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Li R, Zhang R, Shi X, Jiao X, Li Y, Zhao Y, Liu T, Zhang C. Expression of FAP in Oral Leukoplakia and Oral Squamous Cell Carcinoma. Int Dent J 2024; 74:581-588. [PMID: 38278714 PMCID: PMC11123527 DOI: 10.1016/j.identj.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/20/2023] [Accepted: 12/29/2023] [Indexed: 01/28/2024] Open
Abstract
OBJECTIVE This study aimed to investigate the potential of fibroblast activation protein (FAP) as a biomarker in the progression of oral leukoplakia (OLK) carcinogenesis. This was achieved by evaluating FAP expression at different levels of the organisation, namely oral normal mucosa (NM), OLK, and oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS Altogether, 88 paraffin-embedded tissue samples were examined, including 55 cases of OLK, 13 cases of OSCC, and 20 cases of NM (control group). An exhaustive investigation was performed to examine FAP expression in NM, OLK, and OSCC tissues via immunohistochemistry (IHC). The relationship between FAP expression and clinical pathologic characteristics was analysed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB) also proved the expression of FAP in NM, OLK, and OSCC cells. Aberrant FAP expression in OLK and OSCC was explored using in vitro experiments. RESULTS Immunohistochemical results showed that high FAP expression was significantly correlated with histopathologic grade (P = .038) but not correlated with age, sex, or region (P = .953, .622, and .108, respectively). The expression level of FAP in NM tissues (0.15 ± 0.01) was minimal, whereas it was observed in OLK (0.28 ± 0.04) and OSCC (0.39 ± 0.02) tissues with a noticeable increase in expression levels (P < .001). The expression level of FAP in OLK with severe abnormal hyperplasia (S-OLK) tissues (0.33 ± 0.04) was significantly higher than in OLK with mild abnormal hyperplasia (MI-OLK, 0.26 ± 0.02) and OLK with moderate abnormal hyperplasia (MO-OLK, 0.28 ± 0.03) tissues (P < .001 and P = .039, respectively). The results of RT-PCR illustrated that the relative expression of FAP mRNA in OLK cells (2.63 ± 0.62) was higher than in NM cells (0.87 ± 0.14), but lower than in OSCC cells (5.63 ± 1.06; P = .027 and .012, respectively). FAP expression was minimal in NM cells (0.78 ± 0.06), modest in OLK cells (1.04 ± 0.06), and significantly elevated in OSCC cells (1.61 ± 0.09) based on the results of WB (P < .001). CONCLUSIONS Significant variations in FAP expression were observed in NM, OLK, and OSCC tissues and cells. These findings revealed that FAP may be a reliable biomarker for the early diagnosis and evaluation of OLK carcinogenesis.
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Affiliation(s)
- Ran Li
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China.
| | - Rongrong Zhang
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Xiaotong Shi
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Xiaofeng Jiao
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Yanwei Li
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Yingjiao Zhao
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Tiantian Liu
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China; Department of Pediatric and Preventive Dentistry, Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, China
| | - Chunye Zhang
- Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology.
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Egloff S, Reichler IM, Kowalewski MP, Keller S, Goericke-Pesch S, Balogh O. Uterine expression of smooth muscle alpha- and gamma-actin and smooth muscle myosin in bitches diagnosed with uterine inertia and obstructive dystocia. Theriogenology 2020; 156:162-170. [PMID: 32750597 DOI: 10.1016/j.theriogenology.2020.06.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/15/2020] [Accepted: 06/27/2020] [Indexed: 02/03/2023]
Abstract
Primary uterine inertia (PUI) is the most common type of dystocia in dogs. We hypothesized that PUI develops because of lower than normal expression of the basic contractile elements in the uterus, i.e., smooth muscle (SM) α- and γ-actin and SM-myosin, and that the expression of these proteins is influenced by the number of fetuses present in utero. Full-thickness inter-placental uterine biopsies were collected during Cesarean sections from dogs with PUI (n = 11), and from bitches with obstructive dystocia (OD) still presenting strong labor contractions (designated as the control group, n = 7). Relative gene expression was determined by semi-quantitative real-time (TaqMan) PCR, and protein localization by immunohistochemistry. Gene expression between PUI and OD bitches, and between PUI bitches carrying small, large, or average number of fetuses according to their breed, were compared. Uterine SM-γ-actin and SM-myosin mRNA levels were significantly higher in PUI than in OD dogs, while SM-α-actin did not differ. PUI bitches carrying large litters had lower uterine SM-γ-actin gene expression than those with small litters (P = 0.008). Immunostaining for SM-actin isoforms and SM-myosin was present in the myometrium, and localization pattern and staining intensity appeared similar in the PUI and OD groups. All proteins stained in blood vessels, and SM-γ-actin was also present in endometrial luminal and glandular epithelium. In conclusion, higher uterine SM-γ-actin and SM-myosin gene expression in PUI bitches, compared with OD dogs, might be an indication of abnormal progression with labor. Whether this is the cause of PUI due to an intrinsic error of the myometrium not becoming committed to labor, or the consequence of inadequate endocrine or mechanical stimuli, is not clear. Litter size was previously shown to be one of the risk factors for the development of uterine inertia in dogs, and our findings suggest possible differing uterine pathophysiology of PUI with respect to litter size.
