Total Glycosaminoglycans Research Articles

B-253 Using biomarkers in recurrent renal stone formers to detect silent stones

Abstract Background Glycosaminoglycans (GAGs) protect cells from binding of calcium oxalate (CaOx) crystals to prevent CaOx stone formation. Hyaluronan (HA) is a non-sulfated GAG with crystallization-promoting activity during renal stone formation. The excretion of urinary GAGs and HA were measured in stone-formers (SF), post-treated SF, and normal controls to reveal their relationship with renal stone disease. Methods Three groups were included - active SF, post-treated SF (SF after extracorporeal shock wave lithotripsy) and normal controls with 40 subjects in each group. Early morning urine was collected for each subject. The hexuronate content of the GAGs were measured by carbazole reaction and values for GAGs were standardized against creatinine. Individual GAGs extracts were then digested sequentially with Streptomyces hyaluronidase and chondroitinase ABC to yield the HA disaccharides for analysis by high performance liquid chromatography. Results Hexuronate content of GAGs were in the order of post-treated SF < SF << normal controls. SF had an enhanced urinary excretion of HA with no increase of urinary HA in post-treated SF group. However, both the SF and post-treated SF groups had increased proportion of HA (of total GAGs) compared to normal controls. Active-SF and post-treated SF groups had lower total GAGs content but increased proportion of HA than that of the normal controls indicating that urinary GAGs and HA are probably protective/risk factors, respectively, for renal stone disease. Conclusions The higher recurrence rate of renal stone disease may be due to the presence of sub-species of GAGs, HA, that becomes an accidental participant for renal stone formation. Concomitantly, other species of charged sulfated GAGs, which are protective to the cells and prevent crystal binding, are found to be in lesser content in active SF and post-treated SF. Clinicians can use these two markers, which are easily detectable (by ELISA) for prevention and monitoring of silent renal stone formation.

Comparing the effects of various fluid resuscitative strategies on Glycocalyx damage in a canine hemorrhage model

Hemorrhagic shock and subsequent resuscitation can cause significant dysregulation of critical systems, including the vascular endothelium. Following hemorrhage, the endothelial lining (glycocalyx) can shed, causing release of glycocalyx components, endothelial activation, and systemic inflammation. A canine model of hemorrhagic shock was used to evaluate five resuscitation fluids, including Lactated Ringers+Hetastarch, Whole Blood (WB), Fresh Frozen Plasma+packed Red Blood Cells (FFP+pRBC), and two hemoglobin-based oxygen carrier (HBOC) fluids, for their impact on glycocalyx shedding. Under anesthesia, purpose-bred adult canines were instrumented and subjected to a controlled hemorrhage with blood being drawn until a mean arterial pressure of <50 mmHg was reached or 40 % of the estimated blood volume was removed. Canines were left in shock for 45 mins before being resuscitated with one of the resuscitation fluids over 30 mins. Following resuscitation, the dogs were monitored up to 2 weeks. Following an additional 3–4 weeks for washout, the canines repeated the protocol, undergoing each resuscitation fluid individually. Blood samples were collected during each round at various timepoints for serum isolation, which was used for detection of glycocalyx biomarker. Comparison of baseline and post-hemorrhage alone showed a significant reduction in serum protein (p<0.0001), heparan sulfate (p<0.001), and syndecan-1 (p<0.0001) concentrations, and a significant increase in hyaluronan (p<0.0001) concentration. Intercomparisons of resuscitation fluids indicated minimal differences in glycocalyx markers over time. Comparisons within each fluid showed dynamic responses in glycocalyx biomarkers over time. Relative to individual baselines, syndecan-1 was significantly reduced after resuscitation in most cases (p<0.0001), excluding WB and FFP+pRBC. In all cases, VE-cadherin was significantly elevated at 24 hr compared to baseline (p<0.001). Hyaluronan was significantly elevated by 3 hr in all cases (p<0.01), except for HBOC fluids. Total glycosaminoglycans were significantly reduced only at 3 hr (p<0.001) for non-HBOC fluids. Similarly, heparan sulfate was significantly reduced with all fluids between resuscitation and 24 hr (p<0.01), except WB. The temporal changes in canine glycocalyx biomarkers were atypical of hemorrhage response in other species. This suggests that the hemorrhage lacked severity and/or typical glycocalyx biomarkers do not reflect the canine endothelium compared to other species. Further research is needed to characterize the canine endothelium and the response to resuscitation fluids.

