Functional implications of the Golgi and microtubular network in gonadotropes

Abstract

In contrast to the widely accepted images of the Golgi apparatus as a cup-like shape, the Golgi in pituitary gonadotropes is organized as a spherical shape in which the outer and inner faces are cis-and trans-Golgi elements, respectively. At the center of the spherical Golgi, a pair of centrioles is situated as a microtubule-organizing center from which radiating microtubules isotropically extend toward the cell periphery. This review focuses on the significance of the characteristic organization of the Golgi and microtubule network in gonadotropes, considering the roles of microtubule-dependent membrane transport in the formation and maintenance of the Golgi structure. Because the highly symmetrical organization of the Golgi is possibly perturbed in response to experimental treatments of gonadotropes, monitoring of the Golgi structure in gonadotropes under various experimental conditions will be a novel in vivo approach to elucidate the biogenesis of the Golgi apparatus.

<b>Integrative method for three-dimensional imaging of the entire Golgi apparatus by combining thiamine pyrophosphatase cytochemistry and array tomography using backscattered electron-mode scanning electron micr</b><b>oscopy </b>

“…The Golgi apparatus is generally composed of stacks containing several distinct layers of cisterns, designated as cis-, medial-, trans-cisterns in order from the entry side facing the rough ER (6, 7, 10). However, numerous studies also suggest that the overall three-dimensional (3D) organization of the intracellular Golgi apparatus varies with the cell type and their functional state (31,36,38,39,46). A wide variety of microscopic techniques have been developed to assess the organization and ultrastructure of the Golgi apparatus.…”

Cytoplasmic dynein and its regulatory proteins in Golgi pathology in nervous system disorders

“…In vertebrate cells, the Golgi stacks are laterally connected to form a single continuous membrane system, termed the Golgi ribbon that usually localizes near the centrosome (Klumperman, 2011 ). Golgi ribbon size and morphology may vary between cell types according to specific requirements of the secretory pathway (Yadav and Linstedt, 2011 ; Nakamura et al, 2012 ; Watanabe et al, 2014 ). In neurons the Golgi ribbon forms an extensive perinuclear network that in multiple neuron types may extend into one or more dendrites (Figure 1 ) (Gardiol et al, 1999 ; Hanus and Schuman, 2013 ), and is complemented by Golgi fragments in distal dendrites, designated Golgi outposts (Horton et al, 2005 ; Ori-McKenney et al, 2012 ; Quassollo et al, 2015 ).…”

Soy Phytoestrogens Do Not Fully Reverse Changes in Rat Pituitary Castration Cells: Unbiased Stereological Study

“…Daidzein, chronically applied to Orx rats, induced significant decreases of intracellular bFSH and bLH protein content and the volume of FSH-and LH-containing cells, thus expressing the potential to suppress gonadotropin production, like estradiol. Because enlargement of castration cells mostly originates from expansion of organelles included in protein synthesis, that is, Golgi apparatus and rough endoplasmic reticulum (Watanabe et al, 2014), our results suggest that daidzein inhibited the synthesis of gonadotropic hormones, but much more mildly than estradiol. In addition, the volume densities of gonadotropic cells were decreased, although in the case of FSH-immunopositive cells the decline did not reach statistical significance.…”