scholarly journals Taurine Attenuates Catabolic Processes Related to the Onset of Sarcopenia

2020 ◽  
Vol 21 (22) ◽  
pp. 8865
Author(s):  
Alessandra Barbiera ◽  
Silvia Sorrentino ◽  
Elisa Lepore ◽  
Andrea Carfì ◽  
Gigliola Sica ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Muscle Protein ◽  
Myogenic Differentiation ◽  
Low Grade ◽  
Inflammatory Factor ◽  
Taurine Supplementation ◽  
Ion Channel Regulation ◽  
Loss Of Mass ◽  
Factor Α

Sarcopenia that occurs with advancing age is characterized by a gradual loss of muscle protein component due to the activation of catabolic pathways, increased level of inflammation, and mitochondrial dysfunction. Experimental evidence demonstrates that several physio-pathological processes involved in the onset of sarcopenia may be counteracted by the intake of specific amino acids or antioxidant molecules, suggesting that diet may represent an effective strategy for improving the anabolic response of muscle during aging. The non-essential amino acid taurine is highly expressed in several mammalian tissues, including skeletal muscle where it is involved in the ion channel regulation, in the modulation of intracellular calcium concentration, and where it plays an important role as an antioxidant and anti-inflammatory factor. Here, with the purpose to reproduce the chronic low-grade inflammation characteristics of senescent muscle in an in vitro system, we exploited the role of Tumor Necrosis Factor α (TNF) and we analyzed the effect of taurine in the modulation of different signaling pathways known to be dysregulated in sarcopenia. We demonstrated that the administration of high levels of taurine in myogenic L6 cells stimulates the differentiation process by downregulating the expression of molecules involved in inflammatory pathways and modulating processes such as autophagy and apoptosis. Although further studies are currently ongoing in our laboratory to better elucidate the molecular mechanisms responsible for the positive effect of taurine on myogenic differentiation, this study suggests that taurine supplementation may represent a strategy to delay the loss of mass and functionality characteristic of senescent muscles.

scholarly journals Melatonin Reverses the Loss of Stemness Induced by TNF-α in Human Bone Marrow Mesenchymal Stem Cells through Upregulation of YAP Expression

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xudong Wang ◽  
Tongzhou Liang ◽  
Jincheng Qiu ◽  
Xianjian Qiu ◽  
Bo Gao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Molecular Mechanisms ◽  
Inflammatory Factor ◽  
Cell Transplant ◽  
Alizarin Red ◽  
Marrow Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro culture results in loss of MSC stemness. The inflammation that occurs at stem cell transplant sites (such as that resulting from TNF-α) is a contributing factor for stem cell treatment failure. Currently, there is little evidence regarding the protective role of melatonin with regard to the negative effects of TNF-α on the stemness of MSCs. In this study, we report a melatonin-based method to reduce the inflammatory effects on the stemness of bone marrow mesenchymal stem cells (BMMSCs). The results of colony formation assays, Alizarin red staining, western blotting, and reverse transcription-polymerase chain reactions suggest that melatonin can reverse the inflammatory damage caused by TNF-α treatment in the third, seventh, and tenth generations of primary BMMSCs (vs. control and the TNF-α-treated group). Meanwhile, a detailed analysis of the molecular mechanisms showed that the melatonin receptor and YAP signaling pathway are closely related to the role that melatonin plays in negative inflammatory effects against BMMSCs. In addition, in vivo experiments showed that melatonin could reverse the damage caused by TNF-α on bone regeneration by BMMSCs in nude mice. Overall, our results suggest that melatonin can reverse the loss of stemness caused by inflammatory factor TNF-α in BMMSCs. Our results also provide a practical strategy for the application of BMMSCs in tissue engineering and cell therapy.

Melittin attenuates liver injury in thioacetamide-treated mice through modulating inflammation and fibrogenesis

2011 ◽  
Vol 236 (11) ◽  
pp. 1306-1313 ◽  
Author(s):  
Ji-Hyun Park ◽  
Yoon-Seup Kum ◽  
Tae-Im Lee ◽  
Soo-Jung Kim ◽  
Woo-Ram Lee ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Liver Injury ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Liver Inflammation ◽  
Amphipathic Peptide ◽  
Bioactive Component ◽  
Factor Α ◽  
Necrosis Factor

