Sialic Acid Levels Research Articles

Sialic acid and anti-ganglioside M1 antibodies are invaluable biomarkers correlated with the severity of autism spectrum disorder

BackgroundAutism spectrum disorders (ASD) are devastating neurodevelopmental disorders that showed global increased prevalence. They are characterized by impairment of social communication and stereotyped patterns. ObjectiveThis study aimed at measuring the levels of total sialic acid (SA) and anti-ganglioside M1 (anti- GM1) IgG antibodies as essential biomarkers in a cohort of children with ASD to identify their diagnostic yield as well as their correlation with the severity of autistic behaviors. MethodsThe demographic characteristics, anthropometric measurements, and clinical data were recorded. The levels of total plasma SA and serum anti-GM1 IgG antibodies levels were measured in 100 children with ASD and 100 healthy controls. The severity of ASD-related symptoms was assessed by using the Childhood Autism Rating Scale (CARS). ResultsChildren with ASD had significantly higher levels of both SA and anti-GM1 antibodies than healthy controls (p < 0.001). SA showed a statistically significant moderate diagnostic performance while anti-GM1 antibody showed a statistically significant high diagnostic in differentiating severe from mild to moderate autism. Moreover, both SA and anti-GM1 antibodies levels were significantly correlated to the severity of ASD symptoms (p < 0.001). ConclusionThe significantly increased levels of SA and anti-GM1 antibodies in children with ASD and their correlation with autism-related symptoms suggest their possible etiopathogenic role in autism as one of the pediatric autoimmune neuropsychiatric disorders. However, further large-scale studies are still needed to explore their possible bidirectional relationship as biomarkers for autism.

Increased Sialylation in Alzheimer’s Disease Models

AbstractBackgroundResearch shows evidence of increased sialylation localized to pathological protein aggregates in AD autopsied brains. Sialylation is a type of glycosylation with linkage bonds of sialic acid (SA) residues on glycoproteins and glycolipids. It is unclear how changes in SA distribution in AD contributes to disease. Microglia are partially regulated by sialylation. We hypothesize decreased removal of SA residues on microglia leads to increased sialylation near amyloid‐β (Aβ) plaques, reducing microglia mediated plaque clearance.MethodA plant‐derived lectin was used to recognize α2‐6 SA bonds. Aβ plaques, microglia, and α2‐6 SA were histologically labelled in cortical brain tissue from human AD cases and 5XFAD mouse model of Aβ pathology. Stained hemibrains were imaged with confocal microscopy and quantified. To investigate the effects of reducing SA cleavage, we treated a subset of our 5XFAD and wild‐type (WT) mice with oseltamivir (Tamiflu), an inhibitor of desialylation, for five days. On day 3 and immediately following treatment, we measured cognitive and non‐cognitive behaviors using open field and novel object recognition tests.ResultQualitatively, α2‐6 SA levels displayed similar microglial‐like phenotype in 5XFAD and human AD cortical brain tissue. Two‐way ANOVA of histologically labeled hemibrains revealed 5XFAD mice had significantly increased α2‐6 SA levels compared to WT mice (p = 0.0007). High magnification image analysis supported a significant increase of α2‐6 SA area in 5XFAD mice versus WT (p&lt;0.0001), yet there was no effect of oseltamivir treatment. Behavioral data similarly demonstrated no effect of treatment. Post‐hoc analysis of open field revealed 5XFAD mice exhibited greater velocity compared to WT (p = 0.03) and 5XFAD mice lacked habituation behavior with no decrease in velocity compared to WT (p = 0.02). Investigation of Aβ pathology indicated no oseltamivir effect.ConclusionWe observed a significant increase in α2‐6 SA in 5XFAD mice similar to human AD, suggesting a plaque associated increase in sialylation. Next, we will closely examine localization of SA in the plaque microenvironment to understand the role of sialylation in microglial interactions with disease pathology. We postulate SA residues are localized to microglia interacting with Aβ plaques, potentially aggravating pathology.

Short term deuterium depletion in drinking water reduced tumor induced oxidative stress in mice liver.

