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Dong Y, Yuan H, Ma G, Cao H. Bone-muscle crosstalk under physiological and pathological conditions. Cell Mol Life Sci 2024; 81:310. [PMID: 39066929 PMCID: PMC11335237 DOI: 10.1007/s00018-024-05331-y] [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: 02/22/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024]
Abstract
Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system.
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Affiliation(s)
- Yuechao Dong
- Department of Biochemistry, School of Medicine, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Key University Laboratory of Metabolism and Health of Guangdong, Southern University of Science and Technology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Hongyan Yuan
- Shenzhen Key Laboratory of Soft Mechanics & Smart Manufacturing, Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Guixing Ma
- Department of Biochemistry, School of Medicine, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Key University Laboratory of Metabolism and Health of Guangdong, Southern University of Science and Technology, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Huiling Cao
- Department of Biochemistry, School of Medicine, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Key University Laboratory of Metabolism and Health of Guangdong, Southern University of Science and Technology, Southern University of Science and Technology, Shenzhen, 518055, China.
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Schaub L, Lagou A, Ait-Lounis A, Kiliaridis S, Antonarakis GS. Effects of age and diet consistency on the expression of myosin heavy-chain isoforms on jaw-closing and jaw-opening muscles in a rat model. J Oral Rehabil 2024; 51:1016-1024. [PMID: 38475932 DOI: 10.1111/joor.13676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 11/23/2023] [Accepted: 02/25/2024] [Indexed: 03/14/2024]
Abstract
BACKGROUND Skeletal craniofacial morphology can be influenced by changes in masticatory muscle function, which may also change the functional profile of the muscles. OBJECTIVES To investigate the effects of age and functional demands on the expression of Myosin Heavy-Chain (MyHC) isoforms in representative jaw-closing and jaw-opening muscles, namely the masseter and digastric muscles respectively. METHODS Eighty-four male Wistar rats were divided into four age groups, namely an immature (n = 12; 4-week-old), early adult (n = 24; 16-week-old), adult (n = 24; 26-week-old) and mature adult (n = 24; 38-week-old) group. The three adult groups were divided into two subgroups each based on diet consistency; a control group fed a standard (hard) diet, and an experimental group fed a soft diet. Rats were sacrificed, and masseter and digastric muscles dissected. Real-time quantitative polymerase chain reaction was used to compare the mRNA transcripts of the MyHC isoforms-Myh7 (MyHC-I), Myh2 (MyHC-IIa), Myh4 (MyHC-IIb) and Myh1 (MyHC-IIx)-of deep masseter and digastric muscles. RESULTS In the masseter muscle, hypofunction increases Myh1 (26, 38 weeks; p < .0001) but decreases Myh4 (26 weeks; p = .046) and Myh2 (26 weeks; p < .0001) expression in adult rats. In the digastric muscle, hypofunction increases Myh1 expression in the mature adult rats (38 weeks; p < .0001), while Myh2 expression decreases in adult rats (26 weeks; p = .021) as does Myh4 (26 weeks; p = .001). Myh7 expression is increased in the digastric muscle of mature adult rats subjected to hypofunction (38 weeks; p = <.0001), while it is very weakly expressed in the masseter. CONCLUSION In jaw-opening and jaw-closing muscles, differences in myosin expression between hard- and soft-diet-fed rats become evident in adulthood, suggesting that long-term alteration of jaw function is associated with changes in the expression of MyHC isoforms and potential fibre remodelling. This may give insight into the role of function on masticatory muscles and the resultant craniofacial morphology.
