生理学报最新文献

The maintenance of skeletal muscle quality involves various signal pathways that interact with each other. Under normal physiological conditions, these intersecting signal pathways regulate and coordinate the hypertrophy and atrophy of skeletal muscles, balancing the protein synthesis and degradation of muscle. When the total rate of protein synthesis exceeds that of protein degradation, the muscle gradually becomes enlarged, while when the total rate of protein synthesis is lower than that of protein degradation, the muscle shrinks. Myocyte atrophy mainly involves two protein degradation pathways, namely ubiquitin-proteasome and autophagy-lysosome. Protein degradation pathway is activated during muscle atrophy, resulting in the loss of muscle mass. Muscle atrophy can occur under various conditions such as malnutrition, aging and cachexia. Skeletal muscle atrophy caused by orthopedic diseases mainly includes disuse muscular atrophy caused by fracture and denervation muscular atrophy. The signal pathways that control and coordinate protein synthesis and degradation in skeletal muscle include insulin-like growth factor 1 (IGF1)-Akt-mammalian target of rapamycin (mTOR), myostatin-activin A-Smad, G protein α inhibitory peptide 2 (Gαi2)-PKC, nuclear factor κB (NF-κB), ectodysplasin A2 receptor (EDA2R)-NF-κB inducing kinase (NIK) and mitogen-activated protein kinase (MAPK) pathways. This paper provides a comprehensive review of the protein degradation pathways in skeletal muscle atrophy and the associated signal pathways regulating protein degradation in muscular atrophy.

Arginine vasopressin (AVP) plays a crucial role in various physiological processes including water reabsorption, cardiovascular homeostasis, hormone secretion, and social behavior. AVP acts through three distinct receptor subtypes, i.e., V1a, V1b, and V2. Among them, the vasopressin V2 receptor (V2R) was initially discovered in the principal cells of renal collecting ducts, where it is primarily involved in regulating water reabsorption. However, in recent years, with the advancement of imaging and bioinformatics techniques, there has been a deeper understanding of the microstructure, protein binding capacity, and specific tissue distribution of V2R. Additionally, the pathogenic roles and target effects of V2R in various diseases have been uncovered through ectopic overexpression, activation, or antagonism. This paper aims to provide a brief overview of current research status on the physiological functions, pathophysiological mechanisms, and drug development related to V2R in recent years.

At present, the problem of drug addiction treatment mainly lies in the high relapse rate of drug addicts. Addictive drugs will bring users a strong sense of euphoria and promote drug seeking. Once the drug is withdrawn, there will be withdrawal symptoms such as strong negative emotions and uncomfortable physical reactions. The recurrence of context-induced withdrawal memory is an important reason for drug relapse. Our previous study has shown increased c-Fos expression in prelimbic cortex (PrL) neurons projecting to paraventricular nucleus of the thalamus (PVT) (PrL^-PVT) during conditioned context-induced retrieval of morphine withdrawal memory. However, whether PrL^-PVT neurons are involved in withdrawal memory retrieval and the underlying molecular mechanisms remain unknown. In this study, we used conditioned place aversion (CPA) model combined with in vivo calcium signal recording, chemogenetics and nucleus drug injection methods to investigate the role and molecular mechanism of PrL^-PVT neurons in retrieval of morphine withdrawal memory. The results showed that the calcium signals of PrL^-PVT neurons were significantly enhanced by withdrawal-related context; Inhibition of PrL^-PVT neurons blocked the conditioned context-induced morphine withdrawal memory retrieval; Activation of PrL^-PVT neurons caused animals to escape from the context; After the inhibition of NMDA receptors in the PrL, withdrawal-related context failed to increase c-Fos and Arc expressions in PrL^-PVT neurons. The above results suggest that NMDA receptors in PrL^-PVT neurons are associated with retrieval of morphine withdrawal memory. This study is of great significance for further understanding the neural circuit mechanism of withdrawal memory retrieval as well as the intervention and prevention of drug relapse.

Two-pore-domain potassium channels (K2P) family is widely expressed in many human cell types and organs, which has important regulatory effect on physiological processes. K2P is sensitive to a variety of chemical and physical stimuli, and they have also been critically implicated in transmission of neural signal, ion homeostasis, cell development and death, and synaptic plasticity. Aberrant expression and dysfunction of K2P channels are involved in a range of diseases, including autoimmune, central nervous system, cardiovascular disease and others. The scope of this review is to give a detailed overview of the structure, function, pharmacological regulation, and related diseases of TREK-1 channels, a member of the K2P family.

