COVID-19 generates hyaluronan fragments that directly induce endothelial barrier dysfunction

Vascular injury has emerged as a complication contributing to morbidity in coronavirus disease 2019 (COVID-19). The glycosaminoglycan hyaluronan (HA) is a major component of the glycocalyx, a protective layer of glycoconjugates that lines the vascular lumen and regulates key endothelial cell functions. During critical illness, as in the case of sepsis, enzymes degrade the glycocalyx, releasing fragments with pathologic activities into circulation and thereby exacerbating disease. Here, we analyzed levels of circulating glycosaminoglycans in 46 patients with COVID-19 ranging from moderate to severe clinical severity and measured activities of corresponding degradative enzymes. This report provides evidence that the glycocalyx becomes significantly damaged in patients with COVID-19 and corresponds with severity of disease. Circulating HA fragments and hyaluronidase, 2 signatures of glycocalyx injury, strongly associate with sequential organ failure assessment scores and with increased inflammatory cytokine levels in patients with COVID-19. Pulmonary microvascular endothelial cells exposed to COVID-19 milieu show dysregulated HA biosynthesis and degradation, leading to production of pathological HA fragments that are released into circulation. Finally, we show that HA fragments present at high levels in COVID-19 patient plasma can directly induce endothelial barrier dysfunction in a ROCK- and CD44-dependent manner, indicating a role for HA in the vascular pathology of COVID-19.

The role of hyaluronic acid and hyaluronidase-1 in obstructive sleep apnoea

Biological functions of hyaluronic acid (HA) depend on its molecular size. High-molecular weight HA (HMW-HA) is an important component of the endothelial wall and has anti-inflammatory and antioxidant properties. Under inflammation or hypoxia, HMW-HA is degraded by hyaluronidases, such as HYAL-1 resulting in pro-inflammatory low-molecular weight fragments. Obstructive sleep apnoea (OSA) is characterised by intermittent hypoxia and systemic inflammation. Our aim was to evaluate circulating HMW-HA and HYAL-1 in OSA. We recruited 68 patients with OSA and 40 control volunteers. After full-night sleep study blood samples were taken for HMW-HA and HYAL-1 measurements. HYAL-1 levels were significantly higher in patients with OSA compared to controls (0.59/0.31-0.88/ng/mL vs. 0.31/0.31-0.58/ng/mL; p = 0.005) after adjustment for gender, age, BMI and smoking. There was a trend for reduced HMW-HA concentrations in OSA (31.63/18.11-59.25/ng/mL vs. 46.83/25.41-89.95/ng/mL; p = 0.068). Significant correlation was detected between circulating HMW-HA and apnoea-hypopnoea-index (r = - 0.195, p = 0.043), HYAL-1 and apnoea-hypopnoea-index (r = 0.30, p < 0.01) as well as oxygen desaturation index (r = 0.26, p < 0.01). Our results suggest that chronic hypoxia is associated with increased plasma HYAL-1 concentration and accelerated HMW-HA degradation. Altered hyaluronan metabolism may be involved in the inflammatory cascade potentially leading to endothelial dysfunction in OSA.

HYAL-1-induced autophagy facilitates pancreatic fistula for patients who underwent pancreaticoduodenectomy

The main mechanism of hyaluronidase 1(HYAL-1) in the development of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) was unknown. In this study, a comprehensive inventory of pre-, intra-, and postoperative clinical and biological data of two cohorts (62 pancreatic cancer [PCa] and 111 pancreatic ductal adenocarcinoma [PDAC]) which could induce POPF were retrospectively analyzed. Then, a total of 7644 genes correlated with HYAL-1 was predicted in PDAC tissues and the enriched pathway, kinase targets and biological process of those correlated genes were evaluated. Finally, a mouse pancreatic fistula (PF) model was first built and in vitro studies were performed to investigate the effects of HYAL-1 on PF progression. Our data indicated that preoperative serum HYAL-1 level, pancreatic fibrosis score, and pancreatic duct size were valuable factors for detecting POPF of Grade B and C. The serum HYAL-1 level of 2.07 mg/ml and pancreatic fibrosis score of 2.5 were proposed as the cutoff values for indicating POPF. The bioinformatic analysis and in vitro and in vivo studies demonstrated that HYAL-1 facilitates pancreatic acinar cell autophagy via the dephosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and signal transducers and activators of transcription 3 (STAT3) signaling pathways, which exacerbate pancreatic secretion and inflammation. In summary, the preoperative serum HYAL-1 was a significant predictor for POPF in patients who underwent PD. Tumor-induced HYAL-1 is one of core risk in accelerating PF and then promoting pancreatic secretion and acute inflammation response through the AMPK and STAT3-induced autophagy.