The aim of current work was able to show the oxidant effect of cancer cells found in any part of the body on the liver and to investigate the possible protective effect of deuterium-depleted water (DDW) on this oxidant effect by determining of some liver parameters. Ehrlich ascites tumor bearing BALB/c mice were used for this purpose. BALB/c mice were selected randomly and divided into four groups (n=5 in each group) as control group, tumor group, control+DDW group, tumor+DDW group, fifteen days after tumor cell injection, liver tissue samples were taken for all groups. In the tumor group, liver lipid peroxidation, sialic acid and protein carbonyl levels, xanthine oxidase, myeloperoxidase, catalase, gamma-glutamyl transferase, sorbitol dehydrogenase, glutathione peroxidase and glutathione reductase activities, were significantly higher than those in the control group while glutathione levels and paraoxonase1, sodium potassium ATPase, glutathione-S-transferase, alanine transaminase and aspartate transaminase activities decreased significantly. Compared with the tumor group, the changes in all parameters except sialic acid, catalase, alanine transaminase and aspartate transaminase were reversed in the DDW given tumor groups, while sialic acid and catalase values continued to increase, and alanine transaminase and aspartate transaminase values continued to decrease. In conclusion, the consumption of DDW may be beneficial and protective against excessive oxidative stress in cancer complications.

Comparative study of sialic acid content in saliva between preeclampsia and normal gestation patients

• Sialic acid levels differ between normal pregnancies and preeclampsia cases. • Sialic acid has been reported to play a role in protecting the placenta from maternal immune attacks. • Sialic acid levels may be determined from the human saliva. • Raman spectroscopy allows the determination of sialic acid levels.

Peculiarities of the relationship between aggressive and protective factors of the gastric mucosa in patients with esophagogastroduodenal pathology with impaired adaptive potential and autonomic homeostasis (according to PRECISE-diagnostics)

Background. An imbalance of interaction between the sympathetic and parasympathetic links of the autonomic nervous system leads to autonomic dysregulation of the heart rate resulting in insufficient stress resistance, impaired adaptation and depletion of the protective mechanisms of the gastric mucosa. Therefore, the purpose of our research was to study adaptive potential of the body depending on the aggressive and protective factors of the gastric juice. Materials and methods. Seventy-one patients with esophagogastroduodenal pathology were examined using the method of PRECISE-diagnostics. The level of pH, pepsin, glycoproteins, fucose and sialic acids in the gastric contents was determined. The patients were divided into 3 representative groups: I— 30 individuals with hiatal hernia; II— 20 patients with achalasia cardia; III— 21 people with duodenal ulcer disease complicated by stenosis. Results. An imbalance of sympathetic and parasympathetic links of autonomic system was detected in 85.2% of patients. The sympathetic mechanisms dominated in 71.3% of cases. At the same time, most patients with achalasia cardia had vagotonia. The adaptive and compensatory mechanisms were identified after studying the relationship between the aggressive and protective factors of the gastric mucosa. When analyzing the correlation of aggressive and protective factors of gastric juice, the following adaptive and compensatory options were revealed: 1) hyperreactive, with simultaneous increase in the factors of both aggression and protection; 2)compensatory (an increase in the level of aggressive factors against the background of normal protective indicators); 3) decompensatory (an increase in the level of aggressive factors simultaneously with a decrease in protective factors). Conclusions. The adaptive potential of the body in 85.2% of surgical patients, mostly those with hiatal hernia and achalasia cardia, according to PRECISE-diagnostics was defined as reduced, in the form of impaired adaptation in decompensatory type of the relationship between aggressive and protective factors of gastric juice.

The glycosphingolipid repertoire affects HLA class I function

HLA class I (HLA-I) molecules drive immune responses by presenting antigen-derived peptides to T-lymphocytes. Loading of these peptides into the HLA-I binding groove occurs via a multistep process which can be hijacked by viruses and tumors for immune escape. Using iterative genome-wide haploid genetic screening we identified the protease SPPL3 to enhance HLA-I antigen presentation by inhibiting B3GNT5 activity, an enzyme of the glycosphingolipid (GSL) synthesis pathway. GSL profiling by LCMS demonstrated SPPL3-deficient cells to express high levels of sialic acid containing B3GNT5-synthesized GSLs compared to wild type cells. These GSLs localize in close proximity to HLA-I molecules -as revealed by LCMS analysis of the local membrane surrounding HLA-I-thereby shielding membrane proximal HLA-I epitopes from epitope specific antibody recognition. On a functional level, HLA-I shielding also resulted in loss of ligand (LIR-1) binding and a defect in CD8+ T cells activation. HLA-I shielding GSLs are overexpressed on several subtypes of cancer, suggesting a novel form of immune escape. Moreover, pharmacological inhibition of these GSLs on AML cells abolished HLA-I shielding. Our findings demonstrate that the composition of the GSL repertoire determines the efficacy of antigen presentation and represents a potential treatment target in infection and cancer.

