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Cassia occidentalis whole plant (C.O.W.P), Jatropha curcas leaves (J.C.L.), Ximenia americana Santalales leaves (X.A.L.), and Eucalyptus citriodora leaves (E.C.L.) have been revealed to be widely used by locals of north-western Nigeria for the management of asthma. This study was aimed at providing a pharmacological rationale for the ethnomedical use of these plants in the management of asthma. The four extracts were screened for their effects on the spontaneous contraction of isolated rabbit ileum strip; also on pre-contracted isolated guinea Pig ileum strip; on pre-contracted isolated Guinea Pig trachea chain; and on ovalbumin-induced peritoneal mast cell degranulation in Wistar rats. Ethanol extracts of C.O.W.P., E.C.L., J.C.L., and X.A.L. at 100 mg/mL remarkably relaxed spontaneous contractions of isolated rabbit ileum. Greatest relaxation was obtained with X.A.L. Ethanol extracts of C.O.W.P., E.C.L., J.C.L., and X.A.L. statistically significantly (p ≤ 0.05) inhibited histamine-induced contractions of isolated guinea pig ileum. In addition, the four extracts statistically significantly inhibited (p ≤ 0.05) histamine-induced contraction of isolated guinea pig trachea. The ethanol leaves extracts of C. occidentalis and Jatropha curcas exhibited mast cell stabilizing effect in ovalbumin-induced rat peritoneal mast cell degranulation. However, Eucalyptus citriodora and Ximenia Americana did not protect against ovalbumin-induced rat peritoneal mast cell degranulation. C.O.W.P., E.C.L., J.C.L., and X.A.L all possess broncho-relaxant activity, while only C.O.W.P. and J.C.L. exhibited mast cell stabilizing activity in laboratory animals thus supporting the traditional use of the plant in inflammatory and allergic conditions including asthma. [ABSTRACT FROM AUTHOR]

The transcription factors (TFs) MyoCD (myocardin) and Elk-1 (ETS Like-1 protein) competitively bind to SRF (serum response factor) and control myogenic- and mitogenic-related gene expression in smooth muscle, respectively. Their functions are therefore mutually inhibitory, which results in a contractile-versus-proliferative phenotype dichotomy. Airway smooth muscle cell (ASMC) phenotype alterations occur in various inflammatory airway diseases, promoting pathological remodeling and contributing to airflow obstruction. We characterized MyoCD and Elk-1 interactions and their roles in phenotype determination in human ASMCs. MyoCD overexpression in ASMCs increased smooth muscle gene expression, force generation, and partially restored the loss of smooth muscle protein associated with prolonged culturing while inhibiting Elk-1 transcriptional activities and proliferation induced by EGF (epidermal growth factor). However, MyoCD overexpression failed to suppress these responses induced by FBS, as FBS also upregulated SRF expression to a degree that allowed unopposed function of both TFs. Inhibition of the RhoA pathway reversed said SRF changes, allowing inhibition of Elk-1 by MyoCD overexpression and suppressing FBS-mediated contractile protein gene upregulation. Our study confirmed that MyoCD in increased abundance can competitively inhibit Elk-1 function. However, SRF upregulation permits a dual contractile–proliferative ASMC phenotype that is anticipated to exacerbate pathological alterations, whereas therapies targeting SRF may inhibit pathological ASMC proliferation and contractile protein gene expression. [ABSTRACT FROM AUTHOR]

Aortic aneurysms, which may dissect or rupture acutely and be lethal, can be a part of multisystem disorders that have a heritable basis. We report four patients with deficiency of selenocysteine-containing proteins due to selenocysteine Insertion Sequence Binding Protein 2 (SECISBP2) mutations who show early-onset, progressive, aneurysmal dilatation of the ascending aorta due to cystic medial necrosis. Zebrafish and male mice with global or vascular smooth muscle cell (VSMC)-targeted disruption of Secisbp2 respectively show similar aortopathy. Aortas from patients and animal models exhibit raised cellular reactive oxygen species, oxidative DNA damage and VSMC apoptosis. Antioxidant exposure or chelation of iron prevents oxidative damage in patients cells and aortopathy in the zebrafish model. Our observations suggest a key role for oxidative stress and cell death, including via ferroptosis, in mediating aortic degeneration.

In arterial myocytes, the canonical function of voltage-gated CaV1.2 and KV2.1 channels is to induce myocyte contraction and relaxation through their responses to membrane depolarization, respectively. Paradoxically, KV2.1 also plays a sex-specific role by promoting the clustering and activity of CaV1.2 channels. However, the impact of KV2.1 protein organization on CaV1.2 function remains poorly understood. We discovered that KV2.1 forms micro-clusters, which can transform into large macro-clusters when a critical clustering site (S590) in the channel is phosphorylated in arterial myocytes. Notably, female myocytes exhibit greater phosphorylation of S590, and macro-cluster formation compared to males. Contrary to current models, the activity of KV2.1 channels seems unrelated to density or macro-clustering in arterial myocytes. Disrupting the KV2.1 clustering site (KV2.1S590A) eliminated KV2.1 macro-clustering and sex-specific differences in CaV1.2 cluster size and activity. We propose that the degree of KV2.1 clustering tunes CaV1.2 channel function in a sex-specific manner in arterial myocytes.

Background: Increasing age increases the incidence of chronic constipation and fecal impaction. The contribution of the natural aging process to this phenotype is unclear. This study explored the effects of age on key motility patterns in the murine colon and determined the contribution that altered neurokinin 2 (NK2) ‐mediated signaling made to the aging phenotype. Methods: Mucosal reflexes, colonic migrating motor complexes (CMMCs) and colonic motility assays were explored in isolated ex vivo colons from 3, 12–14, 18‐ and 24‐months old mice and the NK2‐mediated response determined. Electrical field stimulation (EFS) or exogenous drug application were used to explore the role of the mucosa in colonic segments. Key Results: Aging reduced the force of contraction of the distal colon mucosal reflex, the frequency and force of contraction of CMMCs and the NK2‐mediated component of both motility patterns. Ondansetron, a 5‐HT3 receptor antagonist, blocked a component of both motility patterns in full thickness but not in mucosa‐free segments of the distal colon. 5, hydroxytryptamine (5‐HT) and EFS‐evoked NK2‐dependent contractions were reduced with increasing age. Smooth muscle sensitivity to 5‐HT or neurokinin A (NKA) was not altered with age. In isolated colon motility assays application of NKA decreased transit time in 24‐months colon and the NK2 antagonist GR159897 increased transit times in both 3‐ and 24‐months old colons. Conclusions and Inferences: Aging impairs key motility patterns in the murine colon. These changes involve a decrease in mucosally‐evoked NK2‐mediated signaling. Targeting NK2‐mediated signaling may provide a novel approach to treating age‐related motility disorders in the lower bowel. [ABSTRACT FROM AUTHOR]

A glomus tumor is a benign mesenchymal tumor comprised of cells that resemble the perivascular modified smooth muscle cells of the glomus body. Glomus tumors typically appear in the superficial lesions of the soft tissue in the extremities, such as the subungual region. However, their occurrence in the bone is rare, with only about 30 cases reported to date. Half of these cases involved the distal phalanges of the fingers or toes, with only three reported cases involving the long bones. Here, we present the first case, a primary glomus tumor in the humerus of a 14-year-old female. An osteolytic and cystic lesion was detected after a pathological fracture occurred during exercise. Despite the tumor's large size, no pathological findings indicated malignancy. The fracture healed through conservative treatment, while the tumor was effectively managed with curettage. Appropriate medical care can be provided to patients by focusing on pathological findings. [ABSTRACT FROM AUTHOR]