[COMPARATIVE CHARACTERIZATION OF HYALURONIDASE ISOFORMS OF THE 1ST TYPE IN SOMATIC TISSUES AND SERUM OF WHITE RATS]

There are identified 3 proteins with molecular mass of 63, 73 and 132 kDa, exhibiting the properties of the hyaluronidase of the 1st type in the liver, spleen, renal papilla, skin and serum by the method of zymography. A protein with a molecular mass of 73 kDa was detected in all studied tissues and serum, while protein with a molecular mass of 63 kDa was present only in the tissues, and the protein with molecular mass of 132 kDa was present only in the serum. It is discussed the possibility of aggregation of 63 kDa protein molecules in the dimers with the formation of a 132 kDa protein in the serum.

Hyaluronidases and their inhibitors in the serum of colorectal carcinoma patients

Colorectal cancer is the third most commonly diagnosed type of cancer. Hyaluronan is involved in this malignancy. Moreover, hyaluronidases - its degrading enzymes - display controversial roles regarding their involvement in tumor development. HYAL-1 is the major tumor derived hyaluronidase. The aim of the study was the determination and evaluation of hyaluronidase levels in serum of colorectal cancer patients, before and after surgery, with a view to assessing its potential role as a tumor marker for recurrence. By zymography and Western blotting, it was confirmed that HYAL-1 was the only hyaluronidase present in samples. Quantification of its activity indicated a statistically significant decrease in samples seven days postoperatively, compared with the respective ones before surgery. HYAL-1 levels before surgery were significantly reduced in comparison with healthy samples and samples one year postoperatively. Hyaluronidase inhibitor activity was demonstrated under mild alkaline conditions via reverse zymography. A statistically significant increase was observed in samples seven days postoperatively, when compared with samples before surgery. HYAL-1 levels in sera of colorectal cancer patients were lower than those of healthy population, possibly because of the local accumulation of the enzyme in tumor microenvironment. A gradual elevation up to one year postoperatively to reach healthy levels might indicate a role of HYAL-1 levels in cancer.

[The criteria of differentiated diagnostics of early arthritis on the basis of analysis of serum hyaluronidase and deoxyribonuclease activity]

The study analyzed serum hyaluronidase and deoxyribonuclease activity in patients with early arthritis--early rheumatoid arthritis and acute reactive arthritis. The criteria of their differential diagnostics were developed on the basis of data obtained. The genuine methods were applied to analyze hyaluronidase and deoxyribonuclease activity of blood serum based on formation of clot of etacridine acetate (rivanol) with hyaluronic acid and DNA inversely proportionally to their polymerization under the impact of enzymes. The increased serum hyaluronidase and deoxyribonuclease activity was established in patients with early arthritis as compared with control group (p < 0.001). The prevalence of mentioned types of activity under early rheumatoid arthritis as compared with acute reactive arthritis was detected too. The rests for differentiate diagnostics of early rheumatoid arthritis and acute reactive arthritis were developed conformed to criteria of the most useful diagnostic tests in rheumatology.

Improved postprandial glycemic control in patients with type 2 diabetes from subcutaneous injection of insulin lispro with hyaluronidase

BACKGROUND

Coinjection of hyaluronidase has been shown to accelerate insulin absorption in healthy volunteers and patients with type 1 diabetes mellitus. This study was undertaken to compare the postprandial glycemic response of patients with type 2 diabetes mellitus (T2DM) administered insulin lispro with and without recombinant human hyaluronidase (rHuPH20) and regular human insulin (RHI) with rHuPH20.

METHODS

This double-blind three-way crossover study compared the insulin pharmacokinetics and glucodynamic response to a standardized liquid meal (80 g of carbohydrate) in 21 patients with T2DM who received subcutaneous injections of individually optimized doses of lispro±rHuPH20 and RHI+rHuPH20. The optimum dose (targeting postprandial glucose [PPG] of 70-140 mg/dL) of each preparation was selected by the investigator following a fixed-dose escalation procedure in three dose-finding meals.

