In vitro effects of α-tocopherol on teratozoospermic semen samples

A strong positive correlation exists between teratozoospermia and reactive oxygen species production, which in turn has negative effects on their in vitro fertilisation outcome. Our aim of this study was to determine potential protective effects of α-tocopherol on teratozoospermia motility, viability, acrosome reaction and DNA integrity after 1-h in vitro incubation. Teratozoospermic semen samples were obtained from 15 volunteers aged between 20 and 30 years after 3-5 days of sexual abstinence. Samples were washed, centrifuged and incubated in 37 °C and 5% CO(2) until sperm swimmed-up. Spermatozoa were counted in the supernatant and divided into four groups, each contained 2 × 10(6) sperm/ml(-1). Groups one to four were incubated for 1 h with Ham's F-10 solution as control group, 10 μm A23187, 40 μmα-tocopherol and 10 μm A23187 + 40 μmα-tocopherol respectively. The results indicated that α-tocopherol has ability to enhance teratozoospermia viability and motility, while there were no ameliorative effects on acrosome reaction and DNA fragmentation. A23187 induced acrosome reaction in teratozoospermia and α-tocopherol significantly diminished this effect. In conclusion, although α-tocopherol could improve teratozoospermia motility and viability, its effects on DNA integrity and acrosome reaction ability as supplementation IVF culture media are not obvious.     

Distribution of α- and δ-tocopherols in seminal plasma and sperm fractions of men with normal and abnormal semen parameters

The aim of this study was to investigate the presence of the different isoforms of tocopherol (T) in seminal plasma (P) and in the sperm fractions of individuals with abnormal (group 1) and normal (group 2) sperm parameters; the relationships between these isoforms and conventional sperm parameters were also explored. Two vitamin E homologues, α-T and δ-T, were identified in the semen of all participants. Although α-T and δ-T concentrations were similar in the semen of the 2 groups, group 1 showed a lower α-T ratio (S/P) (0.90 vs. 1.20, P < .001) and δ-T ratio (0.86 vs 1.13, P = .007) than group 2. In addition, both T ratios were correlated with the percentage of viable cells, detected by eosin staining. These results suggested that α-T and δ-T are not homogeneously distributed in the semen fractions; in normal semen they are more concentrated in the sperm membrane, whereas in abnormal semen the damaged sperm cells may release both Ts in the plasma. To verify whether sperm membrane breakage could alter α-T and δ-T distribution between the seminal plasma and the spermatozoa, normal sperm samples were sonicated; after sonication a consistent sperm plasma membrane fragmentation, highlighted by transmission electron microscopy, and a concomitant release of α-T and δ-T were observed. In conclusion, the Ts coupled directly with the sperm membrane seem to play the main protective role in the semen, and the release of α-T and δ-T in the P fraction is probably an index of lower antioxidant power and sperm quality.     

Effect of α-lipoic acid on sperm quality, reproductive tract measures in thinner exposed rats

The aim of this study was to investigate the effect of alpha lipoic acid (ALA, an universal antioxidant) on thinner-induced testicular toxicity regarding spermatological features, body and reproductive tract measures in rats. Adult male Sprague-Dawley rats were divided into five treatment groups, eight rats in each. Control group was treated with placebo. Group O was given only olive oil. The group L received only α-lipoic acid. Thinner + Lipoic Acid group received thinner + α-lipoic acid and group T received only thinner. Thinner alone administration caused significant decreases in body and some reproductive organ weights, sperm count, motility and sperm membrane integrity, and significant increases in seminal vesicle weight and abnormal sperm rates compared with the values in the control group. However, concomitant administration of thinner with α-lipoic acid provided significant improvements in sperm parameters compared with values in alone group T. In conclusion, the results of this study suggest that α-lipoic acid has a protective effect against thinner-induced reproductive dysfunction in male rats.     

Effect of α-tocopherol,taurine and selenium on the attenuation of ischemia/reperfusion injury of splanchnic organs

Background: Splanchnic artery occlusion shock is caused by increased capillary permeability and cellular injury precipitated by oxygen derived free radicals following ischemia and reperfusion of splanchnic organs. The purpose of this study was to assess the role of several wellknown oxygen-derived free radical scavengers in ameliorating or preventing this syndrome. Study design: Anesthetized rats were subjected to periods of occlusion of the visceral arteries and reperfusion. Tocopherol, taurine, selenium or a ‘cocktail’ of these three agents was injected subcutaneously for 4 consecutive days prior to operation. Mean arterial blood pressure was measured throughout the experimental period. Fluorometry and technetium-99m pyrophosphate counting of the visceral organs were performed as well as a histologic grading system for intestinal viability. Results: Final mean arterial blood pressure associated with the ‘cocktail’ and selenium groups was 79.1 ± 27.4 mmHg and 83.6 ± 17.8 mmHg, respectively. These values were significantly higher than the control group, 40.8 ± 11.4 mmHg (P < 0.05). Similar patterns of the benefit of selenium in contrast with the other groups were obtained with fluorescein perfusion, radioisotopic activity and histologie analysis. Conclusion: Pretreatment with selenium of splanchnic ischemia and reperfusion in the rat improves mean arterial blood pressure and microcirculatory visceral perfusion. Further analysis of the precise protective mechanism of selenium for reperfusion injury will enable visceral organs to withstand the consequences of increased capillary leakage and oxidant injury.     