Congenital lung malformations are fatal at birth in their severe forms. Prevention and early intervention of these birth defects require a comprehensive understanding of the molecular mechanisms of lung development. We find that the loss of inturned (Intu), a cilia and planar polarity effector gene, severely disrupts growth and branching morphogenesis of the mouse embryonic lungs. Consistent with our previous results indicating an important role for Intu in ciliogenesis and hedgehog (Hh) signaling, we find greatly reduced number of primary cilia in both the epithelial and mesenchymal tissues of the lungs. We also find significantly reduced expression of Gli1 and Ptch1 , direct targets of Hh signaling, suggesting disruption of cilia-dependent Hh signaling in Intu mutant lungs. An agonist of the Hh pathway activator, smoothened, increases Hh target gene expression and tubulogenesis in explanted wild type, but not Intu mutant, lungs, suggesting impaired Hh signaling response underlying lung morphogenetic defects in Intu mutants. Furthermore, removing both Gli2 and Intu completely abolishes branching morphogenesis of the lung, strongly supporting a mechanism by which Intu regulates lung growth and patterning through cilia-dependent Hh signaling. Moreover, a transcriptomics analysis identifies around 200 differentially expressed genes (DEGs) in Intu mutant lungs, including known Hh target genes Gli1, Ptch1/2 and Hhip. Genes involved in muscle differentiation and function are highly enriched among the DEGs, consistent with an important role of Hh signaling in airway smooth muscle differentiation. In addition, we find that the difference in gene expression between the left and right lungs diminishes in Intu mutants, suggesting an important role of Intu in asymmetrical growth and patterning of the mouse lungs. [Display omitted] • Loss of Intu leads to reduced size and abnormal branching of mouse embryonic lungs. • Cilia are reduced in Intu mutant lungs. • Hh signaling is reduced in Intu mutant lungs. • Tubulogenesis and branching morphogenesis ae disrupted in Intu mutant lung explants even with a Smoothened agonist. • Hh target genes and smooth muscle-related genes are differentially expressed in Intu mutant lungs. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) play an important role in the progression of atherosclerosis (AS). This study aimed to explore the exact role and mechanism of circ_0002984 in oxidized low-density lipoprotein (ox-LDL)-mediated human vascular smooth muscle cells (HVSMCs). The model of smooth muscle cell phenotype switching was constructed by treating HVSMCs with ox-LDL. The levels of circ_0002984, let-7a-5p, and kruppel-like factor 5 (KLF5) were measured by quantitative real-time PCR or western blot assay. Cell proliferation, migration, and apoptosis were detected by Cell Counting Kit-8 (CCK-8), EdU staining, wound healing assay, transwell assay, and flow cytometry. The expression of cleaved-caspase-3 and KLF5 was examined by western blot. The relationship between let-7a-5p and circ_0002984 or KLF5 was verified by dual-luciferase reporter assay or RIP assay. The results showed that circ_0002984 and KLF5 were up-regulated, while let-7a-5p was down-regulated in AS patients and ox-LDL-disposed HVSMCs. Silence of circ_0002984 suppressed proliferation and migration, and promoted apoptosis in ox-LDL-stimulated HVSMCs. Moreover, circ_0002984 sponged let-7a-5p to regulate the proliferation, migration, and apoptosis in ox-LDL-resulted HVSMCs. In addition, KLF5 was a target of let-7a-5p and its overexpression reversed the effect of let-7a-5p on the proliferation, migration, and apoptosis in ox-LDL-treated HVSMCs. Also, circ_0002984 positively regulated KLF5 expression by absorbing let-7a-5p. The promotion effect of circ_0002984 on the proliferation and migration of ox-LDL-treated HVSMCs was reversed by KLF5 silencing. Taken together, depletion of circ_0002984 inhibited the proliferation and migration of ox-LDL-stimulated HVSMCs, which might be achieved by modulating the let-7a-5p/KLF5 axis. [ABSTRACT FROM AUTHOR]

Abstract Atherosclerosis is rare in internal thoracic arteries (ITA) even in patients with severe atherosclerotic coronary artery (ACA) disease. To explore cellular differences, ITA SMC from 3 distinct donors and ACA SMC from 3 distinct donors were grown to sub-confluence and growth arrested for 48 h. Proliferation and thrombospondin-1 (TSP1) production were determined using standard techniques. ITA SMC were larger, grew more slowly and survived more passages than ACA SMC. ACA SMC had a more pronounced proliferative response to 10% serum than ITA SMC. Both ACA SMC and ITA SMC proliferated in response to exogenous TSP1 (12.5 µg/ml and 25 µg/ml) and platelet derived growth factor-BB (PDGF-BB; 20 ng/ml) but TSP1- and PDGF-BB-induced proliferation were partially inhibited by anti-TSP1 antibody A4.1, microRNA-21(miR-21)-3p inhibitors and miR-21-5p inhibitors in each of the 3 ACA SMC lines, but not in any of the ITA SMC lines. PDGF-BB stimulated TSP1 production in ACA SMC but not in ITA SMC but there was no increase in TSP1 levels in conditioned media in either SMC type. In summary, there are significant differences in morphology, proliferative capacity and in responses to TSP1 and PDGF-BB in SMC derived from ITA compared to SMC derived from ACA.

Abstract Bile acids regulate gastrointestinal motility by mechanisms that are poorly understood. Standard isolated tissue bath assays might not recapitulate in vivo physiology if contractile responses to certain bile acids require direct application to the intestinal mucosa. We sought to determine the feasibility of quantifying longitudinal smooth muscle contractile responses to bile acids from intact segments of everted mouse ileum. Ileum from adult female C57BL/6J mice was isolated, gently everted over a notched metal rod, and mounted in tissue baths. Individual bile acids and agonists of bile acid receptors were added to the baths, and longitudinal smooth muscle contractile responses were quantified by isometric force transduction. Ursodeoxycholic acid robustly increased contractile responses in a dose‐dependent manner. Deoxycholic acid stimulated contractility at low doses but inhibited contractility at high doses. Chenodeoxycholic acid, glycocholic acid, and lithocholic acid did not alter contractility. The dose‐dependent increase in contractility resulting from the application of ursodeoxycholic acid was recapitulated by INT‐777, an agonist of the Takeda G protein‐coupled receptor 5 (TGR5), and by cevimeline, a muscarinic acetylcholine receptor agonist. Agonists to the nuclear receptors farnesoid X receptor, glucocorticoid receptor, pregnane X receptor, vitamin D receptor, and to the plasma membrane epidermal growth factor receptor did not modify baseline contractile patterns. These results demonstrate that gentle eversion of intact mouse ileum facilitates the quantification of longitudinal smooth muscle contractile responses to individual bile acids. Prokinetic effects of ursodeoxycholic acid and low‐dose deoxycholic acid are replicated by agonists to TGR5 and muscarinic acetylcholine receptors.

The vagina is an essential component of the female reproductive system and is responsible for providing female sexual satisfaction. Vaginal smooth muscle contraction plays a crucial role in various physiological processes, including sexual arousal, childbirth, and urinary continence. In pathophysiological conditions, such as pelvic floor disorders, aberrations in vaginal smooth muscle function can lead to urinary incontinence and pelvic organ prolapse. A set of cellular and sub-cellular physiological mechanisms regulates the contractile properties of the vaginal smooth muscle cells. Calcium influx is a crucial determinant of smooth muscle contraction, facilitated through voltage-dependent calcium channels and calcium release from intracellular stores. Comprehensive reviews on smooth muscle biophysics are relatively scarce within the scientific literature, likely due to the complexity and specialized nature of the topic. The objective of this review is to provide a comprehensive description of alterations in the cellular physiology of vaginal smooth muscle contraction. The benefit associated with this particular approach is that conducting a comprehensive examination of the cellular mechanisms underlying contractile activation will enable the creation of more targeted therapeutic agents to control vaginal contraction disorders.

Abstract Background Congenital inguinal hernia, hydrocele and undescended testis (UDT) are associated with patent processus vaginalis. The smooth muscles present in the processus vaginalis aid in the descent of the testis and undergo programmed cell death after testicular descent leading to obliteration. The persisting amount of smooth muscle in the processus vaginalis influences the clinical outcome as inguinal hernia, hydrocele or UDT. Therefore, a study was conducted to evaluate the processus vaginalis in these three conditions to observe the presence and phenotype of smooth muscle cells and the presence of myofibroblasts. Materials and methods The processus vaginalis sacs in patients with inguinal hernia, hydrocele and UDT were examined using light microscopy for the presence and distribution of smooth muscle cells and immunohistochemical staining for vimentin, desmin, and α-smooth muscle actin (SMA) to identify the smooth muscle phenotype. Transmission electron microscopy was also performed in all the sacs to observe the presence of myofibroblasts. Results Seventy-eight specimens of processus vaginalis (from seventy-four patients), distributed as 47%, 27%, and 26% as inguinal hernia, hydrocele and UDT respectively, were included in the study. The sacs from inguinal hernia and hydrocele had significantly more presence of smooth muscles distributed as multiple smooth muscle bundles (p

