The objective of the present review was to summarize and discuss recent findings on the effects of Mn exposure on Nrf2 signaling in the brain and its relationship with other molecular mechanisms of Mn neurotoxicity. The existing data show that Mn exposure interferes with Nrf2 signaling following a biphasic response model. Upon low-to-moderate dose or following short-term exposure, Mn activates Nrf2 signaling with subsequent upregulation of Nrf2-target antioxidant genes, which limit progression of Mn-induced oxidative stress. Evidence from Nrf2-deficient animal models support the essential role of Nrf2 in counteracting Mn-induced neuronal oxidative stress. In contrast, high-dose and/or long-term Mn exposure down-regulates Nrf2 signaling due to inhibition of SIRT1, REST1, and CYP1B1 expression, as well as upregulation of GSK-3β expression. The observed inhibition of Nrf2 signaling is associated not only with oxidative stress, but is also tightly related to Mn-induced neuroinflammation, pyroptosis, neurodegeneration, endoplasmic reticulum stress, ferroptosis, tau and amyloid-β accumulation, and dysregulated heat-shock protein expression. Although the existing data were derived from laboratory studies and environmentally irrelevant doses, it is assumed that Nrf2 signaling may represent a potential therapeutic strategy for preventing Mn neurotoxicity.

CBL is a multifunctional protein with E3 ubiquitin ligase and adaptor capacities, critical to regulating tyrosine kinase signaling pathways. CBL mutations have been identified and most widely characterized in myeloid malignancies, while alterations in solid tumors have also been found. Given its essential role in signaling regulation, disrupted CBL function contributes to oncogenesis and tumor progression. Here we review the mechanisms of CBL dysregulation in cancer, including an overview of mutations identified in leukemias, the impacts of mutant CBL expression on cellular signaling, and how these signaling alterations have been investigated using targeted inhibitors. In addition, CBL mutations identified in solid tumors are described, as well as the mechanisms underlying dysregulation of wild-type CBL function in several malignancies. A consolidated molecular view of disrupted CBL function in cancer is detailed, concluding with descriptions of preclinical approaches to modulate CBL function and identified tool compounds that target CBL regulation.

The RNA methyltransferase zinc finger CCCH-type containing protein 13 (ZC3H13) is downregulated in atherosclerosis (AS), but its functional mechanism remains unclear. Endothelial-mesenchymal transition (EndMT) is a core pathological driver of endothelial dysfunction in AS. This study aimed to investigate the biological function and molecular mechanism of ZC3H13 in regulating EndMT during AS progression. We found that ZC3H13 expression was reduced in aortic tissues of AS mice and in oxidized low‑density lipoprotein (ox‑LDL)-treated human umbilical vein endothelial cells (HUVECs). In ox-LDL-stimulated HUVECs, overexpression of ZC3H13 markedly upregulated endothelial markers (CD31, VE-cadherin), downregulated mesenchymal markers (α-SMA, vimentin), suppressed cell migration, and restored angiogenesis. Conversely, ZC3H13 silencing induced HUVECs EndMT, enhanced migration and impaired angiogenesis. Mechanistically, ZC3H13 elevated tripartite motif-containing protein 16 (TRIM16) mRNA stability by modulating its N6-methyladenosine (m6A) modification. TRIM16 knockdown abolished the protective effects of ZC3H13 overexpression against ox-LDL-induced EndMT and endothelial dysfunction. Furthermore, TRIM16 interacts with angiopoietin-2 (Ang2) and promotes its K48- and K63-linked ubiquitination, thereby inhibiting TLR4/NLRP3 activation and consequently suppressing EndMT. In vivo, lentivirus-mediated ZC3H13 overexpression attenuated atherosclerotic plaque formation and inhibited EndMT. In conclusion, ZC3H13 alleviates AS by suppressing EndMT via the TRIM16/Ang2/TLR4/NLRP3 pathway, highlighting ZC3H13 as a potential therapeutic target for AS.

