mRNA degradation, leading to mitochondrial dysfunction in both urine tubular epithelial cells and lymphoblasts from patient. Mitochondrial XPNPEP3 was co-immunoprecipitated with respiratory chain complex I and was required for the stability and activity of complex I. Deletion of Xpnpep3 in mice resulted in lower activity of complex I, elongated primary cilium, and predisposition to tubular dilation and fibrosis under stress. Our findings provide valuable insights into the mitochondrial functions involved in the pathogenesis of NPHP.

Discovery of Novel Potent Covalent Glutathione Peroxidase 4 Inhibitors as Highly Selective Ferroptosis Inducers for the Treatment of Triple-Negative Breast Cancer.

Glutathione peroxidase 4 (GPX4) is a promising target to induce ferroptosis for the treatment of triple-negative breast cancer (TNBC). We designed and synthesized a novel series of covalent GPX4 inhibitors based on RSL3 and ML162 by structural integration and simplification strategies. Among them, compound C18 revealed a remarkable inhibitory activity against TNBC cells and significantly inhibited the activity of GPX4 compared to RSL3 and ML162. Moreover, it was identified that C18 could notably induce ferroptosis with high selectivity by increasing the accumulation of lipid peroxides (LPOs) in cells. Further study demonstrated that C18 covalently bound to the Sec46 of GPX4. Surprisingly, C18 exhibited an outstanding potency of tumor growth inhibition in the MDA-MB-231 xenograft model with a TGI value of 81.0%@20 mg/kg without obvious toxicity. Overall, C18 could be a promising GPX4 covalent inhibitor to induce ferroptosis for the treatment of TNBC.

Endothelial progenitor cell-derived exosomes promote anti-inflammatory macrophages via SOCS3/JAK2/STAT3 axis and improve the outcome of spinal cord injury.

BACKGROUND: Macrophage in the spinal cord injury (SCI) area imparts a chronic pro-inflammation effect that challenges the recovery of SCI. Previously, endothelial progenitor cell-produced exosomes (EPC-EXOs) have been noticed to facilitate revascularization and inflammation control after SCI. However, their effects on macrophage polarization remained unclear. This study aimed to investigate the EPC-EXOs' role in macrophage polarization and reveal its underlying mechanism. METHODS: We extracted the macrophages and EPC from the bone marrow suspension of C57BL/L mice by centrifugation. After cell identification, the EPC-EXOs were collected by ultra-high-speed centrifugation and exosome extraction kits and identified by transmission electron microscopy and nanoparticle tracking analysis. Then, macrophages were cultured with EPC-EXOs in different concentrations. We labeled the exosome to confirm its internalization by macrophage and detected the macrophage polarization marker level both in vitro and in vivo. We further estimated EPC-EXOs' protective effects on SCI by mice spinal cord tissue H&E staining and motor behavior evaluation. Finally, we performed RT-qPCR to identify the upregulated miRNA in EPC-EXOs and manipulate its expression to estimate its role in macrophage polarization, SOCS3/JAK2/STAT3 pathway activation, and motor behavior improvement. RESULTS: We found that EPC-EXOs decreased the macrophages' pro-inflammatory marker expression and increased their anti-inflammatory marker expression on the 7 and 14 days after SCI. The spinal cord H&E staining results showed that EPC-EXOs raised the tissue-sparing area rate significantly after 28 days of SCI and the motor behavior evaluation indicated an increased BMS score and motor-evoked potential by EPC-EXOs treatment after SCI. The RT-qPCR assay identified that miR-222-3P upregulated in EPC-EXOs and its miRNA-mimic also decreased the pro-inflammatory macrophages and increased the anti-inflammatory macrophages. Additionally, miR-222-3P mimic activated the SOCS3/JAK2/STAT3 pathway, and SOCS3/JAK2/STAT3 pathway inhibition blocked miR-2223P's effects on macrophage polarization and mouse motor behavior. CONCLUSION: Comprehensively, we discovered that EPC-EXOs-derived miR-222-3p affected macrophage polarization via SOCS3/JAK2/STAT3 pathway and promoted mouse functional repair after SCI, which reveals EPC-EXOs' role in modulation of macrophage phenotype and will provide a novel interventional strategy to induce post-SCI recovery.

