Otis Mélissa, Campbell Shirley, Payet Marcel D, Gallo-Payet Nicole
Service of Endocrinology, University of Sherbrooke, Sherbrooke, 3001, 12th Avenue North, Quebec, Canada J1H 5N4.
J Endocrinol. 2007 Jun;193(3):331-47. doi: 10.1677/JOE-07-0055.
The expression of main extracellular matrix (ECM) and their integrins were studied in the adult rat adrenal gland. Collagen I, IV (CI, CIV), laminin (LN) and fibronectin (FN) expression was observed surrounding each glomerulosa cell and as long fibrils between the cords of fasciculata cells. In the medulla, FN was present around chromaffin cells or bordering blood vessels. Integrin alpha2, alpha3 and alpha5 were present mainly in the cortex, while alpha1 was present in the medulla. In culture, all ECM favoured proliferation of both glomerulosa and fasciculata cells, while protein synthesis was lower on FN and LN in glomerulosa cells. CIV promoted ACTH-induced proliferation whereas FN favoured ACTH-induced protein synthesis in glomerulosa cells. Except for LN, ECM increased expression of 3beta-hydroxysteroid dehydrogenase and enhanced basal aldosterone, although corticosterone secretion was only enhanced by CI and CIV. In fasciculata cells, the potency of ACTH-induced cAMP production was lower on ECM, compared with plastic. Moreover, ACTH, but not ECM, activated mitogenic-activated protein kinase p38 and stress-activated protein kinases. Glomerulosa and fasciculata cells grown on CI and CIV had a polygonal morphology, while cells grown on LN appeared as clusters of small rounded cells. On FN, the glomerulosa cells exhibited polygonal morphology while fasciculata cells appeared as clusters of small rounded cells. Together, these results indicate that ECM modulates basal and ACTH-induced cell functions, with FN, CI and CIV specifically favouring steroid secretion, as opposed to LN which inhibits secretion while promoting proliferation.
在成年大鼠肾上腺中研究了主要细胞外基质（ECM）及其整合素的表达。观察到I型、IV型胶原（CI、CIV）、层粘连蛋白（LN）和纤连蛋白（FN）在每个球状带细胞周围表达，并在束状带细胞索之间呈长纤维状。在髓质中，FN存在于嗜铬细胞周围或血管周围。整合素α2、α3和α5主要存在于皮质，而α1存在于髓质。在培养中，所有ECM均促进球状带和束状带细胞的增殖，而球状带细胞在FN和LN上的蛋白质合成较低。CIV促进促肾上腺皮质激素（ACTH）诱导的增殖，而FN有利于球状带细胞中ACTH诱导的蛋白质合成。除LN外，ECM增加3β-羟基类固醇脱氢酶的表达并增强基础醛固酮水平，尽管皮质酮分泌仅由CI和CIV增强。在束状带细胞中，与塑料相比，ACTH诱导的cAMP产生在ECM上的效力较低。此外，ACTH而非ECM激活丝裂原活化蛋白激酶p38和应激激活蛋白激酶。在CI和CIV上生长的球状带和束状带细胞呈多边形形态，而在LN上生长的细胞则呈小圆形细胞簇状。在FN上，球状带细胞呈现多边形形态，而束状带细胞呈小圆形细胞簇状。总之，这些结果表明ECM调节基础和ACTH诱导的细胞功能，其中FN、CI和CIV特别有利于类固醇分泌，而LN则抑制分泌同时促进增殖。