Liver fibrosis represents a process of healing and scarring in response to chronic liver injury. Following injury, an acute inflammation response takes place resulting in moderate cell necrosis and extracellular matrix damage. Melittin, the major bioactive component in the venom of honey bee Apis mellifera, is a 26-residue amphipathic peptide with well-known cytolytic, antimicrobial and proinflammatory properties. However, the molecular mechanisms responsible for the anti-inflammatory activity of melittin have not been elucidated in liver fibrosis. We investigated whether melittin ameliorates liver inflammation and fibrosis in thioacetamide (TAA)-induced liver fibrosis. Two groups of mice were treated with TAA (200 mg/L, in drinking water), one of the groups of mice was co-treated with melittin (0.1 mg/kg) for 12 weeks while the other was not. Hepatic stellate cells (HSCs) were cultured with tumor necrosis factor α in the absence or presence of melittin. Melittin suppresses the expression of proinflammatory cytokines through the nuclear factor (NF)- κB signaling pathway. Moreover, melittin reduces the activity of HSCs in vitro, and decreases the expression of fibrotic gene responses in TAA-induced liver fibrosis. Taken together, melittin prevents TAA-induced liver fibrosis by inhibiting liver inflammation and fibrosis, the mechanism of which is the interruption of the NF- κB signaling pathway. These results suggest that melittin could be an effective agent for preventing liver fibrosis.

scholarly journals Tetramethylpyrazine improves oxazolone-induced colitis by inhibiting the NF-κB pathway

2014 ◽  
Vol 37 (1) ◽  
pp. 1 ◽  
Author(s):  
Yunmin Lu ◽  
Meiying Zhu ◽  
Wei Chen ◽  
Li Yin ◽  
Jinshui Zhu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Activity Index ◽  
Disease Activity Index ◽  
Positive Control ◽  
In Vitro Assays ◽  
Inflammatory Factors ◽  
Inflammatory Factor ◽  
Inflammatory Status ◽  
Chinese Plant

Purpose: Tetramethylpyrazine (TMP) is an effective Chinese plant-derived medicine for colitis in the clinic, but the underlying molecular mechanisms of its use remain poorly understood. The purpose of this study was to investigate the mechanisms involved in its therapeutic action. Methods: A colitis mouse model was induced by oxazolone enema. TMP was administered at 80 mg/kg/day and sulphasalazine (SASP) was used as positive control and administered at 100 mg/kg/day for the treatment of colitis. On the fourth day after enema, mice were sacrificed. The inflammatory response was assessed by the disease activity index and histology. Colon mucosa was isolated and biochemically analyzed. In addition, in vitro studies were performed to evaluate the activity of TMP in Caco-2 cells. Results: Our results showed that TMP improved the colonic inflammatory status as evidenced by histological findings, as well as SASP. These effects were associated with a decrease in nucleus translocation of NF-κB. Paired with this inhibitive activity, there was a decrease in downstream signaling, such as C-MYC, iNOS and COX-2. In vitro assays revealed that TMP inhibited NF-κB translocation and its downstream production of inflammatory factors, such as TNF-α, IL-6 and IL-8, and that ROS production that was induced by LPS in Caco-2 cells. Conclusion: TMP improved the colitis induced by oxazoline, and its activity was associated with inhibition of NF-κB translocation, and subsequent inhibition of pro-inflammatory factor production and oxidative stress.

scholarly journals Mos activates myogenic differentiation by promoting heterodimerization of MyoD and E12 proteins.

1997 ◽  
Vol 17 (2) ◽  
pp. 584-593 ◽  
Author(s):  
J L Lenormand ◽  
B Benayoun ◽  
M Guillier ◽  
M Vandromme ◽  
M P Leibovitch ◽  
...  
Keyword(s):  
Dna Binding ◽  
Molecular Mechanisms ◽  
Myogenic Differentiation ◽  
Hybrid Approach ◽  
Specific Gene ◽  
Physical Interaction ◽  
Muscle Creatine Kinase ◽  
Bhlh Factors