The role of semaphorin 3A on chondrogenic differentiation

Osteoblast-derived semaphorin3A (Sema3A) has been reported to be involved in bone protection, and Sema3A knockout mice have been reported to exhibit chondrodysplasia. From these reports, Sema3A is considered to be involved in chondrogenic differentiation and skeletal formation, but there are many unclear points about its function and mechanism in chondrogenic differentiation. This study investigated the pharmacological effects of Sema3A in chondrogenic differentiation. The amount of Sema3A secreted into the culture supernatant was measured using an enzyme-linked immunosorbent assay. The expression of chondrogenic differentiation-related factors, such as Type II collagen (COL2A1), Aggrecan (ACAN), hyaluronan synthase 2 (HAS2), SRY-box transcription factor 9 (Sox9), Runt-related transcription factor 2 (Runx2), and Type X collagen (COL10A1) in ATDC5 cells treated with Sema3A (1,10 and 100 ng/mL) was examined using real-time reverse transcription polymerase chain reaction. Further, to assess the deposition of total glycosaminoglycans during chondrogenic differentiation, ATDC5 cells were stained with Alcian Blue. Moreover, the amount of hyaluronan in the culture supernatant was measured by enzyme-linked immunosorbent assay. The addition of Sema3A to cultured ATDC5 cells increased the expression of Sox9, Runx2, COL2A1, ACAN, HAS2, and COL10A1 during chondrogenic differentiation. Moreover, it enhanced total proteoglycan and hyaluronan synthesis. Further, Sema3A was upregulated in the early stages of chondrogenic differentiation, and its secretion decreased later. Sema3A increases extracellular matrix production and promotes chondrogenic differentiation. To the best of our knowledge, this is the first study to demonstrate the role of Sema3A on chondrogenic differentiation.

Elevated Circulating Cell-Free Hemoglobin Drives Endothelial Glycocalyx Destruction and Inflammation in Sepsis

Rationale: Endothelial injury is a hallmark of sepsis-induced acute respiratory distress syndrome (ARDS). Endothelial barrier integrity is regulated by the endothelial glycocalyx, a matrix of proteoglycans and glycosaminoglycans (GAGs) that lines the vascular lumen. In sepsis, this glycocalyx is degraded by heparanase, which cleaves heparan sulfate, the primary glycocalyx GAG. Glycocalyx breakdown is linked to worse sepsis outcomes, but the mechanisms inducing heparanase activity in sepsis are unknown. We previously found that plasma levels of hemoglobin released from red blood cells (cell-free hemoglobin, CFH) are elevated in clinical sepsis and correlate with higher rates of ARDS and death. CFH also worsens endothelial injury and microvascular permeability in murine sepsis. We therefore hypothesized that CFH upregulates heparanase production to drive glycocalyx shedding and inflammation in sepsis. Methods: To test the association between CFH levels, heparanase expression, and glycocalyx degradation, circulating levels of heparanase, heparan sulfate, and total GAGs were measured in 77 sepsis patients and compared across CFH quartiles. In mice with intraabdominal polymicrobial sepsis with elevated CFH (CS [cecal slurry] + intravenous [IV] CFH), plasma heparanase, total GAGs, and syndecan-1 were quantified. Whole lung and plasma pro-inflammatory cytokines were also determined to investigate the impact of CFH on inflammation in sepsis. Results: In sepsis patients, higher circulating CFH levels were associated with increased plasma heparanase (p=0.0304), total GAGs (p=0.0178), and heparan sulfate (p=0.0112). CFH also exacerbated glycocalyx degradation in murine sepsis; circulating syndecan-1 (p=0.0152) and total GAGs (p=0.0094) were elevated in animals that received CS+IV CFH compared to CS alone. This effect may be mediated by upregulation of active heparanase, which was higher in the plasma of CS+IV CFH treated animals (p=0.1333). CFH also worsened illness severity, as CS+IV CFH animals had worse sepsis severity scores (p=0.0074). Whole lung tumor necrosis factor-alpha (TNF-a; p=0.0129) and interferon-gamma (IFN-g; p=0.0264) transcript levels were increased in the CS+IV CFH group, indicating greater lung inflammation. Systemic inflammation was also enhanced in the CS+IV CFH animals, demonstrated by higher plasma TNF-a (p&lt;0.001) and IFN-g (p=0.0221) concentrations. Conclusions: In sepsis, CFH is associated with upregulation of heparanase and endothelial glycocalyx degradation, which may disrupt the endothelial barrier, causing downstream organ injury. Future studies to define the molecular pathways that underlie these findings and their effect on endothelial permeability will be an important next step towards identifying novel treatment targets to improve outcomes for patients with sepsis-associated ARDS. Funding F30HL170483, R01HL164937, R01HL158906, R01HL150783, R01HL125371. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A novel graphene oxide-based fluorescence method for detection of urine glycosaminoglycans.

Glycosaminoglycans (GAGs) serve as a biomarker for mucopolysaccharidoses disease. In this study, a novel fluorometric method was developed to measure total GAGs in urine. Graphene oxide (GO) and rhodamine B (RhB), a cationic fluorescent dye, were employed in the development of the method. RhB attaches to the GO surface via electrostatic attraction, leading to the quenching of its fluorescence upon the establishment of the RhB-GO complex. However, the presence of GAGs prompts a resurgence of intense fluorescence. The linear range of the method is between 5.00 and 70.00mg/L. The total GAG levels of urine samples analyzed using the method agree with the results of the biochemistry analysis laboratory (65.85 and 79.18mg/L; 73.30± 1.76 and 72.21± 2.21). The method is simple, accurate, and sensitive and may be used for both first-step diagnosis of the mucopolysaccharidoses and detection of individual GAGs for studies of GAG-related research and other biological applications.