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Affiliation(s)
- S Egloff
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland
| | - I M Reichler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland
| | - M P Kowalewski
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland
| | - S Keller
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland
| | - S Goericke-Pesch
- Section for Veterinary Reproduction and Obstetrics, Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark; Reproductive Unit of the Clinic - Clinic for Small Animals, University of Veterinary Medicine Hannover, Bünteweg 15, 30559, Hannover, Germany
| | - O Balogh
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland; Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, 215 Duck Pond Dr, Blacksburg, VA, 24061, USA.
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3
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Milewicz DM, Trybus KM, Guo DC, Sweeney HL, Regalado E, Kamm K, Stull JT. Altered Smooth Muscle Cell Force Generation as a Driver of Thoracic Aortic Aneurysms and Dissections. Arterioscler Thromb Vasc Biol 2017; 37:26-34. [PMID: 27879251 PMCID: PMC5222685 DOI: 10.1161/atvbaha.116.303229] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/02/2016] [Indexed: 12/30/2022]
Abstract
The importance of maintaining contractile function in aortic smooth muscle cells (SMCs) is evident by the fact that heterozygous mutations in the major structural proteins or kinases controlling contraction lead to the formation of aneurysms of the ascending thoracic aorta that predispose to life-threatening aortic dissections. Force generation by SMC requires ATP-dependent cyclic interactions between filaments composed of SMC-specific isoforms of α-actin (encoded by ACTA2) and myosin heavy chain (MYH11). ACTA2 and MYH11 mutations are predicted or have been shown to disrupt this cyclic interaction predispose to thoracic aortic disease. Movement of the myosin motor domain is controlled by phosphorylation of the regulatory light chain on the myosin filament, and loss-of-function mutations in the dedicated kinase for this phosphorylation, myosin light chain kinase (MYLK) also predispose to thoracic aortic disease. Finally, a mutation in the cGMP-activated protein kinase (PRKG1) results in constitutive activation of the kinase in the absence of cGMP, thus driving SMC relaxation in part through increased dephosphorylation of the regulatory light chain and predisposes to thoracic aortic disease. Furthermore, SMCs cannot generate force without connections to the extracellular matrix through focal adhesions, and mutations in the major protein in the extracellular matrix, fibrillin-1, linking SMCs to the matrix also cause thoracic aortic disease in individuals with Marfan syndrome. Thus, disruption of the ability of the aortic SMC to generate force through the elastin-contractile units in response to pulsatile blood flow may be a primary driver for thoracic aortic aneurysms and dissections.
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MESH Headings
- Actins/genetics
- Actins/metabolism
- Aortic Dissection/genetics
- Aortic Dissection/metabolism
- Aortic Dissection/pathology
- Aortic Dissection/physiopathology
- Animals
- Aortic Aneurysm, Thoracic/genetics
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Aneurysm, Thoracic/pathology
- Aortic Aneurysm, Thoracic/physiopathology
- Calcium-Binding Proteins/genetics
- Calcium-Binding Proteins/metabolism
- Cyclic GMP-Dependent Protein Kinase Type I/genetics
- Cyclic GMP-Dependent Protein Kinase Type I/metabolism
- Dilatation, Pathologic
- Elastin/metabolism
- Genetic Markers
- Genetic Testing
- Heredity
- Humans
- Mechanotransduction, Cellular
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Mutation
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Myosin Heavy Chains/genetics
- Myosin Heavy Chains/metabolism
- Myosin-Light-Chain Kinase/genetics
- Myosin-Light-Chain Kinase/metabolism
- Phenotype
- Pulsatile Flow
- Vasoconstriction/genetics
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Affiliation(s)
- Dianna M Milewicz
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.).
