1.Altered Redox Status in Erythrocytes From Hypertensive Subjects: Effect of (-)Epicatechin
SYED IBRAHIM RIZVI ; NAVNEET KUMAR
Progress in Biochemistry and Biophysics 2005;32(3):235-238
Hypertension is a major problem worldwide. There is much evidence to suggest that reactive oxygen species (ROS) radical may play a role in the development of organ damage associated with cardiovascular disease and hypertension. (-)Epicatechin, a member of tea catechins belonging to flavonoid group, is known to be a potent anti-oxidant.The study has been undertaken to evaluate the effect of (-)epicatechin on markers of oxidative stress: reduced glutathione (GSH) and membrane sulfhydryl (-SH) groups in erythrocytes from hypertensive patients. The effect of (-)epicatechin was also compared with a known anti-oxidant L-ascorbic acid. The erythrocyte intracellular GSH content and membrane -SH group content were significantly (P<0.01) decreased in hypertensive subjects. In vitro incubation with (-)epicatechin caused an increase in GSH and -SH content, the effect was more pronounced in hypertensive erythrocytes. Similar results were obtained with L-ascorbic acid. The observed decrease in the level of GSH and -SH groups in hypertension is an indicator of oxidative stress condition. Observation of an increase in red cell GSH content and the protection of membrane -SH group oxidation by (-)epicatechin in hypertensive subjects is a convincing reason to suggest that high dietary intake of foods rich in catechins may help to reduce oxidative stress and concomitant free radical damage in hypertensive patients.
2.Endo-beta-N-acetylglucosaminidase: Possible Functions and Mechanisms
Xin-Rong LU ; Yong-Liang TONG ; Wei-Li KONG ; Lin ZOU ; Dan-Feng SHEN ; Shao-Xian LÜ ; Rui-Jie LIU ; Shao-Xing ZHANG ; Yu-Xin ZHANG ; Lin-Lin HOU ; Gui-Qin SUN ; Li CHEN
Progress in Biochemistry and Biophysics 2024;51(5):985-999
Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.
3.Plasticity of Cultured Neural Networks In Vitro
Qi SHAO ; Wei-Wei MENG ; Xiao-Hong LI ; Wen-Wei SHAO
Progress in Biochemistry and Biophysics 2024;51(5):1000-1009
Neuronal network is the structural basis for the execution of higher cognitive functions in the brain. Research has shown that learning, memory, and neurodegenerative diseases are closely related to neuronal network plasticity. Therefore, uncovering the mechanisms that regulate and modify neuronal network plasticity is of great significance for understanding information processing in the nervous system and for the treatment of diseases. Currently, neuronal networks cultured on microelectrode array (MEA) provide an ideal model for investigating learning and memory mechanisms in vitro. Additionally, studying such models offers a unique perspective for the prevention and treatment of neurodegenerative diseases. In this review, we summarize relevant research on functional network construction based on recording the electrical signals of neuronal networks cultivated on MEA. We focus on two aspects: 2D neuronal networks and 3D brain organoid development, as well as the effects of open-loop and closed-loop electrical stimulation on neuronal network plasticity. Lastly, we provide an outlook on the future applications of studying neuronal network plasticity using in vitro cultured networks.
4.Regulation and Mechanism of Macrophage Function by Mechanical Force
Progress in Biochemistry and Biophysics 2024;51(5):1010-1022
As the vanguard of the innate immune system to recognize external environmental stimuli, macrophages can respond to subtle changes in the environment and achieve adaptive regulation of their own functions, playing a crucial role in maintaining homeostasis and resisting infection. Various mechanical stress stimuli including endogenous stress mediated by mechanical characteristics of extracellular matrix, and exogenous stress such as solid/liquid pressure, tension and fluid shear stress, exist in the physiological or pathological tissue microenvironment, which have important effects on the immune function of macrophages. The understanding of macrophage mechanobiology will contribute to the development of new immunotherapies targeting macrophages. This review focuses on the functional regulation of macrophages by mechanical stress, summarizes the research progress from the perspective of influencing cell adhesion, migration, phagocytosis and polarization, and summarizes the molecular mechanisms of macrophage mechanical sensing and transduction from the outside to the inside in three levels: cell membrane mechanical sensors, force signal transduction of cytoskeleton system, and YAP/TAZ-mediated gene expression regulation response to mechanical stress. In addition, the application prospects and future vision of macrophage mechanobiology research in tissue engineering, regenerative medicine, and tumor immunotherapy are discussed, providing strong support for a deeper understanding of the plasticity of macrophage function.
