Effects of hypertension and antihypertensive treatments on sulfatide levels in serum and its metabolism

TIE2 expression in hypertensive ICH and its therapeutic modulation with AKB-9778: Implications for brain vascular health

Hypertensive intracerebral hemorrhage (ICH) is a devastating condition, the molecular underpinnings of which remain not fully understood. By leveraging high-throughput transcriptome sequencing and network pharmacology analysis, this study unveils the significant role of the tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (TIE2) in ICH pathogenesis. Compared to controls, a conspicuous downregulation of TIE2 was observed in the cerebral blood vessels of hypertensive ICH mice. In vitro assays with human brain microvascular endothelial cells (HBMEC), HBEC-5i revealed that modulation of TIE2 expression significantly influences cellular proliferation, migration, and angiogenesis, mediated via the Rap1/MEK/ERK signaling pathway. Notably, the small molecule AKB-9778 was identified to target and activate TIE2, affecting the functional attributes of HBEC-5i. In vivo experiments further demonstrated that combining AKB-9778 with antihypertensive drugs could mitigate the incidence and volume of bleeding in hypertensive ICH mouse models, suggesting potential therapeutic implications.

Serum sulfatide level is associated with severe systemic vasculitis with kidney involvement

Sulfatides are a type of sulfated glycosphingolipid that are secreted with lipoproteins into the serum. These molecules are involved in the inflammatory pathway of vessels in addition to coagulation and platelet aggregation. Previous studies have proposed that sulfatides play a pivotal role in regulating inflammation-related disorders. Systemic vasculitis (SV) diseases are generally caused by autoimmune diseases and often involve kidney vasculitis, which may lead to rapidly progressive kidney dysfunction and end-stage kidney disease. Our earlier pilot study revealed that the level of serum sulfatides (SSs) was significantly decreased in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), a representative disease-causing SV with kidney involvement (SVKI), especially in patients exhibiting active crescentic findings on kidney biopsy. To further explore the clinical significance of an association between SS and SVKI, we analyzed and compared the SS level of patients with various SVKI diseases in this retrospective cohort study. Among patients admitted to our hospital between 2008 and 2021, we ultimately enrolled 26 patients with IgA vasculitis (IgAV), 62 patients with AAV, and 10 patients with anti-glomerular basement membrane disease (GBM) as examples of SVKI diseases, as well as 50 patients with IgA nephropathy (IgAN) and 23 donors for living kidney transplantation as controls. The mean ± standard deviation SS level in the donor, IgAN, IgAV, AAV, and GBM groups was 8.26 ± 1.72, 8.01 ± 2.21, 6.01 ± 1.73, 5.37 ± 1.97, and 2.73 ± 0.99 nmol/mL, respectively. Analysis of patients in the SVKI disease group showed that those with the crescentic class kidney biopsy finding exhibited a significantly lower SS level than did those with other class biopsy features. Additionally, the SS level had a higher detection ability for SVKI patients with crescentic class kidney biopsy findings (area under the receiver operating characteristic curve 0.90, 95% confidence interval 0.82-0.99) than did several other predictor candidates. Our results indicate that the SS level is decreased in more severe SVKI diseases and may be associated with active glomerular lesions in SVKI kidney biopsy samples.

Relationship of Sulfatides Physiological Function and Peroxisome Proliferator-Activated Receptor α

Sulfatides are unique sphingolipids present in the serum and the plasma membrane. Sulfatides exert important functions in a number of systems in the human body, including the nervous, immune, cardiovascular, and coagulation systems.Furthermore, it is closely related to tumor occurrence, development, and metastasis. Peroxisome proliferators-activated receptor α (PPARα) is a class of the nuclear receptor superfamily of transcription factors, which is a potential regulator of sulfatides. This review not only summarizes the current knowledge on the physiological functions of sulfatides in various systems, but also discusses the possible PPARα regulatory mechanisms in sulfatide metabolism and functions. The results of the present analysis provide deep insights and further novel ideas for expanding the research on the physiological function and clinical application of sulfatides.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.