Dually stimulative single-chain polymeric nano lock with dynamic ligands for sensitive detection of circulating tumor cells

Circulating tumor cells (CTCs) are important markers for cancer diagnosis and monitoring. However, CTCs detection remains challenging due to their scarcity, where most of the detection methods are compromised by the loss of CTCs in pre-enrichment, and by the lack of universal antibodies for capturing different kinds of cancer cells. Herein, we report a single-chain based nano lock (SCNL) polymer incorporating dually stimulative dynamic ligands that can bind with a broad spectrum of cancer cells and CTCs overexpressing sialic acid (SA) with high sensitivity and selectivity. The high sensitivity is realized by the polymeric single chain structure and the multi-valent functional moieties, which improve the accessibility and binding stability between the target cells and the SCNL. The highly selective targeting of cancer cells is achieved by the dynamic and dually stimulative nano lock structures, which can be unlocked and functionalized upon simultaneous exposure to overexpressed SA and acidic microenvironment. We applied the SCNL to detecting cancer cells and CTCs in clinical samples, where the detection threshold of SCNL reached 4 cells/mL. Besides CTCs enumeration, the SCNL approach could also be extended to metastasis assessment through monitoring the expressing level of surface SA on cancer cells.

Possible mechanisms involved in the testicular-protective property of quercetin in rats exposed to endosulfan toxicity

The study investigated the effects of quercetin and putative mechanisms involved against endosulfan-testicular impairments in rats. Rats were allotted into five treatment groups (n = 5). Groups 1–2 had normal saline and maize oil (vehicle) (10 mL/kg), group 3 received quercetin (20 mg/kg), 4–5 had endosulfan (5 mg/kg, p.o) orally for 28 days. However, from days 14–28, group 4 received an additional dose of vehicle (10 mL/kg, p.o./day), while group 5 received quercetin (20 mg/kg, p.o./day). Thereafter, blood samples and testes were harvested for markers of cholinergic, hormonal and testicular oxido-nitrergic, inflammatory, apoptosis and proton pump ATPase activities. Also, testicular histopathological changes were also evaluated alongside with germ cell count, testicular injury and spermatogenesis score. Quercetin increased testicular/body weights and spermatogenesis, androgenic hormones (follicle stimulating hormones, FSH; luteinizing hormone, LH; testosterone), acetylcholinesterase levels and attenuated altered membrane integrity, DNA fragmentation, increased caspases-3 levels in rats exposed to endosulfan. Moreover, quercetin increased testicular B-cell lymphoma-2 (Bcl-2), Bcl-2 associated x-protein (Bax) and proton pump adenosine trisphosphate (ATPase) and sialic acid levels. Of note, quercetin reversed endosulfan-mediated increased malondialdehyde, nitrite, peroxynitrite formation, 8-hydroxy-2′-deoxyguanosine and lowered antioxidant enzymes in the testes. The increased levels of testicular myeloperoxidase (MPO), tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) by endosulfan were also reduced by quercetin administration. Additionally, quercetin attenuate endosulfan-induced testicular histopathological changes of rats. Our findings showed that quercetin significantly inhibited endosulfan-induced testicular damage and altered spermatogenesis through inhibition of oxido-nitrergic pathway, inflammatory mediators, apoptosis, acetylcholinesterase activity and enhancement of testicular hormones and improvement in testicular ATPase activity.

Molecular bases of morphologically diffused tumors across multiple cancer types.

Gastric cancer has two distinct subtypes: the diffuse (DGC) and the intestinal (IGC) subtypes. Morphologically, the former each consists of numerous scattered tiny tumors while the latter each has one or a few solid biomasses. The former tends to be more aggressive and takes place in younger patients than the latter. While these have long been documented, little is known about the underlying causes. Our hypothesis is that the level of sialic acid (SA) accumulation on the cancer cell surfaces is a key reason for the observed differences. Our transcriptomic data-based analyses provide evidence that (i) DGCs tend to deploy more SAs on cancer cell surfaces than IGCs; (ii) this gives rise to considerably stronger cell-cell electrostatic repulsion in DGCs due to the negative charge that each SA carries; and (iii) such repulsion drives stronger cell protrusion and metastasis. Similar observations as well as our transcriptomic data-based predictions hold for multiple other cancer types, namely breast, lung, prostate plus liver and thyroid cancers, each known to have diffuse-like vs. non-diffused subtypes as well as more aggressive behaviors like DGCs vs. IGCs. Hence, we speculate that the discovery presented here applies not only to gastric cancer but multiple and even potentially all cancer types having diffuse-like and non-diffused subtypes.

Free urinary sialic acid levels may be elevated in patients with pneumococcal sepsis.