5.Allergy Associated With N-glycans on Glycoprotein Allergens
Yu-Xin ZHANG ; Rui-Jie LIU ; Shao-Xing ZHANG ; Shu-Ying YUAN ; Yan-Wen CHEN ; Yi-Lin YE ; Qian-Ge LIN ; Xin-Rong LU ; Yong-Liang TONG ; Li CHEN ; Gui-Qin SUN
Progress in Biochemistry and Biophysics 2024;51(5):1023-1033
Protein as the allergens could lead to allergy. In addition, a widespread class of allergens were known as glycans of N-glycoprotein. N-glycoprotein contained oligosaccharide linked by covalent bonds with protein. Recently,studies implicated that allergy was associated with glycans of heterologous N-glycoprotein found in food, inhalants, insect toxins, etc. The N-glycan structure of N-glycoprotein allergen has exerted an influence on the binding between allergens and IgE, while the recognition and presentation of allergens by antigen-presenting cells (APCs) were also affected. Some researches showed thatN-glycan structure of allergen was remodeled by N-glycosidase, such as cFase I, gpcXylase, as binding of allergen and IgE partly decreased. Thus, allergic problems caused by N-glycoproteins could potentially be solved by modifying or altering the structure ofN-glycoprotein allergens, addressing the root of the issue. Mechanism of N-glycans associated allergy could also be elaborated through glycosylation enzymes, alterations of host glycosylation. This article hopes to provide a separate insight for glycoimmunology perspective, and an alternative strategy for clinical prevention or therapy of allergic diseases.
6.Pathological Mechanism of Neuronal Autophagy Flow Disturbance Caused by NSF ATPase Inactivation After Cerebral Ischemia
Qian LEI ; Yi-Hao DENG ; Hong-Yun HE
Progress in Biochemistry and Biophysics 2024;51(5):1034-1042
Cerebral ischemic stroke is an acute cerebrovascular disease caused by cerebral vascular occlusion, and it is associated with high incidence, disability, and mortality rates. Studies have found that excessive or insufficient autophagy can lead to cellular damage. Autophagy consists of autophagosome formation and maturation, autophagosome-lysosome fusion, degradation and clearance of autophagic substrates within autolysosomes, and these processes collectively constitute autophagic flux. Research has revealed that cerebral ischemia can induce impaired fusion between autophagosomes and lysosomes, resulting in autophagic flux impairment. Intracellular membrane fusion is mediated by three core components: N-ethylmaleimide sensitive factor (NSF) ATPase, soluble NSF attachment protein (SNAP), and soluble NSF attachment protein receptors (SNAREs). SNAREs, after mediating fusion between autophagosomes and lysosomes, remain in an inactive complex state on the autolysosomal membrane, requiring NSF reactivation into monomers to perform subsequent rounds of membrane fusion-mediated functions. NSF is the sole ATPase capable of reactivating SNAREs. Recent studies have shown that cerebral ischemia significantly inhibits NSF ATPase activity, reducing its reactivation of SNAREs. This may be a pathological mechanism for impaired fusion between autophagosomes and lysosomes, leading to neuronal autophagic flux impairment. This article discusses the pathological mechanisms of NSF ATPase inactivation, including SNAREs dysregulation, impaired fusion between autophagosomes and lysosomes, and insufficient transport of proteolytic enzymes to lysosomes, and explores approaches to improve neuronal autophagic flux through NSF ATPase reactivation. It provides references for stroke treatment improvement and points out directions for further research.
7.Application of CDO1 Gene Promoter Methylation in Tumors
Yu ZHOU ; Hong-Bo YU ; Yuan CAO ; Jun-Jie WANG
Progress in Biochemistry and Biophysics 2024;51(5):1043-1053
Cysteine dioxygenase 1 (CDO1) gene is a non-heme structured, iron-containing metalloenzyme involved in the conversion of cysteine to cysteine sulfinic acid to regulate cysteine accumulation in vivo. Elevated levels of cysteine have been shown to be cytotoxic and neurotoxic, and this is the first important step in the breakdown of cysteine metabolism in mammalian tissues. The human CDO1 gene is located on chromosome 5q23.2. Studies have shown that deletion or epigenetic silencing of this chromosomal region contributes to tumorigenesis. It is highly expressed in the liver and placenta, and weakly in the heart, brain and pancreas. CDO1 is a tumor suppressor gene (TSG) with a wide range of functions, which can be involved in various biological processes such as tumor cell proliferation, differentiation, apoptosis and iron death, thus affecting the tumor development. CDO1 is epigenetically regulated in human cancers, compared to normal tissues. The CDO1’s mRNA or protein expression levels were significantly down-regulated in tumor tissues, whereas promoter DNA methylation of the CDO1 gene usually accumulates with the progression of human cancers. Aberrant hypermethylation on the CDO1 promoter is a common event in tumor cells, which leads to transcriptional inactivation and silencing of the CDO1 gene. High frequency of methylation of CDO1 gene promoter methylation region in a variety of tumors including