Fenofibrate for COVID-19 and related complications as an approach to improve treatment outcomes: the missed key for Holy Grail

Introduction

Fenofibrate is an agonist of peroxisome proliferator activated receptor alpha (PPAR-α), that possesses anti-inflammatory, antioxidant, and anti-thrombotic properties. Fenofibrate is effective against a variety of viral infections and different inflammatory disorders. Therefore, the aim of critical review was to overview the potential role of fenofibrate in the pathogenesis of SARS-CoV-2 and related complications.

Results

By destabilizing SARS-CoV-2 spike protein and preventing it from binding angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 entry, fenofibrate can reduce SARS-CoV-2 entry in human cells Fenofibrate also suppresses inflammatory signaling pathways, which decreases SARS-CoV-2 infection-related inflammatory alterations. In conclusion, fenofibrate anti-inflammatory, antioxidant, and antithrombotic capabilities may help to minimize the inflammatory and thrombotic consequences associated with SARSCoV-2 infection. Through attenuating the interaction between SARS-CoV-2 and ACE2, fenofibrate can directly reduce the risk of SARS-CoV-2 infection.

Conclusions

As a result, fenofibrate could be a potential treatment approach for COVID-19 control.

Serum sulfatide as a biomarker of carotid atherosclerosis in patients with rheumatoid arthritis

PURPOSE

Rheumatoid arthritis (RA) patients have accelerated atherosclerosis (AS) leading to excess cardiovascular morbidity and mortality, but traditional risk factors for cardiovascular disease (CVD) are invalid to explain the problem. Sulfatides, as major components of serum lipoproteins, are synthesized in the liver. These molecules are reported to play an important role in the development of AS, thrombogenesis, and inflammation. However, it is unclear whether sulfatides are responsible for such issue. To elucidate the possible association between serum sulfatide and the accelerated progress of AS, evaluated by carotid intima-media thickness (CIMT), and ascertain the related mechanism underlying the correlation in RA cases.

METHODS

We performed an observational study of 144 patients with RA and 120 sex and age-matched controls. Meanwhile, 107 patients (of the 144 RA patients enrolled at baseline) were invited to undergo a second measurement after 12 months. Serum sulfatide levels of all the enrolled subjects were quantified by mass spectrometry after they were converted into lysosulfatides (LS), and then calculated as the sum of the levels of seven LS molecular species. Serum oxidative stress marker, malondialdehyde (MDA) was detected by ELISA. We subsequently statistically analyzed the causalities between carotid AS and clinical parameters, and the association of serum sulfatide with other variables. Multivariable logistic regression analysis was finally employed by taking all factors to identify independent determinant for carotid atherosclerotic plaque and serum sulfatide level.

RESULTS

A gradual declined trend in serum sulfatide levels was observed in control subjects, non-plaque group, and the plaque group (8.56 ± 1.37 nmol/mL, 5.63 ± 1.57 nmol/mL, 3.18 ± 1.32 nmol/mL, respectively, p < 0.01), along with an increased value of CIMT (0.63 ± 0.07 mm, 0.92 ± 0.14 mm, 1.43 ± 0.22 mm, respectively, p < 0.01). Meanwhile, a negative linear correlation between CIMT and serum sulfatide was further confirmed by Spearman's analysis (r = -0.622, p < 0.01). Eventually, multivariate logistic regression analysis identified serum MDA as the only independent factor for the abnormal level of serum sulfatide, and serum sulfatide was detected as a significant protective factor for the occurrence of carotid plaques in RA cases (p < 0.01), which was confirmed repeatedly by our cross-sectional and longitudinal studies.

CONCLUSION

Excessive abnormal levels of oxidative stress decreased serum sulfatide levels, followed by a high occurrence of AS in RA patients. Serum sulfatide level might be useful as a predictor (biomarker) for the progression of AS in RA cases.

