The role of smooth muscle in regulating prostatic induction

Development ◽  
2002 ◽  
Vol 129 (8) ◽  
pp. 1905-1912 ◽  
Author(s):  
Axel A. Thomson ◽  
Barry G. Timms ◽  
Lesley Barton ◽  
Gerald R. Cunha ◽  
Oliver C. Grace
Keyword(s):  
Smooth Muscle ◽  
Reproductive Tract ◽  
Muscle Layer ◽  
Sexually Dimorphic ◽  
Smooth Muscle Layer ◽  
In Vitro Recombination ◽  
Fold Reduction ◽  
Bud Position

We have examined the role that smooth muscle plays during prostatic organogenesis and propose that differentiation of a smooth muscle layer regulates prostatic induction by controlling mesenchymal/epithelial interactions. During development of the rat reproductive tract, an area of condensed mesenchyme involved in prostatic organogenesis is formed. This mesenchyme (the ventral mesenchymal pad, VMP) is found in both males and females, yet only males develop a prostate. We demonstrate that a layer of smooth muscle differentiates between the VMP and the urethral epithelium, and that there is a sexually dimorphic difference in the development of this layer. Serial section reconstruction showed that the layer formed at approximately embryonic day 20.5 in females, but did not form in males. In cultures of female reproductive tracts, testosterone was able to regulate the thickness of this layer resulting in a 2.4-fold reduction in thickness. We observed that prostatic buds were present in some female reproductive tracts, and determined that testosterone was able to stimulate prostatic organogenesis, depending upon the bud position relative to the smooth muscle layer. In vitro recombination experiments demonstrated that direct contact with the VMP led to the induction of very few epithelial buds, and that androgens dramatically increased bud development. Taken together, our data suggest that differentiation of a smooth muscle layer regulates signalling between mesenchyme and epithelium, and comprises part of the mechanism regulating prostatic induction.

Origin of Motion in the Human Ureter: Mechanics, Energetics and Kinetics of the Myosin Molecular Motors

2012 ◽  
Vol 79 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Romina Vargiu ◽  
Anna Perinu ◽  
Antonello De Lisa ◽  
Frank Tintrup ◽  
Francesco Manca ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Molecular Motors ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Shortening Velocity ◽  
Smooth Muscle Layer ◽  
Circular Smooth Muscle ◽  
Longitudinal Smooth Muscle ◽  
Human Ureter

Background Ureteral peristalsis is the result of coordinated mechanical motor performance of longitudinal and circular smooth muscle layer of the ureter wall. The main aim of this study was to characterize in smooth muscle of proximal segments of human ureter, the mechanical properties at level of muscle tissue and at level of myosin molecular motors. Methods Ureteral samples were collected from 15 patients, who underwent nephrectomy for renal cancer. Smooth muscle strips longitudinally and circularly oriented from proximal segments of human ureter were used for the in vitro experiments. Mechanical indices including the maximum unloaded shortening velocity (Vmax), and the maximum isometric tension (P0) normalized per cross-sectional area, were determined in vitro determined in electrically evoked contractions of longitudinal and circular smooth muscle strips. Myosin cross-bridge (CB) number per mm2 (Ψ) the elementary force per single CB (Ψ) and kinetic parameters were calculated in muscle strips, using Huxley's equations adapted to nonsarcomeric muscles. Results Longitudinal smooth muscle strips exhibited a significantly (p<0.05) faster Vmax (63%) and a higher P0 (40%), if compared to circular strips. Moreover, longitudinal muscle strips showed a significantly higher unitary force (Ψ) per CB. However, no significant differences were observed in CB number, the attachment (f1) and the detachment (g2) rate constants between longitudinal and circular muscle strips. Conclusions The main result obtained in the present work documents that the mechanical, energetic and unitary forces per CB of longitudinal layer of proximal ureter are better compared to the circular one; these preliminary findings suggested, unlike intestinal smooth muscle, a major role of longitudinal smooth muscle layer in the ureter peristalsis.