Urine free sialic acid (UFSA) is an important diagnostic biomarker for sialuria (GNE variants) and infantile sialic acid storage disease/Salla disease (SLC17A5 variants). Traditionally, UFSA has been measured using specific single-plex methodology in relatively small cohorts of patients with clinical symptoms suggestive ofthese disorders. The use of multiplex tandem mass spectrometry urine screening (UMSMS) has meant that UFSA can be measured semi-quantitatively in a muchlarger cohort of patients being investigated for suspected metabolic disorders. We hypothesised that theneuraminidase of Streptococcus pneumoniae may release free sialic acid from endogenous sialylated glycoconjugates and result inincreased UFSA levels. We conducted a retrospective review of clinical records of patients who were identified as having S.pneumoniae infection and who also had UMSMS at the timeof their acute infection. We identified three cases of increased UFSA detected by UMSMS screening that were secondary to S.pneumoniae sepsis. Additional testing ruled out geneticcauses of increased UFSA in the first patient. All three patients had overwhelming sepsis with multiorgan dysfunction which was fatal. Glycosylation abnormalities consistent with the removal of sialic acid were demonstrated in serum transferrin patterns in one patient. We have demonstrated in a retrospective cohort that elevation of UFSA levels have been observed incases of S.pneumoniae sepsis. This expands our knowledge of UFSA as a biomarker in human disease. This research demonstrates that infection with organisms with neuraminidase activity should be considered in patients with unexplained increases in UFSA.

Clinical and Diagnostic Significance of Sialic Acids Determination in Biological Material.

Sialic acids (SA) are neuraminic acid derivatives, located at the terminal position in the chains of monosaccharide residues of various glycoconjugates. SA play a dual role: they either mask recognition sites, or, on the contrary, represent biological targets that can be recognized by receptor proteins and serve as ligands. The desialylation/sialylation processes can be considered as a dynamic modification regulated by sialyltransferases and sialidases in response to external or internal stimuli. This review describes the structural and functional diversity and the potential use of SA fractions as biomarkers for various pathological conditions. Almost any extreme impact on the body and inflammatory processes are accompanied by an increase in the level of both total and free SA in the blood and tissues. Possible reasons for the increase of sialoglycoconjugate metabolism indicators in biological material include: (i) activation of the hepatocyte synthesis and secretion of various acute-phase proteins, many of which are sialoglycoproteins, (ii) impaired membrane integrity and destruction of body cells, (iii) high activity of sialidases (neurominidases) and sialyltransferases. Most acute and chronic liver diseases are characterized by the decrease in the total level of SA in the blood serum (because many plasma proteins are synthesized and glycosylated in hepatocytes). Aberrant sialylation results in changes of sialoglycoconjugate structure, its ability to perform biological functions and sialoglycoconjugate half-life. Glycosylation is the most common post-translational modification of proteins in the virus, which not only promotes the formation of specific conformation of viral proteins, but also modulates their interaction with receptors and affects host cell recognition, viral replication and infectivity. Serum total SA concentration increases in some benign and inflammatory conditions, which indicates a lack of specificity and limits their use for early detection and screening of neoplastic diseases. Clinical and diagnostic value of determining the sialoglycoconjugate metabolic indicators, including changes in the content of both SA fractions and specific proteins in various biological fluids and tissues, consists in establishing the causes and mechanisms of biochemical changes in the body in certain diseases. In combination with the measurement of existing markers, they can be used to improve diagnosis, staging and monitoring of therapeutic response in some pathological conditions where the need for specificity is less than for specific diagnostics.