Background: Asthma's complexity, marked by airway inflammation and remodeling, is influenced by hypoxic conditions. This study focuses on the role of Hypoxia-Inducible Factor-1 Alpha (HIF-1α) and P53 ubiquitination in asthma exacerbation. Methods: High-throughput sequencing and bioinformatics were used to identify genes associated with asthma progression, with an emphasis on GO and KEGG pathway analyses. An asthma mouse model was developed, and airway smooth muscle cells (ASMCs) were isolated to create an in vitro hypoxia model. Cell viability, proliferation, migration, and apoptosis were assessed, along with ELISA and Hematoxylin and Eosin (H&E) staining. Results: A notable increase in HIF-1α was observed in both in vivo and in vitro asthma models. HIF-1α upregulation enhanced ASMCs' viability, proliferation, and migration, while reducing apoptosis, primarily via the promotion of P53 ubiquitination through MDM2. In vivo studies showed increased inflammatory cell infiltration and airway structural changes, which were mitigated by the inhibitor IDF-11,774. Conclusion: The study highlights the critical role of the HIF-1α-MDM2-P53 axis in asthma, suggesting its potential as a target for therapeutic interventions. The findings indicate that modulating this pathway could offer new avenues for treating the complex respiratory disorder of asthma. [ABSTRACT FROM AUTHOR]

The control paradigm of small vessel pathophysiology has changed to focus on the vascular out‐wall rather than the lumen‐intimal factors. As an emerging controller of the external wall, the microvasculature ("vasa vasorum") provides interactional routes between the in‐and out‐sides of the vascular wall. Despite numerous approaches to developing small‐diameter vascular grafts, engineering artificial vasa vasorum (AVV) has not been projected as a multi‐functional solution to address long‐standing issues such as thrombotic and immune controls for wall regeneration. Here, the AVV is engineered using a microchannel network hydrogel after a multi‐study validation of implantation functions and then used to wrap the external wall of the cell‐free vessel post‐decellularization while preserving its mechanical properties. Upon inter‐positional and bypass grafting to rabbit arteries, the AVV graft facilitates the recruitment of vascular cells into the cell‐free wall by promoting invasion of angiogenic and vasculogenic cells through the microchannel‐mediated M2 polarization of macrophages. This function results in the efficient restoration of smooth muscle cells, and the revitalized vascular elasticity helps to maintain long‐term patency. The AVV, therefore, serves as an effective catalyst for vascular wall regeneration, offering a solution to clinically successful small‐diameter vascular grafting. [ABSTRACT FROM AUTHOR]

Introduction: Drotaverine, paracetamol, and peppermint oil are often prescribed for the treatment of gastrointestinal spasm and pain. This study aimed to evaluate the effect of these drugs alone and combined with the well-known antispasmodic hyoscine butylbromide on the human colon. Methods: Colon samples were obtained from macroscopically normal regions of 68 patients undergoing surgery and studied in muscle bath. Drotaverine, paracetamol, and peppermint oil were tested alone and in combination with hyoscine butylbromide on (1) spontaneous contractility induced by isometric stretch (in the presence of 1 µM tetrodotoxin) and (2) contractility induced by 10-5 M carbachol and after (3) electrical field stimulation-induced selective stimulation of excitatory (in the presence of 1 mM Nε-nitro-L-arginine and 10 µM MRS2179) and (4) inhibitory (under non-adrenergic, non-cholinergic conditions) pathways. (5) Drotaverine alone was also tested on cAMPdependent pathway activated by forskolin. Results: Compared with the vehicle, drotaverine and paracetamol (10-9-10-5 M) did not modify spontaneous contractions, carbachol-induced contractions, and responses attributed to selective activation of excitatory pathways. The addition of hyoscine butylbromide (10-7-10-5 M), concentration-dependently reduced myogenic contractions and carbachol- and electrical field stimulation-induced contractile responses. The association of paracetamol (10-4 M) and hyoscine butylbromide (10-7-10-5 M) was not different from hyoscine butylbromide alone (10-7-10-5 M). At higher concentrations (10-3M-3*10-3 M), paracetamol decreased myogenic and carbachol-induced contractions. The adenylate cyclase activator, forskolin, concentration-dependently reduced contractility, leading to smooth muscle relaxation. The effect of forskolin 10-7 M was concentration-dependently enhanced by drotaverine (10-6M-10-5M). Discussion: Peppermint oil reduced myogenic activity and carbachol- and electrical field stimulation-induced contractions. The association of hyoscine butylbromide and peppermint oil was synergistic since the interaction index measured with the isobologram was lower than 1. No effect was seen on the neural-mediated inhibitory responses with any of the drugs studied although peppermint oil reduced the subsequent off-contraction. Drotaverine and hyoscine butylbromide have a complementary effect on human colon motility as one stimulates the cAMP inhibitory pathway and the other inhibits the excitatory pathway. Peppermint oil is synergic with hyoscine butylbromide suggesting that a combination therapy may be more effective in treating patients. In contrast, at therapeutic concentrations, paracetamol does not modify colonic contractility, suggesting that the association of paracetamol and hyoscine butylbromide has independent analgesic and antispasmodic properties. [ABSTRACT FROM AUTHOR]

Background: Leiomyosarcoma is a tumor that can develop in any organ that contains smooth muscles. Although leiomyosarcoma is common, its epididymal localization is quite rare. Case presentation: A 79-year-old male Chinese Han patient presented with mild pain in the right groin and scrotum for 3 years concomitant with right scrotal swelling. Ultrasonography and magnetic resonance imaging of the scrotum showed a irregular and heterogeneous mass that was extratesticular. Right high orchiectomy was performed, and pathological examination of the resected specimen confirmed the diagnosis of leiomyosarcoma of the epididymis with surgical margins clear of tumor. Conclusion: Epididymal leiomyosarcoma is rare and difficult to diagnose preoperatively. The final diagnosis of epididymal leiomyosarcoma requires histologic examination. Resection must be extensive and complete. The effect of chemotherapy and radiation on the epididymal leiomyosarcoma remains unclear. Recurrence is common, so follow-up is necessary. [ABSTRACT FROM AUTHOR]

Aerobic glycolysis is involved in the pathogenesis of pulmonary hypertension (PH). The mechanisms by which glycolysis is increased and how it contributes to pulmonary vascular remodelling are not yet fully understood. In this study, we demonstrated that elevated lipocalin‐2 (LCN2) in PH significantly enhances aerobic glycolysis in human pulmonary artery smooth muscle cells (PASMCs) by up‐regulating LDHA expression. Knockout of Lcn2 or having heterozygous LDHA deficiency in mice significantly inhibits the progression of hypoxic PH. Our study reveals that LCN2 stimulates LDHA expression by activating Akt‐HIF‐1α signalling pathway. Inhibition of Akt or HIF‐1α reduces LDHA expression and proliferation of PASMCs. Both Akt and HIF‐1α play critical roles in the development of PH and are suppressed in the pulmonary vessels of hypoxic PH mice lacking LCN2. These findings shed light on the LCN2‐Akt‐HIF1α‐LDHA axis in aerobic glycolysis in PH. [ABSTRACT FROM AUTHOR]

A variety of ion channels regulate membrane potential and calcium influx in arterial smooth muscle and endothelial cells to modify vascular functions, including contractility. The current (I) generated by a population of ion channels is equally dependent upon their number (N), open probability (Po) and single channel current (i), such that I = N.PO.i. A conventional view had been that ion channels traffic to the plasma membrane in a passive manner, resulting in a static surface population. It was also considered that channels assemble with auxiliary subunits prior to anterograde trafficking of the multimeric complex to the plasma membrane. Recent studies have demonstrated that physiological stimuli can regulate the surface abundance (N) of several different ion channels in arterial smooth muscle and endothelial cells to control arterial contractility. Physiological stimuli can also regulate the number of auxiliary subunits present in the plasma membrane to modify the biophysical properties, regulatory mechanisms and physiological functions of some ion channels. Furthermore, ion channel trafficking becomes dysfunctional in the vasculature during hypertension, which negatively impacts the regulation of contractility. The temporal kinetics of ion channel and auxiliary subunit trafficking can also vary depending on the signalling mechanisms and proteins involved. This review will summarize recent work that has uncovered the mechanisms, functions and pathological modifications of ion channel trafficking in arterial smooth muscle and endothelial cells. [ABSTRACT FROM AUTHOR]

