Muscle Cells Research Articles

Multitranscriptome analysis reveals stromal cells in the papillary dermis to promote angiogenesis in psoriasis vulgaris.

The pathogenesis of psoriasis is incompletely understood. Growing evidence suggests the involvement of stromal cells in the inflammatory process. To investigate the roles of stromal cells, including fibroblasts, vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs), in the psoriatic inflammatory microenvironment, and the possible underlying mechanisms involved. We used a combination of single-cell, spatial transcriptome and bulk RNA sequencing of lesional and nonlesional skin samples from patients with psoriasis vulgaris (PV) and healthy skin samples from unaffected individuals. By analysing transcriptomes from 364 098 single cells, we uncovered WNT5A+ (Wnt-5a) fibroblasts, ITIH5+ (inter-α-trypsin inhibitor heavy chain 5) VECs and VCAN+ (versican) VSMCs, with significantly increased proportions of these cells in the papillary dermis of lesional psoriatic skin. We defined eight unique subclusters of fibroblasts in the skin and observed a shift of WIF1+ (Wnt inhibitory factor 1) fibroblasts toward WNT5A+ fibroblasts, with abnormal activation of the noncanonical Wnt signalling pathway and increased angiogenic and proinflammatory capabilities. VSMCs were able to undergo phenotypic transformation from a contractile to a synthetic phenotype during the development of psoriatic inflammation. ITIH5+ VECs and VCAN+ VSMCs were found to have an essential role in regulating angiogenesis and vascular remodelling in the pathological changes seen in PV. Ligand receptor analyses found that WNT5A+ fibroblasts are extensively implicated in interactions with various skin cell types, especially TIH5+ VECs and VCAN+ VSMCs in the papillary dermis. Interactions of stromal cells in the papillary dermis were identified as possible pathogenic elements in PV. Improving the inflammatory microenvironment by targeting stromal cells might be a potential treatment strategy in PV.

Spatial transcriptomics in the adult Drosophila brain and body.

Recently, we have achieved a significant milestone with the creation of the Fly Cell Atlas. This single-nuclei atlas encompasses the entire fly, covering the entire head and body, in addition to all major organs. This atlas catalogs many hundreds of cell types, of which we annotated 250. Thus, a large number of clusters remain to be fully characterized, in particular in the brain. Furthermore, by applying single-nuclei sequencing, all information about the spatial location of the cells in the body and of about possible subcellular localization of the mRNAs within these cells is lost. Spatial transcriptomics promises to tackle these issues. In a proof-of-concept study, we have here applied spatial transcriptomics using a selected gene panel to pinpoint the locations of 150 mRNA species in the adult fly. This enabled us to map unknown clusters identified in the Fly Cell Atlas to their spatial locations in the fly brain. Additionally, spatial transcriptomics discovered interesting principles of mRNA localization and transcriptional diversity within the large and crowded muscle cells that may spark future mechanistic investigations. Furthermore, we present a set of computational tools that will allow for easier integration of spatial transcriptomics and single-cell datasets.

Single-cell RNA sequencing and spatial transcriptomics reveal the heterogeneity and intercellular communication of cancer-associated fibroblasts in gastric cancer

BackgroundGastric cancer is a highly aggressive malignancy characterized by a complex tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), which are a key component of the TME, exhibit significant heterogeneity and play crucial roles in tumor progression. Therefore, a comprehensive understanding of CAFs is essential for developing novel therapeutic strategies for gastric cancer.MethodsThis study investigates the characteristics and functional information of CAF subtypes and explores the intercellular communication between CAFs and malignant epithelial cells (ECs) in gastric cancer by analyzing single-cell sequencing data from 24 gastric cancer samples. CellChat was employed to map intercellular communication, and Seurat was used to integrate single-cell sequencing data with spatial transcriptome data to reconstruct a comprehensive single-cell spatial map. The spatial relationship between apCAFs and cancer cells was analyzed using multicolor immunohistochemistry.ResultsCells were categorized into nine distinct categories, revealing a positive correlation between the proportions of epithelial cells (ECs) and fibroblasts. Furthermore, six fibroblast subpopulations were identified: inflammatory (iCAFs), pericytes, matrix (mCAFs), antigen-presenting (apCAFs), smooth muscle cells (SMCs), and proliferative CAFs (pCAFs). Each of these subpopulations was linked to various biological processes and immune responses. Malignant ECs exhibited heightened intercellular communication, particularly with CAF subpopulations, through specific ligand-receptor interactions. High-density regions of CAF subpopulations displayed spatial exclusivity, with pericytes serving as a source for iCAFs, mCAFs, and apCAFs. Notably, malignant ECs and apCAFs showed increased interactions, with certain ligand-receptor pairs potentially impacting the prognosis of gastric cancer. Multiplex immunohistochemistry (mIHC) confirmed the close spatial proximity of apCAFs to cancer cells in gastric cancer.ConclusionOur study provided a comprehensive characterization of CAF heterogeneity in gastric cancer and revealed the intricate intercellular networks within the TME. The identified CAF subpopulations and their interactions with malignant cells could serve as potential therapeutic targets.

