Tenascin, also known as hexabrachion and cytotactin, is an extracellular matrix protein with a spatially and temporally
restricted tissue distribution. It is a hexomeric, multidomain protein with disulfide-linked subunits of 190 to 240 kD,
originally characterized as 'myotendinous antigen.' In the embryo it is present in dense mesenchyme surrounding
developing epithelia, in tendon anlagen, and in developing cartilage and bone. In the adult tenascin remains present in
tendons and myotendinous junctions in the perichondrium and periosteum, as well as in smooth muscle. Tenascin is an extracellular matrix glycoprotein, which has been reported to be
involved in parenchymal-mesenchymal interactions during morphogenesis, wound
healing, and carcinogenesis.
NCBI Summary:
This gene encodes an extracellular matrix protein with a spatially and temporally restricted tissue distribution. This protein is homohexameric with disulfide-linked subunits, and contains multiple EGF-like and fibronectin type-III domains. It is implicated in guidance of migrating neurons as well as axons during development, synaptic plasticity, and neuronal regeneration. [provided by RefSeq, Jul 2011]
General function
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Cellular localization
Extracellular Matrix, Secreted
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Ovarian function
Ovulation, Luteolysis, Germ cell development
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Paranko J,et al 1995 reported sex-dependent expression of tenascin-C in the differentiating
fetal rat testis and ovary. Immunocytochemistry and in
situ hybridization of tenascin-C in 15-day-pc fetal testis and ovary showed protein
and mRNA accumulation within the mesenchyme of the mesogonadal connection.
In addition to the male and female mesonephros, some labeling could also be seen
within the testicular tunica albuginea and intraovarian mesenchymal septa.
Expression regulated by
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Ovarian localization
Cumulus, Theca, Surface epithelium
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Temporal expression of tenascin-C and type I collagen in response to gonadotropins in the immature rat ovary. Bagavandoss P 2014 et al.
Ovarian morphogenesis and physiology in mammals take place in the context of hormones, paracrine factors and extracellular matrix molecules. Both fibrillar type I collagen and the multidomain tenascin-C are matrix molecules capable of modulating the behavior of both normal and neoplastic cells in many organs. Therefore, the objective of this qualitative study was to simultaneously examine the distribution of both tenascin-C and type I collagen in ovarian follicles and corpora lutea induced to develop in response to gonadotropin treatments. In preantral follicles both matrix proteins were present in the focimatrix, theca externa and the interstitium. Equine gonadotropin induced the appearance of both proteins in the theca interna. Subsequent to administration with human chorionic gonadotropin, tenascin-C appearance in the thecal capillaries preceded type I collagen expression. Tenascin-C was also observed in the capillaries of functional and regressing corpora lutea, while type I collagen was predominantly present in the interstitium and tunica albuginea. Western blots showed both an increase in and degradation of tenascin-C in the regressing corpora lutea. The ovarian surface epithelium also showed immunoreactivity for both tenascin-C and type I collagen. The study reveals that tenascin-C and type I collagen may participate in the morphogenesis of ovarian follicles, and in the formation and regression of corpora lutea.
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Asem EK, et al 2000 reported the identification of different components of basal lamina of avian ovarian follicle.
Pure and intact basal lamina was isolated from preovulatory
follicles of the chicken ovary. Some components of the basal lamina could be
solubilized with guanidine-HCl (designated Fraction 1) and remaining
components with beta-mercaptomethanol containing guanidine-HU (designated
Fraction 2). With Western blot analysis, monoclonal and polyclonal antibodies
raised against avian, mammalian, and human proteins recognized proteins in
Fractions 1 and 2 of solubilized basal lamina. Thus, antibodies raised against
extracellular matrix proteins, laminin, fibronectin, entactin or nidogen,
tenascin, heparan sulfate proteoglycan, osteonectin, and Type IV collagen
reacted positively with basal lamina proteins.
Wilson KE, et al 1996 reported the expression of the extracellular matrix protein tenascin in malignant and benign
ovarian tumours.
