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Arterial wall active mechanics are driven by resident smooth muscle cells, which respond to biological, chemical, and mechanical stimuli and activate their cytoskeletal machinery to generate contractile stresses. The cellular mechanoresponse is sensitive to environmental perturbations, often leading to maladaptation and disease progression. When investigated at the single cell scale, however, these perturbations do not consistently result in phenotypes observed at the tissue scale. Here, a multiscale model is introduced that translates microscale contractility signaling into a macroscale, tissue-level response. The microscale framework incorporates a biochemical signaling network along with characterization of fiber networks that govern the anisotropic mechanics of vascular tissue. By incorporating both biochemical and mechanical components, the model is more flexible and more broadly applicable to physiological and pathological conditions. The model can be applied to both cell and tissue scale systems, allowing for the analysis of in vitro, traction force microscopy and ex vivo, isometric contraction experiments in parallel. When applied to aortic explant rings and isolated smooth muscle cells, the model predicts that active contractility is not a function of stretch at intermediate strain. The model also successfully predicts cell-scale and tissue-scale contractility and matches experimentally observed behaviors, including the hypercontractile phenotype caused by chronic hyperglycemia. The connection of the microscale framework to the macroscale through the multiscale model presents a framework that can translate the wealth of information already collected at the cell scale to tissue scale phenotypes, potentially easing the development of smooth muscle cell-targeting therapeutics. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effect of rotigaptide (ZP123) on spontaneous contractions of gastric smooth muscle in diabetic rats and explore the underlying mechanisms. Twelve rats were randomly divided into model and normal control groups. Changes in gastric smooth muscle spontaneous contractions in each group were observed. Western blot analysis was performed to detect Cx43 and PKCα expression. Rat gastric smooth muscle cells were cultured in vitro and divided into normal glucose, high glucose and high glucose+rotigaptide group. The intracellular Ca2+ content was observed by immunofluorescence. The amplitude and frequency of gastric smooth muscle spontaneous contractions were reduced in the model group than the normal control group (all p < .01), which were reduced after rotigatide treatment than before treatment in the model group (all p < .01). The model+rotigaptide group showed decreased membrane expression of Cx43, increased cytoplasmic expression of Cx43, increased membrane expression of p‐PKCα Thr497 and lower membrane/cytoplasm ratio of Cx43 expression compared with the model group (all p < .01). The intracellular Ca2+ content was increased in the high glucose group than the normal glucose group (p < .01), while no significant difference was observed between the high glucose+rotigaptide and high glucose groups. Our findings suggest that rotigatide can stabilize the intracellular Ca2+ concentration in gastric smooth muscle cells under high glucose condition by upregulating PKCα activity and downregulating the number of GJs and the opening rate of GJ hemichannels through the PKCα‐Cx43 pathway, thus inhibiting spontaneous contractions of gastric smooth muscle in diabetic rats. [ABSTRACT FROM AUTHOR]

Background Methods Key Results Conclusions and Inferences Capsaicin‐containing red pepper sauce suspension augments esophageal contraction amplitude on conventional manometry. This study used high‐resolution manometry (HRM) to investigate if capsaicin infusion modulates segmental esophageal smooth muscle peristalsis in healthy adults.Sixteen healthy volunteers (mean age 37 years, 14 male) underwent HRM for the evaluation of primary peristalsis and secondary peristalsis using slow and rapid air distensions. Both primary and secondary peristalsis were assessed following infusions of capsaicin‐containing red pepper sauce and saline.Capsaicin infusion significantly increased heartburn symptoms compared to saline infusion (p < 0.001), and significantly decreased threshold volumes of secondary peristalsis during rapid air distensions (p = 0.02). The frequency of secondary peristalsis during rapid air distensions was significantly increased by capsaicin infusion (p = 0.03). Neither capsaicin infusion (p = 0.06) nor saline infusion (p = 0.27) altered threshold volume during slow air distensions. Capsaicin infusion significantly increased distal contractile integral (DCI) of primary peristalsis (p = 0.04), particularly in the proximal smooth muscle segment (p = 0.048). It enhanced secondary peristalsis during rapid air distensions (p = 0.003) but not during slow air distension (p = 0.23). Saline infusion significantly increased DCI of secondary peristalsis during rapid air distension (p = 0.01).Augmentation of distension‐induced secondary peristalsis can be modulated by activation of capsaicin‐sensitive afferents similar to mechanosensitive afferents. Capsaicin‐induced augmentation of primary peristalsis isolates to the cholinergic‐mediated proximal smooth muscle segment, which warrants study in ineffective esophageal motility to determine therapeutic potential. [ABSTRACT FROM AUTHOR]

Intestinal smooth muscle differentiation is a complex physico-biological process involving several different pathways. Here, we investigate the properties of Ca2+ waves in the developing intestinal mesenchyme using GCamp6f expressing mouse embryos and investigate their relationship with smooth muscle differentiation. We find that Ca2+ waves are absent in the pre-differentiation mesenchyme and start propagating immediately following α-SMA expression. Ca2+ waves are abrogated by CaV1.2 and gap-junction blockers, but are independent of the Rho pathway. The myosine light-chain kinase inhibitor ML-7 strongly disorganized or abolished Ca2+ waves, showing that perturbation of the contractile machinery at the myosine level also affected the upstream Ca2+ handling chain. Inhibiting Ca2+ waves and contractility with CaV1.2 blockers did not perturb circular smooth muscle differentiation at early stages. At later stages, CaV1.2 blockers abolished intestinal elongation and differentiation of the longitudinal smooth muscle, leading instead to the emergence of KIT-expressing interstitial cells of Cajal at the gut periphery. CaV1.2 blockers also drove apoptosis of already differentiated, CaV1.2-expressing smooth muscle and enteric neural cells. We provide fundamental new data on Ca2+ waves in the developing murine gut and their relation to myogenesis in this organ. Calcium waves underpin smooth muscle contractions in the gut. The authors examine their developmental dynamics, molecular properties and their impact on differentiation of smooth muscle and interstitial cells of Cajal in the mouse embryo. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Material and Methods Results Conclusion To summarize published information about the desmoplastic fibroma of the gnathic bones into a descriptive analysis of the main features of this condition.A systematic review according to the PRISMA guidelines was conducted. Electronic search was performed in four databases and in the gray literature. Case reports and case series were included. Frequencies were obtained for descriptive analysis.We identified 66 articles, for a total of 96 cases. Female patients (55.8%) in the first decade of life (40.6%) with a mean age of 18.2 years were more affected. The mandible was the most affected bone with 81.2% of the cases. The main clinical feature was painless swelling (54.2%). Most of the imaging examinations (radiological, computed tomography, and magnetic resonance) showed well‐defined radiolucencies (65.4%) lesions. The treatment was surgical removal in all cases. The recurrence rate was 10.8% and all in the posterior mandible. Spindle cell fibroblasts in a collagenized stroma were often described in the histopathological features. Vimentin, smooth muscle actin, and β‐catenin were common immunohistochemical markers.Desmoplastic fibroma is a locally aggressive lesion that commonly affects the jaws in children. Histopathology is essential for diagnosis, and the pathogenesis of this tumor should be further investigated. [ABSTRACT FROM AUTHOR]

The sentinel lymph node (SN) concept has a significant impact on cancer surgery. We aimed to examine which morphology of dendritic cells (DCs) and macrophages corresponds to “preconditioning” of the SN against cancer. Although macrophages are generally able to tolerate cancer metastasis, the CD169‐positive subtype is believed to be a limited exception. Immunohistochemical and morphometric analyses were performed to examine DC‐SIGN‐, CD68‐, and CD169‐positive cells in SNs and non‐SNs of 23 patients with gastric cancer with or without nodal metastasis. All patients survived for >5 years without recurrence. DCs were present in the subcapsular, paracortical, and medullary sinuses, the endothelia of which expressed DC‐SIGN and smooth muscle actin (SMA). In the non‐SNs of patients without metastasis, subcapsular DCs occupied a larger area than SNs, and this difference was statistically significant. Conversely, subcapsular DCs were likely to have migrated to the paracortical area of the SNs. DC clusters often overlapped with macrophage clusters; however, histiocytosis‐like clusters of CD169‐negative macrophages showed a smaller overlap. We found a significantly larger overlap between DC‐SIGN and CD169‐positive clusters in SNs than in non‐SNs; the larger overlap seemed to correspond to a higher cross‐presentation of cancer antigens between these cell populations. DC‐SIGN–CD169‐double positive cells might exist within this overlap. SNs in gastric cancers are usually preconditioned as a frontier of cancer immunity, but they may sometimes be suppressed earlier than non‐SNs. DC‐SIGN‐ and CD169‐positive cells appeared to decrease owing to a long lag time from the primary lesion occurrence and a short distance from the metastasis. [ABSTRACT FROM AUTHOR]