RESULTS

Co-injection of lispro+rHuPH20 accelerated pharmacokinetics relative to lispro alone (time to peak insulin concentration, 43 vs. 74 min; P=0.0045) with increased exposure in the first hour (184% of control; P<0.0001) and reduced exposure after 2 h (67% of control; P=0.0001). These accelerated pharmacokinetics improved both total hyperglycemic excursions (area under the curve for 0-4 h >140 mg/dL, 56% of control; P=0.048) and hypoglycemic excursions (area under the curve for 0-8 h <70 mg/dL, 34% of control; P=0.033), allowing over three times as many patients to reach the American Diabetes Association's target of peak PPG <180 mg/dL without requiring glucose treatment for hypoglycemia. The mean optimum dose of lispro was reduced 8% from 0.275 U/kg without rHuPH20 to 0.254 U/kg with rHuPH20 (P=0.04). RHI+rHuPH20 had responses and optimum doses comparable to insulin lispro alone. All insulin preparations were well tolerated.

CONCLUSIONS

Lispro+rHuPH20 provided superior control of glycemic excursion compared with lispro alone, with lower insulin requirements and reduced hypoglycemic excursions.

Discriminant function based on parameters of hyaluronic acid metabolism and nitric oxide to differentiate metastatic from non-metastatic colorectal cancer patients

Colorectal cancer (CRC) is one of the most common causes of cancer-related deaths worldwide. Because there is currently no useful serological marker for metastatic colorectal cancer, the search for simple biomarkers for colorectal cancer diagnosis and prognosis is needed. Hyaluronic acid level was determined by ELISA; in addition to its degrading enzymes, degradation products and nitric oxide were determined by standard techniques in 185 CRC patients with and without metastases. Statistical analyses were performed by logistic regression and receiver-operating characteristic (ROC) curves. The multivariate discriminate analysis (MDA) selects a function based on absolute values of six biochemical markers; score = [-0.62 (numerical constant) + hyaluronic acid (pg/l) × 0.002 + hyaluronidase (mg N-acetyl glucosamine/ml/18 h) × 0.009-β-glucuronidase (μmol/ml/min) × 0.07 + N-acetyl-β-D-glucosaminidase (μmol/ml/min) × 0.019-glucuronic acid (μg/dl) × 0.001 + nitric oxide (μmol/l) × 0.01]. The selected MDA function correctly classified 92% of the metastatic CRC patients at a discriminate cut-off score = 0.24 (i.e., less than 0.24 indicated patients with non-metastatic colon cancer, and greater than 0.24 indicated patients with metastatic colon cancer with high degrees of sensitivity (100%) and specificity (93%)). The positive predictive and negative predictive values were also high (81% and 85%, respectively). Colorectal cancer patients can be simply and efficiently classified into metastatic or non-metastatic using their MDA score.

Estimation of serum hyaluronidase activity overcoming the turbidity interference

The assay of mammalian hyaluronidases (HAases) is important in understanding the role of the hyaluronan-hyaluronidase (HA-HAase) system in various pathophysiological processes. Despite several quantitative assay method options, the Morgan-Elson colorimetric method modified by Reissig et al is considered the best for determining the activity in clinical samples. However, the sensitivity of the method was greatly limited by presence of protein above 400 microg due to turbidity interference that led to chromogen quenching. Therefore, an effort has been made to reinvestigate the Reissig et al method. In the reinvestigated method, a standardized optimal 0.32 M potassium tetraborate (PTB) was used against 0.13 M (native) to overcome the turbidity interference. The estimated mean OD at 585 nm of serum for native method was 0.043 (95% CI: 0.040 to 0.045), while that for the re-investigated method was 0.138 (95% CI: 0.133 to 0.143, p < 0.0001). The mean OD at 585 nm of serum of native method was significantly lower than that of re-investigated method (p < 0.05) at all protein levels. This was also true for estimated mean OD at 585 nm of plasma. The mean intrasample CVs for native and re-investigated methods were 0.9% and 0.5%, respectively, for normal serum. Furthermore, the repeatability coefficient of normal serum for native was 0.003 IU, while re-investigated method experienced that of 0.002 IU.

[Criteria for the differential diagnosis of spondyloarthropathies, by determining serum hyaluronidase activity]

The study was undertaken to evaluate serum hyaluronidase activity in patients with spondyloarthropatgies and to develop criteria for their differential diagnosis. The author's methods for evaluating serum hyaluronidase activity, which were based on that the formation of a clot of ethacridine lactate (rivanol) with hyaluronic acid is in inverse proportion to its depolymerization under the action of hyaluronidase, were used. Enhanced serum hyaluronidase activity was seen in patients with spondyloarthropathies as compared with the control group (p < 0.0010, which was most evident in psoriatic arthritis. With the diagnostic level of hyaluronidase activity of 4 scores or more, the diagnostic sensitivity of the method in the differential diagnosis of psoriatic arthritis and other spondyloarthropathies was 92% and its diagnostic specificity was 86%.

