AMPK as a Potential Therapeutic Target for Intervertebral Disc Degeneration

As the principal reason for low back pain, intervertebral disc degeneration (IDD) affects the health of people around the world regardless of race or region. Degenerative discs display a series of characteristic pathological changes, including cell apoptosis, senescence, remodeling of extracellular matrix, oxidative stress and inflammatory local microenvironment. As a serine/threonine-protein kinase in eukaryocytes, AMP-activated protein kinase (AMPK) is involved in various cellular processes through the modulation of cell metabolism and energy balance. Recent studies have shown the abnormal activity of AMPK in degenerative disc cells. Besides, AMPK regulates multiple crucial biological behaviors in IDD. In this review, we summarize the pathophysiologic changes of IDD and activation process of AMPK. We also attempt to generalize the role of AMPK in the pathogenesis of IDD. Moreover, therapies targeting AMPK in alleviating IDD are analyzed, for better insight into the potential of AMPK as a therapeutic target.

PPP2R3A Affects the Function and Mechanism of Heterogeneous Fibroblasts in Pulmonary Fibrosis

Background: Fibroblasts have important roles in the synthesis and remodeling of extracellular matrix (ECM) proteins during pulmonary fibrosis. However, the spatiotemporal distribution of heterogeneous fibroblasts during disease progression remains unknown. Methods: Physiological saline and silica were used to generate a chronic pulmonary fibrosis model in mice, and single-cell sequencing, spatial transcriptome sequencing, real-time fluorescent quantitative PCR, immunohistochemistry and immunofluorescence were performed to identify fibroblast subtypes. Small interfering RNA was used to specifically knockdown the target protein, and western blotting, bromodeoxyuridine (BrdU), Cell Counting Kit-8 (CCK-8) and wound healing assays were used to detect the role of GREM1/PPP2R3A in a newly identified fibroblast subtype. Results: Fibroblasts of the new subtype were mainly located in the lesion area and coexpressed inflammation- and proliferation-related genes; they were termed inflammatory-proliferation fibroblasts. Grem1 was the most highly expressed gene in this subtype, as confirmed in HPF-a cells after TGF-β1 treatment. We characterized the downstream mechanism of GREM1/PPP2R3A: these factors mediated the increases in cell viability, proliferation and migration induced by TGF-β1 in fibroblasts. Conclusion: This new subtype of inflammatory, proliferative fibroblasts plays a pivotal role during pulmonary fibrosis, and PPP2R3A, as a downstream regulatory target of GREM1, is involved in pulmonary fibrosis, providing new insights for the prevention and treatment of silicosis.

Identification of Key Modules and Hub Genes in Hypertrophic Cardiomyopathy Based on Integrative Weighted Gene Co-expression Network Analysis

BackgroundHypertrophic cardiomyopathy (HCM) is a heterogeneously inherited cardiac disorder with unclear biological pathogenesis. This study aims to identify the key modules and genes involved in the development of HCM.MethodsUsing weighted gene co-expression network analysis (WGCNA) algorithm, we constructed integrative co-expression networks for the two large sample HCM datasets separately. After selecting clinically significant modules with the same clinical trait, functional enrichment analysis was performed to detect their common pathways. Based on the intramodular connectivity (IC), the shared hub genes were generated, validated, and further explored in gene set enrichment analysis (GSEA).ResultsThe orange and pink modules in GSE141910, the green and brown modules in GSE36961 were mostly related to HCM. Functional enrichment analysis suggested that HCM might exhibit enhanced processes including remodeling of extracellular matrix, activation of abnormal protein signaling, aggregation of calcium ion, and organization of cytoskeleton. SMOC2, COL16A1, RASL11B, TUBA3D, IL18R1 were defined as real hub genes due to their top IC values, significantly different expression levels, and excellent diagnostic performance in both datasets. Moreover, GSEA analysis demonstrated that pathways of the five hub genes were mainly involved in neuroactive ligand-receptor interaction, ECM-receptor interaction, Hedgehog signaling pathway.ConclusionOur study provides more comprehensive insights into the molecular mechanisms of HCM, identifies five hub genes as candidate biomarkers for HCM, which might be theoretically feasible for targeted therapy against HCM.

