Microtubule-associated Protein Research Articles

Sialyltransferase ST3GAL6 silencing reduces α2,3-sialylated glycans to regulate autophagy by decreasing HSPB8-BAG3 in the brain with hepatic encephalopathy.

End-stage liver diseases, such as cirrhosis and liver cancer caused by hepatitis B, are often combined with hepatic encephalopathy (HE); ammonia poisoning is posited as one of its main pathogenesis mechanisms. Ammonia is closely related to autophagy, but the molecular mechanism of ammonia's regulatory effect on autophagy in HE remains unclear. Sialylation is an essential form of glycosylation. In the nervous system, abnormal sialylation affects various physiological processes, such as neural development and synapse formation. ST3 β‍-galactoside α2,‍3-sialyltransferase 6 (ST3GAL6) is one of the significant glycosyltransferases responsible for adding α2,3-linked sialic acid to substrates and generating glycan structures. We found that the expression of ST3GAL6 was upregulated in the brains of mice with HE and in astrocytes after ammonia induction, and the expression levels of α2,3-sialylated glycans and autophagy-related proteins microtubule-associated protein light chain 3 (LC3) and Beclin-1 were upregulated in ammonia-induced astrocytes. These findings suggest that ST3GAL6 is related to autophagy in HE. Therefore, we aimed to determine the regulatory relationship between ST3GAL6 and autophagy. We found that silencing ST3GAL6 and blocking or degrading α2,3-sialylated glycans by way of Maackia amurensis lectin-II (MAL-II) and neuraminidase can inhibit autophagy. In addition, silencing the expression of ST3GAL6 can downregulate the expression of heat shock protein β8 (HSPB8) and Bcl2-associated athanogene 3 (BAG3). Notably, the overexpression of HSPB8 partially restored the reduced autophagy levels caused by silencing ST3GAL6 expression. Our results indicate that ST3GAL6 regulates autophagy through the HSPB8-BAG3 complex.

CKG-IMC: An inductive matrix completion method enhanced by CKG and GNN for Alzheimer’s disease compound-protein interactions prediction

Alzheimer’s disease (AD) is one of the most prevalent chronic neurodegenerative disorders globally, with a rapidly growing population of AD patients and currently no effective therapeutic interventions available. Consequently, the development of therapeutic anti-AD drugs and the identification of AD targets represent one of the most urgent tasks. In this study, in addition to considering known drugs and targets, we explore compound-protein interactions (CPIs) between compounds and proteins relevant to AD. We propose a deep learning model called CKG-IMC to predict Alzheimer’s disease compound-protein interaction relationships. CKG-IMC comprises three modules: a collaborative knowledge graph (CKG), a principal neighborhood aggregation graph neural network (PNA), and an inductive matrix completion (IMC). The collaborative knowledge graph is used to learn semantic associations between entities, PNA is employed to extract structural features of the relationship network, and IMC is utilized for CPIs prediction. Compared with a total of 16 baseline models based on similarities, knowledge graphs, and graph neural networks, our model achieves state-of-the-art performance in experiments of 10-fold cross-validation and independent test. Furthermore, we use CKG-IMC to predict compounds interacting with two confirmed AD targets, 42-amino-acid β-amyloid (Aβ42) protein and microtubule-associated protein tau (tau protein), as well as proteins interacting with five FDA-approved anti-AD drugs. The results indicate that the majority of predictions are supported by literature, and molecular docking experiments demonstrate a strong affinity between the predicted compounds and targets.

MicroRNA-875-5p inhibits the growth and metastasis of cervical cancer cells by promoting autophagy and apoptosis and inhibiting the epithelial-mesenchymal transition.