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Affiliation(s)
- Leandra Schaub
- Division of orthodontics, University clinics of dental medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aikaterini Lagou
- Division of orthodontics, University clinics of dental medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aouatef Ait-Lounis
- Division of orthodontics, University clinics of dental medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Stavros Kiliaridis
- Division of orthodontics, University clinics of dental medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Orthodontics and Dentofacial Orthopedics, Dental School, Medical Faculty, University of Bern, Bern, Switzerland
| | - Gregory S Antonarakis
- Division of orthodontics, University clinics of dental medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Masita Silviana N, Andarini S, Lyrawati D, Hidayat M. Masticatory Functional Load Increases the mRNA Expression Levels of ACTN2 and ACTN3 and the Protein Expression of α-Actinin-2 in Rat Masseter Muscle. Turk J Pharm Sci 2021; 18:28-33. [PMID: 33632512 DOI: 10.4274/tjps.galenos.2019.53323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Objectives α-actinins play structural and regulatory roles in cytoskeletal organization. They form a lattice structure that secures actin in thin filaments, which generate and transmit muscle contractile forces. The morphological and biochemical characteristics of rat masseter muscles are known to change reactions to masticatory functional loads, but their effect on α-actinins remains unknown. This study aimed to determine the response of α-actinins to masticatory functional loads. Materials and Methods Twenty-four male Wistar rats aged 3 weeks were divided randomly into 3 groups of liquid diet (LD), soft diet, and hard diet (HD). The rats were then sacrificed at the end of 8 weeks. The middle part of superficial masseter muscles was examined to investigate the masticatory effect of functional load on the mRNA expression levels of ACTN2 and ACTN3 and the protein expression levels of α-actinin-2 and α-actinin-3. Results The mRNA expression levels of ACTN2 and ACTN3 and the protein expression levels of α-actinin-2 of the HD group were significantly higher than those of the LD group, which served as the control group. Conclusion Masticatory functional load organizes the mRNA expression levels of ACTN2 and ACTN3 and the protein expression levels of α-actinin-2 in rat masseter muscles through stimuli during muscle physiological adaptation.
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Affiliation(s)
- Nur Masita Silviana
- Universitas Brawijaya Faculty of Dentistry, Department of Orthodontics, Malang, Indonesia
| | - Sri Andarini
- Universitas Brawijaya Faculty of Medicine, Department of Public Health, Malang, Indonesia
| | - Diana Lyrawati
- Universitas Brawijaya Faculty of Medicine, Department of Pharmacy, Malang, Indonesia
| | - Mohammad Hidayat
- Syaiful Anwar General Hospital Faculty of Medicine, Universitas Brawijaya, Department of Orthopaedics, Malang, Indonesia
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Buvinic S, Balanta-Melo J, Kupczik K, Vásquez W, Beato C, Toro-Ibacache V. Muscle-Bone Crosstalk in the Masticatory System: From Biomechanical to Molecular Interactions. Front Endocrinol (Lausanne) 2020; 11:606947. [PMID: 33732211 PMCID: PMC7959242 DOI: 10.3389/fendo.2020.606947] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022] Open
Abstract
The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical characteristics than the trunk and limbs, their particular molecular basis and cell biology have been much less explored. In the last decade, the concept of muscle-bone crosstalk has emerged, comprising both the loads generated during muscle contraction and a biochemical component through soluble molecules. Bone cells embedded in the mineralized tissue respond to the biomechanical input by releasing molecular factors that impact the homeostasis of the attaching skeletal muscle. In the same way, muscle-derived factors act as soluble signals that modulate the remodeling process of the underlying bones. This concept of muscle-bone crosstalk at a molecular level is particularly interesting in the mandible, due to its tight anatomical relationship with one of the biggest and strongest masticatory muscles, the masseter. However, despite the close physical and physiological interaction of both tissues for proper functioning, this topic has been poorly addressed. Here we present one of the most detailed reviews of the literature to date regarding the biomechanical and biochemical interaction between muscles and bones of the masticatory system, both during development and in physiological or pathological remodeling processes. Evidence related to how masticatory function shapes the craniofacial bones is discussed, and a proposal presented that the masticatory muscles and craniofacial bones serve as secretory tissues. We furthermore discuss our current findings of myokines-release from masseter muscle in physiological conditions, during functional adaptation or pathology, and their putative role as bone-modulators in the craniofacial system. Finally, we address the physiological implications of the crosstalk between muscles and bones in the masticatory system, analyzing pathologies or clinical procedures in which the alteration of one of them affects the homeostasis of the other. Unveiling the mechanisms of muscle-bone crosstalk in the masticatory system opens broad possibilities for understanding and treating temporomandibular disorders, which severely impair the quality of life, with a high cost for diagnosis and management.