The activities of myogenic basic helix-loop-helix (bHLH) factors are regulated by a number of different positive and negative signals. Extensive information has been published about the molecular mechanisms that interfere with the process of myogenic differentiation, but little is known about the positive signals. We previously showed that overexpression of rat Mos in C2C12 myoblasts increased the expression of myogenic markers whereas repression of Mos products by antisense RNAs inhibited myogenic differentiation. In the present work, our results show that the rat mos proto-oncogene activates transcriptional activity of MyoD protein. In transient transfection assays, Mos promotes transcriptional transactivation by MyoD of the muscle creatine kinase enhancer and/or a reporter gene linked to MyoD-DNA binding sites. Physical interaction between Mos and MyoD, but not with E12, is demonstrated in vivo by using the two-hybrid approach with C3H10T1/2 cells and in vitro by using the glutathione S-transferase (GST) pull-down assays. Unphosphorylated MyoD from myogenic cell lysates and/or bacterially expressed MyoD physically interacts with Mos. This interaction occurs via the helix 2 region of MyoD and a highly conserved region in Mos proteins with 40% similarity to the helix 2 domain of the E-protein class of bHLH factors. Phosphorylation of MyoD by activated GST-Mos protein inhibits the DNA-binding activity of MyoD homodimers and promotes MyoD-E12 heterodimer formation. These data support a novel function for Mos as a mediator (coregulator) of muscle-specific gene(s) expression.

Proliferation modulates intestinal smooth muscle phenotype in vitro and in colitis in vivo

2011 ◽  
Vol 300 (5) ◽  
pp. G903-G913 ◽  
Author(s):  
Dileep G. Nair ◽  
T. Y. Han ◽  
S. Lourenssen ◽  
Michael G. Blennerhassett
Keyword(s):  
Smooth Muscle ◽  
Sulfonic Acid ◽  
Molecular Mechanisms ◽  
Muscle Protein ◽  
Rat Colon ◽  
Intestinal Smooth Muscle ◽  
Trinitrobenzene Sulfonic Acid ◽  
Thymidine Uptake

Intestinal inflammation causes an increased intestinal wall thickness, in part, due to the proliferation of smooth muscle cells, which impairs the contractile phenotype elsewhere. To study this, cells from the circular muscle layer of the rat colon (CSMC) were isolated and studied, both in primary culture and after extended passage, using quantitative PCR, Western blot analysis, and immunocytochemistry. By 4 days in vitro, both mRNA and protein for the smooth muscle marker proteins α-smooth muscle actin, desmin, and SM22-α were reduced by >50%, and mRNA for cyclin D1 was increased threefold, evidence for modulation to a proliferative phenotype. Continued growth caused significant further decrease in expression, evidence that phenotypic loss in CSMC was proportional to the extent of proliferation. In CSMC isolated at day 2 of trinitrobenzene sulfonic acid-induced colitis, flow cytometry and Western blotting showed that these differentiated markers were reduced in mitotic CSMC, while similar to control in nonmitotic CSMC. By day 35 post-trinitrobenzene sulfonic acid, when inflammation has resolved, CSMC were hypertrophic, but, nonetheless, showed markedly decreased expression of smooth muscle protein markers per cell. In vitro, day 35 CSMC displayed an accelerated loss of phenotype and increased thymidine uptake in response to serum or PDGF-BB. Furthermore, carbachol-induced expression of phospho-AKT (a marker of cholinergic response) was lost from day 35 CSMC in vitro, while retained in control cells. Therefore, proliferation reduces the expression of smooth-muscle-specific markers in CSMC, possibly leading to altered contractility. However, inflammation-induced proliferation in vivo also causes lasting changes that include unexpected priming for an exaggerated response to proliferative stimuli. Identification of the molecular mechanisms of intestinal smooth muscle cell phenotypic modulation will be helpful in reducing the detrimental effects of inflammation.

Ιmmunity, Vascular Aging, and Stroke

2022 ◽  
Vol 29 ◽  
Author(s):  
Anna-Maria Louka ◽  
Dimitrios Sagris ◽  
George Ntaios
Keyword(s):  
Blood Brain Barrier ◽  
Molecular Mechanisms ◽  
Vascular Dysfunction ◽  
Vascular Inflammation ◽  
Brain Barrier ◽  
Low Grade ◽  
Vascular Aging ◽  
Barrier Dysfunction ◽  
Blood Brain

Abstract: Stroke is one of the most devastating manifestations of cardiovascular disease. Growing age, arterial hypertension, and atherosclerosis are identified as independent risk factors for stroke, primarily due to structural and functional alterations in the cerebrovascular tree. Recent data from in vitro and clinical studies have suggested that the immune system influences atherosclerosis, promoting vascular stiffness and vascular aging and contributing to ischemic stroke, intracranial haemorrhage and microbleeds, white matter disease, and cognitive decline. Furthermore, aging is related to a chronic low-grade inflammatory state, in which macrophage, neutrophils, natural killer (NK cells), and B and T lymphocytes act as major effectors of the immune-mediated cell responses. Moreover, oxidative stress and vascular inflammation are correlated with endothelial dysfunction, vascular aging, blood-brain barrier disruption, lacunar lesions, and neurodegenerative disorders. This review discusses the pathophysiological roles of fundamental cellular and molecular mechanisms of aging, including the complex interplay between them and innate immunity, as well as vascular dysfunction, arterial stiffness, atherosclerosis, atherothrombosis, systemic inflammation, and blood-brain barrier dysfunction.