MicroRNA-875-5p (miR-875-5p) is a cancer-related microRNA. It has been demonstrated that miR-875-5p participates in the development of various types of cancer such as hepatocellular carcinoma, gastric carcinoma, prostate and bladder cancer. Previous research suggested that miR-875 is implicated in the development of cervical cancer cells. However, the exact role and function of miR-875-5p in cervical cancer remain unexplored. It is important to examine the role and function of miR-875-5p and the associated signaling pathway, as the findings may have diagnostic and therapeutic significance. Thus, in this study, we investigated the effect of miR-875-5p on the growth and metastasis of cervical cancer cells and the possible underlying mechanisms. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-875-5p in cervical cancer cells and normal cervical epithelium. After overexpression or co-expression of miR-875-5p in cells, the changes in cell function were analyzed. Western blot was used to detect the expression changes of epithelial-mesenchymal transition (EMT) -related proteins and autophagy-related proteins. Functional studies demonstrated that miR-875-5p overexpression significantly inhibited the proliferation, migration, invasion, and EMT, and promotes apoptosis and autophagy of cervical cancer cells., while miR-875-5p knockdown promoted the proliferation, migration, invasion, and EMT, and inhibited apoptosis and autophagy cervical cancer cells. Furthermore, Western blot results showed that overexpression of miR-875-5p downregulated the expressions of N-cadherin, Snail, Vimentin and microtubule-associated protein 1 light chain 3B I (LC3B I). Conversely, miR-875-5p upregulated the expression of E-cadherin. In conclusion, our findings suggest that miR-875-5p functions as a tumor inhibitor suppressing the growth and metastasis of cervical cancer. Overexpression of miR-875-5p inhibits malignant behavior and promotes autophagy and apoptosis in cervical cancer cells. These findings advance our understanding of the role and function of miR-875-5p in cervical cancer and could facilitate the development of early genetic markers or biomarkers and therapeutic targets for cervical cancer.

A novel histone deacetylase inhibitor Se-SAHA attenuates isoproterenol-induced heart failure via antioxidative stress and autophagy inhibition

Heart failure is associated with histone deacetylase (HDAC) regulation of gene expression, the inhibition of which is thought to be beneficial for heart failure therapy. Here, we explored the cardioprotective effects and underlying mechanism of a novel selenium-containing HDAC inhibitor, Se-SAHA, on isoproterenol (ISO)-induced heart failure. We found that pretreatment with Se-SAHA attenuated ISO-induced cardiac hypertrophy and fibrosis in neonatal rat ventricular myocytes (NRVMs). Se-SAHA significantly attenuated the generation of ISO-induced reactive oxygen species (ROS) and restored the expression levels of superoxide dismutase 2 (SOD2) and heme oxygenase-1 (HO-1) in vitro. Furthermore, Se-SAHA pretreatment prevented the accumulation of autophagosomes. Se-SAHA reversed the high expression of HDAC1 and HDAC6 induced by ISO incubation. However, after the addition of the HDAC agonist, the effect of Se-SAHA on blocking autophagy was inhibited. Using ISO-induced mouse models, cardiac ventricular contractile dysfunction, hypertrophy, and fibrosis was reduced treated by Se-SAHA. In addition, Se-SAHA inhibited HDAC1 and HDAC6 overexpression in ISO-treated mice. Se-SAHA treatment significantly increased the activity of SOD2 and improved the ability to eliminate free radicals. Se-SAHA hindered the excessive levels of the microtubule-associated protein 1 light chain 3 (LC3)-II and Beclin-1 in heart failure mice. Collectively, our results indicate that Se-SAHA exerts cardio-protection against ISO-induced heart failure via antioxidative stress and autophagy inhibition.

Study of proanthocyanidin promotes osteogenic differentiation of human periodontal ligament stem cells through the transcription factor EB-induced autophagy-lysosome pathway