Plasma hyaluronidase activity as an indicator of atherosclerosis in patients with coronary artery disease

BACKGROUND AND OBJECTIVE

Recent information has highlightened the impact of HA metabolism alterations in vascular permeability through its actions on endothelial glycocalyx and the importance of HA-cell interactions in cell behavior of arterial endothelial and smooth muscle cells. Therefore hyaluronan is thought to involve in pathophysiology of atherosclerosis. The aim of this study is to investigate the association of plasma hyaluronidase activity with atherosclerosis in non-diabetic patients with stable coronary artery disease.

METHODS

In the present study we used plasma hyaluronidase measurement as an indicator of hyaluronan metabolism and activity. A total of 162 subjects undergoing to coronary angiography were divided into two groups according to presence or absence of coronary artery disease, and their serum hyaluronidase activity were measured.

RESULTS

Serum hyaluronidase activities were 3797+/-670.62 mU/L and 2838+/-417.67 mU/L for patients with CAD (n:109) and control patients without CAD (n:53), respectively. Serum hyaluronidase activity in patients with coronary artery disease (CAD) were significantly higher than control subjects without CAD (p<0.001).

CONCLUSION

In the present study hyaluronidase activity was found to be associated with coronary artery disease reflecting the role of hyaluronan in atherosclerosis. We believe that the demonstration of relationship between serum hyaluronidase activity and atherosclerosis represents a remarkable finding highlighting the potential role of hyaluronan in pathophysiology of atherosclerosis (Tab. 2, Fig. 3, Ref. 28). Full Text (Free, PDF) www.bmj.sk.

Serum hyaluronidase levels in patients with aneurysmal subarachnoid haemorrhage

INTRODUCTION

The purpose of this study was to investigate the time course(s) of the serum hyaluronidase levels in patients with aneurysmal subarachnoid haemorrhage and to show whether there is a correlation between symptomatic vasospasm and serum levels of hyaluronidase.

METHODS

This prospective, open, non-randomised clinical study consisted of 20 patients with aneurysmal subarachnoid haemorrhage, and eight patients with normotensive hydrocephalus who served as the control group. Serum hyaluronidase levels were detected within the first three days, days five and seven after aneurysmal subarachnoid haemorrhage, and the results were compared with those from the control group. The results were also compared with those of the clinical parameters, including the patient's outcome at six months and symptomatic vasospasm.

RESULTS

Mean serum hyaluronidase levels were higher on days five and seven, and comparisons with either day five (p-value is 0.001) and/or day seven (p-value is 0.00001) showed a statistical difference between subarachnoid haemorrhage and controls. However, no relationship was found between elevated serum hyaluronidase levels and the clinical parameters including symptomatic vasospasm (p-value is greater than 0.05) and outcome at sixth months (p-value is greater than 0.05).

CONCLUSION

Our results indicate that serum hyaluronidase is elevated in the acute stage(s) of subarachnoid haemorrhage; however, no difference was found between serum hyaluronidase levels and subarachnoid haemorrhage severity. Clinical studies with larger population of patients with aneurysmal subarachnoid haemorrhage are required.

Evaluation of serum hyaluronic acid level and hyaluronidase activity in acute and chronic hepatitis C

Following major tissue injury, hyaluronic acid production increases as a rapid response survival mechanism. Increased hyaluronic acid production and turnover are often associated with increased hyaluronidase activity, the enzyme that degrades hyaluronic acid. We investigated whether hyaluronic acid and hyaluronidase can be used as non-invasive markers of acute disease activity in hepatitis C by studying 26 patients with acute hepatitis C, 89 with chronic hepatitis C and 32 healthy controls. Chronic hepatitis C subjects were classified into five subgroups according to the stage of liver fibrosis. Serum aspartate aminotransferase and alanine aminotransferase activities and hyaluronic acid levels were increased in hepatitis C patients compared with the controls. Serum hyaluronic acid elevation correlated with disease progression. Serum hyaluronidase activities were also increased in patients compared with the controls, but decreased with disease progression. We conclude that both hyaluronidase and hyaluronic acid may be useful as early non-invasive serum indicators of disease activity in acute hepatitis C.