Pomegranate for Diabetes and its’ Complications Amelioration

Diabetes mellitus is a metabolic disease affecting various body organs and systemscausing several complications such ascardiovascular diseases, stroke, nephropathy, retinopathy, neuropathy, erectile dysfunction and diabetic foot ulcer development. Diabetic patients are under oxidative stress and inflammation that play crucial role in complications development.Pomegranate, containingvarious phytochemicals with antioxidant, anti-inflammatory, antihyperglycemic, antihyperlipidemic, antihypertensive, antiatherogenic, antimicrobial, cardioprotective, neuroprotective, regenerative, wound healing andimmuno modulatory bioactivities, at the same time is sufficiently treating diabetesand its’ complications without any side effects as safety tests have shown. Pomegranate treatment improves antioxidant status of the patients, reduces inflammation, ameliorates diabetes improving insulin sensitivity, increasing insulin production and secretion,reducing blood glucose levels, inhibiting hemoglobin glycosylation, protecting pancreas and is contributing to pancreatic islets regeneration and stimulation. It also ameliorates cardiovascular complications decreasing total cholesterol, triglycerides, LDL, lipid peroxidation, atherosclerosis, increasing the beneficial HDL. Pomegranate alsoenhances wound healing byreducing bacterial count, inhibiting quorum sensing and biofilm formation, increasing collagen production, upregulating the EGF, VEGF and TGF-β1 levelsand leading to excellent epithelialization and neovascularization. Besides, pomegranate treatment ameliorates nephropathy reducing serum creatinine, urine albumin, blood urea nitrogen, urine albumin to creatinine ratio,renal fibrosis, glomerular sclerosis, hypertrophyand interstitial hyperplasia. Pomegranate treatment is preventing or ameliorating neuropathy and alsoimproving erectile function by increasingintracavernosal blood flow and MICP/MAP percentage in patients with atherosclerosis. Moreover, pomegranate ameliorates retinopathy reducing the oxidative stress biomarker 8-OHdG, decreasing the levels of sialic acid, malondialdehyde, improving retina cell layers and delaying cataract onset. Is important to be mentioned that while in diabetic individuals the values of several biochemical parameters were significantly improved, at the same time there were not changes on thehealthy individuals’ biochemical parameters which were normal, indicatingexcept its’ excellent pharmaceutical properties alsoa regulatory role of pomegranate as it is acting only whenever it is needed for health achievement and maintenance.These results indicate that pomegranate can offer an alternative,safe, holistic treatment for diabetes and its’ complications, improving the general health and quality of life of the patient.

Evaluation of sialic acid, malondialdehyde and glutathione levels in infertile male

Introduction and objectivesAround 15% of productive couples in the world are infertile. Recent years, biochemical mechanisms leads to male infertility are started to research. Redox regulation and oxidative stress (OS) show importance in the pathogenesis of infertility in male. Malondialdehyde (MDA) and Glutathione (GSH) are biochemical indicatives of sperm damage by reactive oxygen species (ROS). In addition, sperm are coated with a thick glycocalyx rich in sialic acids. It is aimed to determine and evaluate the differences between normozoospermic and oligozoospermic individuals according to sialic acid, MDA and GSH concentrations and correlations between spermyogram and these parameters. Material and methodsThis study was carried out on seminal plasma of individuals who admitted to Selcuk University Faculty of Medicine IVF Unit Andrology Laboratory. The groups were divided into two as normozoospermics (n=30, sperm concentration≥15million/mL), and oligozoospermics (n=30, sperm concentration<15million/mL). Spermyogram were evaluated regarding WHO (2010) Kruger criteria. GSH, MDA and sialic acid concentrations were analyzed in seminal plasma. Diagnostic performance of sialic acid has been determined with ROC curve analysis. ResultsSialic acid levels were significantly lower in Normozoospermic than Oligozoospermic individuals (p<0.0001), MDA and GSH levels were not differ significantly in both groups (p>0.05). Sialic acid correlated significantly with most of the spermyogram findings. When diagnostic performance of sialic acid was evaluated, the cut off value of sialic acid found as 4.175nmol/mL by ROC curve. ConclusionHigh seminal plasma sialic acid levels may be used as a biomarker and sialic acid is important determinant in oligozoospermia.

Sialylated and sulfated N-Glycans in MDCK and engineered MDCK cells for influenza virus studies

The Madin-Darby canine kidney (MDCK) cell line is an in vitro model for influenza A virus (IAV) infection and propagation. MDCK-SIAT1 (SIAT1) and humanized MDCK (hCK) cell lines are engineered MDCK cells that express N-glycans with elevated levels of sialic acid (Sia) in α2,6-linkage (α2,6-Sia) that are recognized by many human IAVs. To characterize the N-glycan structures in these cells and the potential changes compared to the parental MDCK cell line resulting from engineering, we analyzed the N-glycans from these cells at different passages, using both mass spectrometry and specific lectin and antibody binding. We observed significant differences between the three cell lines in overall complex N-glycans and terminal galactose modifications. MDCK cells express core fucosylated, bisected complex-type N-glycans at all passage stages, in addition to expressing α2,6-Sia on short N-glycans and α2,3-Sia on larger N-glycans. By contrast, SIAT1 cells predominantly express α2,6-Sia glycans and greatly reduced level of α2,3-Sia glycans. Additionally, they express bisected, sialylated N-glycans that are scant in MDCK cells. The hCK cells exclusively express α2,6-Sia glycans. Unexpectedly, hCK glycoproteins bound robustly to the plant lectin MAL-1, indicating α2,3-Sia glycans, but such binding was not Sia-dependent and closely mirrored that of an antibody that recognizes glycans with terminal 3-O-sulfate galactose (3-O-SGal). The 3-O-SGal epitope is highly expressed in N-glycans on multiple hCK glycoproteins. These results indicate vastly different N-glycomes between MDCK cells and the engineered clones that could relate to IAV infectivity.