Specific GAG ratios in the diagnosis of mucopolysaccharidoses.

Mucopolysaccharidoses (MPS) screening is tedious and still performed by analysis of total glycosaminoglycans (GAG) using 1,9-dimethylmethylene blue (DMB) photometric assay, although false positive and negative tests have been reported. Analysis of differentiated GAGs have been pursued classically by gel electrophoresis or more recently by quantitative LC-MS assays. Secondary elevations of GAGs have been reported in urinary tract infections (UTI). In this manuscript, we describe the diagnostic accuracy of urinary GAG measurements by LC-MS for MPS typing in 68 untreated MPS and mucolipidosis (ML) patients, 183 controls and 153 UTI samples. We report age-dependent reference values and cut-offs for chondroitin sulfate (CS), dermatan sulfate (DS), heparan sulfate (HS) and keratan sulfate (KS) and specific GAG ratios. The use of HS/DS ratio in combination to GAG concentrations normalized to creatinine improves the diagnostic accuracy in MPS type I, II, VI and VII. In total 15 samples classified to the wrong MPS type could be correctly assigned using HS/DS ratio. Increased KS/HS ratio in addition to increased KS improves discrimination of MPS type IV by excluding false positives. Some samples of UTI patients showed elevation of specific GAGs, mainly CS, KS and KS/HS ratio and could be misclassified as MPS type IV. Finally, DMB photometric assay performed in MPS and ML samples reveal four false negative tests (sensitivity of 94%). In conclusion, specific GAG ratios in complement to quantitative GAG values obtained by LC-MS enhance discrimination of MPS types. Exclusion of patients with UTI improve diagnostic accuracy in MPS IV but not in other types.

The influence of phenformin on the extracellular matrix of the liver of rats under long-term administration of ethanol [

Experimental and clinical studies have revealed the influence of AMP-activated protein kinase (AMPK) signaling on the development of non-alcoholic liver fibrosis. Currently, the results of experimental studies demonstrate that inhibition of AMPK promotes fibrogenesis, while its activation prevents the development of liver fibrosis. The purpose of this work is to establish the effect of activation of AMP-activated protein kinase by the administration of phenformin on the content of glycosaminoglycans, oxyproline and sialic acids in the liver of rats under the conditions of long-term administration of ethanol. The study was conducted on 24 male Wistar rats. The animals were randomly divided into 4 groups of 6 animals each, on which we modeled ethanol-induced liver damage and administered phenformin hydrochloride at a dose of 10 mg/kg. The experiment lasted 63 days. In the liver of rats, the content of total glycosaminoglycans, the concentration of heparin-heparan, keratan-dermatan and chondroitin fractions of glycosaminoglycans, the content of free oxyproline and sialic acids were studied. Long-term alcoholization leads to a violation of the extracellular matrix of the liver of rats, which is evidenced by a decrease in the concentration of proteoglycans and a redistribution of their fractions in the direction of a decrease in anti-inflammatory and regenerative fractions. Chronic intake of alcohol increases the processes of desialylation of glycoconjugates and the intensity of collagenolysis. Activation of AMP-activated protein kinase by administration of phenformin under the conditions of simulating ethanol-induced liver damage leads to an increase in the concentration of glycosaminoglycans due to the growth of heparin-heparan and chondroitin fractions and reduces the intensity of desialylation of glycoconjugates and collagenolysis in the liver of rats.

Sodium loading in ambulatory patients with heart failure with reduced ejection fraction: Mechanistic insights into sodium handling.

Sodium restriction was not associated with improved outcomes in heart failure patients in recent trials. The skin might act as a sodium buffer, potentially explaining tolerance to fluctuations in sodium intake without volume overload, but this is insufficiently understood. Therefore, we studied the handling of an increased sodium load in patients with heart failure with reduced ejection fraction (HFrEF). Twenty-one ambulatory, stable HFrEF patients and 10 healthy controls underwent a 2-week run-in phase, followed by a 4-week period of daily 1.2 g (51 mmol) sodium intake increment. Clinical, echocardiographic, 24-h urine collection, and bioelectrical impedance data were collected every 2 weeks. Blood volume, skin sodium content, and skin glycosaminoglycan content were assessed before and after sodium loading. Sodium loading did not significantly affect weight, blood pressure, congestion score, N-terminal pro-brain natriuretic peptide, echocardiographic indices of congestion, or total body water in HFrEF (all p > 0.09). There was no change in total blood volume (4748 ml vs. 4885 ml; p = 0.327). Natriuresis increased from 150 mmol/24 h to 173 mmol/24 h (p = 0.024), while plasma renin decreased from 286 to 88 μU/L (p = 0.002). There were no significant changes in skin sodium content, total glycosaminoglycan content, or sulfated glycosaminoglycan content (all p > 0.265). Healthy controls had no change in volume status, but a higher increase in natriuresis without any change in renin. Selected HFrEF patients can tolerate sodium loading, with increased renal sodium excretion and decreased neurohormonal activation.