This study evaluated the protective effects of asperulosidic acid (ASP) against myocardial ischemia/reperfusion (I/R) injury and investigated the underlying mechanisms. An in vitro oxygen-glucose deprivation/reoxygenation model was established in H9c2 cells, and an in vivo rat I/R model was generated by left anterior descending coronary artery ligation. ASP treatment significantly improved cell viability and reduced apoptosis in vitro. In vivo, ASP decreased myocardial infarct size, alleviated histopathological damage, and reduced serum creatine kinase and lactate dehydrogenase levels. Additionally, ASP suppressed inflammatory cytokine expression, reduced reactive oxygen species and malondialdehyde levels, enhanced antioxidant enzyme activities, and inhibited myocardial apoptosis. Network pharmacology and molecular docking identified the MAPK signaling pathway as a potential target. Mechanistically, ASP reduced the phosphorylation of p38, ERK, and JNK in myocardial tissue. These findings demonstrate that ASP attenuates myocardial I/R injury by reducing oxidative stress, inflammation, and apoptosis, associated with suppression of the MAPK signaling pathway.

This study investigated the role of LRRK2, a protein implicated in cancers but poorly understood in atherosclerosis, in oxidized low-density lipoprotein (Ox-LDL)-induced endothelial dysfunction. An in vitro model was established using HUVECs treated with Ox-LDL. Cell viability, apoptosis, reactive oxygen species (ROS) levels, and mitochondrial membrane potential were assessed using standard assays. Results showed that Ox-LDL exposure caused dose- and time-dependent decreases in cell viability and concurrent upregulation of LRRK2 expression. Silencing LRRK2 significantly improved cell survival and suppressed Ox-LDL-induced apoptosis, as evidenced by modulation of key apoptotic proteins (decreased cleaved-caspase-3, cleaved-caspase-9, and Bax; increased Bcl-2). LRRK2 silencing alleviated oxidative stress by elevating antioxidant superoxide dismutase and glutathione levels, reducing malondialdehyde and ROS production, and restoring mitochondrial membrane potential. Mechanistically, si-LRRK2 enhanced NRF2 expression and nuclear translocation, leading to increased levels of its downstream targets heme oxygenase-1 and NAD(P)H quinone dehydrogenase 1. The critical role of this pathway was confirmed, as pharmacological inhibition of NRF2 with ML385 reversed all protective effects of si-LRRK2. LRRK2 is a key mediator of Ox-LDL-induced endothelial damage. Its inhibition protects HUVECs by activating the NRF2 signaling pathway, suggesting LRRK2 as a promising novel therapeutic target for combating endothelial dysfunction in atherosclerosis and related cardiovascular diseases.

Immune checkpoint inhibitors (ICIs) are widely used in cancer treatment but can cause severe cardiotoxicity. Anti-inflammatory and cardioprotective effects of sinomenine have been documented in existing research. However, it remains unclear what role sinomenine plays in myocardial injury induced by PD-1 inhibitors. Myocardial injury in mice, induced by PD-1 inhibitors, was used to establish an experimental model. After administering sinomenine to the mice, assessments of cardiac function were conducted using echocardiographic techniques. Histological examination and ELISA were performed to evaluate myocardial injury, inflammation, and mitochondrial dysfunction. The expression of key proteins in the TLR4/NF-κB pathway was determined via Western blotting. Treatment with sinomenine notably enhanced cardiac function and mitigated myocardial injury in mice subjected to PD-1 inhibitors. It also attenuated myocardial inflammation and mitochondrial dysfunction. Mechanistic studies shed light on the fact that the activation of the TLR4/NF-κB pathway was inhibited by sinomenine. The alleviation of PD-1 inhibitor-induced myocardial injury by sinomenine is achieved through the reduction of inflammation and the restoration of mitochondrial function, with this process being regulated by the inhibition of the TLR4/NF-κB signaling pathway. These observations imply that sinomenine has the potential to serve as a therapeutic option for managing cardiotoxicity linked to immune checkpoint inhibitors.

Escherichia coli cells can grow in a DnaA- and oriC-independent manner in rnhA-deficient cells that lack the major RNaseH activity. This mode of replication is named cSDR (constitutive stable DNA replication) and is believed to initiate from the sites of RNA-DNA hybrids, although the detailed mechanisms of cSDR are unclear. In this study, we discovered that dif sequence and XerC/D are essential for cSDR-dependent growth. cSDR was observed in either dif or xerC/D mutant cells as efficiently as in the control cells, as measured by the incorporation of [[3]H]-thymine. However, we found that these mutants accumulate cells with extra DNA contents in the presence of rifampicin and cefalexin, suggesting accumulation of unresolved dimeric or multimeric chromosomes or that of catenated chromosomes due to potential problems in resolution of the replicated chromosomes or in decatenation process. These results indicate that site-specific recombination mediated by dif-XerC/D is essential for cSDR-dependent growth.