scholarly journals Nutrition and microRNAs: Novel Insights to Fight Sarcopenia

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 951
Author(s):  
Alessandra Barbiera ◽  
Laura Pelosi ◽  
Gigliola Sica ◽  
Bianca Maria Scicchitano
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Molecular Mechanisms ◽  
Muscle Protein ◽  
Low Grade ◽  
Protein Homeostasis ◽  
Dietary Interventions ◽  
Physiological Processes ◽  
Age Related ◽  
And Function

Sarcopenia is a progressive age-related loss of skeletal muscle mass and strength, which may result in increased physical frailty and a higher risk of adverse events. Low-grade systemic inflammation, loss of muscle protein homeostasis, mitochondrial dysfunction, and reduced number and function of satellite cells seem to be the key points for the induction of muscle wasting, contributing to the pathophysiological mechanisms of sarcopenia. While a range of genetic, hormonal, and environmental factors has been reported to contribute to the onset of sarcopenia, dietary interventions targeting protein or antioxidant intake may have a positive effect in increasing muscle mass and strength, regulating protein homeostasis, oxidative reaction, and cell autophagy, thus providing a cellular lifespan extension. MicroRNAs (miRNAs) are endogenous small non-coding RNAs, which control gene expression in different tissues. In skeletal muscle, a range of miRNAs, named myomiRNAs, are involved in many physiological processes, such as growth, development, and maintenance of muscle mass and function. This review aims to present and to discuss some of the most relevant molecular mechanisms related to the pathophysiological effect of sarcopenia. Besides, we explored the role of nutrition as a possible way to counteract the loss of muscle mass and function associated with ageing, with special attention paid to nutrient-dependent miRNAs regulation. This review will provide important information to better understand sarcopenia and, thus, to facilitate research and therapeutic strategies to counteract the pathophysiological effect of ageing.

scholarly journals Yangxin granules alleviate doxorubicin-induced cardiotoxicity by suppressing oxidative stress and apoptosis mediated by AKT/GSK3β/β-catenin signaling

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052094516
Author(s):  
Dezhi Ren ◽  
Fang Li ◽  
Qingwen Cao ◽  
An Gao ◽  
Yingna Ai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Molecular Mechanisms ◽  
Inflammatory Factor ◽  
H9c2 Cells ◽  
Akt Inhibitor ◽  
Phosphorylated Akt ◽  
H9c2 Cardiomyocytes ◽  
Clinical Benefits

Background Yangxin granules (YXC), a Chinese herbal medicine, have been confirmed to have clinical benefits in the treatment of heart failure. This study examined the effects and molecular mechanisms of YXC in the treatment of doxorubicin-induced cardiotoxicity in vitro. Methods H9c2 cardiomyocytes were pretreated with YXC (5, 10, or 20 mg/mL) or the AKT inhibitor MK-2206 (50 nM) before doxorubicin treatment (1 µM). Cell apoptosis, viability, inflammatory factor expression (TNF-α, IL-1β, and IL-6), and oxidative stress mediator levels including superoxide dismutase, reactive oxygen species, and malondialdehyde were detected. Results YXC increased the viability of H9c2 cells. In addition, doxorubicin inhibited AKT/GSK3β/β-catenin signaling, whereas YXC increased the expression of phosphorylated AKT and GSK3β, and β-catenin in doxorubicin-treated H9c2 cells. Moreover, T-cell factor/lymphoid enhancer factor signaling downstream of β-catenin was also activated by YXC. YXC pretreatment also inhibited doxorubicin-induced inflammation, oxidative stress, and apoptosis. However, MK-2206 reversed the effects of YXC in doxorubicin-treated H9c2 cells. Conclusions YXC alleviates doxorubicin-induced inflammation, oxidative stress, and apoptosis in H9c2 cells. These effects might be mediated by the AKT/GSK3β/β-catenin signaling pathway. YXC might have preventive effects against doxorubicin-induced heart failure.

scholarly journals A Comprehensive Molecular and Clinical Analysis of the piRNA Pathway Genes in Ovarian Cancer

Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 4
Author(s):  
Eunice Lee ◽  
Noor A. Lokman ◽  
Martin K. Oehler ◽  
Carmela Ricciardelli ◽  
Frank Grutzner
Keyword(s):  
Gene Expression ◽  
Ovarian Cancer ◽  
Molecular Mechanisms ◽  
Clinical Analysis ◽  
Malignant Neoplasms ◽  
Low Grade ◽  
Pathway Gene ◽  
Pirna Pathway

Ovarian cancer (OC) is one of the most lethal gynecological malignancies, yet molecular mechanisms underlying its origin and progression remain poorly understood. With increasing reports of piRNA pathway deregulation in various cancers, we aimed to better understand its role in OC through a comprehensive analysis of key genes: PIWIL1-4, DDX4, HENMT1, MAEL, PLD6, TDRD1,9 and mutants of PIWIL1 (P1∆17) and PIWIL2 (PL2L60). High-throughput qRT-PCR (n = 45) and CSIOVDB (n = 3431) showed differential gene expression when comparing benign ovarian tumors, low grade OC and high grade serous OC (HGSOC). Significant correlation of disparate piRNA pathway gene expression levels with better progression free, post-progression free and overall survival suggests a complex role of this pathway in OC. We discovered PIWIL3 expression in chemosensitive but not chemoresistant primary HGSOC cells, providing a potential target against chemoresistant disease. As a first, we revealed that follicle stimulating hormone increased PIWIL2 expression in OV-90 cells. PIWIL1, P1∆17, PIWIL2, PL2L60 and MAEL overexpression in vitro and in vivo decreased motility and invasion of OVCAR-3 and OV-90 cells. Interestingly, P1∆17 and PL2L60, induced increased motility and invasion compared to PIWIL1 and PIWIL2. Our results in HGSOC highlight the intricate role piRNA pathway genes play in the development of malignant neoplasms.

scholarly journals Prediction of Rhizoma Drynariae Targets in the Treatment of Osteoarthritis Based on Network Pharmacology and Experimental Verification

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Guang-yao Chen ◽  
Xiao-yu Liu ◽  
Jia-qi Chen ◽  
Xin-bo Yu ◽  
Jing Luo ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Network Pharmacology ◽  
Inflammatory Factor ◽  
In Vitro Experiments ◽  
Ppi Network ◽  
Rhizoma Drynariae

Rhizoma Drynariae has been widely used for the treatment of osteoarthritis (OA), but its potential targets and molecular mechanisms remain to be further explored. Targets of Rhizoma Drynariae and OA were predicted by relevant databases, and a protein-protein interaction (PPI) network was constructed to identify key targets. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to obtain related pathways and then select significant pathways associated with OA. The OA chondrocyte model was established by inflammatory factor-induced SW1353 chondrocytes, and molecular docking was conducted to verify the above theoretical prediction. The results showed that a total of 86 Rhizoma Drynariae-OA interaction targets were identified, among which IL-6 and AKT1 were the key targets in the PPI network. Luteolin was the most critical component of Rhizoma Drynariae. KEGG results indicated that the effects of Rhizoma Drynariae on OA are associated with the PI3K/AKT, TNF, IL-17, apoptosis, and HIF-1 signaling pathway. The PI3K/AKT pathway can activate the downstream NF-κB pathway and further regulate the transcription and expression of downstream IL-6, IL-17, HIF-1α, Bax, and TNF, suggesting that the PI3K/AKT/NF-κB pathway is the critical pathway in the treatment of OA with Rhizoma Drynariae. Active components of Rhizoma Drynariae and key proteins of the PI3K/AKT/NF-κB signaling pathway were subjected to molecular docking, whose results showed that luteolin and IKK-α played a critical role. In vitro experiments indicated that both aqueous extracts of Rhizoma Drynariae (AERD) and luteolin inhibited the expression of IL-6 and HIF-1α and suppressed the activation of PI3K/AKT/NF-κB, IL-17, and TNF pathways. The measurement of mitochondrial membrane potential (Δψm) indicated that AERD and luteolin can decrease the LPS-induced early apoptotic cells. Luteolin had a more prominent inhibitory effect than AERD in the abovementioned in vitro experiments. In conclusion, the therapeutic mechanism of Rhizoma Drynariae against OA may be closely related to the inhibition of the PI3K/AKT/NF-κB pathway and downstream pathways, and luteolin plays a vital role in the treatment.

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