BIOCHEMICAL MARKERS OF BLOOD SERUM AND ARTICULAR CARTILAGE IN DIFFERENT FORMS OF IDIOPATHIC COXARTHROSIS PROGRESSION

Deformation due to arthrosis of the hip joint affects 40 % of the total number of patients with osteoarthritis, which is from 7 to 25 % of the adult population. For the activity of the pathological process evaluation we studied biochemical changes in the metabolism of collagen, namely: glycosaminoglycans (GAG), hydroxyproline (HP) fractions, collagenase, hyaluronidase activity, etc. Objective. To determine the biochemical changes in blood serum and articular cartilage depending on the form of progression of idiopathic coxarthrosis. Methods. 23 patients were examined (8 (34.8 %) men, 15 (65.2 %) women, age 45‒75 years and more) with idiopathic arthrosis of the hip joint IV stage (Kellgren–Lawrence). Progression forms of idiopathic coxarthrosis were distinguished: group I — rapid (the period from the initial to the final stage of the disease was 5 years and less), II — moderate (5‒10 years), III — slow (over 10 years). Collagenase activity, HP fractions, total GAG content were determined in patients’ blood serum, and collagen content was determined in the cartilage tissue of the femoral head. Results. Compared with the age reference norm in the blood serum of patients of group I activity collagenase increased to 114 %, in II and III — 122 and 135 %, respectively; the content of the free fraction of GP — up to 111, 169, 128 %, respectively; GAG concentrations — up to 110, 122, and 135 %, respectively; protein-bound HP was reduced to 60% in group II, up to 84 % — in group III. In cartilage tissue, the GAG content decreased in group III to 63 %, II — 55 %, I — 47 %; collagen — 32, 25, 24 % in accordance. Conclusions. The course of idiopathic coxarthrosis is determined by metabolic changes in the components of the organic basis of connective and cartilaginous tissues in blood serum. The most profound changes were found in the synthetic phase of HP metabolism, especially in the group with a rapid course disease. A decrease in the content of organic components of connective tissue (GAG and collagen) was determined

Optimization of Automated Dimethylmethylene Blue Assay for Quantification of Pediatric Urine Samples.

The metachromatic dye dimethylmethylene blue is used to quantify total glycosaminoglycans in urine. Understanding the interaction of dimethylmethylene blue with glycosaminoglycans is pertinent to optimize the assay procedure depending on the type of sample and interpret the findings meaningfully. The present spectrophotometric study determined the optimum sample-to-dye ratio, primary wavelength for measuring absorbance, after studying the interaction of two different chondroitin sulfate species (unfractionated chondroitin sulfate from bovine trachea vs. chondroitin sulfate oligosaccharide with degree of polymerization of 12, from shark cartilage) with dimethylmethylene blue. Respective dye-glycosaminoglycan complexes of the two chondroitin sulfate species showed significantly different absorbance maxima, while that of the chondroitin sulfate oligosaccharide was closer to absorbance maxima of urine glycosaminoglycans. The chondroitin sulfate oligosaccharide showed relatively less stable absorbance readings at higher concentrations in the reaction volume. Furthermore, the chondroitin sulfate reference materials exhibited differences in the linearity of standard curves and hence parallelism. Based on the findings, the method was semiautomated on Beckman Coulter D✕C 700 biochemistry analyzer using the chondroitin sulfate oligosaccharide as the standard. The urine glycosaminoglycan concentration obtained was slightly lower but reasonably close to that obtained through the External Quality Assurance (EQA) scheme administrated by ERNDIM (European Research Network, Inherited Disorders of Metabolism). The findings of the present study can be used to guide the dimethylmethylene blue assay optimization, redevelopment efforts, and harmonization across laboratories. The chondroitin sulfate oligosaccharide is better than the unfractionated chondroitin sulfate from bovine trachea due to its absorbance maxima closer to urine glycosaminoglycans. On the other hand, unfractionated chondroitin sulfate exhibit poor parallelism leading to falsely lower urine glycosaminoglycan levels.