Objective: To investigate the mechanism of proanthocyanidin (PA) in regulating the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs), and to explore the effects of PA on the expression and nuclear translocation of transcription factor EB (TFEB) and on the autophagy-lysosome pathway. Methods: PDLSCs were divided into control group and PA group, which were subjected to RNA sequencing analysis (RNA Seq) to detect differentially expressed genes. The osteogenic differentiation ability and autophagy level were observed by real-time fluorescence quantitative PCR (RT-qPCR) analysis, alkaline phosphatase (ALP) staining and transmission electron microscope (TEM), respectively. Scratch assay and Transwell assay were used to detect the migration ability of PDLSCs. Lysotracker and immunofluorescence staining were used to detect the biogenesis of lysosomes. The total protein expression of transcription factor EB (TFEB) as well as that in cytoplasm and nucleus were detected by Western blotting. Confocal laser scanning microscope (CLSM) was used to observe the nuclear translocation of TFEB. The PDLSCs were treated with small interfering RNA (siRNA) technology to knock down the expression levels of TFEB gene with or without PA treatment. Western blotting was used to analyze the expressions of autophagy-related proteins Beclin1 and microtubule-associated protein 1 light chain 3 (LC3B), as well as osteogenic-related proteins runt-related transcription factor 2 (RUNX2), ALP, and osteocalcin in PDLSCs. Results: Compared with the control group, the osteogenic-related and autophagy-related genes showed differential expression in PDLSCs after PA treatment (P<0.05). The mRNA expression levels of osteogenic-related genes RUNX2 (2.32±0.15) and collagen type Ⅰ alpha 1 (COL1α1) (1.80±0.18), as well as the autophagy related genes LC3B (1.87±0.08) and Beclin1 (1.63±0.08) were significantly increased in the PA group, compared with the control group (1.01±0.16, 1.00±0.10, 1.00±0.07, 1.00±0.06, respectively, all P<0.01). Compared with the control group, the PA group had higher ALP activity, and more autophagosomes and autophagolysosomes observed by TEM. PA promoted the migration of PDLSCs (P<0.05) and the increased number of lysosomes and the expression of lysosomal associated membrane protein 1 (LAMP1). In the PA group, the relative expression level of total TFEB protein (1.49±0.07) and the nuclear/cytoplasmic expression of TFEB protein (1.52±0.12) were significantly higher than the control group (1.00±0.11, 1.00±0.13, respectively) (t=6.43, P<0.01; t=5.07, P<0.01). The relative nuclear/cytoplasmic fluorescence intensity of TFEB in the PA group (0.79±0.09) was increased compared with the control group (0.11±0.08) (t=8.32, P<0.01). Knocking down TFEB significantly reduced the expression of TFEB (1.00±0.15 vs 0.64±0.04), LAMP1 (1.00±0.10 vs 0.69±0.09), Beclin1 (1.00±0.05 vs 0.60±0.05), and LC3B Ⅱ/Ⅰ (1.00±0.06 vs 0.73±0.07) in PDLSCs (P<0.05, P<0.05, P<0.01, P<0.01). When TFEB gene was knocked down, the expression levels of Beclin1 (1.05±0.11), LC3B Ⅱ/Ⅰ (1.02±0.09), RUNX2 (1.04±0.10), ALP (1.04±0.16), and osteocalcin (1.03±0.15) proteins were significantly decreased in the PA group compared with the pre-knockdown period (1.28±0.03, 1.44±0.11, 1.38±0.11, 1.62±0.11, 1.65±0.17, respectively) (P<0.05, P<0.01, P<0.05, P<0.01, and P<0.01, respectively). Conclusions: PA promotes the osteogenic differentiation of PDLSCs through inducing the expression and nuclear translocation of TFEB and activating the autophagy-lysosome pathway.

Bortezomib exerts its anti-cancer activity through the regulation of Skp2/p53 axis in non-melanoma skin cancer cells and C. elegans

Non-melanoma skin cancer (NMSC), encompassing basal and squamous cell carcinoma, is the most prevalent cancer in the United States. While surgical removal remains the conventional therapy with a 95% 5-year cure rate, there is a growing interest in exploring alternative treatment strategies. In this study, we investigated the role of Bortezomib (BTZ), a proteasome inhibitor, in NMSC. Using two NMSC cell lines (A431 and A388), we examined the effects of BTZ treatment. Our results demonstrated that 48 h of BTZ treatment led to downregulating Skp2 expression in both A431 and A388 cells while upregulating p53 expression, specifically in A388 cells. These alterations resulted in impaired cellular growth and caspase-dependent cell death. Silencing Skp2 in A388 cells with siRNA confirmed the upregulation of p53 as a direct target. Furthermore, BTZ treatment increased the Bax to Bcl-2 ratio, promoting mitochondrial permeability and the subsequent release of cytochrome C, thereby activating caspases. We also found that BTZ exerted its antitumor effects by generating reactive oxygen species (ROS), as blocking ROS production significantly reduced BTZ-induced apoptotic cell death. Interestingly, BTZ treatment induced autophagy, which is evident from the increased expression of microtubule-associated proteins nucleoporin p62 and LC-3A/B. In addition to cell lines, we assessed the impact of BTZ in an in vivo setting using Caenorhabditis elegans (C. elegans). Our findings demonstrated that BTZ induced germline apoptosis in worms even at low concentrations. Notably, this increased apoptosis was mediated through the activity of CEP-1, the worm’s counterpart to mammalian p53. In summary, our study elucidated the molecular mechanism underlying BTZ-induced apoptosis in NMSC cell lines and C. elegans. By targeting the skp2/p53 axis, inducing mitochondrial permeability, generating ROS, and promoting autophagy, BTZ demonstrates promising anti-cancer activity in NMSC. These findings provide novel insights into potential therapeutic strategies for controlling the unregulated growth of NMSC.

Association of Uterine Tissue Innervation and Peripheral Nerve Density with Adenomyosis Related Pain. A Systematic Review.