Autoradiographical localization of oxytocin binding sites on ovine oviduct and uterus throughout the oestrous cycle

1991 ◽  
Vol 3 (2) ◽  
pp. 127 ◽  
Author(s):  
JM Wallace ◽  
R Helliwell ◽  
PJ Morgan
Keyword(s):  
Smooth Muscle ◽  
Binding Sites ◽  
Specific Binding ◽  
Muscle Layer ◽  
Oestrous Cycle ◽  
Luminal Epithelium ◽  
Binding Assays ◽  
Smooth Muscle Layer ◽  
Receptor Assays

A highly specific oxytocin receptor ligand, 125I-labelled d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH9(2)] vasotocin (125I-OTA), was used to localize high affinity oxytocin receptors in ovine uterine and oviduct tissues throughout the oestrous cycle. The pattern of binding revealed by in vitro autoradiography correlated well with the results of the homogenate receptor assays using the same ligand and with previous binding assays using the tritiated ligand. At oestrus, specific 125I-OTA binding was evident on the luminal epithelium of the caruncular and intercaruncular regions, on the epithelial cells lining the secretory uterine glands and in the stroma underlying the caruncular epithelium. In the myometrium diffuse labelling was evident in the outer longitudinal smooth muscle layer. At Day 4 of the cycle, binding to the stroma was diffuse and virtually absent from the glandular epithelium. No specific binding was evident in either tissue at Day 12 of the luteal phase, but by Day 14, prior to the decrease in peripheral progesterone concentrations, binding was again apparent on the luminal epithelium only. Specific binding to the oviduct was localized to the smooth muscle layer of the isthmus region of oestrous ewes and was not detected at any other stage of the oestrous cycle. These studies extend our knowledge of the distribution of oxytocin binding sites in uterine and oviduct tissues throughout the oestrous cycle and suggest that oxytocin has an important role in stimulating oviduct and uterine motility at a time crucial to successful egg collection and/or sperm embryo transport.

Reconstruction of Engineered Uterine Tissues Containing Smooth Muscle Layer in Collagen/Matrigel Scaffold In Vitro

2009 ◽  
Vol 15 (7) ◽  
pp. 1611-1618 ◽  
Author(s):  
Shuang-Hong Lü ◽  
Hai-Bin Wang ◽  
Hui Liu ◽  
He-Ping Wang ◽  
Qiu-Xia Lin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Layer ◽  
Smooth Muscle Layer

Testosterone exposure in prenatal life disrupts epithelial nuclear morphology, smooth muscle layer pattern, and FGF10 and Shh expression in prostate

Life Sciences ◽  
2021 ◽  
Vol 271 ◽  
pp. 119198
Author(s):  
Luana Araújo Manso ◽  
Barbara Costa Malmann Medeiros ◽  
Giovanna Amaral Rodrigues ◽  
Jordana Gomes Ramos ◽  
Mara Rúbia Marques ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Layer ◽  
Nuclear Morphology ◽  
Smooth Muscle Layer

scholarly journals Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a

2016 ◽  
Vol 311 (5) ◽  
pp. G964-G973 ◽  
Author(s):  
Jagmohan Singh ◽  
Ettickan Boopathi ◽  
Sankar Addya ◽  
Benjamin Phillips ◽  
Isidore Rigoutsos ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Anal Sphincter ◽  
Internal Anal Sphincter ◽  
Smooth Muscles ◽  
Smooth Muscle Contractility ◽  
Network Analyses ◽  
Rhoa Signaling

A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets ( Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A2analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.

Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury

2014 ◽  
Vol 307 (3) ◽  
pp. H337-H345 ◽  
Author(s):  
Lara Gotha ◽  
Sang Yup Lim ◽  
Azriel B. Osherov ◽  
Rafael Wolff ◽  
Beiping Qiang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Critical Role ◽  
Arterial Injury ◽  
Side Chains ◽  
Wild Type ◽  
Injury Response ◽  
Migratory Response

Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2Δ3/Δ3 (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type ( P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB ( P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall.

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