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Zhonghua Kou Qiang Yi Xue Za Zhi =... Jul 2024Periodontitis is a chronic inflammatory condition of the periodontal tissues triggered by bacterial biofilm, leading to manifestations such as gingival bleeding, tooth...
Periodontitis is a chronic inflammatory condition of the periodontal tissues triggered by bacterial biofilm, leading to manifestations such as gingival bleeding, tooth mobility, and eventual exfoliation. Neutrophils exhibit a dual role throughout the course of periodontitis, both in defense against pathogens and in potentially detrimental effects on periodontal tissues. This article elucidates the intricate mechanisms underlying the dual functions of neutrophils in periodontitis, including respiratory burst, neutrophil extracellular traps (NETs) formation, degranulation, and phagocytosis. By providing a comprehensive understanding of neutrophils involvement in periodontitis, this study aims to empower clinicians with insights into the pathogenesis of periodontitis, thereby fostering novel strategies for its prevention and treatment.
PubMed: 38949141
DOI: 10.3760/cma.j.cn112144-20231105-00237 -
BioRxiv : the Preprint Server For... Jun 2024Cascade is a class 1, type 1 CRISPR-Cas system with a variety of roles in prokaryote defense, specifically against DNA-based viruses. The transposon, Tn6677, encodes a...
Cascade is a class 1, type 1 CRISPR-Cas system with a variety of roles in prokaryote defense, specifically against DNA-based viruses. The transposon, Tn6677, encodes a variant of the type 1F Cascade known as type 1F-3. This Cascade variant complexes with a homodimer of the transposition protein TniQ and leverages the sequence specificity of Cascade to direct the integration activity of the heteromeric transposase tnsA/B, resulting in site-specific transposition of Tn6677. We desire to uncover the molecular details behind R Loop formation of 'Cascade-TniQ.' Due to the lack of a complete model of Cascade-TniQ available at atom-level resolution, we first build a complete model using AlphaFold V2.1. We then simulate this model via classical molecular dynamics and umbrella sampling to study an important regulatory component within Cascade-TniQ, known as the Cas8 'bundle.' Particularly, we show that this alpha helical bundle experiences a free energy barrier to its large-scale translatory motions and relative free energies of its states primarily dependent on a loop within a Cas7 subunit in Cascade-TniQ. Further, we comment on additional structural and dynamical regulatory points of Cascade-TniQ during R Loop formation, such as Cascade-TniQ backbone rigidity, and the potential role TniQ plays in regulating bundle dynamics. In summary, our outcomes provide the first all-atom dynamic representation of one of the largest CRISPR systems, with information that can contribute to understanding the mechanism of nucleic acid binding and, eventually, to transposase recruitment itself. Such information may prove informative to advance genome engineering efforts.
PubMed: 38948825
DOI: 10.1101/2024.06.21.600075 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... May 2024This study aims to systematically evaluate the protective role of quercetin (QCT), a naturally occurring flavonoid, against oxidative damage in human endometrial stromal...
OBJECTIVE
This study aims to systematically evaluate the protective role of quercetin (QCT), a naturally occurring flavonoid, against oxidative damage in human endometrial stromal cells (HESCs) induced by hydrogen peroxide (HO). Oxidative stress, such as that induced by HO, is known to contribute significantly to cellular damage and has been implicated in various reproductive health issues. The study is focused on investigating how QCT interacts with specific molecular pathways to mitigate this damage. Special attention was given to the p38 MAPK/NOX4 signaling pathway, which is crucial to the regulation of oxidative stress responses in cellular systems. By elucidating these mechanisms, the study seeks to confirm the potential of QCT not only as a protective agent against oxidative stress but also as a therapeutic agent that could be integrated in treatments of conditions characterized by heightened oxidative stress in endometrial cells.