Primary liver cancer is an increasing problem worldwide and is associated with significant mortality. A popular method of modeling liver cancer in mice is plasmid hydrodynamic tail vein injection (HTVI). However, plasmid-HTVI models rarely recapitulate the chronic liver injury which precedes the development of most human liver cancer. We sought to investigate how liver injury using thioacetamide contributes to the pathogenesis and progression of liver cancer in two oncogenic plasmid-HTVI-induced mouse liver cancer models. Fourteen-week-old male mice received double-oncogene plasmid-HTVI (SB/AKT/c-Met and SB/AKT/NRas) and then twice-weekly intraperitoneal injections of thioacetamide for 6 weeks. Liver tissue was examined for histopathological changes, including fibrosis and steatosis. Further characterization of fibrosis and inflammation was performed with immunostaining and real-time quantitative PCR. RNA sequencing with pathway analysis was used to explore novel pathways altered in the cancer models. Hepatocellular and cholangiocellular tumors were observed in mice injected with double-oncogene plasmid-HTVI models (SB/AKT/c-Met and SB/AKT/NRas). Thioacetamide induced mild fibrosis and increased alpha smooth muscle actin-expressing cells. However, the combination of plasmids and thioacetamide did not significantly increase tumor size, but increased multiplicity of small neoplastic lesions. Cancer and/or liver injury up-regulated profibrotic and proinflammatory genes while metabolic pathway genes were mostly down-regulated. We conclude that the liver injury microenvironment can interact with liver cancer and alter its presentation. However, the effects on cancer development vary depending on the genetic drivers with differing active oncogenic pathways. Therefore, the choice of plasmid-HTVI model and injury agent may influence the extent to which injury promotes liver cancer development. [ABSTRACT FROM AUTHOR]

Hypoxic pulmonary hypertension (HPH), a chronic condition affecting the cardiopulmonary system, has high mortality. Echinacoside (ECH) is a phenylethanoid glycoside, which is used to ameliorate pulmonary vascular remodeling and pulmonary vasoconstriction in rats. Accordingly, we aimed to explore the mechanism of ECH in preventing and treating HPH. Sprague Dawley rats were housed in a hypobaric hypoxia chamber for 28 days to obtain the HPH model. The experimental rats were randomly allocated into the following several groups: normoxia group, chronic hypoxia group, and ECH group. The therapeutic results of ECH (10, 20, and 40 mg/kg) showed that ECH reduced mPAP, Hb, Hct, and RVHI in HPH rats. Then this work employed label‐free quantitative proteomic analysis, western blotting, and RT‐PCR to investigate the mechanism by which ECH prevents HPH. The results found that in the chronic hypoxia group, the levels of ACSL1, COL6A1, COL4A2, COL1A1, and PC increased compared to the normoxia group. However, the opposite effect was observed in the chronic hypoxia group treated with ECH. The study indicates that the administration of ECH may slow the pathological progression of HPH by suppressing the inflammatory response, inhibiting smooth muscle cell proliferation, and minimizing the deposition of extracellular matrix. [ABSTRACT FROM AUTHOR]

Background/Objective: Sensitization to specific IgE Staphylococcus aureus enterotoxins (SEs) is associated with an increased risk for severe asthma development. Limited data exist regarding the association of seropositivity for specific IgE SEs and the different aspects of severe asthma. We aimed to determine whether the presence of SEs is associated with asthma-related parameters such as inflammatory cells in the airways, features of airway remodeling, and other variables relating to asthma assessment and severity. Methods: Fifty patients with severe asthma were recruited in the study. Demographics, comorbidities, asthma duration, and asthma medication were recorded by treating physicians. Specific IgE SE measurement, lung function, atopic status, asthma control test (ACT), sputum induction, bronchoscopy with BAL, and indices of airway remodeling were also assessed. Results: Twelve patients were positive to enterotoxin sensitization. Patients seropositive to specific IgE SEs significantly differed in regard to FEV1% pred and FEV1/FVC ratio compared to seronegative ones. Analyzing the inflammatory variables obtained from induced sputum, BAL, and endobronchial biopsies, the only significant difference was that of smooth muscle area (SMA), which was greater in specific IgE SE seropositive patients. The multivariate linear regression analysis showed two significant associations of specific IgE SE seropositivity. We found a negative with FEV1% pred with beta standardized coefficient 95%CI −0.054 (−0.083, −0.031), p < 0.001, and a positive with SMA with beta standardized coefficient 95%CI 0.054 (0.081, 0.037), p < 0.001. Conclusions: Seropositivity to specific IgE SEs in severe asthma is associated with more severe airflow limitation, obstruction, and upregulation in SMA, indicating a possible role in the remodeling process. [ABSTRACT FROM AUTHOR]

Calcium influx via the L‐type voltage‐gated Cav1.2 calcium channel in smooth muscle cells regulates vascular contraction. Calcium channel blockers (CCBs) are widely used to treat hypertension by inhibiting Cav1.2 channels. Using the vascular smooth muscle cell line, A7r5 and primary culture of cerebral vascular smooth muscle cells, we found that the expression and function of Cav1.2 channels are downregulated during hypoxia. Furthermore, hypoxia induces structural changes in Cav1.2 channels via alternative splicing. The expression of exon 9* is upregulated, whereas exon 33 is downregulated. Such structural alterations of Cav1.2 channels are caused by the decreased expression of RNA‐binding proteins RNA‐binding protein fox‐1 homolog 1 and 2 (RbFox1 and RbFox2). Overexpression of RbFox1 and RbFox2 prevents hypoxia‐induced exon 9* inclusion and exon 33 exclusion. Importantly, such structural alterations of the Cav1.2 channel partly contribute to the enhanced sensitivity of Cav1.2 to isradipine (a CCB) under hypoxia. Overexpression of RbFox1 and RbFox2 successfully reduces isradipine sensitivity in hypoxic smooth muscle cells. Our results suggest a new strategy to manage ischemic diseases such as stroke and myocardial infarction. [ABSTRACT FROM AUTHOR]

(-)-Carvone, a ketone monoterpene, is the main component of essential oils from several medicinal plants and has been reported to have anti-arthriric, anticonvulsive, antidiabetic, anti-inflammatory, anticancer, and immunomodulatory effects. Therefore, this study aimed to investigate the spasmolytic activity of (-)-carvone in rodent models. The isolated virgin rat uterus was mounted in an organ bath apparatus, and the relaxing effect of (−)-carvone and its mechanism of action were evaluated in tonic contractions induced by carbachol, KCl, PGF2α, or oxytocin. The animal model of primary dysmenorrhea was replicated with the injection of estradiol benzoate in female mice for three consecutive days, followed by intraperitoneal administration of oxytocin. Non-clinical acute toxicity evaluation was also performed. (-)-Carvone potency and effectiveness were larger in carbachol (pEC50 = 5.41 ± 0.14 and Emax = 92.63 ± 1.90% at 10–3 M) or oxytocin (pEC50 = 4.29 ± 0.17 and Emax = 86.69 ± 1.56% at 10–3 M) contractions. The effect of (−)-carvone was altered in the presence of 4-aminopyridine, glibenclamide, L-NAME, or methylene blue. Mice pre-treated with (-)-carvone at a dose of 100 mg/kg showed a significant reduction in the number of writhing after oxytocin administration. No toxicity was observed after oral administration of 1 g/kg (−)-carvone. Taken together, we showed that (-)-carvone reduced writhing by a spasmolytic effect, probably through the participation of KV and KATP channels and the nitric oxide pathway. [ABSTRACT FROM AUTHOR]

This article discusses the misdiagnosis of synaptophysin-expressing gastric glomus tumors as gastric neuroendocrine tumors. The authors present two cases of patients with gastric glomus tumors that were initially misdiagnosed due to the expression of synaptophysin. The article emphasizes the importance of using a comprehensive panel of immunomarkers, including chromogranin, CD56, and keratin, to differentiate between neuroendocrine tumors and glomus tumors. The authors also highlight the potential diagnostic pitfalls and implications of synaptophysin expression in visceral glomus tumors. [Extracted from the article]

The aim of this study was to investigate the underlying mechanism of miR-9-5p in airway smooth muscle cells (ASMCs) of asthmatic mice. An asthmatic mouse model was established through the intraperitoneal injection of ovalbumin. Histopathological changes in lung tissues of asthmatic mice were observed using HE staining. ASMCs was identified using immunofluorescence staining and cell morphology. The mRNA expressions of miR-9-5p, KLF5, and IL-1β were measured using RT-qPCR. Additionally, CCK8 assay and flow cytometry were applied for ASMC proliferation and apoptosis, respectively. The protein levels of OPN, KLF5, and IL-1β were assessed using western blotting. The results showed that miR-9-5p was abnormally downregulated in lung tissues and ASMCs of asthmatic mice. Dual-Luciferase Reporter Assay and Chromatin immunoprecipitation confirmed that miR-9-5p targeted KLF5 that bounds to IL-1β promoter. Besides, miR-9-5p negatively regulated IL-1β mRNA and protein level via KLF5. Moreover, miR-9-5p was found to positively regulate ASMC apoptosis, negatively regulate ASMC proliferation and OPN protein expression, albeit with partial reversal by KLF5. Mechanistically, the regulation of ASMC proliferation and apoptosis by miR-9-5p is achieved by targeting KLF5/IL-1β axis. [ABSTRACT FROM AUTHOR]