Perturbation of hyaluronan metabolism predisposes patients with type 1 diabetes mellitus to atherosclerosis

AIMS/HYPOTHESIS

Cardiovascular disease contributes to mortality in type 1 diabetes mellitus, but the specific pathophysiological mechanisms remain to be established. We recently showed that the endothelial glycocalyx, a protective layer of proteoglycans covering the endothelium, is severely perturbed in type 1 diabetes, with concomitantly increased plasma levels of hyaluronan and hyaluronidase. In the present study, we evaluated the relationship between hyaluronan and hyaluronidase with carotid intima-media thickness (cIMT), an established surrogate marker for cardiovascular disease.

SUBJECTS AND METHODS

Non-smoking type 1 diabetes patients without micro- or macrovascular complications and matched controls were recruited and cIMT of both carotid arteries was measured. To evaluate the relationship between cIMT and hyaluronan and hyaluronidase as well as other parameters, uni- or multivariate regression analyses were performed.

RESULTS

We included 99 type 1 diabetes patients (age 10-72 years) and 99 age- and sex-matched controls. Mean cIMT, HbA(1c), high sensitivity C-reactive protein, hyaluronan and hyaluronidase were significantly increased in type 1 diabetes vs controls. Plasma hyaluronan and hyaluronidase were correlated in type 1 diabetes. In univariate regression analyses, mean IMT was associated with plasma hyaluronan, age and male sex, whereas after multivariate analysis only age and sex remained statistically significant.

CONCLUSIONS/INTERPRETATION

We conclude that type 1 diabetes patients show structural changes of the arterial wall associated with increased hyaluronan metabolism. These data may lend further support to altered glycosaminoglycan metabolism in type 1 diabetes as a potential mechanism involved in accelerated atherogenesis.

[Comparative study of the clinical effects of salvia miltiorrhiza injection and shengmai injection on chronic hepatitis B]

OBJECTIVE

To observe the effect of Salvia miltiorrhiza Injection (SMI) and Shengmai Injection (SI) on liver function and fibrosis related indexes in patients with chronic hepatitis B.

METHODS

Seventy-nine chronic hepatitis B patients were randomly divided into the SMI group (n=47) and the SI group (n=32), they were treated with SMI and SI respectively on the basis of conventional treatment. The therapeutic course was 35 days for both groups. The changes of main symptoms and physical signs were observed, and indexes of liver function and fibrosis including serum hyaluronidase, laminin, III type precollagen (PC-III) and IV type collagen (IV-C) were investigated before and after treatment.

RESULTS

Symptoms, physical signs and liver functions were improved obviously in both SMI and SI groups, SI showed better effect than SMI (P < 0.05). The four liver fibrosis indexes declined significantly in the SMI group after treatment (P < 0.05), but no obvious change of those was found in the SI group (P > 0.05), showing significant difference between the two groups (P < 0.05). Conclusion SMI is effective in improving liver function and inhibiting liver fibrosis, and SI has even better effect in improving liver function than SMI, though it shows no anti-liver fibrosis effect.

Serum hyaluronidase aberrations in metabolic and morphogenetic disorders

Hyaluronidases are endo-glycosidases that degrade both hyaluronan (hyaluronic acid) (HA) and chondroitin sulfates. Deficiency of hyaluronidase activity has been predicted to result in a phenotype similar to that observed in mucopolysaccharidosis (MPS). In the present study, we surveyed a variety of patients with phenotypes similar to those observed in MPS, but without significant mucopolysacchariduria to determine if some are based on aberrations in serum hyaluronidase (Hyal-1) activity. The study included patients with well-characterized dysmorphic disorders occurring on genetic basis, as well as those of unkown etiology. The purpose of the study was to establish how wide spread were abnormalities in levels of circulating Hyal-1 activity. A simple and sensitive semi-quantitative zymographic procedure was used for the determination of activity. Levels of both beta-N-acetylglucosaminidase and beta-glucuronidase whose activities contribute to the total breakdown of hyaluronan (HA) were also measured, as well as the concentration of circulating HA. Among 48 patients with bone or connective tissue abnormalities, low levels of Hyal-1 activity were found in six patients compared to levels in 100 healthy donors (2.0-3.2 units/microL vs 6(+/- 1 SE) units/microL). These six patients exhibited a wide spectrum of clinical abnormalities, in particular shortened extremities: they included three patients with unknown causes of clinical symptoms, one patient with Sanfilippo disease, one of the seven patients with achondroplasia, and one with hypophosphotemic rickets. Normal levels of serum Hyal-1 activities were found in patients with Morquio disease, GM1 gangliosidosis, I cell-disease, 6 of the 7 patients with achondroplasia, Marfan's-syndrome and Ehlers-Danlos syndrome. No patient totally lacked serum Hyal-1 activity. Serum HA concentration was elevated in patients with Sanfilippo A and I-cell disease. Determination of serum and leukocyte Hyal-1 and serum HA may be useful to evaluate patients with metabolic and morphogenetic disorders.