METHODS
cultures of HESCs were treated with QCT at different concentrations (0, 10, 20, and 40 μmol/L) for 24 h to verify the non-toxic effects of QCT on normal endometrial cells. Subsequently, 250 μmol/L HO was used to incubate the cells for 12 h to establish an HO-induced HESCs injury model. HESCs were pretreated with QCT for 24 h, which was followed by stimulation with HO. Then, CCK-8 assay was performed to examine the cell viability and to screen for the effective intervention concentration. HESCs were divided into 3 groups, the control group, the HO model group, and the HO+QCT group. Intracellular levels of reactive oxygen species (ROS) were precisely quantified using the DCFH-DA fluorescence assay, a method known for its accuracy in detecting and quantifying oxidative changes within the cell. The mitochondrial membrane potential was determined by JC-1 staining. Annexin Ⅴ/PI double staining and flow cytometry were performed to determine the effect of QCT on HO-induced apoptosis of HESCs. Furthermore, to delve deeper into the cellular mechanisms underlying the observed effects, Western blot analysis was conducted to measure the expression levels of the critical proteins involved in oxidative stress response, including NADPH oxidase 4 (NOX4), p38 mitogen-activated protein kinase (p38 MAPK), and phosphorylated p38 MAPK (p-p38 MAPK). This analysis helps increase understanding of the specific intracellular signaling pathways affected by QCT treatment, giving special attention to its potential for modulation of the p38 MAPK/NOX4 pathway, which plays a significant role in cellular defense mechanisms against oxidative stress.
RESULTS
In this study, we started off by assessing the toxicity of QCT on normal endometrial cells. Our findings revealed that QCT at various concentrations (0, 10, 20, and 40 μmol/L) did not exhibit any cytotoxic effects, which laid the foundation for further investigation into its protective roles. In the HO-induced HESCs injury model, a significant reduction in cell viability was observed, which was linked to the generation of ROS and the resultant oxidative damage. However, pretreatment with QCT (10 μmol/L and 20 μmol/L) significantly enhanced cell viability after 24 h (<0.05), with the 20 μmol/L concentration showing the most substantial effect. This suggests that QCT can effectively reverse the cellular damage caused by HO. Furthermore, the apoptosis assays demonstrated a significant increase in the apoptosis rates in the HO model group compared to those in the control group (<0.01). However, co-treatment with QCT significantly reversed this trend (<0.05), indicating QCT's potential protective role in mitigating cell apoptosis. ROS assays showed that, compared to that in the control group, the average fluorescence intensity of ROS in the HO model group significantly increased (<0.01). QCT treatment significantly reduced the ROS fluorescence intensity in the HO+QCT group compared to the that in the HO model group, suggesting an effective alleviation of oxidative damage (<0.05). JC-1 staining for mitochondrial membrane potential changes revealed that compared to that in the control, the proportion of cells with decreased mitochondrial membrane potential significantly increased in the HO model group (<0.01). However, this proportion was significantly reduced in the QCT-treated group compared to that of the HO model group (<0.05). Finally, Western blot analysis indicated that the expression levels of NOX4 and p-p38 MAPK proteins were elevated in the HO model group compared to those of the control group (<0.05). Following QCT treatment, these protein levels significantly decreased compared to those of the HO model group (<0.05). These results suggest that QCT may exert its protective effects against oxidative stress by modulating the p38 MAPK/NOX4 signaling pathway.
CONCLUSION
QCT has demonstrated significant protective effects against HO-induced oxidative damage in HESCs. This protection is primarily achieved through the effective reduction of ROS accumulation and the inhibition of critical signaling pathways involved in the oxidative stress response, notably the p38 MAPK/NOX4 pathway. The results of this study reveal that QCT's ability to modulate these pathways plays a key role in alleviating cellular damage associated with oxidative stress conditions. This indicates not only its potential as a protective agent against cellular oxidative stress, but also highlights its potential for therapeutic applications in treating conditions characterized by increased oxidative stress in the endometrium, thereby offering the prospect of enhancing reproductive health. Future studies should explore the long-term effects of QCT and its clinical efficacy , thereby providing a clear path toward its integration into therapeutic protocols.
Topics: Humans; Hydrogen Peroxide; Oxidative Stress; Female; NADPH Oxidase 4; Quercetin; Endometrium; p38 Mitogen-Activated Protein Kinases; Stromal Cells; Signal Transduction; Reactive Oxygen Species; Apoptosis; Cells, Cultured
PubMed: 38948281
DOI: 10.12182/20240560107 -
Open Forum Infectious Diseases Jul 2024is an opportunistic fungal pathogen that can cause disseminated infection with predominant central nervous system involvement in patients with compromised immunity.... (Review)
Review
is an opportunistic fungal pathogen that can cause disseminated infection with predominant central nervous system involvement in patients with compromised immunity. Biologics are increasingly used in the treatment of neoplasms and autoimmune/inflammatory conditions and the prevention of transplant rejection, which may affect human defense mechanisms against cryptococcosis. In this review, we comprehensively investigate the association between cryptococcosis and various biologics, highlighting their risks of infection, clinical manifestations, and clinical outcomes. Clinicians should remain vigilant for the risk of cryptococcosis in patients receiving biologics that affect the Th1/macrophage activation pathways, such as tumor necrosis factor α antagonists, Bruton tyrosine kinase inhibitors, fingolimod, JAK/STAT inhibitors (Janus kinase/signal transducer and activator of transcription), and monoclonal antibody against CD52. Other risk factors-such as age, underlying condition, and concurrent immunosuppressants, especially corticosteroids-should also be taken into account during risk stratification.