STING mediates SU5416/hypoxia-induced pulmonary arterial hypertension in rats by regulating macrophage NLRP3 inflammasome activation.

BACKGROUND: The NLRP3 inflammasome in macrophages is known to promote infection-related vascular growth, and NLRP3 inflammasome activation interacts with PAH. STING is a crucial inflammatory reaction link that can increase the overexpression of NLRP3. However, the expression and effect of STING in PAH have not been elucidated. We examined the expression and articulation of STING in PAH and researched its hidden mechanism. METHODS: A SU5416 plus hypoxia (Su/Hy)-induced rat model of PAH was constructed to examine STING activation. Su/Hy induced PAH rats were given a prophylactic injection of STING the inhibitor C-176. After modeling, hemodynamic changes, right ventricular hypertrophy index, lung morphological features, inflammasome activation, and proinflammatory cytokine secretion levels were assessed. In addition, the STING agonist DMXAA or inhibitor C-176 was used to interfere with LPS-induced BMDMs, NLRP3 inflammasome activation and cytokine secretion were examined, and the effect on PASMCs was evaluated in a coculture system. RESULTS: STING expression increased significantly in the lung tissue of Su/Hy-treated PAH rats compared with normoxia-treated rats. Moreover, STING inhibitors can alleviate the Su/Hy-induced increase in pulmonary artery pressure and restrain the activation of the NLRP3 inflammasome and proinflammatory cytokines. In vitro experiments confirmed that STING affected the expression of the NLRP3 inflammasome and the secretion of inflammatory cytokines in BMDMs and promoted the proliferation of PASMCs in the coculture system. CONCLUSION: Our study shows that STING is activated in Su/Hy-induced PAH and boosts the actuation of the macrophage NLRP3 inflammasome to advance the inflammatory response and vascular proliferation in rats with Su/Hy-induced pulmonary hypertension.

Co-dependent regulation of p-BRAF and potassium channel KCNMA1 levels drives glioma progression.

BRAF mutations have been found in gliomas which exhibit abnormal electrophysiological activities, implying their potential links with the ion channel functions. In this study, we identified the Drosophila potassium channel, Slowpoke (Slo), the ortholog of human KCNMA1, as a critical factor involved in dRafGOF glioma progression. Slo was upregulated in dRafGOF glioma. Knockdown of slo led to decreases in dRafGOF levels, glioma cell proliferation, and tumor-related phenotypes. Overexpression of slo in glial cells elevated dRaf expression and promoted cell proliferation. Similar mutual regulations of p-BRAF and KCNMA1 levels were then recapitulated in human glioma cells with the BRAF mutation. Elevated p-BRAF and KCNMA1 were also observed in HEK293T cells upon the treatment of 20 mM KCl, which causes membrane depolarization. Knockdown KCNMA1 in these cells led to a further decrease in cell viability. Based on these results, we conclude that the levels of p-BRAF and KCNMA1 are co-dependent and mutually regulated. We propose that, in depolarized glioma cells with BRAF mutations, high KCNMA1 levels act to repolarize membrane potential and facilitate cell growth. Our study provides a new strategy to antagonize the progression of gliomas as induced by BRAF mutations.

Discovery of Novel N-Heterocyclic-Fused Deoxypodophyllotoxin Analogues as Tubulin Polymerization Inhibitors Targeting the Colchicine-Binding Site for Cancer Treatment.

Natural products are a major source of anticancer agents and play critical roles in anticancer drug development. Inspired by the complexity-to-diversity strategy, novel deoxypodophyllotoxin (DPT) analogues were designed and synthesized. Among them, compound C3 exhibited the potent antiproliferative activity against four human cancer cell lines with IC50 values in the low nanomolar range. Additionally, it showed marked activity against paclitaxel-resistant MCF-7 cells and A549 cells. Moreover, compound C3 can inhibit tubulin polymerization by targeting the colchicine-binding site of tubulin. Further study revealed that compound C3 could arrest cancer cells in the G2/M phase and disrupt the angiogenesis in human umbilical vein endothelial cells. Meanwhile, C3 remarkably inhibited cancer cell motility and migration, as well as considerably inhibited tumor growth in MCF-7 and MCF-7/TxR xenograft model without obvious toxicity. Collectively, these results indicated that compound C3 may be a promising tubulin polymerization inhibitor development for cancer treatment.