Adenomyosis is associated with dysmenorrhea and chronic pelvic pain; however, the triggering mechanisms of painful stimuli and the role of uterine nerve fibers in the manifestation of pain remain poorly understood. The objective of this study was to systematically review the role of uterine nerve fibers' presence and density in the occurrence of pain in patients with adenomyosis. An electronic search was performed using the Embase, PubMed/Medline, and Cochrane databases. We included all studies from inception to November 2023. A total of ten studies that compared uterine biopsies samples of women with and without adenomyosis were included. The biomarker antiprotein gene product 9.5 was decreased or absent in the endometrium of most included women with adenomyosis. None of the included studies observed a difference in neurofilament (NF) staining between the adenomyosis and non-adenomyosis groups. Studies that assessed nerve growth factor (NGF) staining were heterogeneous in design. One study reported no difference in immunohistochemistry staining in any endometrial layer between the adenomyosis and non-adenomyosis groups, while another reported increased staining in the adenomyosis functional endometrial layer, and a third study reported overexpression of NGF, synaptophysin (SYN), and microtubule-associated protein 2 mRNA in focal adenomyosis alone. Preliminary data from poor-quality studies suggest an increase in the uterine density of nerve fibers in patients with adenomyosis. Well-designed studies are essential to assess the cause-and-effect relationship between uterine nerve fibers and pain in patients with adenomyosis.

Characterization and expression of the microtubule associated protein tau gene isoforms and their impact on clinical outcomes in glioma patients

Gliomas are the most common tumors found in the central nervous system. They are classified based on their histopathological malignancy. Low-grade gliomas (LGG) can turn into glioblastomas (GBM), the most aggressive form of brain cancer with the worst prognosis. Previous studies have shown that microtubule-associated protein tau (MAPT) is increased in GBM and that reducing it can improve survival in animal models. On the other hand, elevated MAPT expression has been linked to increased survival in LGG, indicating its potential as a survival biomarker. However, previous studies have primarily focused on the canonical protein-coding transcripts and gene-level expression of MAPT, disregarding the diversity of its many isoforms. Many diseases in almost every tissue have been associated with a dysregulation of alternative splicing, either through an altered ratio of the expressed isoforms or by expressing aberrant transcripts with different alternative transcription start and termination sites. This study investigates the association of specific MAPT transcripts with survival in LGG and GBM using publicly available genomic datasets and performing statistical analyses. The results of the study indicated coding and several non-coding isoforms associated with overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI). After including the relevant predictors as covariates, it was observed that among the protein-coding isoforms, MAPT-205 and MAPT-201 were significantly associated with clinical survival endpoints, but with opposite trends. These findings highlight the importance of studying the role of MAPT isoforms in glioma cellular phenotypes, aggressiveness, and patient survival.

Norditerpenoid alkaloids from Aconitum refractum var. circinatum as autophagy inducers

A total of twenty-two diterpenoid alkaloids, including ten unprecedented ones, namely refractines C–L, were isolated from the roots of Aconitum refractum (Finet et Gagnep.) Hand.-Mazz. Refractine C was the first example of a natural diterpenoid alkaloid wherein C-19 is linked to N position by an oxaziridine ring. Refractine L was a rare glycosidic diterpenoid alkaloid with fructofuranoside. Most of the isolated compounds obtained from a previous study were screened for their anti-inflammatory and myocardial protective activities. The autophagy-inducing effects of some of these compounds on RAW 264.7 cells were evaluated by assessing the expression of microtubule-associated protein 1 light chain 3 (LC3-II/LC3-I). Results revealed that some compounds exerted varying levels of inhibitory effects on the proliferative activity of RAW 264.7 cells.

Hhatl ameliorates endoplasmic reticulum stress through autophagy by associating with LC3

Endoplasmic reticulum (ER) stress, a common cellular stress response induced by various factors that interfere with cellular homeostasis, may trigger cell apoptosis. Autophagy is an important and conserved mechanism for eliminating aggregated proteins and maintaining protein stability of cells, which is closely associated with ER stress and ER stress-induced apoptosis. In this paper, we report for the first time that Hhatl, an ER-resident protein, is downregulated in response to ER stress. Hhatl overexpression alleviated ER stress and ER stress induced apoptosis in cells treated with tunicamycin or thapsigargin, whereas Hhatl knockdown exacerbated ER stress and apoptosis. Further study showed that Hhatl attenuates ER stress by promoting autophagic flux. Mechanistically, we found that Hhatl promotes autophagy by associating with autophagic protein LC3 (microtubule-associated protein 1A/1B-light chain 3) via the conserved LC3-interacting region (LIR) motif. Noticeably, the LIR motif was essential for Hhatl-regulated promotion of autophagy and reduction of ER stress. These findings demonstrate that Hhatl ameliorates ER stress via autophagy activation by interacting with LC3, thereby alleviating cellular pressure. The study indicates that pharmacological or genetic regulation of Hhatl-autophagy signaling might be potential for mediating ER stress and related diseases.