Introduction: Mounier-Kuhn syndrome or tracheobronchomegaly, is a rare condition that consists of abnormal dilation of the trachea and main bronchi due to a pathological arrangement of smooth muscle fibers in this area. Case report: We present the case of a 46-year-old woman with poorly controlled asthma and recurrent infections, who was diagnosed with Mounier-Kuhn syndrome through a computed tomography scan revealing an unusual enlargement of the trachea with associated bronchiectasis. Results: The diagnosis of Mounier-Kuhn syndrome is radiological, involving measurement of the trachea where a diameter >25 mm in men and >21 mm in women is observed. While diagnosis is sometimes incidental, there is an association with respiratory diseases such as asthma or COPD, hence clinical suspicion is important in patients with poorly controlled underlying conditions who present with recurrent infections, inadequate secretion management, or even hemoptysis. Conclusions: Despite its rarity, this syndrome significantly impacts patients' quality of life. Diagnosis and management involve comprehensive evaluations including computed tomography, with a multidisciplinary approach including pulmonologists and radiologists. Exploring its clinical features, associations with other respiratory diseases and treatment options is crucial in managing this rare respiratory condition. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the expression of core molecular clock genes/proteins in penile cavernous tissue from healthy male subjects and to determine whether their expression has circadian variation. Materials and Methods: Corpus cavernosum biopsy samples were obtained from 10 healthy males with penile deviation or fracture who underwent surgical intervention during the day and night. The daytime group (n=5) underwent corpus cavernosum tissue sampling during zeitgeber time (ZT) 8–12, while the nighttime group (n=5) underwent sampling during ZT 20–24. The expression and localization of BMAL1, CLOCK, PER1, PER2, PER3, CRY1, and CRY2 proteins were analyzed using immunohistochemistry and quantified using H-score analysis. RT-qPCR analysis was performed to assess the expression of core molecular clock genes in the corpus cavernosum tissue of 5 additional daytime patients. Results: The expression of core molecular clock proteins was detected in vascular endothelial cells (VECs) and smooth muscle cells (SMCs) in corpus cavernosum during daytime and nighttime. BMAL1 exhibited the most significant nuclear expression during daytime in both cell types, whereas its expression decreased significantly at night. In VECs, a significant decrease in the nuclear expression of CRY1 was observed at night. In SMCs, a significant decrease in the cytoplasmic expression of PER3 was observed at night. The expression patterns of the core molecular clock genes were ascertained through a RT-qPCR analysis. Conclusions: Our research provides compelling evidence that core molecular clock genes are distinctly expressed in penile tissue in humans. Furthermore, we observed the expression of molecular clock proteins within the VECs and SMCs of the corpus cavernosum, with BMAL1 being the most prominently expressed. The discovery of core molecular clock genes in penile tissue, as well as proteins within the SMCs and VECs of the corpus cavernosum, introduces the potential significance of the molecular clock mechanism in the physiology of penile erection. [ABSTRACT FROM AUTHOR]

Background and purpose: Pulmonary arterial hypertension (PAH) is a progressive disease in which chronic membrane potential (Em) depolarisation of the pulmonary arterial smooth muscle cells (PASMCs) causes calcium overload, a key pathological alteration. Under resting conditions, the negative Em is mainly set by two pore domain potassium (K2P) channels, of which the TASK‐1 has been extensively investigated. Experimental Approach: Ion channel currents and membrane potential of primary cultured human(h) PASMCs were measured using the voltage‐ and current clamp methods. Intracellular [Ca2+] was monitored using fluorescent microscopy. Pulmonary BP and vascular tone measurements were also performed ex vivo using a rat PAH model. Key Results: TREK‐1 was the most abundantly expressed K2P in hPASMCs of healthy donors and idiopathic(I) PAH patients. Background K+‐current was similar in hPASMCs for both groups and significantly enhanced by the TREK activator ML‐335. In donor hPASMCs, siRNA silencing or pharmacological inhibition of TREK‐1 caused depolarisation, reminiscent of the electrophysiological phenotype of idiopathic PAH. ML‐335 hyperpolarised donor hPASMCs and normalised the Em of IPAH hPASMCs. A close link was found between TREK‐1 activity and intracellular Ca2+‐signalling using a channel activator, ML‐335, and an inhibitor, spadin. In the rat, ML‐335 relaxed isolated pre‐constricted pulmonary arteries and significantly decreased pulmonary arterial pressure in the isolated perfused lung. Conclusions and Implications: These data suggest that TREK‐1is a key factor in Em setting and Ca2+ homeostasis of hPASMC, and therefore, essential for maintenance of a low resting pulmonary vascular tone. Thus TREK‐1 may represent a new therapeutic target for PAH. [ABSTRACT FROM AUTHOR]

Objective(s): In the present study, the relaxant effect of crocetin on tracheal smooth muscle cells (TSM) and its possible mechanisms were evaluated. Materials and Methods: The study was conducted on 54 male Wistar rats in 8 groups. TSM was contracted by methacholine (10 μM) and KCl (60 mM), and the relaxant effects of four cumulative concentrations of crocetin, petal extract of saffron, and theophylline were examined on non-incubated and TSM incubated with propranolol, chlorpheniramine, diltiazem, atropine, glibenclamide, and indomethacin were investigated. Results: In non-incubated TSM contracted by methacholine or KCl, crocetin and theophylline showed concentration-dependent relaxant effects (all, P<0.001). However, various concentrations of crocetin showed significantly lower relaxant effects compared to those of theophylline (all, P<0.001). In the methacholine-induced contraction of TSM, the relaxation effect of the last concentration of crocetin in the TSM incubated with propranolol was lower than in non-incubated TSM (P<0.05). In the incubated TSM with chlorpheniramine, the relaxant effects of the two last concentrations of crocetin were significantly lower than in the non-incubated tissues contracted by KCl (P<0.05 and P<0.0). The levels of EC50 crocetin in the incubated TSM with glibenclamide, chlorpheniramine, and indomethacin were markedly lower than in non-incubated (all, P<0.05). Conclusion: The results showed potent relaxation effects of crocetin on TSM and were suggested to be through stimulation of ß-adrenergic receptors, inhibition of histamine (H1 ) receptors, and potassium channel opening mechanisms. [ABSTRACT FROM AUTHOR]

Smooth muscle organs of the lower urinary tract comprise the bladder detrusor and urethral wall, which have a reciprocal contractile relationship during urine storage and micturition. As the bladder fills with urine, detrusor smooth muscle cells (DSMCs) remain relaxed to accommodate increases in intravesical pressure while urethral smooth muscle cells (USMCs) sustain tone to occlude the urethral orifice, preventing leakage. While neither organ displays coordinated regular contractions as occurs in small intestine, lymphatics or renal pelvis, they do exhibit patterns of rhythmicity at cellular and tissue levels. In rabbit and guinea‐pig urethra, electrical slow waves are recorded from USMCs. This activity is linked to cells expressing vimentin, c‐kit and Ca2+‐activated Cl− channels, like interstitial cells of Cajal in the gastrointestinal tract. In mouse, USMCs are rhythmically active (firing propagating Ca2+ waves linked to contraction), and this cellular rhythmicity is asynchronous across tissues and summates to form tone. Experiments in mice have failed to demonstrate a voltage‐dependent mechanism for regulating this rhythmicity or contractions in vitro, suggesting that urethral tone results from an intrinsic ability of USMCs to ‘pace’ their own Ca2+ mobilization pathways required for contraction. DSMCs exhibit spontaneous transient contractions, increases in intracellular Ca2+ and action potentials. Consistent across numerous species, including humans, this activity relies on voltage‐dependent Ca2+ influx in DSMCs. While interstitial cells are present in the bladder, they do not ‘pace’ the organ in an excitatory manner. Instead, specialized cells (PDGFRα+ interstitial cells) may ‘negatively pace’ DSMCs to prevent bladder overexcitability. [ABSTRACT FROM AUTHOR]