Investigating the Potential Therapeutic Targeting of the JAK-STAT Pathway in Cerebrovascular Diseases: Opportunities and Challenges.

Cerebrovascular disease (CVD) is a significant neurological condition resulting from pathological changes in the brain's blood supply and is currently the leading cause of death and disability worldwide. The progression of CVD is closely associated with endothelial damage, plaque formation, and thrombosis, driven by long-term alterations in vascular endothelial cells, smooth muscle cells, microglia, and other immune-inflammatory cells. Among the key molecular pathways involved, the Janus kinase/signal transducer and activator of transcription (JAK-STAT) signaling pathway plays a central role. Dysregulation of the JAK-STAT pathway is implicated in the pathogenesis of CVD by influencing the aforementioned cell types and associated pathological processes. Importantly, the role of the JAK-STAT pathway varies across different types of CVD and throughout different stages of disease progression (e.g., pre-morbid, acute, and chronic phases). This review examines the composition, activation, and regulation of the JAK-STAT pathway and summarizes recent findings on its involvement in CVD. We discuss the distinct roles of JAK-STAT signaling in various CVD conditions, the potential reasons for these differences, and explore the clinical translational prospects and technical challenges of targeting the JAK-STAT pathway for therapeutic intervention in CVD.

Microgravity-induced changes in skeletal muscle and possible countermeasures: What we can learn from bed rest and human space studies.

Despite exercise countermeasures to sustain health and performance in spaceflight, complete maintenance of muscle mass and functions in microgravity is still not possible for most astronauts. The principal cause of the limited effectiveness of existing exercise countermeasures is the difficulty in achieving full loading forces in space. The implementation of countermeasures which require small devices and simulate Earth-like loading forces to maintain muscle mass, strength and endurance is therefore highly desirable. At present, the cellular mechanisms that induce muscle atrophy in weightlessness are not yet fully known; a better understanding of how skeletal muscle cells adapt to microgravity will help in designing more effective countermeasures to sustain the health and operational capacity of the crew during long- and short-duration missions. The 6° head-down-tilt bed rest is a powerful ground-based analogue platform to simulate and study the physiological effects of spaceflight on the human body, and test the effectiveness of countermeasures before they are potentially applied in space. The aims of this narrative review are therefore to provide an overview of (i) the main mechanisms underlining muscle atrophy learnt from space and bed rest studies, (ii) the currently available countermeasures, and (iii) potential suitable countermeasures - such as neuromuscular electrical stimulation that is delivered with light and small portable units - to attenuate muscle wasting in astronauts during spaceflight.

Cellular and molecular features of asthma mucus plugs provide clues about their formation and persistence.