Enrichment of oligodendrocyte precursor phenotypes in subsets of low-grade glioneuronal tumours.

Current histological classification of low-grade glioneuronal tumours does not adequately represent their underlying biology. The neural lineage(s) and differentiation stage(s) involved and the cell state(s) affected by the recurrent genomic alterations are unclear. Here, we describe dysregulated oligodendrocyte lineage developmental programmes in three low-grade glioneuronal tumour subtypes. Ten dysembryoplastic neuroepithelial tumours, four myxoid glioneuronal tumours and five rosette-forming glioneuronal tumours were collected. Besides a comprehensive characterization of clinical features, known diagnostic markers and genomic alterations, we used comprehensive immunohistochemical stainings to characterize activation of rat sarcoma/mitogen-activated protein kinase pathway, involvement of neuronal component, resemblance to glial lineages and differentiation blockage along the stages of oligodendrocyte lineage. The findings were further complemented by gene set enrichment analysis with transcriptome data of dysembryoplastic neuroepithelial tumours from the literature. Dysembryoplastic neuroepithelial tumours, myxoid glioneuronal tumours and rosette-forming glioneuronal tumours occur at different ages, with symptoms closely related to tumour location. Dysembryoplastic neuroepithelial tumours and myxoid glioneuronal tumours contain oligodendrocyte-like cells and neuronal component. Rosette-forming glioneuronal tumours contained regions of rosette-forming neurocytic and astrocytic features. Scattered neurons, identified by neuronal nuclei antigen and microtubule-associated protein-2 staining, were consistently observed in all dysembryoplastic neuroepithelial tumours and myxoid glioneuronal tumours examined, but only in one rosette-forming glioneuronal tumour. Pervasive neurofilament-positive axons were observed only in dysembryoplastic neuroepithelial tumour and myxoid glioneuronal tumour samples. Alterations in B-Raf proto-oncogene, serine/threonine kinase, fibroblast growth factor receptor 1, fibroblast growth factor receptor 3 and platelet-derived growth factor receptor alpha occurred in a mutually exclusive manner, coinciding with strong staining of phospho-p44/42 mitogen-activated protein kinase and low apoptotic signal. All dysembryoplastic neuroepithelial tumours, myxoid glioneuronal tumours and the neurocytic regions of rosette-forming glioneuronal tumours showed strong expression of neuron-glia antigen 2, platelet-derived growth factor receptor alpha (markers of oligodendrocyte precursor cells) and neurite outgrowth inhibitor-A (a marker of developing oligodendrocytes), but lacked the expression of oligodendrocyte markers ectonucleotide pyrophosphatase/phosphodiesterase family member 6 and myelin basic protein. Notably, transcriptomes of dysembryoplastic neuroepithelial tumours were enriched in oligodendrocyte precursor cell signature, but not in signatures of neural stem cells, myelinating oligodendrocytes and astrocytes. Dysembryoplastic neuroepithelial tumour, myxoid glioneuronal tumour and rosette-forming glioneuronal tumour resemble oligodendrocyte precursor cells, and their enrichment of oligodendrocyte precursor cell phenotypes is closely associated with the recurrent mutations in rat sarcoma/mitogen-activated protein kinase pathway.

Ruthenium red alleviates post-resuscitation myocardial dysfunction by upregulating mitophagy through inhibition of USP33 in a cardiac arrest rat model

Cardiac arrest (CA) remains a leading cause of death, with suboptimal survival rates despite efforts involving cardiopulmonary resuscitation and advanced life-support technology. Post-resuscitation myocardial dysfunction (PRMD) is an important determinant of patient outcomes. Myocardial ischemia/reperfusion injury underlies this dysfunction. Previous reports have shown that ruthenium red (RR) has a protective effect against cardiac ischemia-reperfusion injury; however, its precise mechanism of action in PRMD remains unclear. This study investigated the effects of RR on PRMD and analyzed its underlying mechanisms. Ventricular fibrillation was induced in rats, which were then subjected to cardiopulmonary resuscitation to establish an experimental CA model. At the onset of return of spontaneous circulation, RR (2.5 mg/kg) was administered intraperitoneally. Our study showed that RR improved myocardial function and reduced the production of oxidative stress markers such as malondialdehyde (MDA), glutathione peroxidase (GSSG), and reactive oxygen species (ROS) production. RR also helped maintain mitochondrial structure and increased ATP and GTP levels. Additionally, RR effectively attenuated myocardial apoptosis. Furthermore, we observed downregulation of proteins closely related to mitophagy, including ubiquitin-specific protease 33 (USP33) and P62, whereas LC3B (microtubule-associated protein light chain 3B) was upregulated. The upregulation of mitophagy may play a critical role in reducing myocardial injury. These results demonstrate that RR may attenuate PRMD by promoting mitophagy through the inhibition of USP33. These effects are likely mediated through diverse mechanisms, including antioxidant activity, apoptosis suppression, and preservation of mitochondrial integrity and energy metabolism. Consequently, RR has emerged as a promising therapeutic approach for addressing post-resuscitation myocardial dysfunction.