PubMed: 38947739
DOI: 10.1093/ofid/ofae316 -
Journal of the Chinese Medical... Jul 2024Hirsutella sinensis (HS) is a mycelium isolated from the fruiting body of the medicinal mushroom Cordyceps sinensis. This study explored whether HS treatment affects...
BACKGROUND
Hirsutella sinensis (HS) is a mycelium isolated from the fruiting body of the medicinal mushroom Cordyceps sinensis. This study explored whether HS treatment affects reproductive dysfunction in a high-fat diet (HFD)-induced mouse model and regulates various mechanisms, focusing on oxidative stress, apoptosis, inflammation, and autophagy.
METHODS
Twenty-four C57BL/6J (B6) mice were randomly divided into a standard chow diet (NCD)- or HFD-fed group for 24 weeks. During the final 8 weeks, half of the HFD-fed mice were orally administered HS (HFD+HS). Biochemical markers, including glucose, insulin, triglycerides, and total cholesterol, were assessed, and hormones, including testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH), were analyzed. Liver and testicular histology, as well as sperm quality markers such as sperm motility, sperm count, and percentage of sperm with normal morphology, were observed. The activities of the testicular antioxidants superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) and the products of lipid peroxidation, such as MDA, were measured. The protein expression levels of apoptosis-, autophagy- and inflammation-related markers were measured.
RESULTS
The HFD-fed mice had abnormal sex hormone levels, poor sperm quality, and a destroyed testicular structure, with increased oxidative stress and apoptosis in the testis. HS supplementation in HFD-fed mice attenuated testicular apoptosis by suppressing the Bax/Bcl-xl ratio and cleaved caspase 3 protein expression. The HS-treated mice exhibited improved reproductive function, possibly due to reduced oxidative stress and apoptosis, suggesting that HS has a protective effect against HFD-induced testicular damage.
CONCLUSION
Male mice supplemented with HS exhibited attenuated poor semen quality and reduced testosterone levels brought about by high-fat diet-induced obesity by reducing oxidative stress.
PubMed: 38946025
DOI: 10.1097/JCMA.0000000000001128 -
Experimental & Molecular Medicine Jul 2024Proinflammatory cytokines and chemokines play a crucial role in regulating the inflammatory response, which is essential for the proper functioning of our immune system.... (Review)
Review
Proinflammatory cytokines and chemokines play a crucial role in regulating the inflammatory response, which is essential for the proper functioning of our immune system. When infections or threats to the body's defense mechanisms are detected, the innate immune system takes the lead. However, an excessive inflammatory response can lead to the production of high concentrations of cytotoxic molecules, resulting in tissue damage. Inflammasomes are significant contributors to innate immunity, and one of the most extensively studied inflammasome complexes is NOD-like receptor 3 (NLRP3). NLRP3 has a wide range of recognition mechanisms that streamline immune activation and eliminate pathogens. These cytosolic multiprotein complexes are composed of effector, adaptor, and sensor proteins, which are crucial for identifying intracellular bacterial breakdown products and initiating an innate immune cascade. To understand the diverse behavior of NLRP3 activation and its significance in the development of lifestyle-related diseases, one must delve into the study of the immune response and apoptosis mediated by the release of proinflammatory cytokines. In this review, we briefly explore the immune response in the context of lifestyle associated disorders such as obesity, hyperlipidemia, diabetes, chronic respiratory disease, oral disease, and cardiovascular disease.
PubMed: 38945951
DOI: 10.1038/s12276-024-01261-8 -
Biomaterials Jun 2024Extracellular matrix (ECM) scaffold membranes have exhibited promising potential to better the outcomes of wound healing by creating a regenerative microenvironment...