Changes in hyaluronan production and metabolism following ischaemic stroke in man

The extent of recovery from stroke is dependent on the survival of neurons, particularly in peri-infarcted regions. Angiogenesis is critical for the development of new microvessels and leads to re-formation of collateral circulation, reperfusion and better recovery. Hyaluronan (HA) is an important component of the brain extracellular matrix and a regulator of cellular differentiation, migration, proliferation and angiogenesis. We have found that the production of total HA and low molecular mass 3-10 disaccharides of HA (o-HA) was increased in post-mortem tissue and in the serum of patients 1, 3, 7 and 14 days (peaking at 7 days) after ischaemic stroke. Hyaluronidase activity was also increased in serum samples (peaking after 3 days), which might explain the subsequent increase in o-HA. Affinity-histochemical staining was performed using a HA-specific biotinylated binding protein, and it showed enhanced deposition of HA in blood vessels and intracellularly as well as in the nuclei of peri-infarcted neurons. Western blotting and immunohistochemistry demonstrated upregulation of HA synthases (HAS1 and 2) and hyaluronidases (HYAL1 and 2) in inflammatory cells from both stroke and peri-infarcted regions of the brain. HYAL1 was upregulated in microvesssels and intracellularly in neurons, whilst HAS2 became translocated into the nuclei of neurons in peri-infarcted areas. Receptor for HA-mediated motility was observed intracellularly and in the nuclei of neurons, in the tunica media of larger blood vessels and in the endothelial cells of microvessels in stroke-affected tissue, whilst expression of other receptors for HA, CD44 and tumour necrosis factor-stimulated gene 6 (TSG-6) were mainly increased in infiltrating mononuclear cells from inflammatory regions. The data presented here demonstrate that HA breakdown is a feature of the acute stage of stroke injury. Increased o-HA production soon after stroke may be detrimental through enhancement of the inflammatory response, whilst activation of HA and/or o-HA-induced cellular signalling pathways in neurons and microvessels may impact on the remodelling process by stimulating angiogenesis and revascularization, as well as the survival of susceptible neurons.

[Metabolism of the main substance of the connective tissue in chronic obstructive pulmonary disease]

AIM

To reveal metabolic disturbances of connective tissue main substance in chronic obstructive pulmonary disease (COPD) and to assess their informative value in determination of treatment efficacy.

MATERIAL AND METHODS

Peripheral blood of 130 COPD patients was studied for total glycosaminoglycanes, hyaluronidase activity, sialic acids fractions (free, oligobound and proteinbound), fucose fractions (oligobound and proteinbound) and activity of sialidase.

RESULTS

The levels of total glycosaminoglycanes, sialo- and fucose-containing compounds in the blood change with COPD severity and phase of the disease.

CONCLUSION

The data obtained may be used to assess activity of respiratory inflammation and efficacy of the treatment.

Short term effects of dexamethasone on hyaluronidase activity and sperm characteristics in rams

The aim of this study was to determine the effects of dexamethasone on sperm characteristics and hyaluronidase activity of serum and semen. In this investigation, 14 healthy Akkaraman rams, at the age of 2 years and weighing between 50-60 kg, were used. The rams were randomly divided into two groups. After the last administration of dexamethasone intramuscularly at a dose of 0.25 mg/kg, semen and blood samples were taken at different times. The results showed that the serum hyaluronidase activity was increased significantly (p<0.001) in the treatment group when compared with the control group except for the 1st hour. There was a significant difference (p<0.001, 0.01, 0.05) in the hyaluronidase activity of semen between the treatment group and the control group. Furthermore, there was a significant difference (p<0.01) in sperm concentration between both groups at all the times except the 96th hour. There were statistically significant (p<0.05) differences in semen volume between the treatment and control groups. There were also significant differences (p<0.05) in sperm motility between the treatment and control groups except for the 72 and 96th hours. These findings indicate that dexamethasone increases hyaluronidase activity of serum and semen, but it decreases sperm concentration, semen volume and sperm motility in rams. Therefore the use of these drugs in breeding rams during breeding season is not suitable.