Ca2+ signalling plays a crucial role in determining lymphatic muscle cell excitability and contractility through its interaction with the Ca2+‐activated Cl− channel anoctamin 1 (ANO1). In contrast, the large‐conductance (BK) Ca2+‐activated K+ channel (KCa) and other KCa channels have prominent vasodilatory actions by hyperpolarizing vascular smooth muscle cells. Here, we assessed the expression and contribution of the KCa family to mouse and rat lymphatic collecting vessel contractile function. The BK channel was the only KCa channel consistently expressed in fluorescence‐activated cell sorting‐purified mouse lymphatic muscle cell lymphatic muscle cells. We used a pharmacological inhibitor of BK channels, iberiotoxin, and small‐conductance Ca2+‐activated K+ channels, apamin, to inhibit KCa channels acutely in ex vivo isobaric myography experiments and intracellular membrane potential recordings. In basal conditions, BK channel inhibition had little to no effect on either mouse inguinal–axillary lymphatic vessel (MIALV) or rat mesenteric lymphatic vessel contractions or action potentials (APs). We also tested BK channel inhibition under loss of ANO1 either by genetic ablation (Myh11CreERT2‐Ano1 fl/fl, Ano1ismKO) or by pharmacological inhibition with Ani9. In both Ano1ismKO MIALVs and Ani9‐pretreated MIALVs, inhibition of BK channels increased contraction amplitude, increased peak AP and broadened the peak of the AP spike. In rat mesenteric lymphatic vessels, BK channel inhibition also abolished the characteristic post‐spike notch, which was exaggerated with ANO1 inhibition, and significantly increased the peak potential and broadened the AP spike. We conclude that BK channels are present and functional on mouse and rat lymphatic muscle cells but are otherwise masked by the dominance of ANO1. Key points: Mouse and rat lymphatic muscle cells express functional BK channels.BK channels make little contribution to either rat or mouse lymphatic collecting vessel contractile function in basal conditions across a physiological pressure range.ANO1 limits the peak membrane potential achieved in the action potential and sets a plateau potential limiting the voltage‐dependent activation of BK.BK channels are activated when ANO1 is absent or blocked and slightly impair contractile strength by reducing the peak membrane potential achieved in the action potential spike and accelerating the post‐spike repolarization. [ABSTRACT FROM AUTHOR]

The primary hepatic leiomyosarcoma is a rare malignant tumor arising from the smooth muscle cells in the hepatic vessels, bile ducts, and ligamentum teres. It is considered a subtype of hepatic sarcomas. We report awkward 18F-FDG PET-CT findings of a primary hepatic leiomyosarcoma masquerading as a benign hepatic tumor, which were confirmed by histopathological and immunohistochemical examinations in a 78-year-old woman. [ABSTRACT FROM AUTHOR]

Bitter taste receptors (TAS2Rs) expressed in extraoral tissues represent a whole-body sensory system, whose role and mechanisms could be of interest for the identification of new therapeutic targets. It is known that TAS2R46s in pre-contracted airway smooth muscle cells increase mitochondrial calcium uptake, leading to bronchodilation, and that several SNPs have been identified in its gene sequence. There are very few reports on the structure–function analysis of TAS2Rs. Thus, we delved into the subject by using mutagenesis and in silico studies. We generated a cellular model that expresses native TAS2R46 to evaluate the influence of the four most common SNPs on calcium fluxes following the activation of the receptor by its specific ligand absinthin. Then, docking studies were conducted to correlate the calcium flux results to the structural mutation. The analysed SNPs differently modulate the TAS2R46 signal cascade according to the altered protein domain. In particular, the SNP in the sixth transmembrane domain of the receptors did not modulate calcium homeostasis, while the SNPs in the sequence coding for the fourth transmembrane domain completely abolished the mitochondrial calcium uptake. In conclusion, these results indicate the fourth transmembrane domain of TAS2R46 is critical for the intrinsic receptor activity. [ABSTRACT FROM AUTHOR]

Introduction: Soft tissue sarcomas, similar in incidence to cervical and esophageal cancers, arise from various soft tissues like smooth muscle, fat, and fibrous tissue. Effective segmentation of sarcomas in imaging is crucial for accurate diagnosis. Methods: This study collected multi-modal MRI images from 45 patients with thigh soft tissue sarcoma, totaling 8,640 images. These images were annotated by clinicians to delineate the sarcoma regions, creating a comprehensive dataset. We developed a novel segmentation model based on the UNet framework, enhanced with residual networks and attention mechanisms for improved modality-specific information extraction. Additionally, self-supervised learning strategies were employed to optimize feature extraction capabilities of the encoders. Results: The new model demonstrated superior segmentation performance when using multi-modal MRI images compared to single-modal inputs. The effectiveness of the model in utilizing the created dataset was validated through various experimental setups, confirming the enhanced ability to characterize tumor regions across different modalities. Discussion: The integration of multi-modal MRI images and advanced machine learning techniques in our model significantly improves the segmentation of soft tissue sarcomas in thigh imaging. This advancement aids clinicians in better diagnosing and understanding the patient's condition, leveraging the strengths of different imaging modalities. Further studies could explore the application of these techniques to other types of soft tissue sarcomas and additional anatomical sites. [ABSTRACT FROM AUTHOR]

Hypoxia plays an important role in the pathological process of bladder outlet obstruction. Previous research has mostly focused on the dysfunction of bladder smooth muscle cells, which are directly related to bladder contraction. This study delves into the barrier function changes of the urothelial cells under exposure to hypoxia. Results indicated that after a 5‐day culture, SV‐HUC‐1 formed a monolayer and/or bilayer of cell sheets, with tight junction formation, but no asymmetrical unit membrane was observed. qPCR and western blotting revealed the expression of TJ‐associated proteins (occludin, claudin1 and ZO‐1) was significantly decreased in the hypoxia group in a time‐dependent manner. No expression changes were observed in uroplakins. When compared to normoxic groups, immunofluorescent staining revealed a reduction in the expression of TJ‐associated proteins in the hypoxia group. Transepithelial electrical resistance (TEER) revealed a statistically significant decrease in resistance in the hypoxia group. Fluorescein isothiocyanate‐conjugated dextran assay was inversely proportional to the results of TEER. Taken together, hypoxia down‐regulates the expression of TJ‐associated proteins and breaks tight junctions, thus impairing the barrier function in human urothelial cells. [ABSTRACT FROM AUTHOR]

Background: Fibroblast differentiation to a myofibroblast phenotype is a feature of airway remodeling in asthma. Lung fibroblasts express the integrin receptor α4β7 and fibronectin induces myofibroblast differentiation via this receptor. Objectives: To investigate the role of the β7 integrin receptor subunit and α4β7 integrin complex in airway remodeling and airway hyperresponsiveness (AHR) in a murine model of chronic allergen exposure. Methods: C57BL/6 wild type (WT) and β7 integrin null mice (β7 -/-) were sensitized (days 1,10) and challenged with ovalbumin (OVA) three times a week for one or 4 weeks. Similar experiments were performed with WT mice in the presence or absence of α4β7 blocking antibodies. Bronchoalveolar (BAL) cell counts, AHR, histological evaluation, soluble collagen content, Transforming growth factor-β (TGFβ) and Interleukin-13 (IL13) were measured. Phenotype of fibroblasts cultured from WT and β7 -/- saline (SAL) and OVA treated mice was evaluated. Results: Eosinophil numbers were similar in WT vs β7-/- mice. Prolonged OVA exposure in β7-/- mice was associated with reduced AHR, lung collagen content, peribronchial smooth muscle, lung tissue TGFβ and IL13 expression as compared to WT. Similar findings were observed in WT mice treated with α4β7 blocking antibodies. Fibroblast migration was enhanced in response to OVA in WT but not β7 -/- fibroblasts. α-SMA and fibronectin expression were reduced in β7-/- fibroblasts relative to WT. Conclusions: The β7 integrin subunit and the α4β7 integrin complex modulate AHR and airway remodeling in a murine model of allergen exposure. This effect is, at least in part, explained by inhibition of fibroblast activation and is independent of eosinophilic inflammation. [ABSTRACT FROM AUTHOR]

Progerin, the protein that causes Hutchinson-Gilford progeria syndrome, triggers nuclear membrane (NM) ruptures and blebs, but the mechanisms are unclear. We suspected that the expression of progerin changes the overall structure of the nuclear lamina. High-resolution microscopy of smooth muscle cells (SMCs) revealed that lamin A and lamin B1 form independent meshworks with uniformly spaced openings (~0.085 μm²). The expression of progerin in SMCs resulted in the formation of an irregular meshwork with clusters of large openings (up to 1.4 μm²). The expression of progerin acted in a dominant-negative fashion to disrupt the morphology of the endogenous lamin B1 meshwork, triggering irregularities and large openings that closely resembled the irregularities and openings in the progerin meshwork. These abnormal meshworks were strongly associated with NM ruptures and blebs. Of note, the progerin meshwork was markedly abnormal in nuclear blebs that were deficient in lamin B1 (~50% of all blebs). That observation suggested that higher levels of lamin B1 expression might normalize the progerin meshwork and prevent NM ruptures and blebs. Indeed, increased lamin B1 expression reversed the morphological abnormalities in the progerin meshwork and markedly reduced the frequency of NM ruptures and blebs. Thus, progerin expression disrupts the overall structure of the nuclear lamina, but that effect--along with NM ruptures and blebs--can be abrogated by increased lamin B1 expression. [ABSTRACT FROM AUTHOR]