| | - Kathleen M Trybus
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
| | - Dong-Chuan Guo
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
| | - H Lee Sweeney
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
| | - Ellen Regalado
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
| | - Kristine Kamm
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
| | - James T Stull
- From the Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (D.M.M., D.-c.G., E.R.); Department of Molecular Physiology and Biophysics, University of Vermont, Burlington (K.M.T.); Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville (H.L.S.); and Department of Physiology, University of Texas Southwestern Medical Center, Dallas (K.K. J.T.S.)
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4
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Affiliation(s)
- Chun Y Seow
- University of British Columbia, Pathology and Laboratory Medicine, James Hogg Research Centre/St Paul's Hospital, 1081 Burrard Street, Rm 166, Vancouver, BC, Canada, V0N 2E0.
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Mercer RCC, Mudalige WAKA, Ige TO, Heeley DH. Vertebrate slow skeletal muscle actin - conservation, distribution and conformational flexibility. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1253-60. [PMID: 21722757 DOI: 10.1016/j.bbapap.2011.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Revised: 06/02/2011] [Accepted: 06/16/2011] [Indexed: 11/16/2022]
Abstract
The existence of a unique sarcomeric actin is demonstrated in teleosts that possess substantial amounts of slow skeletal muscle in the trunk. The slow skeletal isotype is conserved. There is one amino acid substitution between Atlantic herring slow skeletal actin and the equivalent in salmonids. Conversely, the intra-species variation is considerable; 13 substitutions between different herring skeletal isotypes (slow versus fast). The isomorphisms (non-conservative underlined: residues, 2, 3, 103, 155, 160, 165, 278, 281, 310, 329, 358, 360 and 363) are restricted to sub-domains 1 and 3 and include the substitution Asp-360 in 'slow' to Gln in 'fast' which results in an electrophoretic shift at alkaline pH. The musculature of the trunk facilitates the preparation of isoactins for biochemical study. Herring slow skeletal G-actin (Ca.ATP) is more susceptible to thermal, and urea, -induced denaturation and subtilisin cleavage than that in fast skeletal, but more stable than the counterpart in salmonids (one substitution, Gln354Ala) highlighting the critical nature of actin's carboxyl-terminal insert. Fluorescent spectra of G-actin isoforms containing the isomorphism Ser155Ala in complexation with 2'-deoxy 3' O-(N'-Methylanthraniloyl) ATP infer similar polarity of the nucleotide binding cleft. An electrophoretic survey detected two skeletal actins in some (smelt and mackerel) but not all teleosts. One skeletal muscle actin was detected in frog and bird.
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Affiliation(s)
- Robert C C Mercer
- Department of Biochemistry, Memorial University of Newfoundland, Newfoundland, Canada.
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6
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Abstract
The control of force production in vascular smooth muscle is critical to the normal regulation of blood flow and pressure, and altered regulation is common to diseases such as hypertension, heart failure, and ischemia. A great deal has been learned about imbalances in vasoconstrictor and vasodilator signals, e.g., angiotensin, endothelin, norepinephrine, and nitric oxide, that regulate vascular tone in normal and disease contexts. In contrast there has been limited study of how the phenotypic state of the vascular smooth muscle cell may influence the contractile response to these signaling pathways dependent upon the developmental, tissue-specific (vascular bed) or disease context. Smooth, skeletal, and cardiac muscle lineages are traditionally classified into fast or slow sublineages based on rates of contraction and relaxation, recognizing that this simple dichotomy vastly underrepresents muscle phenotypic diversity. A great deal has been learned about developmental specification of the striated muscle sublineages and their phenotypic interconversions in the mature animal under the control of mechanical load, neural input, and hormones. In contrast there has been relatively limited study of smooth muscle contractile phenotypic diversity. This is surprising given the number of diseases in which smooth muscle contractile dysfunction plays a key role. This review focuses on smooth muscle contractile phenotypic diversity in the vascular system, how it is generated, and how it may determine vascular function in developmental and disease contexts.