Microglia Depletion-Induced Remodeling of Extracellular Matrix and Excitatory Synapses in the Hippocampus of Adult Mice

The extracellular matrix (ECM) plays a key role in synaptogenesis and the regulation of synaptic functions in the central nervous system. Recent studies revealed that in addition to dopaminergic and serotoninergic neuromodulatory systems, microglia also contribute to the regulation of ECM remodeling. In the present work, we investigated the physiological role of microglia in the remodeling of perineuronal nets (PNNs), predominantly associated with parvalbumin-immunopositive (PV+) interneurons, and the perisynaptic ECM around pyramidal neurons in the hippocampus. Adult mice were treated with PLX3397 (pexidartinib), as the inhibitor of colony-stimulating factor 1 receptor (CSF1-R), to deplete microglia. Then, confocal analysis of the ECM and synapses was performed. Although the elimination of microglia did not alter the overall number or intensity of PNNs in the CA1 region of the hippocampus, it decreased the size of PNN holes and elevated the expression of the surrounding ECM. In the neuropil area in the CA1 str. radiatum, the depletion of microglia increased the expression of perisynaptic ECM proteoglycan brevican, which was accompanied by the elevated expression of presynaptic marker vGluT1 and the increased density of dendritic spines. Thus, microglia regulate the homeostasis of pre- and postsynaptic excitatory terminals and the surrounding perisynaptic ECM as well as the fine structure of PNNs enveloping perisomatic—predominantly GABAergic—synapses.

Peptide hormone relaxin: from molecular effects to clinical results

Introduction. The peptide hormone relaxin, which is produced by cells of the corpus luteum during and outside pregnancy, has a huge number of clinically significant effects, mediating many biological mechanisms, including antifibrotic, vasodilatory, angiogenic, anti-inflammatory and antiapoptotic effects.Purpose of the study: based on the study of modern literature data, to analyze the results of scientific research, representing the current system of views on the physiological and pathophysilogical effects of relaxin.Materials and methods. A study f scientific publications for the period from 2005 to 2020 in e PubMed and Elibrary databases was carried out using the keywords: relaxin, pregnancy, relaxin signaling pathway, reproductive system, extracellular matrix.Results and Discussion. The study of modern views on the physiology of relaxin has shown that this hormone mediates its effects by binding to the specific receptor RXFP1, which is localized in a large number of reproductive nonproductive tissues. Relaxin performs many functions related to the remodeling of the extracellular matrix and vasculature. The main uterotropic effects of this peptide include stimulation of growth and vascularization of the uterus, remodeling of extracellular matrix components, and regulation of vascular endothelial growth factor in preparation for implantation.Conclusion. The progress of the last decade in understanding the biochemistry of the hormone relaxin has formed the basis for a deeper penetration into all the variety of its physiological roles. The participation of relaxin in the mechanisms of relaxation of the myometrium during pregnancy, remodeling of the connective tissue of target organs in the antenatal period creases its potential clinical significance. The prospect of a possible therapeutic use of relaxin preparations in stimulating antenatal transformation of the cervix, in vitro fertilization, therapy of preeclampsia, acute heart failure and myocardial ischemia turns it into a potential therapeutic agent for these pathological conditions.

After one year of COVID-19 Pandemic and Hundreds of Suggested Drugs, Will Cathepsin L Inhibitors be the Solution?