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Affiliation(s)
- Sonja Buvinic
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Center for Exercise, Metabolism and Cancer Studies CEMC2016, Faculty of Medicine, Universidad de Chile, Santiago, Chile
- *Correspondence: Sonja Buvinic,
| | - Julián Balanta-Melo
- School of Dentistry, Faculty of Health, Universidad del Valle, Cali, Colombia
- Evidence-Based Practice Unit Univalle, Hospital Universitario del Valle, Cali, Colombia
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Kornelius Kupczik
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Walter Vásquez
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Carolina Beato
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Viviana Toro-Ibacache
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Seiryu M, Daimaruya T, Iikubo M, Watanabe K, Takano-Yamamoto T. Decreases of occlusal vertical dimension induce changes in masticatory muscle fiber composition. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.odw.2012.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Masahiro Seiryu
- Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Takayoshi Daimaruya
- Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Masahiro Iikubo
- Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Kouichi Watanabe
- Department of Animal Production Science, Graduate School of Agricultural Science, Faculty of Agriculture, Tohoku University, Sendai, Japan
| | - Teruko Takano-Yamamoto
- Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan
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Glass TJ, Twadell SL, Valmadrid LC, Connor NP. Early impacts of modified food consistency on oromotor outcomes in mouse models of Down syndrome. Physiol Behav 2018; 199:273-281. [PMID: 30496741 DOI: 10.1016/j.physbeh.2018.11.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/16/2018] [Accepted: 11/25/2018] [Indexed: 12/12/2022]
Abstract
Down syndrome (DS) in humans is associated with differences of the central nervous system and oromotor development. DS also increases risks for pediatric feeding challenges, which sometimes involve the use of altered food consistencies. Therefore, experimental food consistency paradigms are of interest to oromotor investigations in mouse models of Down syndrome (DS). The present work reports impacts of an altered food consistency paradigm on the Ts65Dn and Dp(16)1Yey mouse models of DS, and sibling control mice. At weaning, Ts65Dn, Dp(16)1Yey and respective controls were assigned to receive either a hard food or a soft food (eight experimental groups, n = 8-10 per group). Two weeks later, mice were assessed for mastication speeds and then euthanized for muscle analysis. Soft food conditions were associated with significantly smaller weight gain (p = .003), significantly less volitional water intake through licking (p = .0001), and significant reductions in size of anterior digastric myofibers positive for myosin heavy chain isoform (MyHC) 2b (p = .049). Genotype was associated with significant differences in weight gain (p = .004), significant differences in mastication rate (p = .001), significant differences in a measure of anterior digastric muscle size (p = .03), and significant reductions in size of anterior digastric myofibers positive for MyHC 2a (p = .04). In multiple measures, the Ts65Dn model of DS was more affected than other genotype groups. Findings indicate a soft food consistency condition in mice is associated with significant reductions in weight gain and oromotor activity, and may impact digastric muscle. This suggests extended periods of food consistency modifications may have impacts that extend beyond their immediate roles in facilitating deglutition.
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Affiliation(s)
- Tiffany J Glass
- Department of Surgery, University of Wisconsin, Madison, WI, USA.