\nIntroduction: Asthma is a common chronic respiratory disease characterized by chronic airway inflammation and abnormal airway remodeling. The RhoA/ROCK pathway and myocardin-related transcription factor A (MRTF-A) demonstrate significant associations with the proliferation of airway smooth muscle cells (ASCMs), which tightly correlates with the process of airway remodeling. MYOCD, which is homologous to MRTF-A but specifically expressed in smooth muscle cells, potentially regulates RhoA/ROCK activated cell proliferation and subsequent airway remodeling. Methods: The RhoA/ROCK overexpression and silencing cell lines were constructed in vitro, as well as MYOCD overexpression/silencing. The cytoskeleton alterations induced by RhoA/ROCK pathway were identified by the measuring of globular actin and filamentous actin. Results: The comparison between controls for overexpression/silencing and ROCK overexpression/silencing revealed that MYOCD presented consistent change trends with cytoskeleton and RhoA/ROCK pathway. The ROCK1 facilitates the proliferation and migration of ASCMs. The MYOCD enhanced the proliferation and migration of HASMCs. Conclusion: Our study indicates that Rho/ROCK/MYOCD is a key pathway involved in the migration and proliferation of airway smooth muscle cells. Inhibition of Rho/ROCK may be an effective approach to breaking the vicious cycle of asthmatic ASCMs proliferation, providing a novel strategy in treating asthma airway remodeling. Asthma is a common chronic respiratory disease characterized by chronic airway inflammation and abnormal airway remodeling. The regulation process of RhoA/ROCK signaling pathway and downstream MRTF-A gene is well studied and exhibits significant associations with cell contraction and cell proliferation, which correlates tightly with airway remodeling. While most studies focusing on the MRTF-A to clarify the mechanism of cell growth, we paid close attention to MYOCD gene, which shares homology with MRTF-A but expressed specifically in smooth muscle cells. Through the series cell experiments, molecular assays, and literature review, we firstly illustrated the potential function of MYOCD underlying the regulation of RhoA/ROCK activated cell proliferation and subsequent airway remodeling in airway smooth muscle cells. This novel sight provides therapeutic targets for asthma. [ABSTRACT FROM AUTHOR]

AbstractIntroduction: Angiosarcoma is an exceedingly rare entity in pediatric population. Herein, we report two pediatric angiosarcoma with novel phenotypic and genotypic profile. Methods: The two patients’ information was summarized by clinical data, histopathology, immunohistochemistry, genetic, treatment, and prognosis. Results: Two Chinese children presented with abdominal mass or consumptive hypothyroidism at 2 and 6 years. A patient presented with a unique histopathology of epithelioid AS with smooth muscle hyperplasia, and carried a novel somatic mutation in FAT1 (c.3929C > T/p. Ser1310Leu) along with germ-line variants in CDK8 (c.895A > C/p. Lys299Gln), FANCI (c.3906-07inv/p. Glu1303Lys), and MST1R (c.3581-83delinsACG/p. Arg1194-Ser1195delinsHisGly). The other patient presented with a novel ­clinical phenotype of consumptive hypothyroidism. They received postoperative treatment and were monitored for 20 and 26 months, showing good recovery. Conclusion: The phenotypic and genotypic spectrum of AS in pediatric population was expanded by these two patients, which requires the accumulating more cases to gain a deeper understanding. [ABSTRACT FROM AUTHOR]

Background: Understanding the characteristics of pulmonary resistance and elastance in relation to the location of airway narrowing, e.g., tracheal stenosis vs. intrapulmonary airway obstruction, will help us understand lung function characteristics and mechanisms related to different airway diseases. Methods: In this study, we used ex vivo sheep lungs as a model to measure lung resistance and elastance across a range of transpulmonary pressures (5–30 cmH2O) and ventilation frequencies (0.125–2 Hz). We established two tracheal stenosis models by inserting plastic tubes into the tracheas, representing mild (71.8% lumen area reduction) and severe (92.1%) obstructions. For intrapulmonary airway obstruction, we induced airway narrowing by challenging the lung with acetylcholine (ACh). Results: We found a pattern change in the lung resistance and apparent lung elastance as functions of ventilation frequency that depended on the transpulmonary pressure (or lung volume). At a transpulmonary pressure of 10 cmH2O, lung resistance increased with ventilation frequency in severe tracheal stenosis, whereas in ACh-induced airway narrowing the opposite occurred. Furthermore, apparent lung elastance at 10 cmH2O decreased with increasing ventilation frequency in severe tracheal stenosis whereas in ACh-induced airway narrowing the opposite occurred. Flow-volume analysis revealed that the flow amplitude was much sensitive to ventilation frequency in tracheal stenosis than it was in ACh induced airway constriction. Conclusions: Results from this study suggest that lung resistance and apparent elastance measured at 10 cmH2O over the frequency range of 0.125-2 Hz can differentiate tracheal stenosis vs. intrapulmonary airway narrowing in ex vivo sheep lungs. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to reveal the role and mechanism of MG-132 in delaying hyperlipidemia-induced senescence of vascular smooth muscle cells (VSMCs). Methods: Immunohistochemistry and hematoxylin-eosin staining confirmed the therapeutic effect of MG-132 on arterial senescence in vivo and its possible mechanism. Subsequently, VSMCs were treated with sodium palmitate (PA), an activator (Recilisib) or an inhibitor (Pictilisib) to activate or inhibit PI3K, and CCK-8 and EdU staining, wound healing assays, Transwell cell migration assays, autophagy staining assays, reactive oxygen species assays, senescence-associated β-galactosidase staining, and Western blotting were performed to determine the molecular mechanism by which MG-132 inhibits VSMC senescence. Validation of the interaction between MG-132 and PI3K using molecular docking. Results: Increased expression of p-PI3K, a key protein of the autophagy regulatory system, and decreased expression of the autophagy-associated proteins Beclin 1 and ULK1 were observed in the aortas of C57BL/6J mice fed a high-fat diet (HFD), and autophagy was inhibited in aortic smooth muscle. MG-132 inhibits atherosclerosis by activating autophagy in VSMCs to counteract PA-induced cell proliferation, migration, oxidative stress, and senescence, thereby inhibiting VSMC senescence in the aorta. This process is achieved through the PI3K/AKT/mTOR signaling pathway. Conclusion: MG-132 activates autophagy by inhibiting the PI3K/AKT/mTOR pathway, thereby inhibiting palmitate-induced proliferation, migration, and oxidative stress in vascular smooth muscle cells and suppressing their senescence. [ABSTRACT FROM AUTHOR]

Objective: This study aims to explore the impact of Nesfatin-1 on type 2 diabetic erectile dysfunction (T2DMED) and its underlying mechanism in regulating the phenotypic switching of corpus cavernosum smooth muscle cells (CCSMCs). Methods: Twenty-four 4-week-old male C57 wild-type mice were randomly assigned to the control group, model group, and Nesfatin-1 treatment group. Monitoring included body weight, blood glucose levels, and penile cavernous pressure (ICP). Histochemistry and Western blot analyses were conducted to assess the expressions of α-SMA, OPN, and factors related to the PI3K/AKT/mTOR signaling pathway. CCSMCs were categorized into the control group, high glucose and high oleic acid group (GO group), Nesfatin-1 treatment group (GO+N group), sildenafil positive control group (GO+S group), and PI3K inhibitor group (GO+N+E group). Changes in phenotypic markers, cell morphology, and the PI3K/AKT/mTOR signaling pathway were observed in each group. Results: (1) Nesfatin-1 significantly ameliorated the body size, body weight, blood glucose, glucose tolerance, and insulin resistance in T2DMED mice. (2) Following Nesfatin-1 treatment, the ICP/MSBP ratio and the peak of the ICP curve demonstrated a significant increase. (3) Nesfatin-1 significantly enhanced smooth muscle and reduced collagen fibers in the corpus cavernosum. (4) Nesfatin-1 notably increased α-SMA expression and decreased OPN expression in CCSMCs. (5) Nesfatin-1 elevated PI3K, p-AKT/AKT, and p-mTOR/mTOR levels in penile cavernous tissue. Conclusions: Nesfatin-1 not only effectively improves body weight and blood glucose levels in diabetic mice but also enhances erectile function and regulates the phenotypic switching of corpus cavernosum smooth muscle. The potential mechanism involves Nesfatin-1 activating the PI3K/AKT/mTOR signaling pathway to induce the conversion of CCSMCs to a contractile phenotype. [ABSTRACT FROM AUTHOR]

The study was designed to explore the association between the immunolocalization of alpha-smooth muscle actin (α-SMA) and S100 proteins within the efferent ductules (ED) from one side, and the sexual maturity and seasonality from the other side. For each season, tissue specimens were obtained from 7 adult and 7 juvenile, clinically healthy male dromedaries. Specimens were investigated by the standard immunohistochemical procedures. The immunohistochemical findings displayed that the pattern of expression was similar for both proteins, either in adults or in juveniles. Expression was significantly higher in adults during season of sexual activity (winter), fairly reduced during periods of transition from activity to inactivity (spring) or from inactivity to activity (autumn) and reaches its lowest magnitude during season of sexual inactivity (summer). On the other hand, a moderate immunoreactivity of both proteins in ED from juvenile male camels was nearly uniform throughout the year. The immunoreactivity for both α-SMA (smooth muscle cells in ductular and vascular walls) and S100 (ductular ciliated cells), was evident during periods of sexual activity. It can be concluded that the immunoreactivity is androgen- dependent and positively correlated with both of sexual activity and maturity, suggesting a crucial role of both α-SMA and S100 proteins in the regulation of the diverse functions of the ED in male dromedaries. [ABSTRACT FROM AUTHOR]