Gene expression profiles of cumulus cell oocyte complexes (COCs) during ovulation reveal cumulus cells express neuronal and immune-related genes: Does this expand their role in the ovulation process
Hernandez-Gonzalez I, et al ?
Ovulation is a complex process initiated by the preovulatory LH surge, characterized by cumulus oocyte complex (COC) expansion and completed by the release of a mature oocyte. Although many ovarian genes that impact ovulation have been identified, we hypothesized that genes selectively expressed in COCs would be overlooked by approaches using whole ovary or granulosa cell samples. RNA isolated from COCs collected from preovulatory follicles of eCG-primed mice and at selected times following hCG treatment was subjected to microarray analyses and results confirmed by RT-PCR analyses, Western blotting and immunofluorescent studies. A remarkable number of genes was up-regulated in COCs including Areg, Ereg, and Btc. Several genes selectively expressed in cumulus cells compared with granulosa cells were related to neuronal (Mbp, Tnc, Nts) or immune (Alcam, Pdcd1, Cd34, Cd52 and Cxcr4) cell function. In addition to Sfrp2, other members of the Wnt/Fzd family (Sfrp4, Fdz1 and Fdz2) were expressed in COCs. Thus, there is a cumulus cell-specific, terminal differentiation process. Furthermore, immunofluorescent analyses documented that cumulus cells are highly mitotic for 4-8 h after hCG and then cease dividing in association with reduced levels of Ccnd2 mRNA. Other down-regulated genes included: Cyp19a1, Fshr, Inhb, and the oocyte factors Zp1-3 and Gja4. In summary, the vast number of matrix, neuronal and especially immune cell-related genes identified by the gene profiling data of COCs constitutes strong and novel evidence that cumulus cells possess a repertoire of immune functions that could be far greater than simply mediating an inflammatory-like response.
Follicle stages
Preovulatory, Corpus luteum
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Tamura M et al reported the distribution of tenascin in normal cycling human ovary. Tenascin immunolocalization was performed in 51
specimens of morphologically normal human ovaries by using a specific
monoclonal antibody against purified human fibroblast tenascin. In preovulatory
follicles, no significant immunoreactivity was detected. In functioning corpora
lutea, immunoreactivity was present as a fine border around the periphery. In
association with the involution of the corpora lutea, marked diffuse tenascin
immunostaining in the intercellular space was observed. These data raise the
question of whether tenascin may be involved in luteolysis and may play an
important role in the ovarian cycle by regulating the involution of corpora lutea.
........Changes in the distribution of tenascin and fibronectin in the mouse ovary during folliculogenesis, atresia, corpus luteum formation and luteolysisYasuda K, et al .
Tenascin and fibronectin are components of the extracellular matrices that oppose and promote adhesion, respectively. Using immunohistochemical techniques, we studied the distribution of tenascin and fibronectin in the mouse ovary, in which dynamic reconstruction and degeneration occur during folliculogenesis, atresia, ovulation, corpus luteum formation and luteolysis. In growing follicles, tenascin was only detected in the theca externa layer, while fibronectin was detected in the theca externa layer, theca interna layer and basement membrane. During follicular atresia, granulosa cells, which are surrounded by the basement membrane, began to die through apoptosis. In atretic follicles, tenascin was detected in the basement membrane and theca externa layer. Distribution of fibronectin in atretic follicles was similar to that in healthy growing follicles, except that granulosa cells were slightly immunopositive for fibronectin. In young corpus luteum, luteal cells exhibit high 3 beta -hydroxysteroid dehydrogenase (3 beta -HSD) activity, an enzyme indispensable for progesterone production. Tenascin was barely detected in young luteal cells. 3 beta -HSD activity in luteal cells declines with corpus luteum age, and in older corpus luteum there is an increase in apoptotic death of luteal cells. Tenascin was intensely immunopositive in old luteal cells.In contrast, fibronectin immunostaining in luteal cells was relatively constant during corpus luteum formation and luteolysis. Our observations suggest that tenascin is critical in controlling the degenerative changes of tissues in mouse ovaries. Moreover, in all circumstances observed in this study, tenascin always co-localized with fibronectin, suggesting fibronectin is indispensable for the function of tenascin.