Research progress on post-translational modification of proteins and cardiovascular diseases

Rapid Characterization of the Potential Active of Sinomenine in Rats by Ultra-High-Performance Liquid Chromatography-Quadrupole-Exactive Orbitrap Mass Spectrometry and Molecular Docking

Sinomenium acutum (Thunb.) Rehd. et Wils is widely used in the treatment of rheumatoid arthritis, with its alkaloid compound sinomenine (SIN) being renowned for its significant anti-inflammatory properties. However, despite its widespread application, the in vivo anti-inflammatory mechanisms and metabolic pathways of SIN remain incompletely understood. This study established a rapid and reliable method based on an ultra-high-performance liquid chromatography method coupled with Quadrupole-Exactive Orbitrap mass spectrometry and molecular docking to identify and characterize SIN and 69 metabolites in rat plasma, urine, and feces, revealing primary metabolic pathways of hydroxylation, demethylation, sulfation, and glucuronidation. Molecular docking results revealed that phase I reactions, including dedimethylation, demethylation, dehydrogenation, and dihydroxylation, along with their composite reactions, were pivotal in influencing SIN's in vivo anti-inflammatory activity. M28, M36, and M59 are potentially the most anti-inflammatory active metabolites of SIN in vivo. This comprehensive analysis unveils SIN's metabolic pathways, offering insights into its biological processes and suggesting a novel approach for exploring active drug constituents. These findings pave the way for further understanding SIN's anti-inflammatory mechanisms, contributing significantly to the development of new therapeutic strategies.

Recent advances in serum response factor posttranslational modifications and their therapeutic potential in cardiovascular and neurological diseases

Serum Response Factor (SRF) is a key regulatory transcription factor present in various cell types throughout the body, playing essential roles in cellular functions under physiological conditions. Mutations and abnormal expression of SRF have been linked to the development of various diseases and disorders. Recent evidence highlights that post-translational modifications (PTMs) are critical for regulating SRF function in different cell types and contribute to disease pathogenesis. Targeting SRF-related PTMs is emerging as a promising therapeutic approach for treating SRF-associated diseases. In this review, we summarize recent advances in understanding SRF PTMs and their underlying regulatory mechanisms. We also explore the implications of SRF-PTM in related cardiovascular and neurological diseases and their potential for therapeutic intervention. This information underscores the significance of SRF PTMs in both physiological and pathological contexts, enhancing our understanding of disease mechanisms and paving the way for the development of novel therapeutic strategies.

The double whammy of ER-retention and dominant-negative effects in numerous autosomal dominant diseases: significance in disease mechanisms and therapy

The endoplasmic reticulum (ER) employs stringent quality control mechanisms to ensure the integrity of protein folding, allowing only properly folded, processed and assembled proteins to exit the ER and reach their functional destinations. Mutant proteins unable to attain their correct tertiary conformation or form complexes with their partners are retained in the ER and subsequently degraded through ER-associated protein degradation (ERAD) and associated mechanisms. ER retention contributes to a spectrum of monogenic diseases with diverse modes of inheritance and molecular mechanisms. In autosomal dominant diseases, when mutant proteins get retained in the ER, they can interact with their wild-type counterparts. This interaction may lead to the formation of mixed dimers or aberrant complexes, disrupting their normal trafficking and function in a dominant-negative manner. The combination of ER retention and dominant-negative effects has been frequently documented to cause a significant loss of functional proteins, thereby exacerbating disease severity. This review aims to examine existing literature and provide insights into the impact of dominant-negative effects exerted by mutant proteins retained in the ER in a range of autosomal dominant diseases including skeletal and connective tissue disorders, vascular disorders, neurological disorders, eye disorders and serpinopathies. Most crucially, we aim to emphasize the importance of this area of research, offering substantial potential for understanding the factors influencing phenotypic variability associated with genetic variants. Furthermore, we highlight current and prospective therapeutic approaches targeted at ameliorating the effects of mutations exhibiting dominant-negative effects. These approaches encompass experimental studies exploring treatments and their translation into clinical practice.