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Affiliation(s)
- Steven A Fisher
- Department of Medicine, and Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio 44106-7290, USA.
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Kim HR, Appel S, Vetterkind S, Gangopadhyay SS, Morgan KG. Smooth muscle signalling pathways in health and disease. J Cell Mol Med 2008; 12:2165-80. [PMID: 19120701 PMCID: PMC2692531 DOI: 10.1111/j.1582-4934.2008.00552.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 10/08/2008] [Indexed: 12/24/2022] Open
Abstract
Smooth muscle contractile activity is a major regulator of function of the vascular system, respiratory system, gastrointestinal system and the genitourinary systems. Malfunction of contractility in these systems leads to a host of clinical disorders, and yet, we still have major gaps in our understanding of the molecular mechanisms by which contractility of the differentiated smooth muscle cell is regulated. This review will summarize recent advances in the molecular understanding of the regulation of smooth muscle myosin activity via phosphorylation/dephosphorylation of myosin, the regulation of the accessibility of actin to myosin via the actin-binding proteins calponin and caldesmon, and the remodelling of the actin cytoskeleton. Understanding of the molecular 'players' should identify target molecules that could point the way to novel drug discovery programs for the treatment of smooth muscle disorders such as cardiovascular disease, asthma, functional bowel disease and pre-term labour.
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Affiliation(s)
- H R Kim
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | - S Appel
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | - S Vetterkind
- Department of Health Sciences, Boston UniversityBoston, MA, USA
| | | | - K G Morgan
- Department of Health Sciences, Boston UniversityBoston, MA, USA
- Boston Biomedical Research InstituteWatertown, MA, USA
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Herrera AM, McParland BE, Bienkowska A, Tait R, Paré PD, Seow CY. 'Sarcomeres' of smooth muscle: functional characteristics and ultrastructural evidence. J Cell Sci 2005; 118:2381-92. [PMID: 15923651 DOI: 10.1242/jcs.02368] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Smooth muscle cells line the walls of hollow organs and control the organ dimension and mechanical function by generating force and changing length. Although significant progress has been made in our understanding of the molecular mechanism of actomyosin interaction that produces sliding of actin (thin) and myosin (thick) filaments in smooth muscle, the sarcomeric structure akin to that in striated muscle, which allows the sliding of contractile filaments to be translated into cell shortening has yet to be elucidated. Here we show evidence from porcine airway smooth muscle that supports a model of malleable sarcomeric structure composed of contractile units assembled in series and in parallel. The geometric organization of the basic building blocks (contractile units) within the assembly and the dimension of individual contractile units can be altered when the muscle cells adapt to different lengths. These structural alterations can account for the different length-force relationships of the muscle obtained at different adapted cell lengths. The structural malleability necessary for length adaptation precludes formation of a permanent filament lattice and explains the lack of aligned filament arrays in registers, which also explains why smooth muscle is 'smooth'.
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Affiliation(s)
- Ana M Herrera
- Department of Pathology and Laboratory Medicine, St Paul's Hospital/Providence Health Care, University of British Columbia, 1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada
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9
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Andersson KE, Arner A. Urinary bladder contraction and relaxation: physiology and pathophysiology. Physiol Rev 2004; 84:935-86. [PMID: 15269341 DOI: 10.1152/physrev.00038.2003] [Citation(s) in RCA: 607] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The detrusor smooth muscle is the main muscle component of the urinary bladder wall. Its ability to contract over a large length interval and to relax determines the bladder function during filling and micturition. These processes are regulated by several external nervous and hormonal control systems, and the detrusor contains multiple receptors and signaling pathways. Functional changes of the detrusor can be found in several clinically important conditions, e.g., lower urinary tract symptoms (LUTS) and bladder outlet obstruction. The aim of this review is to summarize and synthesize basic information and recent advances in the understanding of the properties of the detrusor smooth muscle, its contractile system, cellular signaling, membrane properties, and cellular receptors. Alterations in these systems in pathological conditions of the bladder wall are described, and some areas for future research are suggested.