Background: Bicuspid aortic valves (BAV) are frequently associated with ascending aortic aneurysms. The etiology is incompletely understood, but genetic factors, in addition to flow perturbations, are likely involved. Since loss of contractility and elaboration of extracellular matrix in the vessel wall are features of BAV-associated aortopathy, phenotypic modulation of smooth muscle cells (SMCs) may play a role. Methods: Ascending aortic tissue was collected intra-operatively from 25 individuals with normal (i.e., tricuspid) aortic valves (TAV) and from 25 individuals with BAVs. For both TAV and BAV, 10 patients had non-dilated (ND) and 15 patients had dilated (D) aortas. SMCs were isolated and cultured from a subset of patients from each group. Aortic tissue and SMCs were fluorescently immunolabeled for SMC phenotypic markers (i.e., alpha-smooth muscle actin (ASMA, contractile), vimentin (synthetic) and p16INK4a and p21Cip1 (senescence). SMCs were also analyzed for replicative senescence in culture. Results: In normal-sized and dilated BAV aortas, SMCs switched from the contractile state to either synthetic or senescent phenotypes, as observed by loss of ASMA (ND: P = 0.001, D: P = 0.002) and associated increases in vimentin (ND: P = 0.03, D: P = 0.004) or p16/p21 (ND: P = 0.03, D: P<0.0001) compared to TAV. Dilatation of the aorta exacerbated SMC phenotypic switching in both BAV and TAV aortas (all P<0.05). In SMCs cultured from normal and dilated aortas, those isolated from BAV reached replicative senescence faster than those from TAV aortas (all P = 0.02). Furthermore, there was a stark inverse correlation between ASMA and cell passage number in BAV SMCs (ND: P = 0.0006, D: P = 0.01), but not in TAV SMCs (ND: P = 0.93, D: P = 0.20). Conclusions: The findings of this study provide direct evidence from cell culture studies implying that SMCs switch from the contractile state to either synthetic or senescent phenotypes in the non-dilated BAV aorta. In cultured SMCs from both non-dilated and dilated aortas, we found that this process may precede dilatation and accompany aneurysm development in BAV. Our findings suggest that therapeutically targeting SMC phenotypic modulation in BAV patients may be a viable option to prevent or delay ascending aortic aneurysm formation. [ABSTRACT FROM AUTHOR]

Leiomyomas are benign mesenchymal tumors which arise from smooth muscle cells. They are most commonly encountered in the uterus but leiomyomas originating from the scrotum is a rare entity and very few cases are reported in literature so far. There are three types of superficial leiomyoma based on their site of origin: piloleiomyoma arising from arrector pili, scrotal leiomyoma arising from dartos muscle, and angioleiomyoma arising from smooth muscles of blood vessels. Herein, we report a case of scrotal leiomyoma in a 60 years old male which was clinically diagnosed as sebaceous adenoma and was excised. Histopathological and Immunohistochemical features were consistent with leiomyoma and final diagnosis of scrotal leiomyoma was given. [ABSTRACT FROM AUTHOR]

The study was conducted on spleen of 18 healthy pigs (6 each of 0-4 weeks, 4-10 weeks and above 10 weeks of age) to evaluate the postnatal development. The sections were processed and stained to obtain the histological details. The spleen consisted of stroma and parenchyma. The stroma was composed of capsule and trabeculae. Microscopic details obtained by staining with H&E, Van Gieson, Verhoeff, Masson trichome revealed that splenic capsule was thick with two layers, viz., an outer dense irregular fibrous connective tissue layer and inner smooth muscle layer. Collagen fibers were predominant over elastic and reticular fibers. Trabeculae extended from the capsule dividing the splenic parenchyma into compartments and served as a frame work to support muscle, collagen, elastic and reticular fibers. The collagen, elastic, reticular and smooth muscle fibers increased with age. There was also a significant increase in trabecular branching, capsule thickness as the age progressed. [ABSTRACT FROM AUTHOR]

Treatment modalities for pulmonary arterial hypertension (PAH) improve quality of life and walk distance. However, none of these therapies alter the structural/functional pulmonary vascular integrity that results in vascular remodeling. PAH smooth muscle cells share biological characteristics with cancer cells, which may be potential therapeutic targets for PAH. We present a case of a patient with connective tissue disease (CTD)‐associated PAH treated on triple therapy who developed metastatic lung adenocarcinoma. While on PAH triple‐therapy, she received a combination of carboplatin, pemetrexed, and pembrolizumab. She eventually had a complete pathologic response, no evidence of cancer recurrence, and significant improvement of PAH/overall clinical status. After discontinuation of neoplastic therapy, her clinical status worsened, she eventually passed away, and lung biopsy findings revealed evidence of severe pulmonary smooth muscle cell hypertrophy and pulmonary veno‐occlusive disease. This report suggests that combined chemotherapy and immunotherapy may influence the efficacy of PAH therapies and improve clinical status. [ABSTRACT FROM AUTHOR]

Impaction is one of the most common disease of the cecum in horses. It is important to distinguish between acute and chronic recurrent cases. Acute impaction occurs suddenly and resolves within a few days with medical and/or surgical treatment whereas in chronic cases the impaction within the base or the whole cecum occurs repeatedly at irregular intervals. The chronic recurrent cecal impaction (CRCI) is characterized by hypertrophy of muscle in the cecal base or entire cecum. The pathogenesis is not fully understood: hypothesis is that the cecal impaction induces a distension during the contraction of the circular muscle layer which is a stimulus of a hypertrophy of the circular and longitudinal muscle layer in the cecum. Furthermore, neuronal density in the plexus myentericus was found to be decreased significantly in the cecal wall of CRCI. Initially, in cases of CRCI the cecocolic orifice is not entirely blocked allowing partial transit of ingesta. Hypertrophy of the muscle layer (longitudinal and circular muscle) begins at the cecal base and as the disease progresses, the cecocolic opening becomes completely obstructed due to the automatic closure mechanism. The rectal and ultrasound exam are the most useful diagnostic steps while different degrees of cecal impaction and/or tympany, a marked thickening and cecal wall contractility due to palpation are found. The hypertrophy can be regarded as a pathognomonic sign. Treatment in our study was done by surgical enlargement of the cecocolic orifice (created by Huskamp 1990). Tissue samples of defined cecal regions were taken during surgery or necropsy: the circular and longitudinal muscle layer were significantly thicker, linear neuron densities were significantly lower each compared to clinically healthy horses. Based on smooth muscle thickening and neuron deficit, rectally palpable and ultrasound visible cecal wall thickening, horses suffering from CRI have a poor prognosis. Surgery by enlargement of the cecocolic orifice in horses with CRCI have a better prognosis if only the cecal base has a thickening and a normal cecal body wall. [ABSTRACT FROM AUTHOR]

Unlike adult mammalian cardiomyocytes, cardiomyocytes in teleosts display high proliferative capacity throughout adulthood. This study aimed to identify the immunohistochemical profiles of cardiomyocytes and immune cells in the hearts of Molly fish by assessing the immunolabelling expression of key proteins involved in cell proliferation, differentiation, and tissue protection. The cardiac anatomy of Molly fish includes the atrium, ventricle, and bulbus arteriosus. The expression of SOX9, NF-κB, myostatin, and S100 proteins in myocardial cells indicates the proliferative features of the heart in Molly fish. The bulbus arteriosus is characterized by collagenous chambers and smooth muscle cells that express Ach and iba1. The atrium of Molly fish serves as a storage unit for rodlet cells and immune cells. Rodlet cells displayed immunoreactivity to NF-κB, iba1, Olig2, Ach, and S100 proteins, suggesting their roles in the immune response within the heart. Furthermore, telocytes (TCs) have emerged as a significant component of the atrium of Molly fish, expressing Ach, CD68, S100 protein, and iba1. These expressions indicate the involvement of TCs in multiple signaling pathways that contribute to heart architecture. This study delineates the intricate relationship between cardiomyocytes and innate immune cells in Molly fish. [ABSTRACT FROM AUTHOR]