Various cellular stressors inhibit translation initiation and promote ribosome disassembly, thereby transiently inducing stress granules (SGs), dynamic ribonucleoprotein condensates that contain mRNAs and RNA-binding proteins. Although SG assembly is usually reversible, dysregulated SG dynamics can trigger the formation of persistent ubiquitin-positive protein inclusions. There is increasing evidence that this conversion of SGs into insoluble aggregates represents a central pathogenic mechanism in neurodegenerative proteinopathies, such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD). TAR DNA-binding protein 43 (TDP-43) and Tau are causative factors in ALS and AD, respectively, and both localize to SGs under stress conditions. During disease progression, TDP-43 or Tau within SGs undergoes pathological changes that promote the formation of neurotoxic inclusions, which propagate neuronal dysfunction and death. This review summarizes recent advances in understanding the molecular factors that regulate SG assembly and disassembly, as well as the pathological processes that drive the conversion of SGs into aggregates associated with neurodegenerative diseases. Particular emphasis is placed on the role of the ubiquitin-specific protease 10 (USP10), which modulates SG dynamics and has been mechanistically implicated in both ALS and AD. Finally, we discuss the therapeutic potential of targeting these pathways to mitigate neurodegenerative disease progression.

Cellular biochemistry arises from various interactions between macromolecules, including proteins, nucleic acids, and lipids. These make up membrane-bound organelles, membrane-less compartments, and molecular assemblies and scaffolds. Changes due to stimuli or disease can significantly impact cell fate and metabolism. We recently reported our protocol combining crosslinking and size exclusion chromatography with mass spectrometry (SEC-MS). In this study, we explore global changes to subcellular structure in Ewing sarcoma cell lines or in response to drug treatment. Crosslinking-dependent differential enrichment across four human cell lines is seen for proteins involved in splicing, mitochondria function, and cell division. We confirmed changes to nucleoli structure. We also examine structures affected by a transcription inhibitor, flavopiridol. Following flavopiridol treatment, we observed changes to the levels of transcription and mRNA processing machinery present in large subcellular structures. Unexpected effects were also found, including structural changes to a cytoplasmic organelle, the peroxisome. Along with a reduction in peroxisome function, dissociation of peroxisome pore proteins PEX13 and PEX14 was detected by STORM microscopy. We conclude that SEC-MS combined with crosslinking is a valuable method to detect and quantify drug or disease effects on subcellular structures and may shed light on new aspects to mechanisms underlying their biologic outcomes.

Genome wide association studies (GWAS) have identified many haplotype blocks linked to a wide range of complex human traits, including intelligence, neuropsychiatric disorders, and immunological disorders, among many others. Approximately a quarter of these haplotype blocks lack protein-coding sequences but most express long noncoding RNAs (lncRNAs). Here we show that human loci orthologous with mammalian lncRNAs involved in neurological or immunological functions are commonly associated with a human trait that is commensurate with the reported lncRNA function. We also show that for many neurological, autoimmune, and cancer complex traits, the vast majority (> 90%) of associated haplotype blocks express one or more lncRNAs. We present a database of lncRNAs expressed from human haplotype blocks associated with GWAS traits, with their putative mouse orthologs, as a resource for functional analysis. Our analyses establish a framework for investigating the molecular etiology of complex traits and suggest a general solution may exist to the challenge of diagnosing and treating many complex disorders.

Pyruvate kinase M (PKM) catalyzes the conversion of phosphoenolpyruvate to pyruvate in glycolysis and exists as two splice isoforms, PKM1 and PKM2, generated from alternative splicing of mutually exclusive exons 9 or 10, respectively. The expression balance between PKM1 and PKM2 is tightly regulated in a cell-type-specific manner. PKM1 is predominantly expressed in tissues such as skeletal muscle, heart, and brain, whereas PKM2 is prevalent in most other tissues and various cancer cells. Despite its importance, the trans-acting factors promoting exon 9 selection in a tissue-specific context remain largely unknown. Here, using a multi-color splicing reporter system for cell-based cDNA screening, we identified PUF60 as a novel trans-acting factor that promotes PKM1-type splicing. We also demonstrated that PUF60 induction and the resulting splicing switch are essential for myotube formation during C2C12 differentiation. This study establishes PUF60 as a critical regulator of muscle-specific splicing and provides new insights into the fundamental mechanisms governing skeletal muscle differentiation.