Extracellular matrix (ECM) scaffold membranes have exhibited promising potential to better the outcomes of wound healing by creating a regenerative microenvironment around. However, when compared to the application in younger individuals, the performance of the same scaffold membrane in promoting re-epithelialization and collagen deposition was observed dissatisfying in aged mice. To comprehensively explore the mechanisms underlying this age-related disparity, we conducted the integrated analysis, combing single-cell RNA sequencing (scRNA-Seq) with spatial transcriptomics, and elucidated six functionally and spatially distinctive macrophage groups and lymphocytes surrounding the ECM scaffolds. Through intergroup comparative analysis and cell-cell communication, we characterized the dysfunction of Spp1+ macrophages in aged mice impeded the activation of the type Ⅱ immune response, thus inhibiting the repair ability of epidermal cells and fibroblasts around the ECM scaffolds. These findings contribute to a deeper understanding of biomaterial applications in varied physiological contexts, thereby paving the way for the development of precision-based biomaterials tailored specifically for aged individuals in future therapeutic strategies.
PubMed: 38944969
DOI: 10.1016/j.biomaterials.2024.122685 -
Mutation Research Jun 2024Reactive aldehydes, for instance, formaldehyde and acetaldehyde, are important endogenous or environmental mutagens by virtue of their abilities to produce a DNA lesion... (Review)
Review
Reactive aldehydes, for instance, formaldehyde and acetaldehyde, are important endogenous or environmental mutagens by virtue of their abilities to produce a DNA lesion called interstrand crosslink (ICL). Aldehyde-metabolizing enzymes such as aldehyde dehydrogenases (ALDHs) and the Fanconi anemia (FA) pathway constitute the main defense lines against aldehyde-induced genotoxicity. Biallelic mutations of genes in any one of the FA complementation groups can impair the ICL repair mechanism and cause FA, a heterogeneous disorder manifested by bone marrow failure (BMF), congenital abnormality and a strong predisposition to cancer. The defective ALDH2 polymorphism rs671 (ALDH2*2) is a known risk and prognostic factor for alcohol drinking-associated cancers. Recent studies suggest that it also promotes BMF and cancer development in FA, and its combination with alcohol dehydrogenase 5 (ADH5) mutations causes aldehyde degradation deficiency syndrome (ADDS), also known by its symptoms as aplastic anemia, mental retardation, and dwarfism syndrome. ALDH2*2 and another pathogenic variant in the alcohol-metabolizing pathway, ADH1B1*1, is prevalent among East Asians. Also, other ALDH2 genotypes with disease-modifying potentials have lately been identified in different populations. Therefore, it would be appropriate to summarize current knowledge of genotoxic aldehydes and defense mechanisms against them to shed new light on the pathogenic effects of ALDH2 variants together with other genetic and environmental modifiers on cancer and inherited BMF syndromes. Lastly, we also presented potential treatment strategies for FA, ADDS and cancer based on the manipulation of aldehyde-induced genotoxicity.
PubMed: 38944932
DOI: 10.1016/j.mrfmmm.2024.111870 -
Soins. Psychiatrie 2024In a child psychiatry unit, where it is said that men are reassuring and women are mothering, the group experience of carers on the function of their gender in child... (Review)
Review
In a child psychiatry unit, where it is said that men are reassuring and women are mothering, the group experience of carers on the function of their gender in child care was explored. Gender is relevant to institutional care, but creates a divide. Representations focus on fear, sexuality, violence and fragility. Caregivers, ambivalent about neutralising gender, suffer from representations of what it does to children and to the institution.
Topics: Adolescent; Adult; Child; Child, Preschool; Female; Humans; Male; Caregivers; France; Gender Identity; Mental Disorders
PubMed: 38944538
DOI: 10.1016/j.spsy.2024.05.011 -
Soins. Psychiatrie 2024Peer support is based on the mirror effect between the peer carer and the person being supported, which is a powerful lever for recovery. Through their work, peer...
Peer support is based on the mirror effect between the peer carer and the person being supported, which is a powerful lever for recovery. Through their work, peer helpers also hold up a mirror to "non-peer" carers. The reflection they see is a litmus test that can lead to changes in care practices, but it can also generate defensive reactions.
Topics: Humans; Peer Group; Mental Disorders; Social Support; Psychiatric Nursing; France; Caregivers; Defense Mechanisms
PubMed: 38944532
DOI: 10.1016/j.spsy.2024.05.005