Risk factors and postnatal biomarkers for acute placental inflammatory lesions and intrauterine infections in preterm infants

The purpose of this study is to explore risk factors of acute placental inflammatory lesions and the potential postnatal serum biomarkers for predicting the severity of intrauterine infection in preterm infants. We performed a retrospective analysis of premature infants with or without acute placental inflammatory lesions and their mothers by chart review for clinical data and placental histopathology. The preterm infants with acute placental inflammatory lesions had a higher rate of premature rupture of membranes (PROM), a longer duration of PROM, and a higher level of serum sialic acid (SIA) than those of the non-inflammation group (all p < 0.001). According to the different inflammatory histological structures, preterm infants with funisitis had a dominant longer duration of PROM than others (p < 0.05), and their gestational age was youngest among all the infants (p < 0.05). Furthermore, they had the highest content of serum SIA above other groups. The preterm infants in the acute histological chorioamnionitis group showed a similar trend of clinical manifestation and laboratory parameters with the funisitis group. Moreover, the closer the placental lesions were to the fetus, the lower the gestational age of preterm infants was, and the higher the serum SIA content was.Conclusion: We utilized a simple and precise anatomically category method of placental inflammatory histopathology for pediatricians to distinguish the extent of fetal inflammatory response for representing early-onset infectious diseases of preterm infants. SIA might be one of the potential early-stage serum biomarkers to reflect the severe intrauterine infections and could guide the postnatal anti-infection treatment.What is Known:• Acute placental inflammatory lesion contributes to preterm birth and a series of complications in preterm infants.• C-reactive protein and interleukin-6 in neonatal blood can be used as biomarkers for potential early-onset sepsis, but they are influenced by the postnatal physiological changes of preterm infants.What is New:• The value of serum sialic acids of preterm infants within 1-hour afterbirth may be one of the rapid postnatal biomarkers for evaluating the severity of intra-amniotic infection.• The closer the placental lesions are to the fetus, the higher the content of serum sialic acid is.

Single-cell glycomics analysis by CyTOF-Lec reveals glycan features defining cells differentially susceptible to HIV.

High-parameter single-cell phenotyping has enabled in-depth classification and interrogation of immune cells, but to date has not allowed for glycan characterization. Here, we develop CyTOF-Lec as an approach to simultaneously characterize many protein and glycan features of human immune cells at the single-cell level. We implemented CyTOF-Lec to compare glycan features between different immune subsets from blood and multiple tissue compartments, and to characterize HIV-infected cell cultures. Using bioinformatics approaches to distinguish preferential infection of cellular subsets from viral-induced remodeling, we demonstrate that HIV upregulates the levels of cell-surface fucose and sialic acid in a cell-intrinsic manner, and that memory CD4+ T cells co-expressing high levels of fucose and sialic acid are highly susceptible to HIV infection. Sialic acid levels were found to distinguish memory CD4+ T cell subsets expressing different amounts of viral entry receptors, pro-survival factors, homing receptors, and activation markers, and to play a direct role in memory CD4+ T cells' susceptibility to HIV infection. The ability of sialic acid to distinguish memory CD4+ T cells with different susceptibilities to HIV infection was experimentally validated through sorting experiments. Together, these results suggest that HIV remodels not only cellular proteins but also glycans, and that glycan expression can differentiate memory CD4+ T cells with vastly different susceptibility to HIV infection.

Elevated Serum Sialic Acid Levels May be Associated With Diabetes Retinopathy: A Cross-Sectional Study in Ghana.

This study determined the association between serum sialic acid (SSA) and metabolic risk factors in Ghanaian Type 2 diabetes (T2DM) with and without micro vascular complications. This cross-sectional study recruited 150 T2DM out-patients visiting the diabetic Clinic at the Tema General Hospital, Ghana. Fasting blood samples were collected and analyzed for Total Cholesterol (TC), Triglyceride (TG), Low Density Lipoprotein Cholesterol (LDL-C), High Density Lipoprotein Cholesterol (HDL-C), Fasting Plasma Glucose (FPG), Glycated Haemoglobin (HbA1c), SSA and C-Reactive Protein. SSA levels were significantly higher in diabetics with retinopathy (210.12 ± 85.09mg/dl) compared with those with nephropathy and those without complication (p-value= 0.005). Body adiposity index (BAI) (r= -0.419, p-value = 0.037) and Triglyceride (r= -0.576, p-value = 0.003), had a moderate negative correlation with SSA levels. In a One-Way Analysis of Covariance (Adjusted for TG and BAI), SSA could distinguish between diabetics with retinopathy and those without complications (p-value = 0.004) but not nephropathy (p-value = 0.099). Within group linear regression analysis showed that Elevated serum sialic acid was found in type 2 diabetic patients with retinopathic micro-vascular complications. Therefore, estimation of sialic acid levels may help with the early prediction and prevention of microvascular complications occurring due to diabetes, thereby decreasing the mortality and morbidity.