Bile acids regulate gastrointestinal motility by mechanisms that are poorly understood. Standard isolated tissue bath assays might not recapitulate in vivo physiology if contractile responses to certain bile acids require direct application to the intestinal mucosa. We sought to determine the feasibility of quantifying longitudinal smooth muscle contractile responses to bile acids from intact segments of everted mouse ileum. Ileum from adult female C57BL/6J mice was isolated, gently everted over a notched metal rod, and mounted in tissue baths. Individual bile acids and agonists of bile acid receptors were added to the baths, and longitudinal smooth muscle contractile responses were quantified by isometric force transduction. Ursodeoxycholic acid robustly increased contractile responses in a dose‐dependent manner. Deoxycholic acid stimulated contractility at low doses but inhibited contractility at high doses. Chenodeoxycholic acid, glycocholic acid, and lithocholic acid did not alter contractility. The dose‐dependent increase in contractility resulting from the application of ursodeoxycholic acid was recapitulated by INT‐777, an agonist of the Takeda G protein‐coupled receptor 5 (TGR5), and by cevimeline, a muscarinic acetylcholine receptor agonist. Agonists to the nuclear receptors farnesoid X receptor, glucocorticoid receptor, pregnane X receptor, vitamin D receptor, and to the plasma membrane epidermal growth factor receptor did not modify baseline contractile patterns. These results demonstrate that gentle eversion of intact mouse ileum facilitates the quantification of longitudinal smooth muscle contractile responses to individual bile acids. Prokinetic effects of ursodeoxycholic acid and low‐dose deoxycholic acid are replicated by agonists to TGR5 and muscarinic acetylcholine receptors. [ABSTRACT FROM AUTHOR]

Acute limb ischemia (ALI) is defined as a sudden reduction in blood flow to a limb, resulting in cessation of blood flow and, therefore, cessation of the delivery of nutrients and oxygen to the tissues of the lower limb. Despite optimal treatment to restore blood flow to ischemic tissues, some patients may suffer from ischemia/reperfusion (I/R) syndrome, the most severe complication after a revascularization procedure used to restore blood flow. There are multiple molecular and cellular factors that are involved in each phase of ALI. This review focuses firstly on molecular and cellular factors of arterial thrombosis, highlighting the role of atherosclerotic plaques, smooth muscle cells (SMCs), and cytokine which may alter key components of the extracellular matrix (ECM). Then, molecular and cellular factors of arterial embolism will be discussed, highlighting the importance of thrombi composition. Molecular and cellular factors of ischemia/reperfusion syndrome are analyzed in depth, highlighting several important mechanisms related to tissue damage, such as inflammation, apoptosis, autophagy, necrosis, and necroptosis. Furthermore, local and general complications of ALI are discussed in the context of molecular alterations. Ultimately, the role of novel biomarkers and targeted therapies is discussed. [ABSTRACT FROM AUTHOR]

Artemisia monosperma is a plant with many traditional uses including some affecting smooth muscles. The A. momosperma essential oil (AMEO) prepared by hydrodistillation from fresh and dry aerial parts was compared qualitatively and quantitatively using GC/MS. The drying process affected the yield and composition of AMEO. The bronchodilator potential was explored using isolated guinea-pig trachea in ex-vivo organ bath setup. In the tracheal contractions induced by different spasmogens, AMEO was able to completely relax contractions induced by carbachol (CCh; 1 μM) and high K+ (80 mM) at closely related doses (p > 0.05) indicating a dual inhibition of phosphodiesterase enzyme (PDE) and voltage-mediated L-type Ca++ channels blocker (CCB) as papaverine. The current study provides scientific support to the medicinal use A. monosperma in respiratory disorders. [ABSTRACT FROM AUTHOR]

The epididymal duct exhibits spontaneous phasic contractions (SPCs) to store and transport sperm. Here, we explored molecular identification of pacemaker cells driving SPCs in the caudal epididymal duct and also investigated properties of pacemaker currents underlying SPCs focusing on ANO1 Ca2+-activated Cl− channels (CaCCs). Immunohistochemistry was performed to visualise the distribution of platelet-derived growth factor receptor α (PDGFRα)- or ANO1-positive cells in the rat caudal epididymal duct. Perforated whole-cell patch clamp technique was applied to enzymatically isolated epididymal cells, while SPCs were recorded with video edge-tracking technique. Immunohistochemistry revealed the distribution of α-smooth muscle actin (α-SMA)-positive cells co-expressing both PDGFRα and ANO1 in the innermost smooth muscle layer. Approximately one-third of isolated epididymis cells exhibited spontaneous transient inward currents (STICs) at the holding potential −60 mV. The reversal potential for STICs was close to the calculated chloride equivalent potential depending on intracellular Cl− concentrations. Ani9 (3 µM), the ANO1 specific inhibitor, decreased both amplitude and frequency of STICs, while cyclopiazonic acid (CPA, 30 µM), a sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor, abolished STICs. Ani9 (3 or 10 µM) reduced the frequency of SPCs without changing their amplitude. Thus, PDGFRα+, ANO1+ specialised smooth muscle cells (SMCs) appear to function as pacemaker cells to electrically drive epididymal SPCs by generating ANO1-dependnet STICs. STICs arising from spontaneous Ca2+ release from intracellular Ca2+ store and subsequent opening of ANO1 result in depolarisations that spread into adjacent SMCs where L-type voltage-dependent Ca2+ channels are activated to develop SPCs. [ABSTRACT FROM AUTHOR]

Introduction: Congenital diaphragmatic hernia (CDH) is a complex congenital disorder, characterized by pulmonary hypertension (PH) and hypoplasia. PH secondary to CDH (CDH-PH) features devastating morbidity and mortality (25–30%) among neonates. An unmet need is determining mechanisms triggering CDH-PH to save infants. Prior data suggest abnormal remodeling of the pulmonary vascular extracellular matrix (ECM), presumed to be driven by endothelial-to-mesenchymal transition (EndoMT), hinders postnatal vasodilation and limits anti-PH therapy in CDH. There are limited data on the role of EndoMT in CDH-PH. Methods: The purpose of the study was to investigate how EndoMT contributes to CDH-PH by identifying cells undergoing EndoMT noted by alpha smooth muscle actin (α-SMA) expression in human umbilical vein endothelial cells (HUVECs) and lung tissue obtained from murine pups using the nitrofen model. N = 8 CDH, N = 8 control HUVECs were stained for α-SMA and CD31 after being exposed for 24 h to TGFB, a known EndoMT promoter. N = 8 nitrofen, N = 8 control murine pup lungs were also stained for α-SMA and CD31. α-SMA and CD31 expression was quantified in HUVECs and murine tissue using Fiji imaging software and normalized to the total number of cells per slide noted by DAPI staining. Results: CDH HUVECs demonstrated a 1.1-fold increase in α-SMA expression (p = 0.02). The murine model did not show statistical significance between nitrofen and control pup lungs; however, there was a 0.4-fold increase in α-SMA expression with a 0.8-fold decrease in CD31 expression in the nitrofen pup lungs when compared to controls. Conclusion: These results suggest that EndoMT could potentially play a role in the ECM remodeling seen in CDH-PH. [ABSTRACT FROM AUTHOR]

The transitional epithelial cells (urothelium) that line the lumen of the urinary bladder form a barrier between potentially harmful pathogens, toxins, and other bladder contents and the inner layers of the bladder wall. The urothelium, however, is not simply a passive barrier, as it can produce signaling factors, such as ATP, nitric oxide, prostaglandins, and other prostanoids, that can modulate bladder function. We investigated whether substances produced by the urothelium could directly modulate the contractility of the underlying urinary bladder smooth muscle. Force was measured in isolated strips of mouse urinary bladder with the urothelium intact or denuded. Bladder strips developed spontaneous tone and phasic contractions. In urothelium-intact strips, basal tone, as well as the frequency and amplitude of phasic contractions, were 25%, 32%, and 338% higher than in urothelium-denuded strips, respectively. Basal tone and phasic contractility in urothelium-intact bladder strips were abolished by the cyclooxygenase (COX) inhibitor indomethacin (10 µM) or the voltage-dependent Ca2+ channel blocker diltiazem (50 µM), whereas blocking neuronal sodium channels with tetrodotoxin (1 µM) had no effect. These results suggest that prostanoids produced in the urothelium enhance smooth muscle tone and phasic contractions by activating voltage-dependent Ca2+ channels in the underlying bladder smooth muscle. We went on to demonstrate that blocking COX inhibits the generation of transient pressure events in isolated pressurized bladders and greatly attenuates the afferent nerve activity during bladder filling, suggesting that urothelial prostanoids may also play a role in sensory nerve signaling. NEW & NOTEWORTHY: This paper provides evidence for the role of urothelial-derived prostanoids in maintaining tone in the urinary bladder during bladder filling, not only underscoring the role of the urothelium as more than a barrier but also contributing to active regulation of the urinary bladder. Furthermore, cyclooxygenase products greatly augment sensory nerve activity generated by bladder afferents during bladder filling and thus may play a role in perception of bladder fullness. [ABSTRACT FROM AUTHOR]

