Co-culture of monocytes and zona fasciculata adrenal cells: An in vitro model to study the immune-adrenal cross-talk

Changes in Rat Adrenal Cortex and Pineal Gland in Inverted Light-Dark Cycle: A Biochemical, Histological, and Immunohistochemical Study

Poor sleep standards are common in everyday life; it is frequently linked to a rise in stress levels. The adrenal gland interacts physiologically with the pineal gland in the stress response. Pineal gland is a small endocrine organ that modulates sleep patterns. This work aimed to evaluate the inverted light-dark cycle rhythm on the histological changes within the adrenal cortex and pineal gland in adult male albino rats. Twenty adult male albino rats were equally divided into two groups: For the first control group, animals were kept on daylight-darkness for 12-12 h. The second group was kept under an inverted 12- to 12-h light-darkness cycle for 4 weeks. Adrenal sections were subjected to biochemical, histological, and immunohistochemical study. Inverted light-dark cycle group recorded a significant elevation of plasma corticosterone, tissue malondialdehyde, tumor necrosis factor-α, and interleukin-1β (IL-1β) associated with a significant reduction of catalase and superoxide dismutase. Adrenal cortex showed biochemical and histological changes. Pineal glands also showed loss of lobular architecture. A significant upregulation in activated inducible nitric oxide synthase (iNOS) and B-cell lymphoma-associated X (Bax) immunohistochemical expression was recorded in adrenal cortex associating with downregulation in B-cell lymphoma 2 (Bcl-2). It could be concluded that subchronic inverted light-dark cycle exerted direct effects on adrenal cortex and the pineal glands.

The roles of tissue-resident macrophages in sepsis-associated organ dysfunction

Sepsis, a syndrome caused by a dysregulated host response to infection and characterized by life-threatening organ dysfunction, particularly septic shock and sepsis-associated organ dysfunction (SAOD), is a medical emergency associated with high morbidity, high mortality, and long-term sequelae. Tissue-resident macrophages (TRMs) are a subpopulation of macrophages derived primarily from yolk sac progenitors and fetal liver during embryogenesis, located primarily in non-lymphoid tissues in adulthood, capable of local self-renewal independent of hematopoiesis, and developmentally and functionally restricted to the non-lymphoid organs in which they reside. TRMs are the first line of defense against life-threatening conditions such as sepsis, tumor growth, traumatic-associated organ injury, and surgical-associated injury. In the context of sepsis, TRMs can be considered as angels or demons involved in organ injury. Our proposal is that sepsis, septic shock, and SAOD can be attenuated by modulating TRMs in different organs. This review summarizes the pathophysiological mechanisms of TRMs in different organs or tissues involved in the development and progression of sepsis.

Preclinical Models of Adrenocortical Cancer

Adrenocortical cancer is an aggressive endocrine malignancy with an incidence of 0.72 to 1.02 per million people/year, and a very poor prognosis with a five-year survival rate of 22%. As an orphan disease, clinical data are scarce, meaning that drug development and mechanistic research depend especially on preclinical models. While a single human ACC cell line was available for the last three decades, over the last five years, many new in vitro and in vivo preclinical models have been generated. Herein, we review both in vitro (cell lines, spheroids, and organoids) and in vivo (xenograft and genetically engineered mouse) models. Striking leaps have been made in terms of the preclinical models of ACC, and there are now several modern models available publicly and in repositories for research in this area.

Update on the Role of Glucocorticoid Signaling in Osteoblasts and Bone Marrow Adipocytes During Aging

PURPOSE OF REVIEW

Bone marrow adipose tissue (BMAT) in the skeleton likely plays a variety of physiological and pathophysiological roles that are not yet fully understood. In elucidating the complex relationship between bone and BMAT, glucocorticoids (GCs) are positioned to play a key role, as they have been implicated in the differentiation of bone marrow mesenchymal stem cells (BMSCs) between osteogenic and adipogenic lineages. The purpose of this review is to illuminate aspects of both endogenous and exogenous GC signaling, including the influence of GC receptors, in mechanisms of bone aging including relationships to BMAT.

RECENT FINDINGS

Harmful effects of GCs on bone mass involve several cellular pathways and events that can include BMSC differentiation bias toward adipogenesis and the influence of mature BMAT on bone remodeling through crosstalk. Interestingly, BMAT involvement remains poorly explored in GC-induced osteoporosis and warrants further investigation. This review provides an update on the current understanding of the role of glucocorticoids in the biology of osteoblasts and bone marrow adipocytes (BMAds).

