Annual review of physiology最新文献

Sex and gender have emerged as critical considerations relevant to chronic obstructive pulmonary disease (COPD). Sex differences in lung development and physiologic response to hormones and environmental exposures influence COPD susceptibility, progression, severity, morbidity, and mortality. Gender has been poorly measured in the context of COPD, and gendered exposures further impact biology. The hormonal milieu is critical to study across the life course. Differences in immunity and inflammation likely impact sex- and gender-related features of COPD. Emerging evidence from multiple types of omics data is revealing new genes and pathways to consider as relevant to sex- and gender-divergent features of COPD. Much research to date has focused on autosomes, but the growing awareness of a role for allosomes is highlighting knowledge gaps. Reproductive aging impacts lung function and requires more investigation. Network medicine holds promise as an approach to sex and gender omics to uncover drivers of COPD in men and women.

Calcium ions mediate the volume homeostasis of human red blood cells (RBCs) in the circulation. The mechanism by which calcium ions affect RBC hydration states always follows the same sequence. Deformation of RBCs traversing capillaries briefly activates mechanosensitive PIEZO1 channels, allowing Ca2+ influx down its steep inward gradient transiently overcoming the calcium pump and elevating [Ca2+]_i. Elevated [Ca2+]_i activates the Ca2+-sensitive Gardos channels, inducing KCl loss and cell dehydration, a sequence operated with infinite variations in vivo and under experimental conditions. The selected health and disease themes for this review focus on landmark experimental results that led to the development of highly constrained models of the circulatory changes in RBC homeostasis. Based on model predictions, a new perspective emerged, pointing to PIEZO1 dysfunction as the main trigger in the formation of the profoundly dehydrated irreversible sickle cells, the main pathogenic participants in vaso-occlusion, the root cause of sickle cell disease.

A healthy heart shows intrinsic electrical heterogeneities that play a significant role in cardiac activation and repolarization. However, cardiac diseases may perturb the baseline electrical properties of the healthy cardiac tissue, leading to increased arrhythmic risk and compromised cardiac functions. Moreover, biological variability among patients produces a wide range of clinical symptoms, which complicates the treatment and diagnosis of cardiac diseases. Ischemic heart disease is usually caused by a partial or complete blockage of a coronary artery. The onset of the disease begins with myocardial ischemia, which can develop into myocardial infarction if it persists for an extended period. The progressive regional tissue remodeling leads to increased electrical heterogeneities, with adverse consequences on arrhythmic risk, cardiac mechanics, and mortality. This review aims to summarize the key role of electrical heterogeneities in the heart on cardiac function and diseases. Ischemic heart disease has been chosen as an example to show how adverse electrical remodeling at different stages may lead to variable manifestations in patients. For this, we have reviewed the dynamic electrophysiological and structural remodeling from the onset of acute myocardial ischemia and reperfusion to acute and chronic stages post-myocardial infarction. The arrhythmic mechanisms, patient phenotypes, risk stratification at different stages, and patient management strategies are also discussed. Finally, we provide a brief review on how computational approaches incorporate human electrophysiological heterogeneity to facilitate basic and translational research.

The lymphatic vasculature maintains lung homeostasis via fluid drainage in the form of lymph and by facilitating immune surveillance and leukocyte trafficking to the draining lymph nodes. Previous studies in both humans and animal models have demonstrated an important role for lymphatics in lung function from the neonatal period through adulthood. In addition, changes in the lymphatic vasculature have been observed in many respiratory diseases, and there is emerging evidence of a causative role for lymphatic dysfunction in the initiation and progression of lung pathology. Despite advances in the field, there are still many unanswered questions, and a more comprehensive understanding of the mechanisms by which the lymphatics affect lung homeostasis and the response to lung injury is needed. In this review, we discuss our current knowledge of the structure, function, and role of the lymphatics in the lung and how these vessels are involved in respiratory disease.

Driven by increased caloric intake relative to expenditure, obesity is a major health concern placing economic and operational strain on healthcare and social care worldwide. Pharmacologically, one of the most effective avenues for the management of excess adiposity is the suppression of appetite. However, owing to the body's natural physiological defense to weight loss and tolerability issues that typically accompany anorectic agents, leveraging this approach to induce sustained weight loss is often easier said than done. As such, to address these challenges, researchers have coupled a thorough understanding of the gut-brain axis with advancements in peptide engineering to design therapeutics mimicking the actions of endocrine hormones to promote a negative energy balance. Indeed, multireceptor agonists targeting the GLP-1, GIP, and glucagon receptors produce meaningful weight loss in people with obesity. Herein, we provide a rationale for how activation of the GIP receptor in the brain and the glucagon receptor in the liver and adipose tissue functions to synergize with GLP-1 receptor agonism to curb the drive to feed and ignite the combustion of excess calories for providing next-generation weight loss.