BACKGROUNDMucus plugs form in acute asthma and persist in chronic disease. Although eosinophils are implicated in mechanisms of mucus pathology, many mechanistic details about mucus plug formation and persistence in asthma are unknown.METHODSUsing histology and spatial, single-cell proteomics, we characterized mucus-plugged airways from nontransplantable donor lungs of 14 patients with asthma (9 with fatal asthma and 5 with nonfatal asthma) and individuals acting as controls (10 with chronic obstructive pulmonary disease and 14 free of lung disease). Additionally, we used an airway epithelial cell-eosinophil (AEC-eosinophil) coculture model to explore how AEC mucus affects eosinophil degranulation.RESULTSAsthma mucus plugs were tethered to airways showing infiltration with innate lymphoid type 2 cells and hyperplasia of smooth muscle cells and MUC5AC-expressing goblet cells. Asthma mucus plugs were infiltrated with immune cells that were mostly dual positive for eosinophil peroxidase (EPX) and neutrophil elastase, suggesting that neutrophils internalize EPX from degranulating eosinophils. Indeed, eosinophils exposed to mucus from IL-13-activated AECs underwent CD11b- and glycan-dependent cytolytic degranulation. Dual-positive granulocytes varied in frequency in mucus plugs. Whereas paucigranulocytic plugs were MUC5AC rich, granulocytic plugs had a mix of MUC5AC, MUC5B, and extracellular DNA traps. Paucigranulocytic plugs occurred more frequently in (acute) fatal asthma and granulocytic plugs predominated in (chronic) nonfatal asthma.CONCLUSIONTogether, our data suggest that mucin-rich mucus plugs in fatal asthma form because of acute goblet cell degranulation in remodeled airways and that granulocytic mucus plugs in chronic asthma persist because of a sustaining niche characterized by epithelial cell-mucin-granulocyte cross-talk.FUNDINGNIH grants HL080414, HL107202, and AI077439.

A molecular systems architecture of neuromuscular junction in amyotrophic lateral sclerosis

A molecular systems architecture is presented for the neuromuscular junction (NMJ) in order to provide a framework for organizing complexity of biomolecular interactions in amyotrophic lateral sclerosis (ALS) using a systematic literature review process. ALS is a fatal motor neuron disease characterized by progressive degeneration of the upper and lower motor neurons that supply voluntary muscles. The neuromuscular junction contains cells such as upper and lower motor neurons, skeletal muscle cells, astrocytes, microglia, Schwann cells, and endothelial cells, which are implicated in pathogenesis of ALS. This molecular systems architecture provides a multi-layered understanding of the intra- and inter-cellular interactions in the ALS neuromuscular junction microenvironment, and may be utilized for target identification, discovery of single and combination therapeutics, and clinical strategies to treat ALS.

Integrated analysis of the expression profiles of the lncRNA-miRNA-mRNA ceRNA network in CASMCs under hypoxia and normoxia conditions in yak heart

Hypoxia causes the occurrence of right heart hypertrophy and right heart failure. However, the yak living in the hypoxic environment, does not exhibit hypoxia-related pathological features. Therefore, It is of great significance to explore the hypoxia adaptation mechanism of yak heart. In this study, the yak heart coronary vascular smooth muscle cells (CASMCs) were treated with 21% O2 (normoxic group) and 5% O2 (hypoxic group). The results showed that hypoxia could promote the proliferation of CASMCs. Subsequently, we sequenced CASMCs in normoxic and hypoxic groups. The analysis revealed differential expression of 835 mRNAs, 285 lncRNAs and 126 miRNAs were between the two groups. GO and KEGG analysis showed that the differentially expressed genes were predominantly associated with extracellular matrix components, transcription factor activity, protein binding, immune system processes, metabolic processes and cell development processes and TGF-β, MAPK, cAMP, mTOR, PI3K-Akt and other signaling pathways. By constructing a network of mRNAs, miRNAs and lncRNAs based on the major differentially expressed RNAs, core regulatory elements associated with hypoxic adaptive function were identified. Our study may help to prove the potential role of differential genes related to hypoxic adaptation, and enhanced understanding of the molecular mechanisms of hypoxic adaptation in yak heart.

Smooth muscle cell Piezo1 depletion results in impaired contractile properties in murine small bowel

Piezo1 is a mechanosensitive cation channel expressed in intestinal muscularis cells (IMCs), including smooth muscle cells (SMCs), interstitial cells of Cajal, and Pdgfrα+ cells, which form the SIP syncytium, crucial for GI contractility. Here, we investigate the effects of SMC-specific Piezo1 deletion on small bowel function. Piezo1 depletion results in weight loss, delayed GI transit, muscularis thinning, and decreased SMCs. Ex vivo analyses demonstrated impaired contractile strength and tone, while in vitro studies using IMC co-cultures show dysrhythmic Ca2+ flux with decreased frequency. Imaging reveal that Piezo1 localizes intracellularly, thereby likely impacting Ca2+ signaling mechanisms modulated by Ca2 + -handling channels located on the sarcoplasmic reticulum and plasma membrane. Our findings suggest that Piezo1 in small bowel SMCs contributes to contractility by maintaining intracellular Ca2+ activity and subsequent signaling within the SIP syncytium. These findings provide new insights into the complex role of Piezo1 in small bowel SMCs and its implications for GI motility.