Serum hyaluronan and hyaluronidase: very early markers of toxic liver injury

BACKGROUND

Dimethylnitrosamine (DMN), a potent hepatotoxin, administered to rats, provides a convenient model for toxic liver injury. Indicators of early liver injury are important clinically, for surveillance, for screening new drugs that are potentially hepatotoxic and for identifying drugs that protect against liver injury. Both cirrhosis and wound healing culminate in deposition of fibrous connective tissue and scarring. Increased hyaluronan (HA) occurs in the earliest stage of wound healing. Hyaluronidase, the enzyme that degrades hyaluronan, is also elevated whenever rapid turnover of hyaluronan occurs. We test the hypothesis that elevated levels of circulating hyaluronan and hyaluronidase could provide indicators of very early liver damage.

METHODS

Dimethylnitrosamine was administered to adult male albino rats by intraperitoneal injections for 7 consecutive days.

RESULTS

Increased serum hyaluronan levels observed on day 2 reached a maximum on day 4. Hyaluronidase was elevated on the first day and reached a maximum on day 2 that was 30-times control levels. Hyaluronan-specific staining in liver sections was maximal on day 7, occurring predominantly in portal triads and in sinusoidal spaces. Individual hepatocytes were slightly enlarged and contained intracellular hyaluronan, which was not evident in control sections. Though circulating hyaluronan levels had decreased after day 4, continued hyaluronan staining persisted in liver sections through day 21. Conventional indicators of liver injury, such as serum aminotransferase enzymes, did not reach a peak until day 7. Conventional gross and histopathological changes, including severe centrilobular congestion and hemorrhagic necrosis, were observed only after day 7. Both hyaluronan and hyaluronidase are indicators of very early liver damage in the dimethylnitrosamine-treated rat, occurring well before conventional indicators appear, or before overt histopathologic changes of liver damage can be seen. However, levels are increased only transiently, indicating that serial assays are necessary.

CONCLUSIONS

Measures of circulating hyaluronidase activity may be used to assess liver damage.

Effects of levamisole on hyaluronidase activity and sperm characteristics in rams

The aim of this study was to determine the effects of levamisole on sperm characteristics and hyaluronidase activity of blood serum and semen. For this purpose, 12 Akkaraman rams (2-3 years old) were used. Levamisole hydrochloride was administered orally at a dose of 7.5mg/kg body weights once daily for 2 days. Serum and semen samples were collected from the rams at post-treatment 1, 2, 4, 24, 48, 72, 96, 120, 144, 216, 288 and 384 h and examined for sperm characteristics and hyaluronidase activity. The results showed that the use of levamisole caused significant (P < 0.01) increase in serum hyaluronidase activity at all times except the 72 h, and in semen hyaluronidase activity at 1, 2, 4, 24, 72, 96 and 120 h compared to the control group. In addition, the levamisole caused significant (P < 0.05) decreases in semen volume, sperm motility, concentration and total sperm number at all times. There was no correlation between semen hyaluronidase activity and the sperm characteristics. In conclusion, levamisole did not have any deleterious effect on hyaluronidase enzyme. However, the use of this drug in rams during the breeding season is harmful due to the decrease of sperm characteristics.

Aberrant serum hyaluronan and hyaluronidase levels in scleroderma

BACKGROUND

Scleroderma, or systemic sclerosis, is characterized by aberrations of extracellular matrix deposition. These changes parallel early stages of wound healing when increased deposition of hyaluronan (HA) and collagen occur. Both processes result ultimately in the formation of fibrotic scar tissue. Activities of HA synthase and hyaluronidase, the enzymes that synthesize and degrade HA, are critical in HA turnover. Both become elevated whenever increased matrix deposition occurs. HA deposition occurs early in wound healing, and increases are documented in the circulation of scleroderma patients. We postulated that elevated HA and hyaluronidase may both be indicators of early-stage disease in scleroderma, in parallel with early changes observed in wound healing. In an attempt to reduce HA accumulation and the associated fibrosis in scleroderma tissues, topical and intravenous hyaluronidase administrations have been used in the past as treatment modalities, with occasional success. This also suggested that hyaluronidase enzyme activity is involved in the disease process. It is now recognized that the hyaluronidases constitute an enzyme family. The somatic hyaluronidase Hyal-1 is the only activity present in human serum.