breast, oesophageal, lung, bladder, gastric and colorectal cancers. CDO1 gene promoter methylation levels reflect cancer progression and malignant tumorigenesis, which is a common molecular indicator explaining poor prognosis in human cancers. Treatment with 5-aza-2′-deoxycytidine (a drug that promotes demethylation) reactivated the CDO1 expression in most cancer cell lines, indicating that the transcriptional expression of CDO1 is closely correlated with its promoter methylation level, CDO1 gene promoter methylation and tumor progression have also received increasing attention from researchers. It was found that CDO1 gene promoter hypermethylation can be used as an early tumor marker for clinical aid diagnosis and helps to differentiate cancerous from benign diseases. It was also found that CDO1 promoter DNA methylation showed reliable tumor monitoring potential in human body fluids, and furthermore, the degree of CDO1 promoter methylation was strongly correlated with resistance to chemotherapy with tumor drugs, which would be helpful in evaluating the efficacy of chemotherapeutic drugs. Thus, CDO1, a common promoter methylation gene in human cancers, is closely associated with the development of a wide range of tumors and is one of the most promising candidate genes for assessing tumor-specific epigenetic changes. This article reviews the biological functions of CDO1 and its promoter DNA methylation in tumors, focusing on the mechanism of CDO1 DNA promoter methylation in tumors, with a view to providing theoretical guidance for the clinical diagnosis and treatment of tumors with CDO1 as a potential therapeutic target.
8.The Roles of Small Extracellular Vesicles and Small Extracellular Vesicles-derived Non-coding RNA in Non-alcoholic Fatty Liver Disease
Progress in Biochemistry and Biophysics 2024;51(5):1054-1066
Extracellular vesicles (EVs) are a kind of exsomes secreted by cells, which all cells release them as part of their normal physiology and during acquired abnormalities. EVs can be broadly divided into two categories by their sizes, small EVs (sEVs) and medium/large EVs (m/l EVs). As a kind of extracellular vesicle, sEVs are mostly discoid vesicles with diameters ranging from 40 nm to 200 nm. The medium/large EVs are elliptical with a diameter more than 200 nm. sEVs play a crucial role in intercellular communication and have emerged as important mediators in the development and progression of liver diseases. In this review, we discussed the current understanding of the role of sEVs, particularly sEV derived non-coding RNA in non-alcoholic fatty liver disease (NAFLD) and their potential as diagnostic and therapeutic targets. sEVs are small membrane-bound particles secreted by cells, which fuse with plasma membrane and release to extracellular matrix. Depending on the cell of origin, sEVs could contain many cell constituents, including various DNA, RNA, lipids, metabolites, and cytosolic and cell-surface proteins, biomolecules. In addition, many RNA and DNA molecules contained by sEVs, such as mRNA, microRNA (miRNA), long noncoding RNA (lncRNA) and mitochondrial DNA (mtDNA), can be transferred to recipient cells to effectively promote their biological response, physiological and pathological functions. Such sEVs-mediated responses can be disease promoting or restraining. The intrinsic properties of sEVs in regulating complex intracellular pathways has advanced their potential utility in the therapeutic control of many diseases. Recent studies reviewed here also indicate a functional, targeted, mechanism-driven accumulation of specific cellular components in sEVs, suggesting that they have a role in regulating intercellular communication. Many studies have also shown the involvement of sEVs’ noncoding RNAs (ncRNAs) in controlling cell activities and their crucial functions in regulating lipid metabolism. sEVs ncRNAs, including miRNAs, lncRNAs, and circular RNAs (circRNAs) regulate physiological functions and maintain lipid metabolism homeostasis. miRNA are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messenger RNA-targets. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response in liver diseases. And lncRNAs have been shown to regulate gene expression by interacting with transcription factors or chromatin-modifying enzymes, which regulate gene expression by binding to target mRNAs. Then circRNAs contributed to NAFLD progression by acting as miRNA sponges, functional protein sponges, or novel templates for protein translation. Finally, sEVs could be engineered to deliver diverse therapeutic payloads, including short interfering RNAs, antisense oligonucleotides and so on, with an ability to direct their delivery to a desired target. The potential of targeting sEVs with lncRNAs and miRNAs not only could be potential diagnostic biomarkers for NAFLD, but also have potential therapeutic effects on NAFLD, which might provide new ideas for the NAFLD treatment. In conclusion, this review provides an overview of the current understanding of the roles of sEVs ncRNAs in NAFLD, so we suggest that further research into sEVs could lead to new diagnostic tools and therapeutic strategies for NAFLD.