Anti-inflammatory properties of the extract of maruna virgin (Tanacetum parthenium L.) on the model of chronic inflammation modeled by the Freund’ adjuvant in rats

Еhe aim of the study was to investigate the effectiveness of a thick extract of feverfew (Tanacetum parthenium L.) herb in chronic inflammation (adjuvant arthritis) in rats.&#x0D; The anti-inflammatory properties of the water-alcohol thick extract of feverfew (Tanacetum parthenium L.) herb (ETP) were studied in the model of adjuvant arthritis (ADA) (0.1 ml of Freund's adjuvant (PAF), once subcutaneously at the base of the tail of white nonlinear male rats (body weight 200–220 g). After 7 days, the introduction of PAF was repeated (subcutaneously in the right hind paw of rats). The animals were divided into 4 groups of 9 rats each, in the intact group – 6 animals. Distilled water (1 ml/100 g) was administered to positive control animals (PCs) on the background of pathology. An aqueous solution of ETP (50 mg/kg) and diclofenac sodium (1% starch suspension, 8 mg/kg) were administered from day 1 of the experiment and for four weeks daily intragastrically once daily. The volume of the affected foot (V) was measured using a LE7500 plethysmometer (PANLAB, Italy) in dynamics – at 1, 5, 10, 15, 20, 25 and 30 days after administration of a permissive dose of PAF. The intensity of inflammation in rats was assessed by peripheral blood parameters, biochemical indicators - markers of the inflammatory process. Statistical analysis of data was performed using the standard software package «Statistica v. 6.0». Differences between groups were considered statistically significant at p &lt;0.05.&#x0D; The course of ADA was characterized by the development of systemic inflammation, as evidenced by an increase in the number of leukocytes, increased erythrocyte sedimentation rate (ESR) and the content of C-reactive protein (CRP). A statistically significant increase in the level of LF and sialic acids indicates membrane-destructive processes in connective tissue. Against the background of ETP significantly decreased the level of the main indicator of inflammation CRP 2 times, the content of markers of destruction of joint tissue – sialic acid and LF decreased by 1.9 times relative to PC animals, indicating a positive effect on local and systemic manifestations of inflammation in ADA. The effectiveness of ETP was not inferior to diclofenac sodium (DS).&#x0D; Based on the data obtained, it can be concluded that the studied ETP at a dose of 50 mg/kg in the ADA model in rats has a pronounced anti-inflammatory effect and is not inferior to diclofenac sodium, which makes it promising further research as an effective anti-inflammatory agent.

P-635 The impact of force-degraded variants of recombinant human follicle stimulating hormone alfa (r-hFSH alfa) on in-vitro and in-vivo biological activity