New insights into resveratrol attenuates hepatotoxicity in emamectin benzoate-exposed grass carp (Ctenopharyngodon idella) via NO system/NF-κB signaling pathway

Emamectin benzoate (EMB) is extensively used as a crop protection agent. Overuse of EMB poses a serious threat to the quality of water and non-target organisms in the environment. Resveratrol (RES) is a natural phytoalexin with the function of anti-oxidation and anti-inflammation. Nonetheless, it is unclear whether EMB affects the expression of cytokines and induces autophagy, apoptosis, and necroptosis of hepatocytes (L8824 cell) in grass carp (Ctenopharyngodon idella), and whether RES has an attenuate function in this process. Therefore, we established the L8824 cells model of EMB exposure and treated it with RES. The results showed that compared with the control (CON) group, EMB exposure significantly increased the nitric oxide (NO) content, inducible nitric oxide synthase (iNOS) activity, and the expression of iNOS and phosphorylated nuclear factor kappa B (p-NF-κB) (P < 0.05). In addition, compared with the CON group, the results of flow cytometry and dansylcadaverine (MDC) staining showed a significant increase in apoptosis and autophagy in the EMB-exposed group (P < 0.05) with the activation of the B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X (Bax)/cysteine-aspartic acid protease 3 (Caspase-3)/cysteine-aspartic acid protease 9 (Caspase-9) pathway and microtubule-associated protein light chain 3 (LC3)/sequestosome 1 (p62)/Beclin1 pathway. EMB exposure significantly increased the mRNA and protein expression of receptor-interacting protein 1 (RIPK1)/receptor-interacting protein 3 (RIPK3)/mixed the lineage kinase domain-like (MLKL) pathway (P < 0.05). Moreover, EMB exposure significantly increased the expression of genes related to immunity (immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin D (IgD), and antimicrobial peptide-related genes expression including β-defensin and hepcidin) (P < 0.05). The addition of RES significantly diminished autophagy, apoptosis, necroptosis, and immunity-related gene expression by inhibiting iNOS activity, NO content, and the protein expression of iNOS and p-NF-κB. In conclusion, RES attenuated autophagy, apoptosis, and necroptosis in EMB-exposed L8824 cells via suppression of the NO system/NF-κB signaling pathway.

Sevoflurane postconditioning ameliorates cerebral hypoxia/reoxygenation injury in zebrafish involving the Akt/GSK-3β pathway activation and the microtubule-associated protein 2 promotion

Sevoflurane postconditioning has been shown to provide neuroprotection against cerebral hypoxia-ischemia injury, but the mechanisms remain elusive. Microtubule-associated protein 2 (MAP2) is implicated in early neuronal hypoxia-ischemia injury. This study aimed to investigate whether the neuroprotective effects of sevoflurane postconditioning are related to the Akt/GSK-3β pathway and its downstream target MAP2 in zebrafish hypoxia/reoxygenation (H/R) model. Sevoflurane postconditioning or GSK-3β inhibitor TDZD-8 were used to treat H/R zebrafish. The cerebral infarction, neuronal apoptosis, and mitochondrial changes were evaluated using TTC staining, TUNEL staining, and transmission electron microscopy, respectively. The distribution of MAP2 in the brain was determined by immunofluorescence imaging. The levels of Akt, p-Akt, GSK-3β, p-GSK-3β, and MAP2 proteins were evaluated by Western blotting. The neurobehavioral recovery of zebrafish was assessed based on optokinetic response behavior. Our results indicated that sevoflurane postconditioning and TDZD-8 significantly reduced the cerebral infarction area, suppressed cell apoptosis, and improved mitochondrial integrity in zebrafish subjected to H/R. Furthermore, sevoflurane postconditioning and TDZD-8 elevated the ratios of p-Akt/Akt and p-GSK-3β/GSK-3β. However, the neuroprotective effect of sevoflurane postconditioning was effectively abolished upon suppression of MAP2 expression. In conclusion, sevoflurane postconditioning ameliorated cerebral H/R injury and facilitated the restoration of neurobehavioral function through the activation of Akt/GSK-3β pathway and promotion of MAP2 expression.