| | - Sara L Twadell
- Department of Surgery, University of Wisconsin, Madison, WI, USA
| | - Luke C Valmadrid
- Department of Surgery, University of Wisconsin, Madison, WI, USA
| | - Nadine P Connor
- Department of Surgery, University of Wisconsin, Madison, WI, USA; Department of Communication Sciences and Disorders, University of Wisconsin, Madison, WI, USA
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Kuijpers MAR, Grefte S, Bronkhorst EM, Carels CEL, Kiliaridis S, Von den Hoff JW. Reduced masticatory function is related to lower satellite cell numbers in masseter muscle. Eur J Orthod 2012; 36:262-7. [DOI: 10.1093/ejo/cjs044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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8
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Nariyama M, Kota Y, Kaneko S, Asada Y, Yamane A. Association between the lack of teeth and the expression of myosins in masticatory muscles of microphthalmic mouse. Cell Biochem Funct 2011; 30:82-8. [PMID: 22034127 DOI: 10.1002/cbf.1821] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/22/2011] [Accepted: 09/27/2011] [Indexed: 11/11/2022]
Abstract
The purposes of the present study were to elucidate the influences of the deficiency of teeth on masticatory muscles, such as the masseter, temporalis and digastric muscles and compare the influence among masticatory muscles. We analysed the expressions of myosin heavy chain (MyHC) isoform messenger RNA (mRNA) and protein in these muscles in the microphthalmic (mi/mi) mouse, whose teeth cannot erupt because of a mutation in the mitf gene locus. The expression levels of MyHC mRNA and protein in the masseter, temporalis, digastric, tibialis anterior and gastrocnemius muscles of +/+ and mi/mi mice were analysed with real-time polymerase chain reaction and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. The mi/mi masseter muscle at 8 weeks of age expressed 4.1-fold (p < 0.05) and 3.3-fold (p < 0.01) more MyHC neonatal mRNA and protein than that in the +/+, respectively; the expression level of MyHC neonatal protein was 19% of the total MyHC protein in the masseter muscle of mi/mi mice. In the digastric muscle, the expression levels of MyHC I mRNA and protein in the mi/mi mice were 4.7-fold (p < 0.05) and 5-fold (p < 0.01) higher than those in the +/+ mice. In the temporalis, tibialis anterior and gastrocnemius muscles, there was no significant difference in the expression levels of any MyHC isoform mRNA and protein between +/+ and mi/mi mice. These results indicate associations between the lack of teeth and the expression of MyHC in the masseter and digastric muscles but not such associations in the temporalis muscle, suggesting that the influence of tooth deficiency varies among the masticatory muscles.
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Affiliation(s)
- Megumi Nariyama
- Department of Pediatric Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Japan
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Xu XF, Guo CY, Liu J, Yang WJ, Xia YJ, Xu L, Yu YC, Wang XP. Gli1 maintains cell survival by up-regulating IGFBP6 and Bcl-2 through promoter regions in parallel manner in pancreatic cancer cells. J Carcinog 2011; 8:13. [PMID: 19736394 PMCID: PMC2746911 DOI: 10.4103/1477-3163.55429] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background: Aberrant activation of Hedgehog (Hh) signaling pathway has been reported to be related to malignant biological behavior of pancreatic cancer but its mechanism is unclear yet. Since IGF pathway and Bcl-2 family are involved in proliferation and apoptosis of pancreatic cancer cells, we hypothesize that they are possibly associated with Hh pathway. Materials and Methods: We studied the relationship of Shh-Gli1 signaling pathway with proliferation and apoptosis of pancreatic cancer cells and the regulation of transcription factor Gli1 to insulin-like growth factor binding protein 6 (IGFBP6) and Bcl-2 genes at the level of transcription. Results: Sonic hedgehog (Shh), Smoothened (Smo), patched and Gli1 were expressed in pancreatic cancer cells. Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration. Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis. The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01). Finally PCNA, IGFBP6 and Bcl-2 mRNA were upregulated as well as Shh or Gli1 in pancreatic cancer tissues (p < 0.01). Conclusions: Our study reveals that Gli1 maintained cell survival by binding the promoter regions and facilitating transcription of IGFBP6 and Bcl-2 genes in a parallel manner in pancreatic cancer cells and suggests it may be one of the mechanisms of Shh-Gli1 signaling pathway in pancreatic cancer.
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Affiliation(s)
- Xuan-Fu Xu
- Department of Gastroenterology, The Tenth Hospital, Tongji University, Shanghai, China.