Neuroimmune Regulation in Sepsis-Associated Encephalopathy: The Interaction Between the Brain and Peripheral Immunity

Sepsis-associated encephalopathy (SAE), the most popular cause of coma in the intensive care unit (ICU), is the diffuse cerebral damage caused by the septic challenge. SAE is closely related to high mortality and extended cognitive impairment in patients in septic shock. At present, many studies have demonstrated that SAE might be mainly associated with blood–brain barrier damage, abnormal neurotransmitter secretion, oxidative stress, and neuroimmune dysfunction. Nevertheless, the precise mechanism which initiates SAE and contributes to the long-term cognitive impairment remains largely unknown. Recently, a growing body of evidence has indicated that there is close crosstalk between SAE and peripheral immunity. The excessive migration of peripheral immune cells to the brain, the activation of glia, and resulting dysfunction of the central immune system are the main causes of septic nerve damage. This study reviews the update on the pathogenesis of septic encephalopathy, focusing on the over-activation of immune cells in the central nervous system (CNS) and the “neurocentral–endocrine–immune” networks in the development of SAE, aiming to further understand the potential mechanism of SAE and provide new targets for diagnosis and management of septic complications.

Effects of Coculture Fibroblasts and Vascular Endothelial Cells on Proliferation and Osteogenesis of Adipose Stem Cells

Background

The development of tissue engineering provides a new method for the clinical treatment of bone defects, but the problems of slow formation and slow vascularization of tissue engineered bone have always existed. Studies have shown that the combined culture system of vascular endothelial cells and adipose stem cells is superior to single cell in repairing bone defects. With the excellent proliferation ability, secretion of synthetic collagen and a variety of regulatory factors and fibroblasts can differentiate into osteoblasts and have the potential to be excellent seed cells involved in tissue engineering bone construction.

Objective

To investigate the effects of combined culture of fibroblasts, vascular endothelial cells, and adipose stem cells on proliferation and osteogenic differentiation of adipose stem cells.

Methods

The cells were divided into 4 groups: adipose stem cell group, adipose stem cell+vascular endothelial cell coculture group, adipose stem cell+fibroblast coculture group, and adipose stem cell+vascular endothelial cell+fibroblast coculture group. The morphological changes of the cells were observed under an inverted microscope. After 1, 3, 5, 7, and 9 days of coculture, the proliferation of adipose stem cells in each group was detected by a CCK-8 method and the growth curve was plotted. Adipose stem cells in each group were stained with alizarin red and alkaline phosphatase at days 7, 14, 21, and 28. At the third week of coculture, Western blot was used to detect the expression level of bone morphogenetic protein 2 of adipose stem cells in each group. Results and Conclusions. (1) After 14 days of culture, some cells in the adipose stem cell+vascular endothelial cell+fibroblast coculture group fused into clumps and distributed in nests, while the adipose stem cells in the adipose stem cell group had a single cell morphology and no cell clusters were observed. (2) The cell growth curves were basically the same in each group, and the absorbance value increased gradually. The absorbance value of the adipocyte+vascular endothelial cell+fibroblast coculture group was the highest, followed by the adipocyte+fibroblast coculture group and then the adipocyte+fibroblast coculture group. (3) Alizarin red staining showed negative reaction in each group on the 7th day, and a small number of red positive cells gradually appeared in each group as time went on. On the 28th day, red positive cells were found in all groups, and most of them were in the coculture group of adipose stem cells+vascular endothelial cells+fibroblasts, showing red focal. The coculture group of adipose stem cells+vascular endothelial cells and adipose stem cells+fibroblasts was less, and the adipose stem cell group was the least. On day 28 of alkaline phosphatase staining, cells in each group had red positive particles, and the adipose stem cell+vascular endothelial cell+fibroblast coculture group and adipose stem cell+fibroblast coculture group had the most, followed by the adipose stem cell+vascular endothelial cell coculture group and then the adipose stem cell group. (4) Bone morphogenetic protein 2 was expressed in all groups, especially in adipose stem cell+fibroblast coculture group and adipose stem cell+vascular endothelial cell+ fibroblast coculture group. (5) Fibroblast could promote adipose stem cell osteogenic differentiation better than vascular endothelial cells, but the proliferation effect was not as good as vascular endothelial cells. The coculture system of fibroblast combined with vascular endothelial cells and adipose stem cells promoted the proliferation of adipose stem cells and the rapid and efficient differentiation of adipose stem cells into osteoblasts.

Steroidogenic cell microenvironment and adrenal function in physiological and pathophysiological conditions

The human adrenal cortex is a complex organ which is composed of various cell types including not only steroidogenic cells but also mesenchymal cells, immunocompetent cells and neurons. Intermingling of these diverse cell populations favors cell-to-cell communication processes involving local release of numerous bioactive signals such as biogenic amines, cytokines and neuropeptides. The resulting paracrine interactions play an important role in the regulation of adrenocortical cell functions both in physiological and pathophysiological conditions. Especially, recent evidence indicates that adrenocortical cell microenvironment is involved in the pathogenesis of adrenal disorders associated with corticosteroid excess. The paracrine factors involved in these intraadrenal regulatory mechanisms may thus represent valuable targets for future pharmacological treatments of adrenal diseases.