Tetrahydropalmatine improves mitochondrial function in vascular smooth muscle cells of atherosclerosis in vitro by inhibiting Ras homolog gene family A/Rho-associated protein kinase-1 signaling pathway.

Tetrahydropalmatine (THP) regulates mitochondrial function in vascular smooth muscle cells (VSMCs) to prevent or alleviate atherosclerosis (AS), with unclear specific mechanism. AS models were constructed by oxidized low-density lipoprotein (ox-LDL)-treated VSMCs. Cell counting kit-8 for cell viability, wound scratch assay for cell migration, and flow cytometry for cell cycle, intracellular reactive oxygen species, and mitochondrial membrane potential (MMP) were performed. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels by biochemical kits, oxygen consumption rate (OCR) by seahorse apparatus, apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL) staining, and apoptosis-related expression by western blot were detected. Ras homolog gene family A/Rho-associated protein kinase-1 (RhoA/ROCK1) levels were measured by western blot and ELISA. The RhoA agonist, U46619, was employed to validate mechanism of THP. THP suppressed cell cycle progression and cell migration whereas alleviating cell viability and oxidative stress, as reduced MDA and enhanced SOD levels in ox-LDL-incubated VSMCs. THP protected mitochondrial function by higher MMP levels and OCR values. Additionally, THP decreased TUNEL-positive cells, Bax, Caspase-3, RhoA, ROCK1, and osteopontin expression, while increased Bcl-2 and smooth muscle myosin heavy chain levels. Furthermore, U46619 intervention antagonized effects of THP. THP improved mitochondrial function in VSMCs of AS by inhibiting RhoA/ROCK1 signaling pathway.

MLC2: Physiological Functions and Potential Roles in Tumorigenesis.

The myosin regulatory light chain 2 (MLC2) is a crucial regulator of myosin activity. Its phosphorylation, mediated by various kinases, plays a vital role in maintaining normal physiological functions in skeletal muscle, myocardium, smooth muscle, and nonmuscle cells. Moreover, MLC2 has been implicated in the development of many cancers through its phosphorylation. An increasing number of studies have shown that MLC2 may influence tumor progression by modulating cancer cell growth, migration, invasion, apoptosis, and autophagy. In this paper, we provide a concise overview of the phosphorylation regulatory mechanisms of MLC2 and its roles in both physiology and tumorigenesis. Furthermore, this study proposes potential directions for future research.

TNAP expressing adventitial pericytes contribute to myogenesis during foetal development.

TNAP expressing adventitial pericytes contribute to myogenesis during foetal development.

Squamate ventricular cardiomyocytes: Ploidy, proliferation, and heart muscle cell size in the leopard gecko (Eublepharis macularius).

While heart function is broadly conserved across vertebrates, the cellular phenotype of muscle cells (cardiomyocytes) varies across taxa and throughout ontogeny. Emerging evidence suggests that some attributes may correlate with the capacity for spontaneous cardiomyocyte replacement following injury. For example, among non-regenerating taxa like adult mammals and birds, cardiomyocytes are polyploid, rarely proliferate, and are large in size. In contrast, in regeneration-competent zebrafish and amphibians, cardiomyocytes are diploid, spontaneously proliferate, and are comparatively small. For other species, less is known. Here, we investigate these attributes in the squamate Eublepharis macularius, the leopard gecko. Using the nuclear counterstain DAPI to measure fluorescence intensity as a proxy for DNA content, we found that >90% of adult cardiomyocytes are diploid. Using serial histology and immunostaining for markers of DNA synthesis and mitosis, we determined that adult gecko cardiomyocytes spontaneously proliferate, albeit at significantly lower levels than previously reported in subadults. Furthermore, using wheat germ agglutinin, we found that the cross-sectional area is maintained across ontogeny and that gecko cardiomyocytes are 10× smaller than those of mice. Taken together, our data show that gecko cardiomyocytes share several key cellular attributes with regeneration-competent species and that postnatal ventricular growth occurs via cardiomyocyte hyperplasia.