As tumors expand and encounter hypoxia and nutrient deprivation, cancer cells must establish tight coordination between metabolic reprogramming, protein synthesis and secretory activity to enable effective adaptation. The mechanistic target of rapamycin (mTOR) pathway plays a major role in coordinating protein synthesis and energy metabolism. Dysregulation of mTOR signaling is a hallmark of neoplasia and it contributes to tumorigenesis, metastasis, and therapeutic resistance. In this review, we discuss the emerging role of mTOR in shaping the cancer secretome and examine the implications of mTOR-dependent secretory regulation within the tumor microenvironment. Specifically, we highlight how alterations in secretory output downstream of mTOR influence extracellular matrix remodeling, angiogenesis, immune evasion, and the development of chemoresistance. This review integrates current evidence to provide a comprehensive perspective on the intersection between mTOR signaling, metabolism, protein synthesis and secretory remodeling in cancer. Specifically, we emphasize emerging links between aberrant mTOR function in cancer and secretory programs in the context of cancer cell plasticity and therapeutic resistance.

Colorectal cancer (CRC) remains one of the most frequently diagnosed and lethal malignancies. Recent studies showed that either adipose-derived mesenchymal stem cells (adMSCs) or the extracellular vesicles (EVs) they secrete retarded CRC progression. Here, we investigated the mechanism underlying the role of adMSCs-EVs in CRC. Here, we found that Krüppel-like factor 11 (KLF11) was upregulated in adMSCs-EVs. adMSCs-EVs[sh-KLF11] (EVs derived from KLF11-depleted adMSCs) effectively promoted lipogenesis, cell viability, proliferation, migration, and invasion of CRC cells, and accelerated tumor growth in mice. Furthermore, KLF11 carried by adMSCs-EVs dampened the PI3K/AKT signaling pathway by transcriptionally repressing sterol o-acyltransferase 1 (SOAT1) expression. SOAT1 knockdown blocked the enhanced lipogenesis, proliferation, migration and invasion induced by adMSCs-EVs[sh-KLF11]. In conclusion, KLF11 derived from adMSCs-EVs inactivated the PI3K/AKT signaling pathway by transcriptionally downregulating SOAT1, therefore suppressing lipogenesis and malignant progression of CRC.

The epithelial-mesenchymal transition (EMT) transcription factor TWIST1 plays a critical role in breast cancer progression. This study reveals that TWIST1 acetylation, which is elevated in metastatic breast cancer tissues, is regulated by a deubiquitination-acetylation crosstalk. We demonstrate that ZRANB1 binds to and deubiquitinates TWIST1, thereby increasing its protein stability. This stabilization enhances the interaction between TWIST1 and the acetyltransferase ACSS2, leading to further TWIST1 acetylation. ACSS2 overexpression reversed ZRANB1 knockdown-induced inhibition of TWIST1 acetylation. Functionally, ZRANB1 overexpression promoted breast cancer cell proliferation, invasion, migration, and EMT in vitro, as well as lung metastasis in vivo, all of which were reversed by ACSS2 knockdown. Conversely, ACSS2 knockdown suppressed TWIST1 acetylation, EMT, and metastatic capabilities. Consistently, ACSS2 overexpression rescued the inhibitory effects of ZRANB1 knockdown on breast cancer cell viability, proliferation, migration, and invasion. In summary, our findings identify a novel regulatory axis wherein ZRANB1-mediated deubiquitination facilitates ACSS2-dependent acetylation to stabilize TWIST1, thereby driving EMT and metastasis in breast cancer. The ZRANB1/ACSS2 axis presents a promising therapeutic target for combating metastasis.

Heart failure with preserved ejection fraction (HFpEF) represents the most prevalent subtype of heart failure globally, with its underlying pathogenesis remaining incompletely elucidated. Pyroptosis and mitochondrial dysfunction have been implicated in HFpEF progression. In addition, gasdermin D (GSDMD) has been shown to mediate both mitochondrial dysfunction and pyroptosis, yet the specific regulatory mechanisms involved in HFpEF remain to be elucidated. In this study, we found that HFpEF mouse models exhibited elevated blood glucose and blood pressure, impaired diastolic cardiac function, upregulated serum NT-proBNP, increased heart weight-to-tibia length (HW/TL) ratio, reduced exercise tolerance, obvious myocardial structural damage, excessive mitochondrial ROS accumulation, increased mitochondrial GSDMD-N expression, mitochondrial morphological abnormalities, and activated myocardial pyroptosis pathway. Treatment with GI-Y2 significantly ameliorated these changes. Collectively, GSDMD contributes to HFpEF progression by promoting mitochondrial damage and cardiomyocyte pyroptosis.