In-stent restenosis(ISR) is a significant cause of long-term prognosis after percutaneous coronary intervention (PCI). The inflammatory response is a critical factor in its development. Unlike the chronic inflammatory process of traditional atherosclerosis, ISR may develop acute coronary events within even months or years, and the inflammatory mechanisms of ISR are more complex. Inflammatory factors regulate various mechanisms, including monocyte macrophage proliferation, endothelial cell damage and repair, foam cell formation, and smooth muscle cell proliferation and migration after PCI. The review briefly describes the classification and risk factors of ISR. It emphasizes the role of various inflammatory factors in ISR to provide new ideas for investigating the inflammatory mechanism of ISR and clinical intervention. [ABSTRACT FROM AUTHOR]

Background: Leiomyomas are benign neoplasms that originate from smooth muscle cells and most commonly occur in soft tis- sues, the gastrointestinal tract, and the uterus. Leiomyomas of the pancreas are exceptionally rare, with, to our knowledge, only 6 documented cases prior to this report. This case was also challenging because of the young age of the patient and an atypical initial presentation. Case Report: A 21-year-old male presented with progressive jaundice and severe anemia. Contrast-enhanced computed tomography revealed a heterogeneously hyper enhancing mass in the arterial phase in the head of the pancreas with a double-duct sign. Endoscopic biliary drainage was performed, followed by endoscopic biopsy that revealed amesenchymal tumor; leiomyoma was confirmed with an immunohistochemical evaluation. The patient underwent pancreatic oduodenectomy, and the histopathologic and immunohistochemical examinations of the resected specimen conirmed the diagnosis of a low-grade leiomyoma arising from the ampulla of Vater. Conclusion: This case not only highlights the rarity of pancreatic leiomyomas and the potential for atypical presentation but also emphasizes the importance of considering leiomyoma in the differential diagnosis, even in young patients, and supports surgical resection as the preferred treatment approach. [ABSTRACT FROM AUTHOR]

Cantú syndrome (CS), a multisystem disease with a complex cardiovascular phenotype, is caused by gain-of-function (GoF) variants in the Kir6.1/SUR2 subunits of ATP-sensitive potassium (KATP) channels and is characterized by low systemic vascular resistance, as well as tortuous, dilated, vessels, and decreased pulse-wave velocity. Thus, CS vascular dysfunction is multifactorial, with both hypomyotonic and hyperelastic components. To dissect whether such complexities arise cell autonomously within vascular smooth muscle cells (VSMCs) or as secondary responses to the pathophysiological milieu, we assessed electrical properties and gene expression in human induced pluripotent stem cell-derived VSMCs (hiPSC-VSMCs), differentiated from control and CS patient-derived hiPSCs, and in native mouse control and CS VSMCs. Whole-cell voltage clamp of isolated aortic and mesenteric arterial VSMCs isolated from wild-type (WT) and Kir6.1[V65M] (CS) mice revealed no clear differences in voltage-gated K+ (Kv) or Ca2+ currents. Kv and Ca2+ currents were also not different between validated hiPSC-VSMCs differentiated from control and CS patient-derived hiPSCs. While pinacidil-sensitive KATP currents in control hiPSC-VSMCs were similar to those in WT mouse VSMCs, they were considerably larger in CS hiPSC-VSMCs. Under current-clamp conditions, CS hiPSC-VSMCs were also hyperpolarized, consistent with increased basal K conductance and providing an explanation for decreased tone and decreased vascular resistance in CS. Increased compliance was observed in isolated CS mouse aortae and was associated with increased elastin mRNA expression. This was consistent with higher levels of elastin mRNA in CS hiPSC-VSMCs and suggesting that the hyperelastic component of CS vasculopathy is a cell-autonomous consequence of vascular KATP GoF. The results show that hiPSC-VSMCs reiterate expression of the same major ion currents as primary VSMCs, validating the use of these cells to study vascular disease. Results in hiPSC-VSMCs derived from CS patient cells suggest that both the hypomyotonic and hyperelastic components of CS vasculopathy are cell-autonomous phenomena driven by KATP overactivity within VSMCs. Graphical Abstract [ABSTRACT FROM AUTHOR]

Cross talk between T cells and airway smooth muscle (ASM) may play a role in modulating asthmatic airway inflammation and remodeling. Infiltrating T cells have been observed within the ASM bundles of asthmatics, and a wide range of direct and indirect interactions between T cells and ASM has been demonstrated using various in vitro and in vivo model systems. Contact-dependent mechanisms such as ligation and activation of cellular adhesion and costimulatory molecules, as well as the formation of lymphocyte-derived membrane conduits, facilitate the adhesion, bidirectional communication, and transfer of materials between T and ASM cells. T cell-derived cytokines, particularly of the Th1, Th2, and Th17 subsets, modulate the secretome, proliferation, and contractility of ASM cells. This review summarizes the mechanisms governing T cell-ASM cross talk in the context of asthma. Understanding the underlying mechanistic basis is important for directing future research and developing therapeutic interventions targeted toward this complex interaction. [ABSTRACT FROM AUTHOR]

Fibrostenosing Crohn's disease (CD) represents a challenging clinical condition characterized by the development of symptomatic strictures within the gastrointestinal tract. Despite therapeutic advancements in managing inflammation, the progression of fibrostenotic complications remains a significant concern, often necessitating surgical intervention. Recent investigations have unveiled the pivotal role of smooth muscle cell hyperplasia in driving luminal narrowing and clinical symptomatology. Drawing parallels to analogous inflammatory conditions affecting other organs, such as the airways and blood vessels, sheds light on common underlying mechanisms of muscular hyperplasia. This review synthesizes current evidence to elucidate the mechanisms underlying smooth muscle cell proliferation in CD-associated strictures, offering insights into potential therapeutic targets. By highlighting the emerging significance of muscle thickening as a novel therapeutic target, this review aims to inform future research endeavors and clinical strategies with the goal to mitigate the burden of fibrostenotic complications in CD and other conditions. [ABSTRACT FROM AUTHOR]

Objective To observe the connection of the orbital septum with surrounding structures and its histology in relation to mild ptosis in blepharoplasty patients. Methods From May 2018 to December 2019, 276 patients (549 eyes) who underwent blepharoplasty were divided into normal group and mild ptosis group according to the condition of upper eyelid, and the orbital septum was observed. The connection between the orbital septum and the surrounding structures, and the histologic structure of the orbital septum were observed. Results There were 498 eyes in the normal group and 51 eyes in the mild ptosis group. Comparing between the two groups, the incidence of adhesions between the orbital septum and the orbital lipid envelope was higher in the mild ptosis group (X² =95.00, P＜0.001), and the incidence of transverse ligament between the orbital septum and the levator aponeurosis was higher in the mild ptosis group (X² =99.00, P＜0.001). HE staining showed that the orbital septum in both groups was mainly a connective tissue structure that could be divided into two layers. The anterior layer was looser and the posterior layer was denser. In the mild ptosis group, the connective tissue fibers were less and looser than in the normal group. Masson staining showed that no muscular structures were found in the orbital septum of both groups. SMA staining showed that in the orbital septum of both groups, except for the blood vessels running through the orbital septum which were positive, the rest of the tissues stained negatively by SMA staining, and no smooth muscle structures were found in the orbital septum of both groups. Conclusion Adhesions between the orbital septum and the orbital lipid envelope and restrictive ligament between the orbital septum and the levator aponeurosis may be the cause of mild ptosis. [ABSTRACT FROM AUTHOR]

Pulmonary surfactant serves as a barrier to respiratory epithelium but can also regulate airway smooth muscle (ASM) tone. Surfactant (SF) relaxes contracted ASM, similar to β2‐agonists, anticholinergics, nitric oxide, and prostanoids. The exact mechanism of surfactant relaxation and whether surfactant relaxes hyperresponsive ASM remains unknown. Based on previous research, relaxation requires an intact epithelium and prostanoid synthesis. We sought to examine the mechanisms by which surfactant causes ASM relaxation. Organ bath measurements of isometric tension of ASM of guinea pigs in response to exogenous surfactant revealed that surfactant reduces tension of healthy and hyperresponsive tracheal tissue. The relaxant effect of surfactant was reduced if prostanoid synthesis was inhibited and/or if prostaglandin E2‐related EP2 receptors were antagonized. Atomic force microscopy revealed that human ASM cells stiffen during contraction and soften during relaxation. Surfactant softened ASM cells, similarly to the known bronchodilator prostaglandin E2 (PGE2) and the cell softening was abolished when EP4 receptors for PGE2 were antagonized. Elevated levels of PGE2 were found in cultures of normal human bronchial epithelial cells exposed to pulmonary surfactant. We conclude that prostaglandin E2 and its EP2 and EP4 receptors are likely involved in the relaxant effect of pulmonary surfactant in airways. [ABSTRACT FROM AUTHOR]