Zebrafish and cellular models of SELENON-Congenital myopathy exhibit novel embryonic and metabolic phenotypes

BackgroundSELENON-Congenital Myopathy (SELENON-CM) is a rare congenital myopathy caused by mutations of the SELENON gene characterized by axial muscle weakness and progressive respiratory insufficiency. Muscle histopathology may be non-specific, but commonly includes multiminicores or a dystrophic pattern. The SELENON gene encodes selenoprotein N (SelN), a selenocysteine-containing redox enzyme located in the endo/sarcoplasmic reticulum membrane where it colocalizes with mitochondria-associated membranes. However, the molecular mechanism(s) by which SelN deficiency cause SELENON-CM remain poorly understood. A hurdle is the lack of cellular and animal models that show easily assayable phenotypes.MethodsUsing CRISPR-Cas9 we generated three zebrafish models of SELENON-CM, which were then studied by spontaneous coiling, hatching, and activity assays. We also performed selenon coexpression analysis using a single cell RNAseq zebrafish embryo-atlas. SelN-deficient myoblasts were generated and assayed for glutathione, reactive oxygen species, carbonylation, and nytrosylation levels. Finally, we tested Selenon-deficient myoblasts’ metabolism using a Seahorse cell respirometer.ResultsWe report deep-phenotyping of SelN-deficient zebrafish and muscle cells. SelN-deficient zebrafish exhibit changes in embryonic muscle function and swimming activity in larvae. Analysis of single cell RNAseq data in a zebrafish embryo-atlas revealed coexpression of selenon and genes involved in the glutathione redox pathway. SelN-deficient zebrafish and mouse myoblasts exhibit altered glutathione and redox homeostasis, as well as abnormal patterns of energy metabolism, suggesting roles for SelN in these functions.ConclusionsThese data demonstrate a role for SelN in zebrafish early development and myoblast metabolism and provide a basis for cellular and animal model assays for SELENON-CM.

A satellite cell-dependent epigenetic fingerprint in skeletal muscle identity genes after lifelong physical activity.

Satellite cells comprise a small proportion of mononuclear cells in adult skeletal muscle. Despite their relative rarity, satellite cells have critical functions in muscle adaptation, particularly during prolonged exercise training. The mechanisms by which satellite cells mediate skeletal muscle responsiveness to physical activity throughout the lifespan are still being defined, but epigenetic regulation may play a role. To explore this possibility, we analyzed global DNA methylation patterns in muscle tissue from female mice that engaged in lifelong voluntary unweighted wheel running with or without satellite cells. Satellite cells were ablated in adulthood using the tamoxifen-inducible Pax7-DTA model. Compared to sedentary mice, wheel running for 13 months caused muscle DNA methylation differences in the promoter regions of numerous muscle fiber-enriched genes-Cacgn1, Dnm2, Mlip, Myl1, Myom2, Mstn, Sgca, Sgcg, Tnnc1, Tnni2, Tpm1, and Ttn-only when satellite cells were present. These genes relate to muscle fiber identity, cytoarchitecture, and size as well as overall muscle function. Epigenetic alterations to such genes are consistent with previously observed histological and invivo impairments to running adaptation after satellite cell depletion in these same mice. Musk promoter region methylation was affected only in the absence of satellite cells with lifelong running relative to sedentary; this dovetails with work showing that satellite cells influence skeletal muscle innervation. Defining the epigenetic effects of satellite cells on identity genes in muscle fibers after lifelong physical activity provides new directions for how these rare stem cells can promote muscle adaptation and function throughout the lifespan.

Insulin receptor responsiveness governs TGFβ-induced hepatic stellate cell activation: Insulin resistance instigates liver fibrosis.

The insulin receptor (INSR) has been shown to be hyperactive in hepatic stellate cells (HSCs) in humans and rodents with liver fibrosis. To explore HSC cellular mechanisms that INSR regulates during pro-fibrotic stimulation, we used CRISPR-Cas9 technology. We knocked out a portion of the INSR gene in human LX2 HSC cells (INSRe5-8 KO) that regulates insulin responsiveness but not the insulin-like growth factor (IGF) or transforming growth factor-β (TGFβ) signaling. The INSRe5-8 KO HSCs had significantly higher cell growth, BrdU incorporation, and lower TP53 expression that suppresses growth, and they also exhibited increased migration compared to the Scramble control. We treated the scramble control and INSRe5-8 KO HSCs with insulin or TGFβ and profiled hundreds of kinase activities using the PamGene PamStation kinome technology. Our analysis showed that serine/threonine kinase (STK) activities were reduced, and most of the protein-tyrosine kinase (PTK) activities were increased in the INSRe5-8 KO compared to the Scramble control HSCs. To study gene transcripts altered in activated Scramble control and INSRe5-8 KO HSCs, we treated them with TGFβ for 24 h. We isolated RNA for sequencing and found that the INSRe5-8 KO cells, compared to control HSCs, had altered transcriptional responsiveness to TGFβ stimulation, collagen-activated signaling, smooth muscle cell differentiation pathways, SMAD protein signaling, collagen metabolic process, integrin-mediated cell adhesion, and notch signaling. This study demonstrates that reduced INSR responsiveness enhances HSC growth and selectively mediates TGFβ-induced HSC activation. These findings provide new insights into the development of more effective treatments for liver fibrosis.