Abstract Study question Can an in-vitro bioassay assess the potency of r-hFSH-alfa force-degraded variants with similar ability to the in-vivo rat bioassay described in EU Pharmacopoeia (EU-Pharm 2285)? Summary answer The in-vitro bioassay showed similar ability to the in-vivo bioassay for estimating the impact of r-hFSH-alfa variants, resulting from process-related modifications, on biological activity. What is known already The active ingredient of Gonal f® (Merck KGaA), follitropin-alfa (INN, r-hFSH-alfa), mimics the action of endogenous FSH by binding to, and subsequently activating, the hFSH-receptor (FSH-R), regulating cellular metabolism and oocyte survival/maturation. Structural modifications in r-hFSH-alfa glycosylation, oxidation, or other biochemical changes, may occur during the r-hFSH-alfa manufacturing process and may impact its efficacy/safety. The rat in-vivo bioassay (EU Pharmacopeia) is routinely used to assess r-hFSH-alfa potency by measuring ovarian weight increase. We evaluated whether an in-vitro bioassay has the same ability as the rat in-vivo bioassay to detect changes in biological activity caused by r-hFSH-alfa structural modifications. Study design, size, duration Three r-hFSH-alfa (Gonal f®) batches were stressed under eight chemical/physical/enzymatic treatments. The resulting degraded samples were compared with untreated samples using in-vivo and in-vitro bioassays. Participants/materials, setting, methods Force-degraded r-hFSH-alfa variants were produced by chromatographic separation (acidic/basic enrichment), chemical/physical stress (acidic/basic pH incubation, thermal/oxidative stress) and enzymatic treatments (de-galactosylation and de-sialylation). r-hFSH-alfa potency was measured via a rat in-vivo bioassay (European Pharmacopoeia 2285), assessing ovarian weight increase, and an in-vitro bioassay (cell line expressing the transmembrane hFSH-R), assessing cell-specific metabolic cascade. Force-degraded and untreated samples were compared via analysis of variance. Main results and the role of chance All force-degraded samples were characterized by the chemical/physical analyses panel for quality control. r-hFSH-alfa forced degradation modified the critical quality attributes of the samples; namely, increased the presence of r-hFSH-alfa oxidized forms and/or free subunits up to 50% above product specification, and modified the sialic acid level across variants, generating significantly more hypo-sialylated forms when compared with the untreated control samples. The increase in r-hFSH-alfa free subunits significantly reduced r-h-FSH-alfa biological activity compared with untreated samples, in both the in-vivo and in-vitro assays (p &amp;lt; 0.001 for both). The increase in r-hFSH-alfa oxidized forms significantly reduced r-hFSH-alfa biological activity in-vitro (p &amp;lt;0.001) and, to a lesser extent, in-vivo (p &amp;lt;0.006). A gradual decrease in r-hFSH-alfa sialylation decreased r-hFSH-alfa biological activity in-vivo, indicating a second-order polynomial correlation, and increased r-hFSH-alfa biological activity in-vitro, indicating a negative linear correlation (slope significance p&amp;lt;0.001, R2=0.996). De-sialylation reduces r-hFSH-alfa steric hindrance during the interaction of r-hFSH-alfa and the FSH-R, increasing both r-hFSH-alfa–FSH-R affinity and r-hFSH-alfa biological activity in-vitro, while increasing the rate of r-hFSH-alfa metabolism, resulting in decreased r-hFSH-alfa biological activity in-vivo. Both assays showed a similar ability to identify differences in critical quality attribute levels (sialylation, oxidation, free-subunits), with the intent to identify out-of-specification batches. Limitations, reasons for caution r-hFSH-alfa forced degradation produced more than one structural/chemical modification in most variants (except for de-sialylation); therefore, the effect of discrete modifications could not be studied. Additional studies are needed to show that in-vitro methods can ultimately replace in-vivo bioassays to identify differences in critical quality attribute levels during r-hFSH-alfa manufacturing. Wider implications of the findings Chemical and/or structural modifications of r-hFSH-alfa strongly impact r-hFSH-alfa biological activity and related potency. The development of an in-vitro bioassay for the accurate measurement of r-hFSH-alfa potency may serve to replace the in-vivo bioassay, according to EMA indications (CPMP/SWP728/95). Trial registration number not applicable

A Cross-Sectional Study of Sialic Acids Level in Breast Cancer Patients Attending Ahmadu Bello University Teaching Hospital Zaria, North-Western Nigeria: Preliminary investigations and Implications on Disease Subtypes, Grade and Chemotherapy Courses

Abstract Due to the challenges associated with breast cancer prognosis, this study examined sialic acid levels based on subtypes, grades and therapeutic courses among breast cancer patients presenting at Ahmadu Bello University Teaching Hospital (ABUTH) in North-Western Nigeria between June 2019 and December 2020. This was a cross-sectional study. Sociodemographic characteristics, total sialic acid (TSA), free sialic acid (FSA), bound sialic acid (BSA) and haematological parameters were determined. The mean age of the respondents was 47.46 ± 10.71 years, and the modal age range was 41-50 years. About 40% of the patients had triple-negative breast cancer subtype, and 83.1% had invasive carcinoma. There was an association between breast cancer grade and body mass index (χ2= 26.306, P= 0.001). The TSA, FSA and BSA concentrations were significantly (P&lt;0.05) higher in luminal A and triple-negative breast cancer patients when compared to apparently healthy controls and were highest in stage IV patients. The TSA correlated with the third and sixth chemotherapy courses. Significant (P&lt;0.05) decrease was observed in PCV and Hb among the breast cancer patients irrespective of subtype compared to healthy control. The results suggest that TSA, FSA and BSA were higher in breast cancer patients, necessitating further research on their possible prognostic implications.