For physiological processes in the vital organs of eutherian mammals to function, it is important to maintain constant core body temperature at ∼37°C. Mammals generate heat internally by thermogenesis. The focus of this review is on heat generated in resting skeletal muscles, using the same cellular components that muscles use to regulate cytoplasmic calcium concentrations [Ca2+] and contraction. Key to this process, known as muscle-based nonshivering thermogenesis (MB-NST), are tiny Ca2+ movements and associated ATP turnover coordinated by the plasma membrane, sarcoplasmic reticulum (SR), and the mitochondria. MB-NST has made mammals with gain-of-function SR ryanodine receptor (RyR) variants vulnerable to excessive heat generation that can be potentially lethal, known as malignant hyperthermia. Studies of RyR variants using recently developed techniques have advanced our understanding of MB-NST.

Epithelial Na+ channels (ENaCs) are known to affect blood pressure through their role in transporting Na+ in the distal nephron of the kidney. While expressed in other epithelial tissues, there is growing evidence that ENaCs are also expressed in nonepithelial tissues where their activity influences blood pressure. This review provides an overview of ENaCs and key mechanisms that regulate channel activity. The role of ENaCs in antigen-presenting dendritic cells is discussed, where ENaC-dependent sensing of increases in the extracellular Na+ concentration leads to activation of a signaling cascade, T cell activation with the release of proinflammatory cytokines, and an increase in blood pressure. The potential contribution of this pathway to human hypertension is discussed.

Store-operated Ca2+ entry (SOCE) is a widespread mechanism of cellular Ca2+ signaling that arises from Ca2+ influx across the plasma membrane through the Orai family of calcium channels in response to depletion of intracellular Ca2+ stores. Orai channels are a crucial Ca2+ entry mechanism in both neurons and glia and are activated by a unique inside-out gating process involving interactions with the endoplasmic reticulum Ca2+ sensors, STIM1 and STIM2. Recent evidence indicates that SOCE is broadly found across all areas of the nervous system where its physiology and pathophysiology is only now beginning to be understood. Here, we review the growing literature on the mechanisms of SOCE in the nervous system and contributions to gene expression, neuronal excitability, synaptic plasticity, and behavior. We also explore the burgeoning links between SOCE and neurological disease and discuss therapeutic implications of targeting SOCE for brain disorders.

Two major functions of the lymphatic system are the reabsorption of excess interstitial fluid/protein and the coordination of immune cell interactions and trafficking. Specialized junctions between lymphatic endothelial cells optimize reabsorption. The spontaneous contractions of collecting vessels provide active lymph propulsion. One-way valves prevent backflow, and chemokine gradients direct the migration of immune cells. Specialized compartments within the lymph node facilitate antigen-immune cell interactions to produce innate and acquired immunity. Lymphatic injury and/or mutations in genes controlling vessel/valve development result in contractile/valve dysfunction, reduced immune cell trafficking and, ultimately, lymph-edema. Activated CD4+ T cells produce inflammatory mediators that exacerbate these processes, potentially leading to interstitial and lymphatic vessel remodeling and negatively impacting overall function. Mouse models have advanced our knowledge of lymphatic disease, but clinical trials to reduce the impact of inflammatory mediators have yielded mixed success, implying that additional factors underlying human lymphedema are not yet understood.

The liver plays a central role in regulating lipid and glucose metabolism, particularly in transitioning between energy storage and provision in fed and fasting states. Loss of metabolic flexibility, characterized by the impaired capacity to shift between different energy substrates, sets the stage for accumulation of hepatic triglyceride as lipid droplets and further metabolic perturbations. Cross talk between the liver and other organs, including adipose tissue, pancreas, and muscle, is relevant in this transition. In addition to the metabolic consequences of steatosis, there are significant liver risks related to triggered inflammatory and fibrotic processes. Steatotic liver diseases affect an estimated one in three adults globally and contribute to substantial morbidity and mortality. This review focuses on the liver's role in lipid metabolism, defining metabolic health and unhealth, the pathogenic underpinnings that lead to steatohepatitis and hepatic fibrosis, and the clinical features and therapies for the most common forms of steatotic liver diseases.