Angiopoietin-2 regulates the phenotypic switch of vascular smooth muscle cells.

During uterine spiral artery remodeling, vascular smooth muscle cells (VSMCs) become disorganized and undergo phenotypic switching from a contractile to a more synthetic phenotype. We have previously reported that uterine natural killer cells induce this VSMC phenotypic switching by secreting angiopoietin-2 (Ang-2). Here, we identified the specific mechanisms by which Ang-2 plays a role in this phenomenon. VSMCs isolated from human umbilical arteries were used as an invitro model to investigate the role of Ang-2 in phenotypic switching. Human decidua tissue from preeclamptic and control pregnancies was collected to compare the expression levels of related proteins. Ang-2 induced a more synthetic phenotype in VSMCs as evidenced by decreased contractile marker expression, increased proliferation and migration, and an altered cytoskeleton. VSMC expressed integrin β6 interacted directly with Ang-2 and induced phosphorylation of FAK (S910 and Y397), AKT (S473), and mTOR (S2448). Knockdown of FAK recovered the calponin loss induced by Ang-2 and resulted in lower EZH2 abundance. Inhibition of FAK and EZH2 both attenuated Ang-2-induced inhibition of the LC3 II/LC3 I ratio and ATG7 expression, and proliferation. Lipid peroxidation inhibition by ferrostatin-1 or the IL-8 receptor antagonist navarixin inhibited the Ang-2-induced migration. IL-8 secretion was significantly lower with lipid peroxidation inhibition. In preeclamptic decidua, there were more unremodeled spiral arteries, and the abundance of Ang-2 was dysregulated. Ang-2 dysregulation may disrupt spiral artery remodeling and contribute to preeclampsia. Ang-2 may be a novel therapeutic target for the treatment of pregnancy complications affected by incomplete spiral artery remodeling.

Mitochondria Isolated From Bone Mesenchymal Stem Cells Restrain Muscle Disuse Atrophy and Fatty Infiltration After Rotator Cuff Tears.

Rotator cuff tears (RCTs) commonly lead to muscle atrophy, fibrosis, and fatty infiltration, complicating treatment. To investigate the use of mitochondria isolated from bone mesenchymal stem cells (BMSC-Mito) for mitigating complications after RCT, focusing on muscle protection. Controlled laboratory study. RCTs were induced by transecting the tendons of the supraspinatus and infraspinatus in Sprague-Dawley rats. In vivo, 90 rats were randomized into 3 groups: sham (no intervention), RCTs treated with BMSC-Mito, and RCTs treated with phosphate-buffered saline. After 6 weeks of intramuscular injections of BMSC-Mito or phosphate-buffered saline, supraspinatus muscles were harvested for analysis. Evaluations included wet muscle weight, muscle fiber cross-sectional area, fibrosis, fatty infiltration, slow-fast myofiber types and muscle biomechanics, capillary density, mitochondria respiratory chain complex activity, adenosine triphosphate (ATP) concentration, oxidative stress, and mitochondrial ultrastructure. In vitro experiments utilized primary rat skeletal muscle cells pretreated with rhodamine 6G to induce mitochondrial dysfunction, assessing the effects of BMSC-Mito on cell viability, mitochondrial membrane potential, and oxidative stress levels. BMSC-Mito can be effectively transplanted into muscles and integrated into the local mitochondrial network. After RCT, the supraspinatus showed significant mass loss, reduced fiber cross-sectional area, fatty infiltration, and a shift from slow to fast myofiber types, which negatively affected muscle biomechanics. These changes were reversed by BMSC-Mito. BMSC-Mito also preserved vascularity (CD31 and α-SMA) impaired by RCT. Additionally, BMSC-Mito notably improved disuse-induced mitochondrial changes, leading to increased mitochondrial number and COX IV expression; furthermore, BMSC-Mito protected mitochondria morphology and enhanced cytosolic superoxide dismutase activity. This treatment also improved mitochondria respiratory chain complex activity and ATP concentration, reducing oxidative stress. In vitro, BMSC-Mito treatment effectively maintained the mitochondrial membrane potential of skeletal muscle cells, improved cell viability, and restored its mitochondrial function and ATP levels. These findings suggest that BMSC-Mito might play a role in preventing muscle atrophy and fatty infiltration after RCT through the protection of mitochondrial function and the promotion of angiogenesis. BMSC-Mito present a promising therapeutic approach for addressing rotator cuff muscle degeneration.