Diagnostic informativeness of markers of bone-tissue metabolism and bone resorption in cows with osteodystrophy

Osteodystrophy is caused by polyetiological factors, the main being disturbance of metabolism of macroelements and D and A vitamins. The disease continues to impose great economic losses on animal husbandry, reduces cattle productivity, and hinders effective work in this sphere. To study the pathogenesis and early diagnostics of bovine osteodystrophy, we examined the markers of metabolism of the connective tissue: macro- and microelements, general glycosaminoglycans and their fractions, chondroitin sulfate, sialoglycoproteins, oxoproline, citric acid, and osteocalcin. In the cows with subclinical course of osteodystrophy, the content of total calcium was decreased by 18.9% and such of phosphorus by 5.7%. In 95% of the clinically ill animals, we diagnosed hypocalcemia, combined with hypophosphatemia, in 35.0% of the cows. In blood serum of the cows with subclinical course of osteodystrophy, we found decrease in the concentration of citric acid down to 157.7 ± 2.1 mmol/L, in the clinically ill – 146.8 ± 1.2 mmol/L and osteocalcin – to 1.12 ± 0.04 and 0.72 ± 0.04 ng/mL, respectively. We determined increases in concentrations of chondroitin sulfates, sialoglycoproteins, total glycosaminoglycans and their fractions: chondroitin-6-sulfate, chondroitine-4-sulfate, keratan- and heparin- and dermatan sulfates, and heparine. The most informative criteria for diagnostics of subclinical course of osteodystrophy were citric acid, total glycosaminoglycans and their first and third fractions, chondroitin sulfates and sialoglycoproteins, because they were above the physiological limits in 100% of the cows with subclinical course of the disease, whereas in the clinically healthy animals, osteocalcin decreased in 60 and 100% of the cases, respectively.

Influence of doxorubicin on the extracellular matrix of the liver of rats under conditions of chronic alcoholic hepatitis

The liver has a high regenerative potential that is dependent on many factors, in particular adenosine monophosphate kinase signaling, however, long-term alteration, such as daily alcohol consumption, turns regeneration into a chronic disease such as fibrosis, the end stage of which is cirrhosis. Hepatic extracellular matrix proteins are important triggers of enhanced stellate cell function during the progression of liver fibrosis. The experiments were performed on Wistar rats divided into four groups: control group; doxorubicin injection group (1.25 mg/kg); chronic alcohol hepatitis group; injection of doxorubicin during alcoholic hepatitis group, where we studied the total concentration of glycosaminoglycans, concentration of heparin-heparan, keratan-dermatan and chondroitin fractions of glycosaminoglycans, free oxyproline and sialic acids in the liver tissue homogenate. Cells with Mallory-Denk bodies were present in the liver of rats from the alcohol hepatitis group, which consisted of tangled balls of intermediate filaments and showed eosinophilia in the cytoplasm of degenerative hepatocytes. There were also necrotic changes in cells. Sinusoidal capillaries were locally dilated. In the central sections of the liver lobules of rats injected with doxorubicin against the background of chronic alcoholic hepatitis, the central veins were expanded, their endothelium was thinned. Sinusoidal capillaries were locally expanded, there were no blood cells in their lumens. The nuclei of the vast majority of hepatocytes were in a state of karyopyknosis, karyorrhexis, and karyolysis. Mallory-Denk bodies were present in the cytoplasm of cells. Administration of doxorubicin to animals with chronic alcoholic hepatitis leads to an increase in the total concentration of glycosaminoglycans, the concentration of chondroitin sulfates, a decrease in the heparin-heparan fraction of glycosaminoglycans and no changes in concentration of the keratan-dermatan fraction in the liver of rats compared to the control group. In the group of rats injected with doxorubicin against the background of chronic alcoholic hepatitis, the concentrations of total glycosaminoglycans, heparin-heparan fraction, and chondroitin fraction significantly increased, and the content of the keratan-dermatan fraction of glycosaminoglycans significantly decreased compared to animals with chronic alcoholic hepatitis. In rats injected with doxorubicin against the background of chronic alcoholic hepatitis, the content of free oxyproline decreased by 1.25 times, sialic acids – by 1.36 times, compared to the group of animals with chronic alcoholic hepatitis. Administration of ethanol or doxorubicin in combination with ethanol to rats causes morphological changes in the liver that are characteristic of chronic alcoholic hepatitis. Administration of doxorubicin to rats leads to degenerative morphological changes in the liver lobules. The administration of doxorubicin prevents alcohol-induced collagenolysis and the breakdown of glycoproteins, but increases the breakdown of proteoglycans due to an increase in the content of chondroitin and heparin-heparan fractions.

On the Mechanical Roles of Glycosaminoglycans in the Tensile Properties of Porcine Corneal Stroma.