The pathophysiology of diverticular disease (DD) is not well outlined. Recent studies performed on the DD human ex vivo model have shown the presence of a predominant transmural oxidative imbalance whose origin remains unknown. Considering the central role of mitochondria in oxidative stress, the present study evaluates their involvement in the alterations of DD clinical phenotypes. Colonic surgical samples of patients with asymptomatic diverticulosis, complicated DD, and controls were analyzed. Electron microscopy, protein expression, and cytofluorimetric analyses were performed to assess the contribution of mitochondrial oxidative stress. Functional muscle activity was tested on cells in response to contractile and relaxant agents. To assess the possibility of reverting oxidative damages, N-acetylcysteine was tested on an in vitro model. Compared with the controls, DD tissues showed a marketed increase in mitochondrial number and fusion accompanied by the altered mitochondrial electron transport chain complexes. In SMCs, the mitochondrial mass increase was accompanied by altered mitochondrial metabolic activity supported by a membrane potential decrease. Ulteriorly, a decrease in antioxidant content and altered contraction–relaxation dynamics reverted by N-acetylcysteine were observed. Therefore, the oxidative stress-driven alterations resulted in mitochondrial impairment. The beneficial effects of antioxidant treatments open new possibilities for tailored therapeutic strategies that have not been tested for this disease. [ABSTRACT FROM AUTHOR]

Large‐conductance, calcium‐activated potassium channels (BK channels) and the Na/K‐ATPase are expressed universally in vascular smooth muscle. The Na/K‐ATPase may act via changes in the intracellular Ca2+ concentration mediated by the Na/Ca exchanger (NCX) and via Src kinase. Both pathways are known to regulate BK channels. Whether BK channels functionally interact in vascular smooth muscle cells with the Na/K‐ATPase remains to be elucidated. Thus, this study addressed the hypothesis that BK channels limit ouabain‐induced vasocontraction. Rat mesenteric arteries were studied using isometric myography, FURA‐2 fluorimetry and proximity ligation assay. The BK channel blocker iberiotoxin potentiated methoxamine‐induced contractions. The cardiotonic steroid, ouabain (10−5 M), induced a contractile effect of IBTX at basal tension prior to methoxamine administration and enhanced the pro‐contractile effect of IBTX on methoxamine‐induced contractions. These facilitating effects of ouabain were prevented by the inhibition of either NCX or Src kinase. Furthermore, inhibition of NCX or Src kinase reduced the BK channel‐mediated negative feedback regulation of arterial contraction. The effects of NCX and Src kinase inhibition were independent of each other. Co‐localization of the Na/K‐ATPase and the BK channel was evident. Our data suggest that BK channels limit ouabain‐induced vasocontraction by a dual mechanism involving the NCX and Src kinase signaling. The data propose that the NCX and the Src kinase pathways, mediating the ouabain‐induced activation of the BK channel, act in an independent manner. [ABSTRACT FROM AUTHOR]

Mammals have approximately 80 genes that encode potassium (K+) channels. They have a wide range of physiological functions, such as modulation of action potential duration and relaxation of smooth muscles. Carvacrol, a compound found in various aromatic plants, has been used traditionally for treating asthma, menstrual spasms, and gastrointestinal disorders. However, its mechanism of action on smooth muscles remains insufficiently understood. This study investigates the role of potassium ion channels in the relaxing effects of carvacrol on isolated rat duodenum smooth muscles. Rats were euthanized and duodenal segments were prepared and placed in an isolated organ bath with Krebs' solution. The segments were equilibrated for 1 h and then treated with chemicals to obtain concentrationresponse curves. The data were evaluated using one-way Analysis of Variance (ANOVA) and Tukey's Honest Significant Difference (Tukey's HSD) test for multiple comparisons. Our findings demonstrate that carvacrol induces a dosedependent relaxation of these muscles. The relaxation effects were significantly reduced in the presence of specific potassium channel inhibitors, including paxilline, UCL1684, linopirdine, barium chloride, and 4-aminopyridine. They were completely blocked by the combination of barium chloride and tetraethylammonium. However, glibenclamide, ruthenium red, and nitroarginine did not alter the relaxing effects of carvacrol. In conclusion: carvacrol relaxes duodenum smooth muscles by opening barium chloride-sensitive Kir2.1 and Kir3.1, as well as tetraethylammoniumsensitive KCa1.1, KCa2.1, KCa2.2, KCa2.3, Kv1.2, Kv1.4, Kv1.5, Kv2.1, Kv2.2, Kv4.1, Kv4.2, Kv4.3, Kv7.1, Kv7.2, Kv7.3, Kv7.4, and Kv7.5 potassium channels. [ABSTRACT FROM AUTHOR]

Objectives: Airway remodeling, a prominent feature of asthma, involves aberrant proliferation, apoptosis, and migration of airway smooth muscle cells (ASMCs). Toll-like receptors (TLRs) are implicated in the regulation of the autophagy pathway. In this study, we aimed to investigate the influence of Toll-like receptor 4 (TLR4) on autophagy and its underlying mechanism in ASMC proliferation, apoptosis, and migration. Methods: Histopathological changes in the lungs of asthmatic mice assessed by Hematoxylin-Eosin (HE) and Masson staining. Cell proliferation, apoptosis and migration were evaluated utilizing CCK8, Edu, Flow cytometry and wound heading assays. The effectiveness of siRNA transfection and the expression of TLR4, autophagy, and proliferation-related proteins after siRNA treatment were examined through RT-PCR and Western blot (WB). Conclusion: We observed an increase in TLR4 expression and autophagy in a mouse model of OVA-induced asthma. In vitro experiments showed that siRNA-mediated inhibition of TLR4 suppressed autophagy, proliferation, and migration of ASMCs, whereas TLR4 activation by lipopolysaccharide (LPS) had the opposite effect. Furthermore, the autophagy inhibitor 3-Methyladenine (3MA) inhibited ASMCs proliferation and migration while promoting apoptosis. Significantly, our study demonstrated that autophagy inhibition reversed the promotion effect of LPS on ASMC proliferation and migration. These findings suggest that TLR4 may modulate ASMC behavior through the regulation of autophagy. [ABSTRACT FROM AUTHOR]

Background: Asthma is a disease characterized by airway hyperresponsiveness and airway inflammation. Icaritin (ICT) is a plant hormone with various pharmacological activities such as anti-inflammatory, immune regulation, and anti-tumor. This study mainly explored the effects of nebulized inhalation of ICT on airway inflammation and airway remodeling in asthmatic mice. Method: Different groups of ovalbumin (OVA)-induced asthma mice with acute and chronic airway inflammation received ICT. Asthmatic mice received budesonide (BDND) aerosol inhalation as a positive control, while normal control and asthma model mice received the same volume of saline. Following finishing of the study, analyses were conducted on behavioral tests, biochemical indices, and histological structures of lung tissues. Results: Aerosol inhalation of ICT can notably reduce inflammatory cells infiltration around the airways and pulmonary vessels, and suppressed goblet cell hyperplasia in asthmatic mice. Long-term inhalation of ICT can decrease airway collagen deposition and airway smooth muscle hyperplasia, and alleviate airway hyperresponsiveness, mirroring the effects observed with hormone employed in clinical practice. Conclusion: Nebulized inhalation of ICT can effectively inhibit airway inflammation in asthmatic mice, improve airway remodeling, and reduce airway hyperresponsiveness, with effects similar to those of hormones. It may serve as a potential candidate used as a hormone replacement asthma treatment. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary microvasculature leading to elevated precapillary pulmonary hypertension. Pulmonary vascular remodeling, a characteristic of PAH, is driven by dysfunctions in the signaling between the pulmonary smooth muscle and endothelial cells with abnormalities that affect cell proliferation and immune dysregulation. Sotatercept, an activin signaling inhibitor, has recently been approved by the US Food and Drug Administration for the treatment of PAH based on two pivotal clinical trials. Evidence-based clinical trials have provided a framework to guide clinicians treating the disease; however, they are not tailored to the individual patient. Often, recommendations from these data are unclear or too general, due to remaining gaps in knowledge. In this edition of "How I Do It," we provide a case-based discussion of common clinical decisions regarding diagnostic testing, choice of first-line agents, escalation of therapy, potential timing of sotatercept, safety awareness, practical use, potential management changes, and the future use of sotatercept in other pulmonary hypertension cohorts. [ABSTRACT FROM AUTHOR]