The Protective Effects of Burdock Fructooligosaccharide on Preterm Labor Through Its Anti-Inflammatory Action

Most pharmacotherapeutic chemicals/interventions used to manage preterm labor (PTL) often cause neonatal morbidity and maternal adverse reactions. Fructooligosaccharides, extracted from traditional Chinese medicine, can alleviate inflammation, demonstrate antiviral capabilities, and protect against antioxidant stress, implying a potential effective PTL treatment. In this study, we explored the protective effects of the purified burdock fructooligosaccharide (BFO), a Gfn-type fructose polymer, on inflammation-induced PTL. It was found that two doses of 30 mg/kg mouse BFO administration to pregnant mice at a 6 h interval can effectively ameliorate lipopolysaccharide (LPS)-induced PTL. Drug dynamic distribution analysis revealed that BFO was rather highly enriched in myometrial tissues, could inhibit oxytocin-induced uterine smooth muscle contraction, and could bind toll-like receptor 4 (TLR4) on the membrane of uterine smooth muscle cells, downregulating the expression of downstream genes, attenuating the upregulation of inflammatory cytokines in serum and the myometrium, as well as reversing the increased macrophage and neutrophil infiltration into the myometrium induced by LPS. It can also interfere with the levels of estrogen and progesterone, alleviating the occurrence of premature birth. These findings collectively suggest that BFO might serve as a promising therapeutic agent for inflammation-related preterm labor to safeguard the health of both the mother and fetus.

Thrombospondin-1 binds to integrin β3 to inhibit vascular calcification through suppression of NF-κB pathway.

Vascular calcification is an important risk factor related to all-cause mortality of cardiovascular events in patients with chronic kidney disease (CKD). Vascular extracellular matrix (ECM) proteins have been demonstrated to regulate vascular calcification. ECM protein thrombospondin 1 (THBS1/TSP-1) plays a critical role in the regulation of vascular diseases. However, whether THBS1 is involved in vascular calcification in CKD patients remains unclear. In this study, RNA sequencing datasets from the Gene Expression Omnibus (GEO) database GSE146638 showed that THBS1 was upregulated in the aortas of CKD rats. Enzyme-linked immunosorbent assay (elisa) revealed that serum THBS1 levels were increased in CKD patients with thoracic calcification. Western blotting and immunofluorescence analysis showed that THBS1 expression was increased in calcified vascular smooth muscle cells (VSMCs) and arteries. THBS1 knockdown exacerbated rat VSMC calcification induced by high phosphorus and calcium, as shown by Alizarin red staining and calcium content assays. Conversely, THBS1 overexpression attenuated VSMC calcification and abdominal aortic calcification in rats with CKD. Moreover, addition of recombinant THBS1 protein inhibited calcification of VSMCS and human arterial rings. Smooth muscle cell-specific knockout of THBS1 mice treated with vitamin D3 displayed aggravated aortic calcification. Mechanistically, the protein-protein interaction database STRING (http://string-db.org/) analysis and coimmunoprecipitation assays revealed THBS1 bound to integrin β3. Reduction of integrin β3 levels abrogated the protective effect of THBS1 on vascular calcification. RNA-seq analysis revealed that THBS1 overexpression modulated the nuclear factor-kappa B (NF-κB) signaling pathway. Of note, the inhibitory effect of THBS1 overexpression on the NF-κB signal was abolished by knockdown of integrin β3. In conclusion, THBS1 interacts with integrin β3 to inhibit vascular calcification through suppression of NF-κB signal, suggesting a promising therapeutic target for vascular calcification in CKD. © 2025 The Pathological Society of Great Britain and Ireland.