Microtubule-Associated Protein 9 Is a Potential Tumor Suppressor That Is Inactivated by Methylation in Cervical Cancer

Microtubule-Associated Protein 9 Is a Potential Tumor Suppressor That Is Inactivated by Methylation in Cervical Cancer

Recent Progress in the Application of Tau Protein Biosensors for Diagnosis of Neurodegenerative Diseases.

The microtubule-associated Tau protein is found in the central nervous system (CNS) in six major isoforms. Neurodegenerative diseases have been linked to post-translational changes of Tau, most notably phosphorylation. Tau protein's molecular diversity is highly helpful in the identification of neurodegenerative illnesses. Nonetheless, one major obstacle to the early detection of brain illness is the nanoscale identification of tau proteins. The standard methods for identifying tau protein include western blotting, polymerase chain reaction (PCR), and real-time PCR. Enzyme-linked immunosorbent assay (ELISA) is another approach used. The limited sensitivity and specificity of these detections, together with the need for sophisticated equipment, are some of their drawbacks. The development of innovative and complex methods for tau protein screening is necessary to address the aforementioned issues. Biosensors are a cutting-edge instrument that may help identify various neurodegenerative biomarkers as early as feasible. This paper provides an overview of the most recent developments in the detection of neurodegenerative diseases employing biosensors built on nanotechnology and methods for imaging, electrochemical, and optical detection of the Tau protein. Furthermore, we outline the present difficulties and suggest a possible course for biosensor-based detection and intervention in the future.

Metformin as an alternative therapeutic intervention in hemorrhagic shock

Hemorrhagic shock (HS) continues to significantly contribute to civilian and military mortality, underscoring the critical need for new resuscitation strategies. Recent discussions have emphasized the pivotal role of impaired oxygen delivery and cellular metabolism in exacerbating HS-related damage. Metformin, a well-established diabetes medication, exhibits promising potential to enhance cellular metabolism and activate pathways linked to improved oxygen uptake, thereby optimizing cellular energy management. Thus, this study aimed to assess metformin's effcacy in ameliorating outcomes in animals subjected to HS. To achieve this, Wistar rats were surgically prepared with femoral artery and vein catheters. HS was induced by controlled blood withdrawal to maintain a mean arterial pressure (MAP) within the range of 35-40 mmHg for 90 minutes. Throughout the protocol, blood pressure (BP) and heart rate (HR) were assessed. The animals were divided into two groups: Lactated Ringer's solution (LR) and LR treated with Metformin (Met). Metformin was administered in three bolus injections: at the start of resuscitation (10mg), 45 minutes into resuscitation (5mg), and 90 minutes into resuscitation (5mg). After 120 minutes, the animals were euthanized, and blood samples were collected for subsequent analysis, including metabolomic profiling of the tricarboxylic acid (TCA) cycle, amino acids, and lipids. Additionally, trypsin-like enzyme activity in the plasma and markers of brain injury were evaluated. Animals treated with Met showed significantly higher systolic blood pressure after resuscitation (LR: 74±5 mmHg vs. LR+Met: 94±3 mmHg) with no significant changes in HR observed. Brain injury markers such as GFAP (Glial fibrillary acidic protein), S100B (astrocytic protein specific to the central nervous system), Tau (microtubule-associated protein), and NFL (axonal protein neurofilament light) were assessed. Animals reperfused with LR and treated with Met displayed a 22% reduction in GFAP levels compared to those reperfused with LR alone, while other markers remained unchanged. Met treatment also led to a reduction in plasmatic metabolites, including Lactate (30%), Succinate (24%), and Fumarate (22%), along with an increase in Citrate (23%) and α-ketoglutarate (24%)—all constituents of the TCA cycle. Additionally, an increase in amino acid metabolites and a decrease in lipid metabolites were observed. Recent research has suggested that HS results in elevated levels of trypsin-like enzymes in the plasma and that inhibiting these enzymes might improve outcomes during resuscitation. Our study revealed that treatment with Met reduced approximately 60% of trypsin-like enzyme activity in the plasma compared to the LR-only group. In conclusion, our study demonstrates that Met, when administered in conjunction with LR as a resuscitation solution, significantly enhances post-resuscitation BP compared to LR alone. This improved outcome may be associated with alterations in the TCA cycle and the inhibition of trypsin-like enzyme activity. However, further investigations are necessary to elucidate the precise role of these changes in the observed enhancements within this experimental model. This work was supported by National Institutes of Health grant R01HL162120. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Colchicine modulates TIMP1, MMP1, and pMAP4 expression to enhance extracellular matrix degradation in 3T3 fibroblast-mediated myocardial infarction