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Affiliation(s)
- Karl-Erik Andersson
- Dept. of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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10
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Abstract
Nonmuscle myosin can generate force and shortening in smooth muscle, as revealed by studies of the urinary bladder from mice lacking smooth muscle myosin heavy chain (SM-MHC) but expressing the nonmuscle myosin heavy chains A and B (NM-MHC A and B; Morano, I., G.X. Chai, L.G. Baltas, V. Lamounier-Zepter, G. Lutsch, M. Kott, H. Haase, and M. Bader. 2000. Nat. Cell Biol. 2:371-375). Intracellular calcium was measured in urinary bladders from SM-MHC-deficient and SM-MHC-expressing mice in relaxed and contracted states. Similar intracellular [Ca2+] transients were observed in the two types of preparations, although the contraction of SM-MHC-deficient bladders was slow and lacked an initial peak in force. The difference in contraction kinetics thus do not reflect differences in calcium handling. Thick filaments were identified with electron microscopy in smooth muscle cells of SM-MHC-deficient bladders, showing that NM-MHC can form filaments in smooth muscle cells. Maximal shortening velocity of maximally activated, skinned smooth muscle preparations from SM-MHC-deficient mice was significantly lower and more sensitive to increased MgADP compared with velocity of SM-MHC-expressing preparations. Active force was significantly lower and less inhibited by increased inorganic phosphate. In conclusion, large differences in nucleotide and phosphate binding exist between smooth and nonmuscle myosins. High ADP binding and low phosphate dependence of nonmuscle myosin would influence both velocity of actin translocation and force generation to promote slow motility and economical force maintenance of the cell.
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Affiliation(s)
- Mia Löfgren
- Department of Physiological Sciences, Medical Faculty, Lund University, SE-221 84 Lund, Sweden
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Stürzenbaum SR, Kille P. Control genes in quantitative molecular biological techniques: the variability of invariance. Comp Biochem Physiol B Biochem Mol Biol 2001; 130:281-9. [PMID: 11567890 DOI: 10.1016/s1096-4959(01)00440-7] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The measurement of transcript levels constitutes the foundation of today's molecular genetics. Independent of the techniques used, quantifications are generally normalised using invariant control genes to account for sample handling, loading and experimental variation. All of the widely used control genes are evaluated, dissecting different methodological approaches and issues regarding the experimental context (e.g. development and tissue type). Furthermore, the major sources of error are highlighted when applying these techniques. Finally, different approaches undertaken to assess the invariance of control genes are critically analysed to generate a procedure that will help to discern the best control for novel experiments.
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Affiliation(s)
- S R Stürzenbaum
- Cardiff University, School of Biosciences (BIOSI 2), P.O. Box 911, Wales, Cardiff, UK.
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Song J, Rolfe BE, Hayward IP, Campbell GR, Campbell JH. Reorganization of structural proteins in vascular smooth muscle cells grown in collagen gel and basement membrane matrices (Matrigel): a comparison with their in situ counterparts. J Struct Biol 2001; 133:43-54. [PMID: 11356063 DOI: 10.1006/jsbi.2001.4327] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When smooth muscle cells are enzyme-dispersed from tissues they lose their original filament architecture and extracellular matrix surrounds. They then reorganize their structural proteins to accommodate a 2-D growth environment when seeded onto culture dishes. The aim of the present study was to determine the expression and reorganization of the structural proteins in rabbit aortic smooth muscle cells seeded into 3-D collagen gel and Matrigel (a basement membrane matrix). It was shown that smooth muscle cells seeded in both gels gradually reorganize their structural proteins into an architecture similar to that of their in vivo counterparts. At the same time, a gradual decrease in levels of smooth muscle-specific contractile proteins (mainly smooth muscle myosin heavy chain-2) and an increase in beta-nonmuscle actin occur, independent of both cell growth and extracellular matrix components. Thus, smooth muscle cells in 3-D extracellular matrix culture and in vivo have a similar filament architecture in which the contractile proteins such as actin, myosin, and alpha-actinin are organized into longitudinally arranged "myofibrils" and the vimentin-containing intermediate filaments form a meshed cytoskeletal network. However, the myofibrils reorganized in vitro contain less smooth muscle-specific and more nonmuscle contractile proteins.