BACKGROUND: Abdominal aortic aneurysm (AAA) is a severe aortic disease without effective pharmacological approaches. The nuclear hormone receptor LXRα (liver X receptor α), encoded by the NR1H3 gene, serves as a critical transcriptional mediator linked to several vascular pathologies, but its role in AAA remains elusive. METHODS: Through integrated analyses of human and murine AAA gene expression microarray data sets, we identified NR1H3 as a candidate gene regulating AAA formation. To investigate the role of LXRα in AAA formation, we used global Nr1h3-knockout and vascular smooth muscle cell--specific Nr1h3-knockout mice in 2 AAA mouse models induced with angiotensin II (1000 ng·kg·min; 28 days) or calcium chloride (CaCl2; 0.5 mol/L; 42 days). RESULTS: Upregulated LXRα was observed in the aortas of patients with AAA and in angiotensin II-- or CaCl2-treated mice. Global or vascular smooth muscle cell--specific Nr1h3 knockout inhibited AAA formation in 2 mouse models. Loss of LXRα function prevented extracellular matrix degeneration, inflammation, and vascular smooth muscle cell phenotypic switching. Uhrf1, an epigenetic master regulator, was identified as a direct target gene of LXRα by integrated analysis of transcriptome sequencing and chromatin immunoprecipitation sequencing. Susceptibility to AAA development was consistently enhanced by UHRF1 (ubiquitin-like containing PHD and RING finger domains 1) in both angiotensin II-- and CaCl2-induced mouse models. We then determined the CpG methylation status and promoter accessibility of UHRF1-mediated genes using CUT&Tag (cleavage under targets and tagmentation), RRBS (reduced representation bisulfite sequencing), and ATACseq (assay for transposase-accessible chromatin with sequencing) in vascular smooth muscle cells, which revealed that the recruitment of UHRF1 to the promoter of miR-26b led to DNA hypermethylation accompanied by relatively closed chromatin states, and caused downregulation of miR-26b expression in AAA. Regarding clinical significance, we found that underexpression of miR-26b-3p correlated with high risk in patients with AAA. Maintaining miR-26b-3p expression prevented AAA progression and alleviated the overall pathological process. CONCLUSIONS: Our study reveals a pivotal role of the LXRα/UHRF1/miR-26b-3p axis in AAA and provides potential biomarkers and therapeutic targets for AAA. [ABSTRACT FROM AUTHOR]

Intermediate filaments (IFs) are key molecular factors of the cell and have been reported to play an important role in maintaining the structural integrity and functionality of the abomasum. This study was designed to determine the regional distribution, cellular localization and expression of several IFs, including CK8, CK18, CK19, vimentin, desmin, peripherin and nestin, as well as the connective tissue component laminin, in the bovine, ovine and caprine abomasa. Immunohistochemical analyses demonstrated varying levels of expression of CK8, CK18, CK19, vimentin, desmin, nestin, peripherin and laminin in the bovine, ovine and caprine abomasa. CK8 immunoreactions were particularly evident in the luminal and glandular epithelia of the glands found in the abomasal cardia, fundus and pylorus in all three species. In the bovine abomasum, CK18 immunoreactions were stronger in the parietal cells, compared to the chief cells. In the abomasum of all three species, the smooth muscle as well as the smooth muscle cells of the vascular media in the cardiac, fundic and pyloric regions showed strong immunoreactivity. In all three species, the cardiac, fundic and pyloric regions of the abomasum showed strong peripherin and nestin immunoreactions in the luminal and glandular epithelial cells, stromal and smooth muscle cells, nervous plexuses and blood vessels. The expression patterns of IFs and laminin in the ruminant abomasum suggest that these proteins play a structural role in the cytoskeleton and are effective in maintaining abomasal tissue integrity and stability. [ABSTRACT FROM AUTHOR]

Fibroids are benign uterine tumors characterized by the proliferation of uterine smooth muscle cells, embedded in an abundant extracellular matrix. Their prevalence is estimated to be >50% in women aged >45 years. Fibroids represent a considerable health burden. It is time to acquire a deeper mechanistic understanding of uterine fibroid-related etiology and pathogenesis, which may help pinpoint new strategies and an individualized approach. There is a need to gather prospective data and conduct studies to compare alternative approaches and assess long-term outcomes with respect to quality of life, recurrence of symptoms (bleeding and bulk symptoms), fertility, and even complications The goal of this review was to evaluate the widely accepted pathogenesis and identify risks factors and future directions for clinical and basic research into fibroids. [ABSTRACT FROM AUTHOR]

Mucus provides a protective barrier that is crucial for host defense in the lungs. However, excessive or abnormal mucus can have pathophysiological consequences in many pulmonary diseases, including asthma. Patients with asthma are treated with agents that relax airway smooth muscle and reduce airway inflammation, but responses are often inadequate. In part, this is due to the inability of existing therapeutic agents to directly target mucus. Accordingly, there is a critical need to better understand how mucus hypersecretion and airway plugging are affected by the epithelial cells that synthesize, secrete, and transport mucus components. This review highlights recent advances in the biology of mucin glycoproteins with a specific focus on MUC5AC and MUC5B, the chief macromolecular components of airway mucus. An improved mechanistic understanding of key steps in mucin production and secretion will help reveal novel potential therapeutic strategies. [ABSTRACT FROM AUTHOR]

Aneurysms are clinical entities that can develop and affect human aorta; and although in most cases they have an asymptomatic course, these pathological dilatations can lead to a lethal outcome when rupture occurs, thus the establishment of predictors is crucial for death prevention. Essential events that take place in the vessel wall have been identified and described, such as inflammation, proteolysis, smooth muscle cell apoptosis, angiogenesis, and vascular remodeling. Porcine and ovine models have been useful for the development and evaluation of endovascular devices of the aorta. However, since the worldwide introduction and adoption of these minimally invasive techniques for aneurysm repair, there is lesser availability of diseased aortic tissue for molecular, cellular, and histopathological analysis, therefore over the last three decades it has been proposed various small species models that have allowed the focal induction of these lesions for the study of physiopathological mechanisms and possible useful biomarkers as diagnostic and therapeutic targets. The present review article presents and discusses the animal models available as their applications, characteristics, advantages, and limitations for the development of preclinical studies, and their importance in the comprehension of this pathology in humans. [ABSTRACT FROM AUTHOR]

A crucial aspect of bladder function is the maintenance of a normo-active detrusor during bladder filling. The physiological mechanisms and pathways underlying this function are yet to be fully elucidated. Premature detrusor contractions are a key phenotype in detrusor overactivity, a common pathophysiological condition of the urinary bladder. Recent literature has identified PDFGRα+ cells as mediators in transducing inhibitory signals to detrusor smooth muscle cells via gap junctions. We employ computational modeling to study transduction pathways via which inhibitory signals are generated in PDFGRα+ cells in response to purinergic, nitrergic and mechanical stimuli. The key focus of our study here is to explore the effect of ATP, stretch and NO on the membrane potential of PDFGRα+ cells, which is driven to hyperpolarized potentials via the activation of SK3 channels. Our results indicate that purinergic, mechanical and nitrergic inputs can induce significant membrane hyperpolarizations of 20–35 mV relative to the resting membrane potential. Given the interconnections between PDFGRα+ cells and detrusor SMCs through gap junctions, these hyperpolarizations can have significant functional implications in the maintenance of a normo-active detrusor as also in departures from this state as seen in detrusor overactivity. [ABSTRACT FROM AUTHOR]

Background: Myofibromas are rare benign neoplasms composed of myoid cells and myofibroblasts. This study aimed to systematically review case reports and a series of myofibromas (MF) and myofibromatosis (MFT) occurring in the oral and maxillofacial regions in order to describe their main clinicopathological features. Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. Electronic searches were conducted in 2023 in four databases: MEDLINE/PubMed, Web of Science, Scopus, and EMBASE. A manual search and a search in the grey literature were also conducted. The lesions were classified as MF or MFT according to their original report. Results: A total of 169 cases were included in this systematic review. Men were slightly more affected, with a painless nodule. When occurring in soft tissue, MF usually developed in the gingiva (mean age:29.23 ± 21.93 years) and when it was intra‐osseous, it occurred more frequently in the posterior mandible (mean age:14.33 ± 15.62 years). MFT occurred mainly in the mandible and was predominantly described as well‐circumscribed masses of spindle cells organized in fascicles with a prominent vascular activity in a hemangiopericytoma‐like pattern. The lesions were mainly positive for smooth muscle actin and vimentin immunomarkers. Surgical excision was the treatment of choice in the majority of cases and recurrence was observed in only three cases. Conclusion: MF and MFT affect more men, with an indolent clinical course. Intra‐osseous tumors and MFT seem to occur more frequently in younger individuals. These lesions seem to have a good prognosis and low recurrence. [ABSTRACT FROM AUTHOR]