Introduction: Here, we report the first case of a soft tissue tumor with a PAK2::RAF1 fusion. Case Presentation: The patient was an 11-year-old female presenting with a 5 cm intramuscular mass in the lower leg. Microscopic examination revealed a mitotically active spindle cell lesion with monomorphic and moderately atypical cells growing in a patternless pattern with the presence of stromal and perivascular keloidal collagen with focal immunoreactivity for smooth muscle actin and S100; negative stains included cytokeratins, CD34, and caldesmon. Whole genome and RNA sequencing detected a chromosome 3 inversion and a resultant PAK2::RAF1 fusion as well as a CDKN2A homozygous deletion. The patient was treated with neoadjuvant chemoradiotherapy with only minimal response and the tumor was excised surgically. There was no evidence of disease progression at 4 months. Conclusion: This is the first case of a soft tissue tumor harboring a PAK2::RAF1 fusion with histological features in keeping with previous cases of RAF1 and other kinase fusion soft tissue tumors. [ABSTRACT FROM AUTHOR]

Mesenchymal tumors may display morphologic and immunohistochemical overlap with melanocytic tumors, presenting a pitfall for misdiagnosis. We report a 62‐year‐old woman who presented with a recurrent dermal and subcutaneous tumor over the Achilles tendon 15 years following complete excision. Both the primary and the recurrent tumors were characterized by nests and sheets of epithelioid and spindle cells with eosinophilic cytoplasm and uniform ovoid nuclei. The tumor was positive for S100, SOX10, HMB45, cathepsin K, and p63 (weak), while negative for Melan‐A, MiTF, smooth muscle actin, and desmin. Gene fusion analysis of the recurrent tumor revealed a NONO::TFE3 fusion which has been recently reported in two similar cutaneous cases. Our case highlights the potential of a NONO::TFE3 cutaneous epithelioid and spindle cell tumor to recur after a prolonged disease‐free interval without evidence of high‐grade transformation or distant metastasis. Our findings support its classification as a cutaneous mesenchymal neoplasm of intermediate malignancy. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we investigated whether neural precursor cell–expressed developmentally down-regulated gene 4-like (NEDD4L) is the E3 enzyme of angiotensin-converting enzyme 2 (ACE2) and whether NEDD4L degrades ACE2 via ubiquitination, leading to the progression of pulmonary arterial hypertension (PAH). Methods: Bioinformatic analyses were used to explore the E3 ligase that ubiquitinates ACE2. Cultured pulmonary arterial smooth muscle cells (PASMCs) and specimens from patients with PAH were used to investigate the crosstalk between NEDD4L and ACE2 and its ubiquitination in the context of PAH. Results: The inhibition of ubiquitination attenuated hypoxia-induced proliferation of PASMCs. The levels of NEDD4L were increased, and those of ACE2 were decreased in lung tissues from patients with PAH and in PASMCs. NEDD4L, the E3 ligase of ACE2, inhibited the expression of ACE2 in PASMCs, possibly through ubiquitination-mediated degradation. PAH was associated with upregulation of NEDD4L expression and downregulation of ACE2 expression. Conclusions: NEDD4L, the E3 ubiquitination enzyme of ACE2, promotes the proliferation of PASMCs, ultimately leading to PAH. [ABSTRACT FROM AUTHOR]

Purpose: The external urethral sphincter (EUS) is critical for urinary continence, but its complex anatomy is not fully understood, complicating its preservation during prostate surgeries. This study aims to elucidate the anatomy and development of the EUS to enhance surgical techniques for continence preservation. Methods: The study consisted of a postmortem examination of three male cadavers, aged 52, 64, and 60, with intact urogenital systems. Specimens including the prostate and EUS were dissected, fixed in formalin, and stained with Hematoxylin-Eosin for microscopic analysis. Histological assessments focused on the muscle composition and structure of the EUS and prostate. Results: Macroscopic examination revealed symmetrical prostates without pathologies. Histologically, the anterior prostate lacked tubuloalveolar glands, showing striated muscle fibers from the external urethral sphincter extending into the prostate and prostatic urethra. Reduced glandular structure and prevalent smooth muscle were noted. This intricate integration of striated muscle fibers at the EUS-prostate interface underscores the anatomical complexity vital for surgical preservation of urinary continence. Conclusion: Our study reveals a complex EUS-prostate relationship, challenging the view of the EUS as merely a circular muscle. The findings demonstrate the importance of the EUS's extension into the prostate for urethral stabilization and continence. Recognizing this anatomy is crucial for maintaining urinary continence in prostate surgeries and enhancing postoperative outcomes. [ABSTRACT FROM AUTHOR]

Integrin activation resulting in enhanced adhesion to the extracellular matrix plays a key role in fundamental cellular processes. Although integrin activation has been extensively studied in circulating cells such as leukocytes and platelets, much less is known about the regulation and functional impact of integrin activation in adherent cells such as smooth muscle. Here, we show that two different asthmagenic cytokines, IL-13 and IL-17A, activate type I and IL-17 cytokine receptor families, respectively, to enhance adhesion of airway smooth muscle. These cytokines also induce activation of β1 integrins detected by the conformation-specific antibody HUTS-4. Moreover, HUTS-4 binding is increased in the smooth muscle of patients with asthma compared to nonsmokers without lung disease, suggesting a disease-relevant role for integrin activation in smooth muscle. Indeed, integrin activation induced by the β1-activating antibody TS2/16, the divalent cation manganese, or the synthetic peptide β1-CHAMP that forces an extended-open integrin conformation dramatically enhances force transmission in smooth muscle cells and airway rings even in the absence of cytokines. We demonstrate that cytokine-induced activation of β1 integrins is regulated by a common pathway of NF-κB-mediated induction of RhoA and its effector Rho kinase, which in turn stimulates PIP5K1γ-mediated synthesis of PIP2 at focal adhesions, resulting in β1 integrin activation. Taken together, these data identify a pathway by which type I and IL-17 cytokine receptor family stimulation induces functionally relevant β1 integrin activation in adherent smooth muscle and help to explain the exaggerated force transmission that characterizes chronic airway diseases such as asthma. [ABSTRACT FROM AUTHOR]

Introduction: Leiomyosarcoma (LMS) is a malignancy with smooth muscle differentiation. Metastatic LMS is associated with poor prognosis and limited efficacy of systemic treatment. Novel treatment modalities are desperately needed for this entity. Case Presentation: We report the first use of pembrolizumab plus pharmacologic ascorbate in 3 patients with metastatic LMS. All cases resulted in persistent objective responses and disease control significantly better than has been reported with chemotherapy or other immunotherapeutic approaches. Three patients with metastatic LMS, one each of uterine, vascular, and soft tissue origin, were treated with pembrolizumab plus pharmacologic ascorbate. The patient with uterine LMS received combination therapy at presentation and had persistent response for 12 months, which is ongoing. The patient with metastatic LMS of the inferior vena cava received combination therapy at presentation and had persistent response for 12 months, at which time new metastases were found. The patient with soft tissue LMS had disease progression on pembrolizumab monotherapy prior to the addition of ascorbate, after which she had a 17-month response, which is ongoing. No side effects attributed to treatment were reported. Conclusion: Pembrolizumab plus pharmacologic ascorbate is a novel immunotherapeutic approach and warrants further study in LMS. [ABSTRACT FROM AUTHOR]

Background: While asthma exacerbations remain a major challenge in patient management, few animal models exist to explore the underlying mechanisms. Here, we established an animal model of asthma that can be used to study pathophysiological mechanisms and therapeutic strategies on asthma exacerbation. Methods: Female BALB/c mice were sensitized and exposed to PBS or Dermatophagoides pteronyssinus (DerP) extract for 11 weeks. Asthmatic phenotype was assessed through lung inflammation, bronchial hyperresponsiveness and bronchial smooth muscle remodeling. Asthmatic and control mice were exposed once or three times to poly(I:C) to simulate virus-induced inflammation. Results: Fourteen days after exposure to DerP, asthmatic mice showed resolution of inflammation with sustained bronchial hyperresponsiveness and bronchial smooth muscle remodeling compared to control. At this stage, when mice were subjected to a single exposure to poly(I:C), control and asthmatic mice were characterized by a significant increase in neutrophilic inflammation and bronchial hyperresponsiveness. When mice were repeatedly exposed to poly(I:C), control mice showed a significant decrease in neutrophilic inflammation and bronchial hyperresponsiveness, while asthmatic mice experienced worsening of these outcomes. Conclusions: This observational study report an asthmatic mouse model that can undergo exacerbation after repeated exposure to poly(I:C). Our findings on pulmonary adaptation in control mice may also pave the way for further research into the mechanism of adaptation that may be impaired in asthma and raise the question of whether asthma exacerbation may be a loss of adaptation. [ABSTRACT FROM AUTHOR]