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10
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Katayama R, Yamane A, Fukui T. Changes in the expression of myosins during postnatal development of masseter muscle in the microphthalmic mouse. Open Dent J 2010; 4:1-7. [PMID: 20224737 PMCID: PMC2835863 DOI: 10.2174/1874210601004010001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 10/19/2009] [Accepted: 11/06/2009] [Indexed: 12/01/2022] Open
Abstract
In the present study, to elucidate the influences of the deficiency of teeth on the masseter muscle, we analyzed changes in the expression of MyHC isoform mRNAs during postnatal development in mi/mi mice using real-time PCR. By 8 weeks of age, MyHC I had nearly disappeared in the +/+ mice, while it was still present in the mi/mi, and the level of MyHC I mRNA in the mi/mi was 5.1-fold higher than that in the +/+ (p<0.01). The levels of MyHC IIx mRNAs in the mi/mi mice were 41 ~ 55% lower than those in the +/+ at both 3 weeks and 4 weeks of age (p<0.05). No significant difference in the expression of MyHC IIa and IIb mRNAs in the masseter muscle was found between the mi/mi and +/+. From these results, we speculate that the deficiency of teeth affects the masseter muscles during the postnatal development.
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Affiliation(s)
- R Katayama
- Orthodontic Science, Graduate School of Tokyo Medical and Dental University, Tokyo, Japan
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Taylor AB, Jones KE, Kunwar R, Ravosa MJ. Dietary consistency and plasticity of masseter fiber architecture in postweaning rabbits. ACTA ACUST UNITED AC 2006; 288:1105-11. [PMID: 16952171 DOI: 10.1002/ar.a.20382] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dietary consistency has been shown to influence cross-sectional area and fiber type composition of the masticatory muscles. However, little is known about the effects of dietary consistency on masticatory muscle fiber architecture. In this study, we explore the effects of dietary consistency on the internal architecture of rabbit masseter muscle. Because activity patterns of the rabbit chewing muscles show inter- and intramuscular heterogeneity, we evaluate if alterations in fiber architecture are homogeneous across various portions of the superficial masseter muscle. We compared masseter muscle fiber architecture between two groups of weanling rabbits raised on different diets for 105 days. One group was raised on a diet of ground rabbit pellets to model underuse of the masticatory complex, while the other group was fed a diet of intact pellets and hay blocks to model an overuse diet. In all portions of the superficial masseter, physiological cross-sectional areas (PCSAs) are greater in the overuse compared to underuse diet rabbits. Thus, the mechanical demands for larger muscle and bite forces associated with early and prolonged exposure to a tough diet are met by an increase in PCSA of the superficial masseter. The larger PCSA is due entirely to increased muscle mass, as the two rabbit groups show no differences in either fiber length or angle of pinnation. Thus, increasing pinnation angle is not a necessary biomechanical solution to improving muscle and bite force during growth. The change in PCSA but not fiber length suggests that variation in dietary consistency has an impact on maximum force production but not necessarily on excursion or contraction velocity.
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Affiliation(s)
- Andrea B Taylor
- Doctor of Physical Therapy Division, Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
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Yamane A. Embryonic and postnatal development of masticatory and tongue muscles. Cell Tissue Res 2005; 322:183-9. [PMID: 16041600 DOI: 10.1007/s00441-005-0019-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 05/17/2005] [Indexed: 11/26/2022]
Abstract
This review summarizes findings concerning the unique developmental characteristics of mouse head muscles (mainly the masticatory and tongue muscles) and compares their characteristics with those of other muscles. The developmental origin of the masticatory muscles is the somitomeres, whereas the tongue and other muscles, such as the trunk (deep muscles of the back, body wall muscles) and limb muscles, originate from the somites. The program controlling the early stages of masticatory myogenesis, such as the specification and migration of muscle progenitor cells, is distinctly different from those in trunk and limb myogenesis. Tongue myogenesis follows a similar regulatory program to that for limb myogenesis. Myogenesis and synaptogenesis in the masticatory muscles are delayed in comparison with other muscles and are not complete even at birth, whereas the development of tongue muscles proceeds faster than those of other muscles and ends at around birth. The regulatory programs for masticatory and tongue myogenesis seem to depend on the developmental origins of the muscles, i.e., the origin being either a somite or somitomere, whereas myogenesis and synaptogenesis seem to progress to serve the functional requirements of the masticatory and tongue muscles.
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Affiliation(s)
- A Yamane
- Department of Pharmacology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
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