Objective: To explore the molecular mechanism by which curcumin affects renal interstitial fibrosis (RIF) progression by regulating ADAM metallopeptidase with thrombospondin type 1 motif 18 (ADAMTS18) methylation. Methods: NRK-49F cells RIF model were induced with transforming growth factor β 1 (TGF- β 1). Effects of different concentrations of curcumin (0, 10, 20, and 30 μmol/L) on cell proliferation, cell cycle, cell apoptosis as well as cyclin D1 expression were analyzed by cell counting kit-8, flow cytometry and Western blot, respectively. ADAMTS18 methylation levels were determined by methylation-specific polymerase chain reaction. ADAMTS18, fibronectin (FN), type I collagen (Col- I) and alpha-smooth muscle actin (α -SMA) mRNA and protein expressions were analyzed by real-time PCR (RT-PCR) and Western blot, respectively. Meanwhile, cells were treated with 50 mmol/L 5-aza-2′-deoxycytidine (5-aza-dC, demethylation agent) for 72 h. Effect of curcumin on extracellular matrix (ECM) deposition was evaluated by immunochemical staining and Western blot. NRK-49F cells were transfected with ADAMTS18 small interfering RNA and grouped into a normal control, ADAMTS18-knock-out (KO), and ADAMTS18-KO+ 30 μmol/L curcumin groups, and whether curcumin can reverse the effect of ADAMTS18 knockdown on RIF was evaluated. Results: Compared with the control group, TGF-β 1 significantly inhibited the proliferation of NRK-49F cells, blocked the G1/G0 phase, promoted cell apoptosis and inhibited cyclin D1 expression (P<0.01). Among the different concentrations of curcumin, 30 μmol/L curcumin significantly reversed these processes (P<0.01). Immunochemical staining and Western blot results showed that curcumin significantly inhibited the deposition of FN, Col- I and α-SMA (P<0.01). Curcumin and 5-zaz-dC had synergistic effects, promoting ADAMTS18 expression, removing ADAMTS18 methylation, and reducing ECM deposition. ADAMTS18 knockdown promoted ECM accumulation, and curcumin reversed this process (P<0.01). Conclusion: TGF-β 1-induced fibrosis in NRK-49F cells. Curcumin promoted ADAMTS18 expression, reduced ECM accumulation, and alleviated RIF progression by inhibiting ADAMTS18 methylation. [ABSTRACT FROM AUTHOR]

This article concerns the spasmolytic activities of some novel 1,3-disubstituted 3,4-dihydroisoquinolines. These compounds can be evaluated as potential therapeutic candidates according to Lipinski's rule of five, showing high gastrointestinal absorption and the ability to cross the blood–brain barrier, which is a very important parameter in the drug discovery processes. In silico simulation predicted smooth muscle relaxant activity for all the compounds. Since smooth muscle contractile failure is a characteristic feature of many disorders, in the current paper, we concentrate on the parameters of the spontaneous contractile responses of smooth muscle (SM) cells compared to the well-known drug mebeverine. Two of the newly synthesized substances can be identified as essential modulating regulators and potentially used as therapeutic molecules. One of these molecules also showed significant DPPH antioxidant activity compared to rutin. [ABSTRACT FROM AUTHOR]

This study aims to investigate whether transfection of miR‐486 in the corpus cavernosum of spontaneously hypertensive rats (SHR) can improve erectile function and its mechanism. SHR penile cavernous smooth muscle cells were divided into control group, mimic negative control transfection group, inhibitor negative control transfection group, miR‐486 mimic transfection group, and miR‐486 inhibitor transfection group. miR‐486 mimic (50 nM), miR‐486 inhibitor (100 nM), and corresponding negative control preparation were transfected into the corresponding groups of cells. The mRNA expressions of miR‐486, TGF‐β1, Collagen I, and Collagen III in each group were detected after transfection. Twelve 12‐week‐old healthy male SHR and 12 WKY rats were randomly divided into WKY control group, SHR control group, SHR + Agomir negative control (NC) group, and SHR + miR‐486 Agomir group. In the SHR + miR‐486 Agomir group, penile cavernosa was transfected with miR‐486 agonist. Penile sponge internal pressure (ICPmax)/mean arterial pressure (MAP), the expression of miR‐486, the ratio of smooth muscle to collagen (SM/C), and the expression of TGF‐β1, Collagen I, and Collagen III in penile cavernosum tissues were determined. Compared with the control group, the expressions of TGF‐β1, Collagen I, and Collagen Ⅲ in the miR‐486 mimic transfection group of SHR rat corpus cavernosum smooth muscle cells were significantly decreased, while those in the miR‐486 inhibitor transfection group were significantly increased (P < 0.05). The ratios of ICPmax/MAP and SM/C in the SHR group were significantly lower than those in the WKY group and in the SHR + miR‐486 Agomir group were significantly higher than those in the SHR group and the SHR + Agomir NC group (P < 0.05). The expressions of TGF‐β1, Collagen I, and Collagen Ⅲ in SHR group were significantly increased compared with those in WKY group, while those in SHR + miR‐486 Agomir group were significantly lower than those in SHR group and SHR + Agomir NC group (P < 0.05). The upregulation of the expression of miR‐486 in the corpus cavernosum of SHR rats can inhibit fibrosis of the corpus cavernosum and improve erectile function. [ABSTRACT FROM AUTHOR]

Abdominal aortic aneurysm (AAA) is a common vascular disease that has attracted widespread attention due to its characteristic of being asymptomatic and high mortality rate. In this study, we present a novel woven vascular stent-graft, which can improve thrombus formation resulting from excessive smooth muscle cell proliferation following blood vessel stent implantation. To achieve this, we adopted the orthogonal design method to optimize the production process parameters and then coated the surface of the woven stent with chitosan/heparin using a layer-by-layer self-assembly technique based on the electrostatic binding principle, and the performance of the stent before and after modification was comprehensively evaluated. The results demonstrated that the coating had no impact on the mechanical properties, wall thickness, and cross-sectional water permeability of the membranes. Remarkably, the release rate of heparin reached as high as 90.88% at 216 h, effectively inhibiting the growth of smooth muscle cells. In conclusion, the new woven polyester vascular stent-graft provides a potential application prospect for the treatment of AAA. [ABSTRACT FROM AUTHOR]

We report the synthesis of two novel halogenated nitro-arylhimachalene derivatives: 2-bromo-3,5,5,9-tetramethyl-1-nitro-6,7,8,9-tetrahydro-5H-benzo[7]annulene (bromo-nitro-arylhimachalene) and 2-chloro-3,5,5,9-tetramethyl-1,4-dinitro-6,7,8,9-tetrahydro-5H-benzo[7]annulene (chloro-dinitro-arylhimachalene). These compounds were derived from arylhimachalene, an important sesquiterpene component of Atlas cedar essential oil, via a two-step halogenation and nitration process. Characterization was performed using 1H and 13C NMR spectrometry, complemented by X-ray structural analysis. Quantum chemical calculations employing density functional theory (DFT) with the Becke3-Lee-Yang-parr (B3LYP) functional and a 6-31++G(d,p) basis set were conducted. The optimized geometries of the synthesized compounds were consistent with X-ray structure data. Frontier molecular orbitals and molecular electrostatic potential (MEP) profiles were identified and discussed. DFT reactivity indices provided insights into the compounds' behaviors. Moreover, Hirshfeld surface and 2D fingerprint analyses revealed significant intermolecular interactions within the crystal structures, predominantly H–H and H–O contacts. Molecular docking studies demonstrate strong binding affinities of the synthesized compounds to the active site of protein 7B2W, suggesting potential therapeutic applications against various isolated smooth muscles and neurotransmitters. [ABSTRACT FROM AUTHOR]

The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of accelerated electron radiation on some pivotal neurotransmitter circuits (cholinergic and serotonergic) of rats' myenteric plexus. Male Wistar rats were irradiated with an electron beam (9 MeV, 5 Gy) generated by a multimodality linear accelerator. The contractile activity of isolated smooth muscle samples from the gastric corpus was measured. Furthermore, an electrical stimulation (200 μs, 20 Hz, 50 s, 60 V) was performed on the samples and an assessment of the cholinergic and serotonergic circuits was made. Five days after irradiation, the recorded mechanical responses were biphasic—contraction/relaxation in controls and contraction/contraction in irradiated samples. The nature of the contractile phase of control samples was cholinergic with serotonin involvement. The relaxation phase involved ACh-induced nitric oxide release from gastric neurons. There was a significant increase in serotonergic involvement during the first and second contractile phases of the irradiated samples, along with a diminished role of acetylcholine in the first phase. This study demonstrates an increased involvement of serotonergic neurotransmitter circuits in the gastric myenteric plexus caused by radiation with accelerated electrons. [ABSTRACT FROM AUTHOR]