Intestinal helminth infection triggers a type 2 immune response that promotes a 'weep-and sweep' response characterised by increased mucus secretion and intestinal hypermotility, which function to dislodge the worm from its intestinal habitat. Recent studies have discovered that several other pathogens cause intestinal dysmotility through major alterations to the immune and enteric nervous systems (ENS), and their interactions, within the gastrointestinal tract. However, the involvement of these systems has not been investigated for helminth infections. Eosinophils represent a key cell type recruited by the type 2 immune response and alter intestinal motility under steady-state conditions. Our study aimed to investigate whether altered intestinal motility driven by the murine hookworm, Nippostrongylus brasiliensis, infection involves eosinophils and how the ENS and smooth muscles of the gut are impacted. Eosinophil deficiency did not influence helminth-induced intestinal hypermotility and hypermotility did not involve gross structural or functional changes to the ENS. Hypermotility was instead associated with a dramatic increase in smooth muscle thickness and contractility, an observation that extended to another rodent nematode, Heligmosomoides polygyrus. In summary our data indicate that, in contrast to other pathogens, helminth-induced intestinal hypermotility is driven by largely by myogenic, rather than neurogenic, alterations with such changes occurring independently of eosinophils. (<300 words) Author summary: Intestinal helminth infection is a global threat to those living in poverty without adequate sanitation. Expulsion of intestinal worms is driven by a host type 2 immune response, characterised by increased eosinophils, that results in the intestinal hypermotility and mucus secretion that dislodge the worm from its luminal habitat. Intestinal motility is largely controlled by the local enteric nervous system (ENS) and can be regulated by close interactions between neurons and intestinal immune cells. Using Nippostrongylus brasiliensis as a model of murine hookworm infection, we investigated the contribution of the ENS and eosinophils to intestinal hypermotility and worm expulsion. Despite the critical role of the ENS in regulating typical intestinal function, very little alteration to ENS structure or function was observed following Nb infection. Instead, Nb infected animals displayed dramatically increased smooth muscle thickness and contractile strength. Alterations of smooth muscle were also observed in response to infection with Heligmosomoides polygyrus. Neither Nippostrongylus brasiliensis -induced intestinal hypermotility nor altered smooth muscle morphology required eosinophils. Our findings reveal that, in contrast to other intestinal pathogens, myogenic rather than neurogenic alterations drive small intestinal hypermotility and pathogen expulsion following intestinal helminth infection. (<200 words) [ABSTRACT FROM AUTHOR]

The synthesized compound 1-(2-chlorophenyl) 6-7-dimethoxy-3-methyl-3,4-dihydroisoquinoline (DIQ) was investigated as a biological agent. Its potential to affect muscle contractility was predicted through in silico PASS analysis. Based on the in silico analysis, its capabilities were experimentally investigated. The study aimed to investigate the effects of DIQ on the ex vivo spontaneous contractile activity (CA) of smooth muscle (SM) tissue. DIQ was observed to reduce the strength of Ca2+-dependent contractions in SM preparations (SMP), possibly by increasing cytosolic Ca2+ levels through the activation of a voltage-gated L-type Ca2+ channel. DIQ potently affected calcium currents by modulating the function of muscarinic acetylcholine receptors (mAChRs) and 5-hydroxytryptamine (5-HT) receptors at a concentration of 50 μM. Immunohistochemical tests showed a 47% reduction in 5-HT2A and 5-HT2B receptor activity in SM cells and neurons in the myenteric plexus (MP), further confirming the effects of DIQ. Furthermore, a significant inhibition of neuronal activity was observed when the compound was co-administered with 5-HT to SM tissues. The conducted experiments confirm the ability of the isoquinoline analog to act as a physiologically active molecule to control muscle contractility and related physiological processes. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) arises from increased pulmonary vascular resistance due to contraction and remodeling of the pulmonary arteries. The structural changes include thickening of the smooth muscle layer from increased proliferation and resistance to apoptosis. The mechanisms underlying apoptosis resistance in PH are not fully understood. In cancer cells, high expression of aquaporin 1 (AQP1), a water channel, is associated with apoptosis resistance. We showed AQP1 protein was expressed in pulmonary arterial smooth muscle cells (PASMCs) and upregulated in preclinical PH models. In this study, we used PASMCs isolated from control male rats and the SU5416 plus hypoxia (SuHx) model to test the role of AQP1 in modulating susceptibility to apoptosis. We found the elevated level of AQP1 in PASMCs from SuHx rats was necessary for resistance to apoptosis and that apoptosis resistance could be conferred by increasing AQP1 in control PASMCs. In exploring the downstream pathways involved, we found AQP1 levels influence the expression of Bcl‐2, with enhanced AQP1 levels corresponding to increased Bcl‐2 expression, reducing the ratio of BAX to Bcl‐2, consistent with apoptosis resistance. These results provide a mechanism by which AQP1 can regulate PASMC fate. [ABSTRACT FROM AUTHOR]

Background and Purpose: With increasing life expectancy, benign prostatic hyperplasia (BPH) consequently affects more ageing men, illustrating the urgent need for advancements in BPH therapy. One emerging possibility may be the use of oxytocin antagonists to relax smooth muscle cells in the prostate, similar to the currently used (although often associated with side effects) α1‐adrenoceptor blockers. Experimental Approach: For the first time we used live‐imaging, combined with a novel image analysis method, to investigate the multidirectional contractions of the human prostate and determine their changes in response to oxytocin and the oxytocin antagonists atosiban and cligosiban. Human prostate samples were obtained and compared from patients undergoing prostatectomy due to prostate cancer as well as from patients with transurethral resection of prostate tissue due to severe BPH. Key Results: The two cohorts of tissue samples showed spontaneous multidirectional contractions, which significantly increased after the addition of oxytocin. Different to atosiban, which showed ambiguous effects of short duration, only long‐acting cligosiban reliably prevented, as well as counteracted, any contractile oxytocin effect. Furthermore, cligosiban visibly reduced not only oxytocin‐induced contractions, but also showed intrinsic activity to relax prostatic tissue. Conclusion and implications: Thus, the oxytocin antagonist cligosiban could be an interesting candidate in the search for novel BPH treatment options. [ABSTRACT FROM AUTHOR]

The combination of lineage tracing and immunohistochemistry has helped to identify subpopulations and fate of hepatic stellate cells (HSC) in murine liver. HSC are sinusoidal pericytes that act as myofibroblast precursors after liver injury. Single cell RNA sequencing approaches have recently helped to differentiate central and portal HSC. A specific Cre line to lineage trace portal HSC has not yet been described. We used three Cre lines (Lrat-Cre, PDGFRβ-CreERT2 and SMMHC-CreERT2) known to label mesenchymal cells including HSC in combination with a tdTomato-expressing reporter. All three Cre lines labeled populations of HSC as well as smooth muscle cells (SMC). Using the SMMHC-CreERT2, we identified a subtype of HSC in the periportal area of the hepatic lobule (termed zone 1-HSC). We lineage traced tdTomato-expressing zone 1-HSC over 1 year, described fibrotic behavior in two fibrosis models and investigated their possible role during fibrosis. This HSC subtype resides in zone 1 under healthy conditions; however, zonation is disrupted in preclinical models of liver fibrosis (CCl4 and MASH). Zone 1-HSC do not transform into αSMA-expressing myofibroblasts. Rather, they participate in sinusoidal capillarization. We describe a novel subtype of HSC restricted to zone 1 under physiological conditions and its possible function after liver injury. In contrast to the accepted notion, this HSC subtype does not transform into αSMA-positive myofibroblasts; rather, zone 1-HSC adopt properties of capillary pericytes, thereby participating in sinusoidal capillarization. [ABSTRACT FROM AUTHOR]

Cyclic ADP‐ribose (cADPR) has emerged as a calcium‐regulating second messenger in smooth muscle cells. CD38 protein possesses ADP‐ribosyl cyclase and cADPR hydrolase activities and mediates cADPR synthesis and degradation. We have previously shown that CD38 expression is regulated by estrogen and progesterone in the myometrium. Considering hormonal regulation in gestation, the objective of the present study was to determine the role of CD38/cADPR signaling in the regulation of intracellular calcium upon contractile agonist stimulation using immortalized pregnant human myometrial (PHM1) cells. Western blot, immunofluorescence, and biochemical studies confirmed CD38 expression and the presence of ADP‐ribosyl cyclase (2.6 ± 0.1 pmol/mg) and cADPR hydrolase (26.8 ± 6.8 nmoles/mg/h) activities on the PHM1 cell membrane. Oxytocin, PGF2α, and ET‐1 elicited [Ca2+]i responses, and 8‐Br‐cADPR, a cADPR antagonist significantly attenuated agonist‐induced [Ca2+]i responses between 20% and 46% in average. The findings suggest that uterine contractile agonists mediate their effects in part through CD38/cADPR signaling to increase [Ca2+]i and presumably uterine contraction. As studies in humans are limited by the availability of myometrium from healthy donors, PHM1 cells form an in vitro model to study human myometrium. [ABSTRACT FROM AUTHOR]