Potential Biomarker Peptides Associated with Acute Alcohol-Induced Reduction of Blood Pressure

Intracellular peptides in SARS-CoV-2-infected patients

Intracellular peptides (InPeps) generated by the orchestrated action of the proteasome and intracellular peptidases have biological and pharmacological significance. Here, human plasma relative concentration of specific InPeps was compared between 175 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and 45 SARS-CoV-2 non-infected patients; 2,466 unique peptides were identified, of which 67% were InPeps. The results revealed differences of a specific group of peptides in human plasma comparing non-infected individuals to patients infected by SARS-CoV-2, following the results of the semi-quantitative analyses by isotope-labeled electrospray mass spectrometry. The protein-protein interactions networks enriched pathways, drawn by genes encoding the proteins from which the peptides originated, revealed the presence of the coronavirus disease/COVID-19 network solely in the group of patients fatally infected by SARS-CoV-2. Thus, modulation of the relative plasma levels of specific InPeps could be employed as a predictive tool for disease outcome.

Peptides associated with hypertensive disorders of pregnancy as possible biomarkers for severity of lower extremity arterial disease

BACKGROUND AND AIMS

Seven circulating peptides, consisting of 18-28 amino acids, were identified as possible biomarkers of hypertensive disorders of pregnancy (HDP) in our previous study. However, it is unknown whether these peptides are relevant to cardiovascular disease. The purpose of this study was to clarify the relationships between serum levels of these peptides and leg arterial blood flow in patients with lower extremity arterial disease (LEAD).

METHODS

The subjects were 165 outpatients with LEAD. Patients with advanced LEAD (stages 5 and 6 of the Rutherford classification) were not included. Leg arterial blood flow was evaluated by ankle brachial pressure index (ABI) and % decrease in ABI after leg exercise induced by a leg loader or treadmill. Concentrations of the seven peptides with m/z 2081 (P-2081), 2091 (P-2091), 2127 (P-2127), 2209 (P-2209), 2378 (P-2378), 2858 (P-2858) and 3156 (P-3156) were measured simultaneously with a mass spectrometer.

RESULTS

P-2081, P-2127 and P-2209 levels showed significant positive correlations with leg arterial blood flow, while P-2091, P-2378 and P-2858 levels showed significant inverse correlations with leg arterial blood flow. There was no significant correlation between P-3156 levels and leg arterial blood flow. The above positive and inverse associations between peptide levels and leg arterial blood flow were also found in logistic regression analysis using tertile groups divided by the concentrations of each peptide.

CONCLUSIONS

Serum levels of six HDP-related peptides (P-2081, P-2091, P-2127, P-2209, P-2378 and P-2858) were associated with lower extremity arterial blood flow in patients with LEAD, and thus these peptides are possible biomarkers for severity of LEAD.

Alcohol and Metabolic-associated Fatty Liver Disease

The diagnosis of metabolic-associated fatty liver disease is based on the detection of liver steatosis together with the presence of metabolic dysfunction. According to this new definition, the diagnosis of metabolic-associated fatty liver disease is independent of the amount of alcohol consumed. Actually, alcohol and its metabolites have various effects on metabolic-associated abnormalities during the process of alcohol metabolism. Studies have shown improved metabolic function in light to moderate alcohol drinkers. There are several studies focusing on the role of light to moderate alcohol intake on metabolic dysfunction. However, the results from studies are diverse, and the conclusions are often controversial. This review systematically discusses the effects of alcohol consumption, focusing on light to moderate alcohol consumption, obesity, lipid and glucose metabolism, and blood pressure.

Decreased serum complement component 4 levels in patients with schizophrenia

Dysregulation of the immune system in mental disease, particularly complement component 4 (C4), which may be associated with schizophrenia, has been repeatedly observed. This study investigated the association between the level of serum component 4 and schizophrenia. Data were derived from a case-control association study of 40 unrelated adult patients with schizophrenia and 40 matched healthy controls. The component 4 level in serum was measured for comparative analysis by a component 4 enzyme-linked immunosorbent assay kit. Our findings suggest that the serum component 4 level is lower in patients with schizophrenia than in the controls, and the results apply to both males and females. Our results will lay an important foundation for establishing diagnostic methods and provide feasible and reliable evidence for the clinical treatment of schizophrenia.

Hypertensive disorders of pregnancy: Strategy to develop clinical peptide biomarkers for more accurate evaluation of the pathophysiological status of this syndrome

Hypertensive disorders of pregnancy (HDP) is the most common and widely known as serious complication of pregnancy. As this syndrome is a major leading cause of maternal, fetal, and neonatal morbidity/mortality worldwide, many studies have sought to identify candidate molecules as potential disease biomarkers (DBMs) for use in clinical examinations. Accumulating evidence over the past 2 decades that the many proteolytic peptides appear in human humoral fluids, including peripheral blood, in association with an individual's health condition. This review provides the potential utility of peptidomic analysis for monitoring for pathophysiological status in HDP, and presents an overview of current status of peptide quantification technology. Especially, the technical limitations of the methods used for DBM discovery in the blood are discussed.