PTMs of PD-1/PD-L1 and PROTACs application for improving cancer immunotherapy

Immunotherapy has been developed, which harnesses and enhances the innate powers of the immune system to fight disease, particularly cancer. PD-1 (programmed death-1) and PD-L1 (programmed death ligand-1) are key components in the regulation of the immune system, particularly in the context of cancer immunotherapy. PD-1 and PD-L1 are regulated by PTMs, including phosphorylation, ubiquitination, deubiquitination, acetylation, palmitoylation and glycosylation. PROTACs (Proteolysis Targeting Chimeras) are a type of new drug design technology. They are specifically engineered molecules that target specific proteins within a cell for degradation. PROTACs have been designed and demonstrated their inhibitory activity against the PD-1/PD-L1 pathway, and showed their ability to degrade PD-1/PD-L1 proteins. In this review, we describe how PROTACs target PD-1 and PD-L1 proteins to improve the efficacy of immunotherapy. PROTACs could be a novel strategy to combine with radiotherapy, chemotherapy and immunotherapy for cancer patients.

The effects of glycosylation modifications on monocyte recruitment and foam cell formation in atherosclerosis

The monocyte recruitment and foam cell formation have been intensively investigated in atherosclerosis. Nevertheless, as the study progressed, it was obvious that crucial molecules participated in the monocyte recruitment and the membrane proteins in macrophages exhibited substantial glycosylation modifications. These modifications can exert a significant influence on protein functions and may even impact the overall progression of diseases. This article provides a review of the effects of glycosylation modifications on monocyte recruitment and foam cell formation. By elaborating on these effects, we aim to understand the underlying mechanisms of atherogenesis further and to provide new insights into the future treatment of atherosclerosis.

Ion channel trafficking implications in heart failure

Heart failure (HF) is recognized as an epidemic in the contemporary world, impacting around 1%-2% of the adult population and affecting around 6 million Americans. HF remains a major cause of mortality, morbidity, and poor quality of life. Several therapies are used to treat HF and improve the survival of patients; however, despite these substantial improvements in treating HF, the incidence of HF is increasing rapidly, posing a significant burden to human health. The total cost of care for HF is USD 69.8 billion in 2023, warranting a better understanding of the mechanisms involved in HF. Among the most serious manifestations associated with HF is arrhythmia due to the electrophysiological changes within the cardiomyocyte. Among these electrophysiological changes, disruptions in sodium and potassium currents' function and trafficking, as well as calcium handling, all of which impact arrhythmia in HF. The mechanisms responsible for the trafficking, anchoring, organization, and recycling of ion channels at the plasma membrane seem to be significant contributors to ion channels dysfunction in HF. Variants, microtubule alterations, or disturbances of anchoring proteins lead to ion channel trafficking defects and the alteration of the cardiomyocyte's electrophysiology. Understanding the mechanisms of ion channels trafficking could provide new therapeutic approaches for the treatment of HF. This review provides an overview of the recent advances in ion channel trafficking in HF.

The mechanisms, regulations, and functions of histone lysine crotonylation

Histone lysine crotonylation (Kcr) is a new acylation modification first discovered in 2011, which has important biological significance for gene expression, cell development, and disease treatment. In the past over ten years, numerous signs of progress have been made in the research on the biochemistry of Kcr modification, especially a series of Kcr modification-related "reader", "eraser", and "writer" enzyme systems are identified. The physiological function of crotonylation and its correlation with development, heredity, and spermatogenesis have been paid more and more attention. However, the development of disease is usually associated with abnormal Kcr modification. In this review, we summarized the identification of crotonylation modification, Kcr-related enzyme system, biological functions, and diseases caused by abnormal Kcr. This knowledge supplies a theoretical basis for further exploring the function of crotonylation in the future.