The cornea is primarily composed of collagen fibrils that are embedded in a ground substance rich in proteoglycans and other glycoproteins. It is known that glycosaminoglycan (GAG) side chains of proteoglycans form anti-parallel duplexes between collagen fibrils. The present work was done in order to investigate the mechanical function of GAGs in defining the tensile properties of porcine corneal stroma. Porcine corneal stromal strips dissected from the nasal-temporal direction were divided into control, buffer-treated, and enzyme-treated groups. The samples in the control group were used immediately after dissection. However, the buffer-treated and enzyme-treated samples were, respectively, incubated for 18 hours at 37°C in a buffer solution made up of 100-mM sodium acetate at pH 6.0 or in an enzyme solution containing keratanase II. The Blyscan assay was used to quantify the total GAG content and assess GAG depletion in the samples treated with the enzyme and buffer solutions. Uniaxial tensile tests were also performed to determine the effect of GAG removal on mechanical properties of the cornea. The GAG content in enzyme-treated samples was significantly lower than that of the normal and buffer-treated specimens (P < 0.05). Moreover, GAG-depleted strips showed significantly softer mechanical responses in comparison with the control and buffer samples (P < 0.05). Removing GAGs from the corneal extracellular matrix led to significant tensile property reduction; supporting the hypothesis that there exists a strong correlation between the GAG content and mechanical properties of the corneal stroma.

Simultaneous production of N-acetylheparosan and recombinant chondroitin using gene-engineered Escherichia coli K5

N-Acetylheparosan and chondroitin are increasingly needed as alternative sources of animal-derived sulfated glycosaminoglycans (GAGs) and as inert substances in medical devices and pharmaceuticals. The N-acetylheparosan productivity of E. coli K5 has achieved levels of industrial applications, whereas E.coli K4 produces a relatively lower amount of fructosylated chondroitin. In this study, the K5 strain was gene-engineered to co-express K4-derived, chondroitin-synthetic genes, namely kfoA and kfoC. The productivities of total GAG and chondroitin in batch culture were 1.2 g/L and 1.0 g/L respectively, which were comparable to the productivity of N-acetylheparosan in the wild K5 strain (0.6–1.2 g/L). The total GAG of the recombinant K5 was partially purified by DEAE-cellulose chromatography and was subjected to degradation tests with specific GAG-degrading enzymes combined with HPLC and 1H NMR analyses. The results indicated that the recombinant K5 simultaneously produced both 100-kDa chondroitin and 45-kDa N-acetylheparosan at a weight ratio of approximately 4:1. The content of chondroitin in total GAG partially purified was 73.2%. The molecular weight of recombinant chondroitin (100 kDa) was 5–10 times higher than that of commercially available chondroitin sulfate. These results indicated that the recombinant K5 strain acquired the chondroitin-producing ability without altering the total GAG productivity of the host.

Interleukin-1β and methylprednisolone acetate demonstrate differential effects on equine deep digital flexor tendon and navicular bone fibrocartilage cells in vitro

To investigate the effects of interleukin-1β (IL-1β) and methylprednisolone acetate (MPA) on equine intrabursal deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) cells in vitro. Third passage DDFT and NBF cells from 5 healthy donor horses ages 11-17 years euthanized for reasons unrelated to musculoskeletal conditions. Aggregate cultures were incubated with culture medium alone (control), 10 ng/mL IL-1β, 10 ng/mL IL-1β + 0.05 mg/mL MPA, or 10 ng/mL IL-1β + 0.5 mg/mL MPA for 24 hours. Extracellular matrix (ECM) gene expressions were assessed via real-time polymerase chain reaction (rtPCR). Culture media matrix metalloproteinase (MMP) -3 and -13 concentrations were quantified via ELISA. Total glycosaminoglycan (GAG) content in the cell pellets and culture media was also assessed. IL-1β and IL-1β combined with MPA significantly downregulated ECM gene expression to a greater extent in NBF cells compared with DDFT cells. IL-1β and IL-1β combined with MPA significantly upregulated MMP-3 culture media concentrations in DDFT cells only, and MMP-13 culture media concentrations to a greater extent in NBF cells compared with DDFT cells. NBF cells were more susceptible to IL-1β and MPA-mediated ECM gene expression downregulation in vitro. These results serve as a first step for future work to determine intrabursal corticosteroid regimens that limits or resolve the inflammation as well as take into consideration NBF cell biosynthesis in horses with navicular disease, for which currently no information exists.

Anti-inflammatory and pro-anabolic effects of 5-aminosalicylic acid on human inflammatory osteoarthritis models.