Context: Cardiovascular disease is a leading cause of mortality worldwide. Following acute myocardial infarction (AMI), cardiac cells release many cytokines and proteolytic enzymes that regulate the extracellular matrix (ECM), including matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), and phosphorylated microtubule-associated protein 4 (Phospho/pMAP4). Aims: To analyze the role of colchicine in ECM regulation post-ischemic in cell line culture towards MMPs, TIMPs, and pMAP4. Methods: This in vitro experimental study was conducted on the 3T3 fibroblast cell line subjected to hypoxic conditions (CoCl2 treatment) and compared with 3T3 cells experiencing hypoxia/ischemic and colchicine treatment. MMP-1, TIMP-1, and pMAP4 expression were measured using flow cytometry. Data analysis was performed using One-Way ANOVA with a 95% confidence level. Results: Treatment with colchicine in the 3T3 fibroblast cell culture regulated the extracellular matrix by increasing TIMP-1 expression and reducing MMP-1 and pMAP4 expression (p&lt;0.0001) following ischemic conditions induced by CoCl2. Conclusions: Colchicine effectively mitigates ECM degradation by enhancing TIMP-1 expression and inhibiting MMP-1 activity and pMAP4 expression post-ischemic conditions.

Isolation, culture, characterization and the functional study of testicular Leydig cells from Hezuo pig.

Testosterone, an important sex hormone, regulates sexual maturation, testicular development, spermatogenesis and the maintenance of secondary sexual characteristics in males. Testicular Leydig cells are the primary source of testosterone production in the body. Hezuo pigs, native to the southern part of Gansu, China, are characterized by early sexual maturity, strong disease resistance and roughage tolerance. This study employed type IV collagenase digestion combined with cell sieve filtration to isolate and purify Leydig cells from the testicular tissue of 1-month-old Hezuo pigs. We also preliminarily investigated the functions of these cells. The results indicated that the purity of the isolated and purified Leydig cells was as high as 95%. Immunofluorescence analysis demonstrated that the isolated cells specifically expressed the 3β-hydroxysteroid dehydrogenase antibody. Enzyme-linked immunosorbent assay results showed that the testosterone secretion of the Leydig cells cultured invitro (generations 5-9) ranged between 1.29-1.67 ng/mL. Additionally, the content of the cellular autophagy signature protein microtubule-associated protein 1 light chain 3 was measured at 230-280 pg/mL. Through this study, we established an invitro system for the isolation, purification and characterization of testicular Leydig cells from 1-month-old Hezuo pigs, providing a reference for exploring the molecular mechanism behind precocious puberty in Hezuo pigs.

The seeds of its regulation: natural antisense transcripts as single-gene control switches in neurodegenerative disorders

Several proteins play critical roles in vulnerability or resistance to neurodegenerative disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and frontotemporal dementia (FTD). Regulation of these proteins is critical to maintaining healthy neurohomeostasis. In addition to transcription factors regulating gene transcription and microRNAs regulating mRNA translation, natural antisense transcripts (NATs) regulate mRNA levels, splicing, and translation. NATs’ roles are significant in regulating key protein-coding genes associated with neurodegenerative disorders. Elucidating the functions of these NATs could prove useful in treating or preventing diseases. NAT activity is not restricted to mRNA translation; it can also regulate DNA (de)methylation and other gene expression steps. NATs are noncoding RNAs (ncRNAs) encoded by DNA sequences overlapping the pertinent protein genes. These NATs have complex structures, including introns and exons, and therefore bind their target genes, precursor mRNAs (pre-mRNAs), and mature RNAs. They can occur at the 5’- or 3’-ends of a mRNA-coding sequence or internally to a parent gene. NATs can downregulate translation, e.g., microtubule-associated protein tau (MAPT) antisense-1 gene (MAPT-AS1), or upregulate translation, e.g., β-Amyloid site Cleaving Enzyme 1 (BACE1) antisense gene (BACE1-AS). Regulation of NATs can parallel pathogenesis, wherein a “pathogenic” NAT (e.g., BACE1-AS) is upregulated under pathogenic conditions, while a “protective” NAT (e.g., MAPT-AS1) is downregulated under pathogenic conditions. As a relatively underexplored endogenous control mechanism of protein expression, NATs may present novel mechanistic targets to prevent or ameliorate aging-related disorders.