Cysteine cathepsins are defined as lysosomal enzymes which are member of the papain family. Cysteine cathepsins (Cts) prevalently exist in whole organisms varying from prokaryotes to mammals and possess in their active site greatly conserved residue of cysteine. Cts are engaged in the digestion of cellular protein, activation of zymogen, and remodeling of extracellular matrix (ECM). Host cells are entered by SARS-CoV-2 via endocytosis. Cathepsin L and phosphatidylinositol 3-phosphate 5-kinase are crucial in terms of the endocytosis by cleaving the spike protein, which permits viral membrane fusion with endosomal membrane, and succeeded by the releasing of viral genome to the host cell. Thereby, inhibition of cathepsin L may be advantageous in terms of decreasing infection caused by SARS-CoV-2. Coordinate inhibition of multiple Cts and lysosomal function by different drugs and biological agents might be of value for some purposes such as parasite or viral infections and anti-neoplastic applications. It has been found that Zn 2+ deficiency or dysregulation leads to an exaggerated activity of Cysteine cathepsin increasing the autoimmune/inflammatory response. At this purpose Zn 2+ metal can be safely combined with a drug that increases the anti-proteolytic effect of endogenous Zn 2+ lowering the excessive activity of some CysCts. Biguanide derivatives complex with Zn 2+ have been found to be promising inhibitors of CysCts protease reactions. Molecular docking studies of Cathepsin L Inhibited by Metformin-Zn+2 complex have been performed showing two strong key interactions ( Cys-25&His-163) and an extra H-bond with Asp-163 compared to the co-crystallized Zn +2 (PDB ID 4axl).

Group phenotypic composition in cancer

Although individual cancer cells are generally considered the Darwinian units of selection in malignant populations, they frequently act as members of groups where fitness of the group cannot be reduced to the average fitness of individual group members. A growing body of studies reveals limitations of reductionist approaches to explaining biological and clinical observations. For example, induction of angiogenesis, inhibition of the immune system, and niche engineering through environmental acidification and/or remodeling of extracellular matrix cannot be achieved by single tumor cells and require collective actions of groups of cells. Success or failure of such group activities depends on the phenotypic makeup of the individual group members. Conversely, these group activities affect the fitness of individual members of the group, ultimately affecting the composition of the group. This phenomenon, where phenotypic makeup of individual group members impacts the fitness of both members and groups, has been captured in the term ‘group phenotypic composition’ (GPC). We provide examples where considerations of GPC could help in understanding the evolution and clinical progression of cancers and argue that use of the GPC framework can facilitate new insights into cancer biology and assist with the development of new therapeutic strategies.

Potential Role of Phytochemicals Against Matrix Metalloproteinase Induced Breast Cancer; An Explanatory Review

World Health Organization (WHO) estimated breast cancer as one of the most prevailed malignancy around the globe. Its incident cases are gradually increasing every year, resulting in considerable healthcare burden. The heterogeneity of breast cancer accounts for its differential molecular subtyping, interaction between pathways, DNA damaging, and chronic inflammation. Matrix metalloproteinases (MMPs) are a group of zinc-containing, calcium dependent endopeptidases which play a substantial role in breast carcinogenesis through several mechanisms. These mechanisms include remodeling of extracellular matrix (ECM), cell proliferation, and angiogenesis which promote metastasis and result in tumor progression. In this context, compounds bearing MMP inhibitory potential can serve as potent therapeutic agents in combating MMPs provoked breast cancer. Current systematic review aimed to encompass the details of potent natural lead molecules that can deter MMPs-provoked breast cancer. Following the critical appraisal of literature, a total of n = 44 studies that explored inhibitory effect of phytochemicals on MMPs were included in this review. These phytoconstituents include alkaloids (n = 11), flavonoids (n = 23), terpenoids (n = 7), and lignans (n = 2). The most common inhibitory methods used to evaluate efficacy of these phytoconstituents included Gelatin Zymography, Western Blotting, and real time polymerase chain reaction (RT-PCR) analysis. Moreover, current limitations, challenges, and future directions of using such compounds have been critically discussed. This review underscores the potential implications of phytochemicals in the management of breast cancer which could lessen the growing encumbrance of disease.