Osteoarthritis (OA) is the most common degenerative joint disease, mainly affecting the elderly worldwide, for which the drug treatment remains a major challenge. Low-grade inflammation plays a pivotal role in OA onset and progression. Exploration of notable anti-inflammatory and disease-modifying drugs on human samples could facilitate the evaluation of therapeutic strategies for OA. The anti-inflammatory drug 5-aminosalicylic acid (5-ASA) is a first-line drug for ulcerative colitis (UC), however no study has explored the effects of 5-ASA on articular chondrocytes. In this work, both in vitro (chondrocyte pellets) and ex vivo (osteochondral explants) human inflammatory OA models were applied to evaluate the effects of 5-ASA. In the inflammatory pellet model, 5-ASA remarkably downregulated the gene expression of interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2) while upregulating proteoglycan 4 (PRG4) and cartilage oligomeric matrix protein (COMP) gene expression. Total glycosaminoglycan (GAG) synthesis by pellets was markedly increased in 5-ASA-treated groups compared with the inflammatory group. In conditioned medium, inflammatory mediators (IL-8, nitric oxide) were markedly inhibited upon 5-ASA treatment. Moreover, histological staining showed 5-ASA retained proteoglycan content and inhibited degradation of extracellular matrix (ECM) core components, aggrecan (ACAN) and collagen type II (COL2). In the inflammatory explant model, 5-ASA mitigated signs of OA development by reducing inflammatory mediators and GAG loss. These findings suggest that 5-ASA has anti-inflammatory and pro-anabolic effects on human chondrocyte pellet and osteochondral explant inflammatory OA models. Disease-modifying OA drugs are an unmet clinical need for the treatment of OA. Our study explored and demonstrated the anti-inflammatory and protective effects of 5-ASA on in vitro and ex vivo human inflammatory OA models, showing its translational potential for OA treatment.

Biochemical markers of connective tissue in the pathogenesis of gastroenteritis in dogs and cats

The aim: to analyze and establish the pathogenetic role of biochemical markers of the state of connective tissue in diseases of the stomach and intestines in dogs and cats.&#x0D; Materials and methods. The research was carried out by the method of analysis of sources of scientific literature (PubMed, Elsevier, electronic resources of the V. I. Vernadskyi National Library), because of which a scheme of the pathogenesis of gastroenteritis in dogs and cats with the participation of connective tissue biopolymers was created.&#x0D; Results. In dogs and cats, the issue of the use of biochemical markers for the diagnosis of diseases of the stomach and intestines has not yet been fully clarified. It is known, that in dogs and cats, lymphocytic-plasmacytic enteritis is histologically determined by fibrosis of the intestinal wall, but biochemical tests for the diagnosis of this condition are not given. Among the biochemical markers of inflammatory bowel disease, tumor necrosis factor, C-reactive protein and microalbumin were identified. Although C-reactive protein was elevated in a greater number of diseased animals, this increase was insignificant. Other tests also did not show high diagnostic informativeness. Several stages can be identified in the pathogenesis of alimentary gastroenteritis in dogs and cats. First, the irritating components of food act on the mucous membrane of the stomach and disrupt its secretory and motor functions, which causes gastritis. Thus, the use of indicators of the state of connective tissue in the diagnosis of intestinal diseases in dogs can be used to assess the degree of the inflammatory process.&#x0D; Conclusions. According to the results of the analysis, it was established, that the development of the inflammatory process in the stomach and intestines causes an increase in the content of glycoproteins in the blood serum of cats and dogs, and a decrease in synthetic processes in the liver is accompanied by a decrease in the concentration of glycosaminoglycans (GAG) in the blood serum of sick animals. It should be noted, that this decrease has peculiarities: in dogs, the content of total chondroitin sulfates remained at the level of clinically healthy animals, while the concentration of total GAG decreased. In cats, on the contrary, the content of total chondroitin sulfates decreased, and the fractional composition of GAG remained unchanged. The level of excretion of oxyproline and uronic acids in the urine of animals with gastroenteritis did not change, which indicates the absence of catabolism of collagen and proteoglycans with gastroenteritis

The role of connective tissue biopolymers in the pathogenesis of dog bronchopneunmonia and cat brochnial asthma

The aim: to analyze the pathogenetic role of connective tissue biopolymers in canine pneumonia and feline asthma.&#x0D; Materials and methods. The study was conducted by analyzing the sources of scientific literature: PubMed, Elsevier, electronic resources of the National Library, named after V.I. Vernadsky and the results of our own scientific and clinical experience.&#x0D; Results. Studies on the pathogenetic justification of the role of biochemical indicators of the connective tissue in the diagnosis and treatment of diseases of the respiratory system of dogs and cats were conducted. This is due to the need to expand knowledge about the peculiarities of the course, to determine the leading pathogenetic links of the most common pathologies –bronchopneumonia and bronchial asthma, which are found in clinical veterinary practice.&#x0D; Conclusions. In bronchopneumonia of dogs on the background of severe clinical symptoms (cough, fever, wheezing in the lungs), radiological signs (inhomogeneous compaction of the lung tissue, lack of clear contours of the bronchi), anemic syndrome, general and neutrophilic leukocytosis, lymphocytopenia, hypoalbuminemia, dysproteinemia (increased concentration of α2- and β-globulins in the blood serum), hypercholesterolemia, hyper-β-lipoproteinemia, hyperfermentemia (increased activity of AST and alkaline phosphatase,) there is an increase in serum glycoproteins and chondroitin sulfates, sialic acids, total glycosaminoglycans (GAG) due to the chondroitin-4-sulfate fraction; urinary excretion of oxyproline and uronic acids increases. Disorders of connective tissue metabolism in dogs with bronchopneumonia are caused by an acute inflammatory process in the lungs with the development of pulmonary fibrosis.&#x0D; Bronchial asthma in cats is manifested by intermittent cough, shortness of breath, hypochromic normocytic anemia, leukocytosis, eosinophilia and lymphocytopenia, increased serum activity of AST and alkaline phosphatase, haptoglobin content, glial acid concentration sulfate; urinary excretion of oxyproline and uronic acids increases. Connective tissue disorders in cats with bronchial asthma are caused by increased mucus excretion with a high content of GAG, as well as chronic inflammation of the bronchial mucosa and their fibrosis