The N-end rule pathway is a protein degradation pathway mediated by the ubiquitin-proteasome system, which specifically targets and degrades target proteins by recognizing specific residues at the N-terminus of the proteins. The residues which play a crucial role in the N-end rule pathway are called degrons, also known as N-degrons, as they are usually unstable at the N-terminal end of the protein. Currently, several N-end rule pathways have been identified in the eukaryotes, including the Arg/N-end rule, Ac/N-end rule, and Pro/N-end rule pathways, as well as the recently discovered Gly/N-end rule pathway. The Ac/N-end rule pathway targets proteins containing N-terminal acetylation (Nt-acetylation) residues. The Arg/N-end rule pathway, on the other hand, targets certain unacetylated residues and involves N-terminal arginylation. For proteins with N-terminal proline (Pro) and glycine (Gly) residues, they are neither modified by acetylation nor recognized through the Arg/N-end rule pathway. Therefore, these proteins are primarily recognized and degraded through the Pro/N-end rule pathway and the Gly/N-end rule pathway. The regulation of specific proteins through N-end rule pathway-mediated degradation plays an important role in numerous physiological and pathological processes, such as cardiovascular development, neurogenesis, meiosis, spermatogenesis, HPV infection, and cell apoptosis. In this review, we summarize the role and mechanisms of several known N-end rule pathways and discuss their relationship with certain diseases. As an independent protein degradation system, the N-end rule pathways still hold countless biological secrets waiting for exploring. The comprehensive understanding of these pathways could potentially uncover novel therapeutic targets for various diseases.

Heart failure is characterized by abnormal β-adrenergic receptor (β-AR) activation and mitochondrial dysfunction. In heart failure, overactivation of β-AR mediates key pathological processes in cardiomyocytes, including oxidative stress, calcium overload and metabolic abnormalities, which subsequently lead to inflammation, myocardial apoptosis and necrosis. Mitochondria are the core organelles for energy metabolism, and also play a vital role in calcium homeostasis, redox balance and signaling transduction. Moderate β-AR activation is conducive to maintaining mitochondrial homeostasis and physiological cardiomyocyte function. However, β-AR overactivation in heart failure disrupts mitochondrial function through multiple mechanisms. Therefore, our review aims to elucidate how β-AR regulates mitochondrial function, particularly under sympathetic stress, impacting oxidative stress, apoptosis, necrosis, and metabolic imbalance. By describing these mechanisms, we seek to propose new insights and therapeutic targets for the prevention and treatment of heart failure.

β-Nicotinamide mononucleotide (NMN), as the precursor of nicotinamide adenine dinucleotide (NAD), plays an important role in enhancing NAD levels. Intake of NMN can alter the composition and vitality of gut microbiota, restore mitochondrial function, inhibit inflammatory pathways, improve metabolism, counteract oxidative stress, and alleviate inflammation. NMN significantly improves recovery from aging-related diseases, such as diminished heart function, reduced fertility, memory decline, and diabetes. NMN demonstrates both efficacy and safety in anti-aging. The use of NMN in China has gradually gained acceptance, highlighting the importance of exploring the mechanism of NMN in anti-aging effects and improving the biosynthesis of NMN. In addition, NMN in combination with stem cells hold promise in the treatment of aging-related degenerative diseases and promote overall human and animal health.

Skin, as the body's largest organ, acts as the primary defense mechanism against infection and injury. The maintenance of skin health heavily relies on the regulation of epidermal stem cells, crucial for ensuring epidermal homeostasis, hair regeneration, and the repair of epidermal injuries. Recent studies have placed a growing emphasis on G protein-coupled receptor (GPCR) in the context of understanding epidermal stem cells, uncovering its significant role in determining their fate. The activation of GPCR triggers the subsequent dissociation of the βγ subunits from the α subunit of G protein, leading to the modulation of various downstream signaling pathways, such as the WNT-BMP signaling crosstalk and the Gαs-PKA signaling pathway. These pathways collectively influence the fate of epidermal stem cells. Consequently, targeted GPCR therapy has emerged as a promising strategy for improving skin health by orchestrating the fate of epidermal stem cells, unveiling potential therapeutic targets that demand further investigation.

Glycine receptors (GlyRs) belong to the ligand-gated ion channel receptor superfamily and are widely distributed throughout the central nervous system. GlyRs are essential for maintaining visual, auditory, sensory and motor functions, and abnormalities in its structure and function can lead to various neurological disorders. This review aims to provide an extensive analysis of the structure, function and regulatory mechanisms of GlyRs, and evaluate its role in various central nervous system diseases. Ultimately, this review will provide theoretical support for the development of novel drugs specifically targeting GlyRs.

Age-related sarcopenia is a degenerative disease characterized by the decline in skeletal muscle mass and function during the aging process. Anabolic resistance, which refers to the diminished response of skeletal muscle to anabolic stimulation from leucine and other nutrients, is a significant contributing factor to its development. Recent studies have suggested that large neutral amino acid-transporter 1 (LAT1/SLC7A5) may play an important role in enhancing leucine's effects on protein synthesis in aging skeletal muscle. In this paper, the structure and function of LAT1 and its key molecules regulating aging skeletal muscle protein synthesis were reviewed, and the potential relationship between LAT1, as a transmembrane transporter of leucine, and protein synthesis in aging skeletal muscle was analyzed. The aim is to explore new mechanisms and insights for prevention and treatment of age-related sarcopenia, and provide reference for the application of relevant targets in clinical translational medicine.