9.Role of Lipid Metabolism Disorders in Renal Ageing and Renal Fibrosis
Sheng-Quan WU ; Meng YANG ; Xin-Guang LIU
Progress in Biochemistry and Biophysics 2024;51(5):1067-1078
Chronic kidney disease (CKD) has become a significant global public health problem. It is defined as chronic renal structural and functional dysfunction caused by various reasons. The prevalence of obesity and diabetes has increased dramatically in developing countries, which substantially affected the patterns of CKD observed in these regions. It’s inevitable that the disease spectrum of CKD is converting to metabolic diseases. CKD is also considered an independent risk factor for renal aging and cardiovascular disease in the elderly, which usually progresses to end-stage renal disease (ESRD). Renal interstitial fibrosis is the pathological basis of ESRD and is a microscopic manifestation of renal aging. Conversely, renal aging is a risk factor for interstitial fibrosis. Although the healthy kidney has a relatively low lipid level, CKD-associated dyslipidemia has been extensively studied. Nevertheless, less is known about the contribution of lipid disorders to the development of renal senescence and interstitial fibrosis. Recent studies have demonstrated that lipid metabolism disorders occur in the progress of renal aging and interstitial fibrosis. Renal lipids accumulate once lipid uptake and synthesis exceed the balance with lipolysis, which is mainly characterized by increased levels of triglyceride (TG) and oxidized low-density lipoprotein, and decreased levels of high-density lipoprotein. Excessive lipid accumulation in the kidney not only induces lipotoxicity and endoplasmic reticulum stress but also increases intracellular and mitochondrial reactive oxygen species, which induce stress injury and senescence in renal tubular epithelial cells. Pro-inflammatory and pro-fibrotic cytokines in a senescence-associated secretory phenotype secreted by senescent renal tubular epithelial cells further accelerate their senescence as well as the occurrence of inflammation and pericyte loss, promoting secretion of extracellular matrix (ECM) and subsequent fibrosis in the tubulointerstitial compartment. In addition, podocyte hypertrophy also leads to glomerulosclerosis. Currently, most of the studies on inhibiting or even reversing renal interstitial fibrosis are still in the experimental stage. What’s more, effective drugs to slow down renal aging have not been reported. Many inflammatory and fibrotic factors are both components of the senescence-associated secretory phenotype (SASP), nevertheless, they are not sufficient to recognize cellular senescence. Given that indicators of senescence may vary from disease to disease and organ to organ, there is a need for more sensitive and specific senescence assays. Crucial enzymes and regulatory proteins of lipid metabolic pathways are expected to be potential targets for ameliorating renal aging and interstitial fibrosis. Lipid-lowering approach might represent another therapeutic in the management of kidney injury associated with metabolic dysfunction. Thus, clarifying the molecular regulatory mechanisms of lipid metabolism in kidney is extremely important for the delay of renal aging and the treatment of interstitial fibrosis. This review outlines the effects of lipid metabolism disorders on renal aging and renal fibrosis, analyses the role of lipid metabolism disorders in the development of renal diseases, and summarizes the potential targets and strategies for the prevention of renal aging and renal fibrosis based on lipid metabolism regulation, which will provide a reference for the discovery of new targets for the treatment of renal fibrosis.
10.The Role of Nrf2 in Exercise Improving of NAFLD
Ge ZHAO ; Yuan LUO ; Ya-Ping LI ; Yan-Qing YAN ; Shu-Jing LIU
Progress in Biochemistry and Biophysics 2024;51(5):1079-1089
In cardiovascular disorders, neurological diseases, and chronic metabolic diseases, the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is essential for maintaining cell homeostasis. According to studies, boosting Nrf2 expression can be used to cure or prevent chronic diseases that are characterized by oxidative stress, inflammation, and mitochondrial dysfunction. Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic liver disease characterized by hepatic steatosis brought on by a number of causes other than alcohol. In recent years, its incidence has gradually risen across the globe. According to relevant studies, NAFLD and the Nrf2 signaling pathway are tightly connected. Inhibiting lipid production and metabolism-related enzymes, repairing impaired liver metabolism, and lowering hepatic lipid storage are all possible with Nrf2 activation. Exercise is a powerful tool for treating and preventing NAFLD. However, exercise type, exercise intensity, environment, and exhaustion all have an impact on the Nrf2 signaling pathway. By activating Nrf2, exercise can lessen liver inflammation, oxidative stress, endoplasmic reticulum stress, and insulin resistance, and ameliorate liver damage to improve NAFLD. The activation of Nrf2 signaling pathway, its associated mechanism of controlling antioxidation, and the impact of exercise on the Nrf2 signaling pathway are all explained in this work. Based on the pathogenesis of NAFLD, this article examines the connection between exercise, Nrf2, and NAFLD, and the current state of knowledge regarding Nrf2’s role in the amelioration of NAFLD through exercise. It offers a theoretical frame of reference for future research into how Nrf2 might be used to improve NAFLD.