Peculiarities of the structural and functional state of bone tissue in children during the second growth spurt

Background. Bone health is relevant for patients of all age groups. Special attention is paid to childhood and adolescence, since it is during this period that bone mass is actively accumulated, which depends on the structural and functional state of the bone tissue of an adult. The purpose of this study was to determine the features of the structural and functional state of bone tissue in children during the second growth spurt based on the analysis of markers of bone modeling, the level of 25(OH)D and the indicators of ultrasound densitometry and DXA. Materials and methods. 205 children aged 9–17 years were examined. They divided into three groups depending on the presence and intensity of growth spurts. Examination included: general clinical examination with an assessment of the levels of physical and sexual development, determine of the levels of 25(OH)D, glycosaminoglycans, chondroitin sulfates and alkaline phosphatase, ultrasound densitometry and DXA. Results. 83.9 % of children had vitamin D deficiency, 16.1 % of children had insufficiency. A decrease in BMD according to UD data was diagnosed in 48.0 % (n = 24) of children with growth spurt, in 60.87 % (n = 28) of children with intense growth spurt, and in 39.45% (n = 43) of children without growth spurt. According to DXA data, BMD reduction was confirmed in 56.25 % (n=18) of 32 examined children: children with growth spurt — 38.9 % (n=7), children with intense growth spurt— 50.0% (n = 9), children without growth spurt — 11.1 % (n = 2). The level of chondroitin sulfates in children with growth spurt and intense growth spurt is significantly higher than in children without growth spurt, which indicates the instability of metabolic processes. At the same time, the level of total glycosaminoglycans is significantly lower in the group of children with growth spurt and intense growth spurt than in the group of children without growth spurt, which indicates the intensity of metabolic processes in children of these groups. Conclusions. 100 % of children had insufficiency and deficiency of vitamin D. A decrease in BMD is more often diagnosed in children during an intense growth spurt and does not have a reliable relationship with the level of vitamin D, in contrast to children without a growth spurt. Children with growth spurts and intense growth spurts had an imbalance in the level of chondroitin sulfates and glycosaminoglycans, which indicates the instability and activity of bone tissue growth processes.

A three-dimensional (3D), serum-free, Collagen Type I system for chondrogenesis of canine bone marrow-derived multipotent stromal cells (cMSCs).

The dog is an underrepresented large animal translational model for orthopedic cell-based tissue engineering. While chondrogenic differentiation of canine multipotent stromal cells (cMSCs) has been reported using the classic micromass technique, cMSCs respond inconsistently to this method. The objectives of this study were to develop a three-dimensional (3D), serum-free, Collagen Type I system to facilitate cMSC chondrogenesis and, once established, to determine the effect of chondrogenic growth factors on cMSC chondrogenesis. Canine MSCs were polymerized in 100 μL Collagen Type I gels (5 mg/mL) at 1 x 106 cells/construct. Constructs were assessed using morphometry, live/dead staining, and histology in 10 various chondrogenic media. Four media were selected for additional in-depth analyses via lactate dehydrogenase release, total glycosaminoglycan content, qPCR (COL1A1, COL2A, SOX9, ACAN, BGLAP and SP7), immunofluorescence, and TUNEL staining. In the presence of dexamethasone and transforming growth factor-β3 (TGF-β3), both bone morphogenic protein-2 (BMP-2) and basic fibroblast growth factor (bFGF) generated larger chondrogenic constructs, although BMP-2 was required to achieve histologic characteristics of chondrocytes. Chondrogenic medium containing dexamethasone, TGF-β3, BMP-2 and bFGF led to a significant decrease in lactate dehydrogenase release at day 3 and glycosaminoglycan content was significantly increased in these constructs at day 3, 10, and 21. Both osteogenic and chondrogenic transcripts were induced in response to dexamethasone, TGF-β3, BMP-2 and bFGF. Collagen Type II and X were detected in all groups via immunofluorescence. Finally, TUNEL staining was positive in constructs lacking BMP-2 or bFGF. In conclusion, the 3D, serum-free, Collagen Type-I assay described herein proved useful in assessing cMSC differentiation and will serve as a productive system to characterize cMSCs or to fabricate tissue engineering constructs for clinical use.