Overnutrition, driven by the consumption of high-fat, high-sugar diets, has reached epidemic proportions and poses a significant global health challenge. Prolonged overnutrition leads to the deposition of excessive lipids in adipose and non-adipose tissues, a condition known as lipotoxicity. The intricate interplay between overnutrition-induced lipotoxicity and the immune system plays a pivotal role in the pathogenesis of various diseases. This review aims to elucidate the consequences of impaired efferocytosis, caused by lipotoxicity-poisoned macrophages, leading to chronic inflammation and the subsequent development of severe infectious diseases, autoimmunity, and cancer, as well as chronic pulmonary and cardiovascular diseases. Chronic overnutrition promotes adipose tissue expansion which induces cellular stress and inflammatory responses, contributing to insulin resistance, dyslipidemia, and metabolic syndrome. Moreover, sustained exposure to lipotoxicity impairs the efferocytic capacity of macrophages, compromising their ability to efficiently engulf and remove dead cells. The unresolved chronic inflammation perpetuates a pro-inflammatory microenvironment, exacerbating tissue damage and promoting the development of various diseases. The interaction between overnutrition, lipotoxicity, and impaired efferocytosis highlights a critical pathway through which chronic inflammation emerges, facilitating the development of severe infectious diseases, autoimmunity, cancer, and chronic pulmonary and cardiovascular diseases. Understanding these intricate connections sheds light on potential therapeutic avenues to mitigate the detrimental effects of overnutrition and lipotoxicity on immune function and tissue homeostasis, thereby paving the way for novel interventions aimed at reducing the burden of these multifaceted diseases on global health.

Human cells, when exposed to both real and simulated microgravity (s-µg), form 3D tissue constructs mirroring in vivo architectures (e.g., cartilage, intima constructs, cancer spheroids and others). In this study, we exposed human foetal osteoblast (hFOB 1.19) cells to a Random Positioning Machine (RPM) for 7 days and 14 days, with the purpose of investigating the effects of s-µg on biological processes and to engineer 3D bone constructs. RPM exposure of the hFOB 1.19 cells induces alterations in the cytoskeleton, cell adhesion, extra cellular matrix (ECM) and the 3D multicellular spheroid (MCS) formation. In addition, after 7 days, it influences the morphological appearance of these cells, as it forces adherent cells to detach from the surface and assemble into 3D structures. The RPM-exposed hFOB 1.19 cells exhibited a differential gene expression of the following genes: transforming growth factor beta 1 (TGFB1, bone morphogenic protein 2 (BMP2), SRY-Box 9 (SOX9), actin beta (ACTB), beta tubulin (TUBB), vimentin (VIM), laminin subunit alpha 1 (LAMA1), collagen type 1 alpha 1 (COL1A1), phosphoprotein 1 (SPP1) and fibronectin 1 (FN1). RPM exposure also induced a significantly altered release of the cytokines and bone biomarkers sclerostin (SOST), osteocalcin (OC), osteoprotegerin (OPG), osteopontin (OPN), interleukin 1 beta (IL-1β) and tumour necrosis factor 1 alpha (TNF-1α). After the two-week RPM exposure, the spheroids presented a bone-specific morphology. In conclusion, culturing cells in s-µg under gravitational unloading represents a novel technology for tissue-engineering of bone constructs and it can be used for investigating the mechanisms behind spaceflight-related bone loss as well as bone diseases such as osteonecrosis or bone injuries.

On space life sciences research is critical. Such research not only improves our knowledge of the basic biological processes but also elucidates the mechanisms and treatment of various earthly medical conditions. However, the study of living organisms in space poses many challenges that may be negligible or nonexistent in ground-based research. In recent years, with an increase in the number of spaceflights, extended periods of stay of astronauts on the International Space station and the imminent possibility of future long term deep space exploration missions, there is a great deal of attention focused on the effects induced by altered gravitation on the human body, and in particular, on bone, skeletal muscle, immunity and brain function. The aim of this review is to collate, encapsulate and examine the effects of altered gravity on neuronal cell structure and function that have been established from data obtained during experiments performed in real microgravity and simulated microgravity like conditions....

The immune system is the body’s defense against infectious organisms and other invaders. It is our immune system that keeps us healthy as we drift through a sea of pathogens. Healthy immune function depends on meticulous regulation of lymphocyte activation. Previous studies have shown unfavorable effects of μg on several physiological systems, including a significant reduction of the adaptive immune response. Lymphocyte movement through interstitium is critically important for the immune response. Thus, the activation of lymphocytes depends on various factors such as cell-to-cell contact due to temporary contact, permanent aggregation or by the uptake of soluble factors such as interleukin 1. Microgravity induced loss of lymphocyte locomotory activity, along with diminished lymphocyte activation, can be counteracted by nutritional supplements such as nucleotides. A study conducted by Andreazzoli et al., proposes that the knowledge of cellular and molecular mechanisms of gravity and its influence on T cells is required for creating the provision of therapeutic and possible preventive targets to keep the bone and immune systems of astronauts fully functional during long-term space missions, in addition to aiding regular people with immune deficiencies. When an immune system is compromised it can lead to various infections as well as cancerous growths. Discovering the ins and outs of the lymphocyte regulatory pathways can account for controlling and studying medicinal treatments for all forms or immune disorders. Therefore, studying both the long-term and short-term effects of microgravity is of great significance, as it has an invalidation nature that affects how the regulators of the immune system are readily able to function.