OBJECTIVES

To determine levels of HA and Hyal-1 in the sera of scleroderma patients at various stages of their disease.

METHODS

Levels of HA and Hyal-1 activity were determined in 25 scleroderma patients. Subjects were separated into two groups, those in the early stage with duration of disease of 2 years or less, and late-stage patients with disease duration of more than 2 years.

RESULTS

In early-stage scleroderma, levels of HA were elevated significantly, as predicted, in comparison with late-stage patients and controls. Late-stage levels of HA were comparable with those found in control sera. By contrast, levels of Hyal-1 activity were normal in early-stage patients, similar to those in controls, but were decreased in late-stage patients, falling even below those of controls.

CONCLUSIONS

We have confirmed that circulating levels of HA are elevated in scleroderma, but show for the first time that such elevations occur predominantly in early-stage disease. Patients with late-stage disease have decreased serum Hyal-1 activity, perhaps reflecting decreased levels of HA turnover. This study also represents the first time that hyaluronidase activity levels have been determined in scleroderma patients.

[Experimental study on the anti-liver fibrosis effect of guzhang tablet in rats]

OBJECTIVE

To observe the anti-liver-fibrosis effect of Guzhang Tablet (GZT) and to explore its mechanism.

METHODS

Fifty female rats, weighing 200-220 g were randomly divided into the blank control group, the model group, the small dosage GZT group, the large dosage GZT group and the Biejiajian Pill (BJJP) group, 10 rats in each group. The changes of related serum enzymes, liver-fibrosis marker, oxygen free radical and liver tissue pathology were observed after 8 weeks of treatment.

RESULTS

(1) Compared with the model group, the serum levels of alanine transaminase (ALT), aspartate aminotransferase (AST), glutamyltranspetidase (GGT), alkaline phosphatase (AKP) were improved in the GZT groups, better effect was got in the large dosage GZT group. (2) Compared with the blank control group, GZT showed no effect on serum total protein (TP) but with raising albumin (ALB) effect. (3) Compared with blank control group, the levels of hyaluronidase (HA), laminin (LN), collagen type IV (IV-C) and procollagen type III (PC III) in both GZT groups were lower, especially in the large dosage GZT group. (4) Small and large dosage of GZT showed effect in reducing malonyldialdehyde (MDA), Glutathione-peroxidose(GSH-Px) and nitric oxide (NO) content, but the effect on increasing superoxide dismutase (SOD) similar to that of BJJP with no significant different. (5) GZT, both small and large dosage, had obvious anti-liver fibrosis action, which was superior to that of BJJP.

CONCLUSION

In the genetic and developing processes of liver fibrosis in rats, GZT could protect the liver cells, inhibit the synthesis and reduce the content of collagens, the mechanism might be related with its action in antagonizing peroxidation injury, indicating that GZT could effectively prevent liver fibrosis formation.

Inhibition of arterial cells proliferation in vivo in injured arteries by hyaluronan fragments

It has been demonstrated previously that administration of high levels of high molecular mass hyaluronan (hyaluronic acid, HA) to rats was able to reduce in a significant way neointima formation in the injured arteries. In the present study, our aim was to verify whether small forms of HA (4-16 saccharides) are still able to reduce the proliferative response of ASMC to aortic injury. Treated rats received a total of 8 injections of a fixed dose of HA fragments (27 mg/kg rat contained in a volume of 550 microl). Two injections were given on the day of balloon catheter injury (BCI): one, intravenous, 10 min before BCI and one, subcutaneous, immediately after the BCI. The others injections (subcutaneous) were at 2, 4, 6, 8, 10 and 12 days after BCI. Control rats received an equivalent volume of the dissolving buffer containing only hyaluronidase, which has been destroyed before injection to rats. Neointima formation was analysed 14 days after the BCI. Intima-media wet weight and DNA content were significantly reduced in rats receiving HA fragments in comparison to controls (2P=0.01 for wet weight and 0.03 for DNA). This finding was confirmed by the histomorphometric study which showed that both neointima area and the ratio neointima/neointima+media were significantly decreased in treated rats (2P=0.03 for intima area and 0.049 for the ratio). Our data showed thus and for the first time that administration of HA fragments with a very low molecular mass (4-16 saccharides) reduces the proliferative reaction of aorta to injury in vivo. In conclusion, HA fragments, which are components with an excellent safety profile, may offer hope for the prevention of restenosis after angioplasty.