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Affiliation(s)
- J Song
- Centre for Research in Vascular Biology, University of Queensland, Brisbane, Queensland 4072, Australia
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Song J, Worth NF, Rolfe BE, Campbell GR, Campbell JH. Heterogeneous distribution of isoactins in cultured vascular smooth muscle cells does not reflect segregation of contractile and cytoskeletal domains. J Histochem Cytochem 2000; 48:1441-52. [PMID: 11036087 DOI: 10.1177/002215540004801101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have previously demonstrated that alpha-smooth muscle (alpha-SM) actin is predominantly distributed in the central region and beta-non-muscle (beta-NM) actin in the periphery of cultured rabbit aortic smooth muscle cells (SMCs). To determine whether this reflects a special form of segregation of contractile and cytoskeletal components in SMCs, this study systematically investigated the distribution relationship of structural proteins using high-resolution confocal laser scanning fluorescent microscopy. Not only isoactins but also smooth muscle myosin heavy chain, alpha-actinin, vinculin, and vimentin were heterogeneously distributed in the cultured SMCs. The predominant distribution of beta-NM actin in the cell periphery was associated with densely distributed vinculin plaques and disrupted or striated myosin and alpha-actinin aggregates, which may reflect a process of stress fiber assembly during cell spreading and focal adhesion formation. The high-level labeling of alpha-SM actin in the central portion of stress fibers was related to continuous myosin and punctate alpha-actinin distribution, which may represent the maturation of the fibrillar structures. The findings also suggest that the stress fibers, in which actin and myosin filaments organize into sarcomere-like units with alpha-actinin-rich dense bodies analogous to Z-lines, are the contractile structures of cultured SMCs that link to the network of vimentin-containing intermediate filaments through the dense bodies and dense plaques.
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Affiliation(s)
- J Song
- Centre for Research in Vascular Biology, Department of Anatomical Sciences, University of Queensland, Brisbane, Australia
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14
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Gunst SJ. Applicability of the sliding filament/crossbridge paradigm to smooth muscle. Rev Physiol Biochem Pharmacol 1999; 134:7-61. [PMID: 10087907 DOI: 10.1007/3-540-64753-8_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- S J Gunst
- Indiana University School of Medicine, USA
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15
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Arner A, Pfitzer G. Regulation of cross-bridge cycling by Ca2+ in smooth muscle. Rev Physiol Biochem Pharmacol 1999; 134:63-146. [PMID: 10087908 DOI: 10.1007/3-540-64753-8_3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Arner
- Department of Physiology and Neuroscience, Lund University, Sweden
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16
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Arner A, Malmqvist U. Cross-bridge cycling in smooth muscle: a short review. ACTA PHYSIOLOGICA SCANDINAVICA 1998; 164:363-72. [PMID: 9887960 DOI: 10.1111/j.1365-201x.1998.tb10694.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This review is focused on the cross-bridge interaction of the organized contractile system of smooth muscle fibres. By using chemically skinned preparations the different enzymatic reactions of actin-myosin interaction have been associated with mechanical events. A rigor state has been identified in smooth muscle and the binding of ATP causes dissociation of rigor cross-bridges at rates slightly slower than those in skeletal muscle, but fast enough not to be rate-limiting for cross-bridge turn over in the muscle fibre. The release of inorganic phosphate (Pi) is associated with force generation, and this process is not rate-limiting for maximal shortening velocity (Vmax) in the fully activated muscle. The binding of ADP to myosin is strong in the smooth muscle contractile system, a property that might be associated with the generally slow cross-bridge turn over. Both force and Vmax are modulated by the extent of myosin light chain phosphorylation. Low levels of activation are considered to be associated with the recruitment of slowly cycling dephosphorylated cross-bridges which reduces shortening velocity. The attachment of these cross-bridge states in skinned smooth muscles can be regulated by cooperative mechanisms and thin filament associated systems. Smooth muscles exhibit a large diversity in their Vmax and the individual smooth muscle tissue can alter its Vmax under physiological conditions. The diversity and the long-term modulation of phenotype are associated with changes in myosin heavy and light chain isoform expression.
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Affiliation(s)
- A Arner
- Department of Physiology and Neuroscience, Lund University, Sweden
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