Novel Insight into the Serum Sphingolipid Fingerprint Characterizing Longevity

Sphingolipids (SLs) are structural components of the lipid bilayer regulating cell functions. In biological fluids, their distribution is sex-specific and is at variance in aging and many disorders. The aim of this study is to identify SL species associated with the decelerated aging of centenarians. SLs, extracted from serum of adults (Ad, 35–37 years old), aged (Ag, 75–77 years old) and centenarian (C, 105–107 years old) women were analyzed by LC-MS/MS in combination with mRNA levels in peripheral blood mononuclear cells (PBMCs) of SL biosynthetic enzymes. Results indicated in Ag and C vs. Ad a comparable ceramides (Cers) increase, whereas dihydroceramide (dhCer) decreased in C vs. Ad. Hexosylceramides (HexCer) species, specifically HexCer 16:0, 22:0 and 24:1 acyl chains, increased in C vs. Ag representing a specific trait of C. Sphingosine (Sph), dihydrosphingosine (dhSph), sphingosine-1-phosphate (S1P) and dihydrosphingosine-1-phosphate (dhS1P), increased both in Ag and C vs. Ad, with higher levels in Ag, indicating a SL fine-tuning associated with a reduced physiological decline in C. mRNA levels of enzymes involved in ceramide de novo biosynthesis increased in Ag whereas enzymes involved in sphingomyelin (SM) degradation increased in C. Collectively, results suggest that Ag produce Cers by de novo synthesis whereas C activate a protective mechanism degrading SMs to Cers converting it into glycosphingolipids.

Serum Sulfatide Levels as a Biomarker of Active Glomerular Lesion in Patients with Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Single Center Pilot Study

Sulfatides are glycosphingolipids that are associated with coagulation and platelet aggregation. Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) activates platelet function and often leads to thrombotic complications. These facts suggest an association between serum sulfatides and AAV. We aimed to clarify the significance of serum sulfatide levels in patients with AAV. We conducted a retrospective, single-center, observational pilot study that included 35 patients who developed AAV and 10 control patients who were candidates for living-donor kidney transplantation. We compared serum sulfatide levels between the control and AAV patients. We analyzed the differences in serum sulfatide levels among four classes (focal, crescentic, mixed, and sclerotic class) of glomerular lesions that were categorized by histopathologic classification of ANCA-associated glomerulonephritis. Serum sulfatide levels in patients with AAV were significantly lower than those in the controls. Serum sulfatide levels were significantly different between the four classes. Additionally, serum sulfatide levels in the crescentic class were significantly lower than those in the other classes. Serum sulfatide levels were significantly correlated with albumin, cholesterol, C-reactive protein, and pentraxin 3. In conclusion, serum sulfatide levels are significantly correlated with inflammation, reflecting crescentic glomerulonephritis, which is an active glomerular lesion in AAV patients.

Nanostructured zinc oxide film amalgamated with functionalized carbon nanotubes for facile electrochemical determination of nifedipine

An innovative approach has been employed for the detection of nifedipine at glassy carbon electrode fabricated with zinc oxide nanoparticles embedded on functionalized multi walled carbon nanotubes. Herein, square wave voltammetry being an expeditious electrochemical technique has been utilized for the first time for the determination of nifedipine. Instrumental variables were altered to acquire optimized operational parameters. The electrochemical oxidation peak of nifedipine was procured at ∼ 807 mV which was recorded versus Ag/AgCl reference electrode. The oxidation peak was used to quantify the analyte in the dynamic linear range of 1 nM to 40 μM with highest sensitivity and lowest detection limit of 21.8 μA μM^-1 and 0.49 nM respectively. The influence of common physiological interferents on the current signal of the analyte was examined. Pronounced stability and reproducibility of fabricated sensor was attained by the neoteric electrochemical approach. The developed protocol was efficaciously applied to quantify nifedipine in pharmaceutical formulations. The urine and blood serum sample of patients being treated for hypertension was effectively detected with nifedipine for the first time. The biological sample assay without the interference of the metabolites coexisting in the samples outlined the insight of selectivity of the developed sensor.

Fenofibrate increases the amount of sulfatide which seems beneficial against Covid-19

Fenofibrate, which is a PPAR-alfpha agonist, increases the level of sulfatide. In this letter we hypothesize on the background of various findings that this is beneficial against COVID-19. Fenofibrate has been used for decades against hypercholesterolemia and has no serious side effects. Therefore, a trial giving fenofibrate to patients with corona virus infection is recommended.