Effect of low-density lipoproteins, spermatozoa concentration and glycerol on functional and motility parameters of bull spermatozoa during storage at 4 °C

An extender has been developed with low-density lipoproteins (LDLs) that eliminates the microbial risks associated with the use of whole egg yolk. The objective of this study was to assess the effects of substituting egg yolk with LDLs for use as an extender in sperm preservation at 4 °C, as well as on spermatozoa motility, plasma membrane and acrosome integrity, at two different concentrations (80×10(6) and 240×10(6) sperm per ml) for 8 days and to evaluate glycerol toxicity in both extenders. A total of 12 ejaculates were collected from three bulls. Spermatozoa motility was examined using computer-assisted semen analysis. Plasma membrane integrity was determined using the hypo-osmotic swelling test and acrosome integrity with the fluorescein isothiocyanate-Pisum sativum agglutinin test. The semen was subsequently divided into four aliquots and diluted with Tris-egg yolk-glycerol (TEG), Tris-egg yolk without glycerol (TE), LDL with glycerol (LDL(+)) and LDL without glycerol (LDL(-)), at 80×10(6) and 240×10(6) sperm per ml. This study showed that the LDL(+) and LDL(-) extenders were more effective at preserving spermatozoa motility, plasma membrane integrity and acrosome integrity than TEG and TE (P<0.05) during 8 days of incubation. After 3 days of incubation, a toxicity of glycerol was observed in TEG, whereas no significant difference was observed between LDL(+) and LDL(-). We can therefore conclude that the LDL extender can be used to refrigerate semen at 4 °C instead of TEG and TE at 80×10(6) and 240×10(6) sperm per ml for elite bulls. This finding can be used to define a policy for the storage of high-quality bull semen.     

Effects of alpha lipoic acid supplementation on serum levels of IL-8 and TNF-α in patient with ESRD undergoing hemodialysis

Background

Chronic renal failure is a progressive and irreversible loss of kidney function, and the hemodialysis (HD) is one of the most common modalities in this regard. Oxidative stresses [like interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)] and inflammation are the main risk factors associated with cardiovascular diseases and other complications in many organs in hemodialysis patients; meanwhile, antioxidants like alpha lipoic acid (ALA) may reduce the oxidative stress markers and the levels of inflammatory cytokines, so can improve of the patient’s quality of life.

Methods

In this randomized clinical trial study, 60 HD patients were randomly categorized in two case and control groups. Case group received a daily capsule of 600 mg of ALA supplementation for 8 weeks, and the control group received placebo capsules daily. The serum level of IL-8 and TNF-α was measured in both groups before and after the intervention.

Results

There were no significant differences in age, gender, duration of dialysis, and causative factor for dialysis between both groups (P > 0.05). The mean of IL-8 and TNF-α after the intervention in case group was 26.20 ± 15.34 and 21.25 ± 9.61, respectively; the difference between both groups was not statistically significant (P > 0.05).

Conclusion

Based on the better feeling and other beneficial effects of ALA were found in our study; we can conclude that it is a beneficial and recommended supplement, especially, for diabetic and dialysis patients.     

Protective effect of ascorbic acid on cyclophosphamide—induced testicular gametogenic and androgenic disorders in male rats

Aim: To study the detrimental effects of cyclophosphamide on the testicular androgenic and gametogenic activities through endocrine inhibition and/or induction of oxidative stress in male albino rats and to evaluate the protective effect of ascorbic acid. Methods: The testicular △~5, 3β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, peroxidase and catalase activities along with the levels of malondialdehyde (MDA) and conjugated dienes in testicular tissue were measured for the evaluation of testicular oxidative stress. The plasma testosterone (T) level was measured by immunoassay. Various germ cells at stage Ⅶ of spermatogenic cycle were quantified from testicular stained sections. Results: Cyclophosphamide treatment results in a significant inhibition in the testicular △~5, 3β-HSD and 17β-HSD activities, a decrease in plasma T level and a diminution in the counts of various germ cells. Moreover, this treatment was also associated with a significant inhibition of the peroxidase and catalase activit     

What is the effect of overactive bladder symptoms on woman's quality of life during and after first pregnancy?

OBJECTIVE

To evaluate the effect of overactive bladder symptoms (OAB) on women's quality of life (QoL) during and after the first pregnancy, using self‐reported symptom‐based QoL questionnaires.

PATIENTS AND METHODS

In a prospective cohort study, 474 women were asked to complete four self‐reported questionnaires. Urogenital symptoms were assessed with the Urogenital Distress Inventory (UDI) and the Incontinence Impact Questionnaire (IIQ). A women was considered to experience ‘dry’ OAB if she replied positively to the following two questions: ‘do you experience a strong feeling of urgency to empty your bladder?’; and ‘do you experience frequent urination?’. A women was considered to experience ‘wet’ OAB if she replied positively to all of the following questions: ‘do you experience a strong feeling of urgency to empty your bladder?’; ‘do you experience frequent urination?’; and ‘do you experience urine leakage related to the feeling of urgency?’.

RESULTS

In all, 344 (72.6%) women who returned all four questionnaires were included in the analysis. After first childbirth there was a rapid decline in the prevalence of dry OAB (45.2% to 7.9%, P < 0.001). In pregnancy the prevalence of wet OAB increased significantly, but a year after childbirth the prevalence of wet OAB decreased and was similar to that at 12 weeks of gestation (P = 0.289). Women with wet OAB had higher scores on all IIQ domains than those with no OAB symptoms at 36 weeks of gestation. Women with dry or wet OAB all had higher scores on the mobility domain than those with no OAB. The scores on the physical, social and emotional functioning domains were low, suggesting a minimal restriction of lifestyle.

CONCLUSION

OAB symptoms are common during pregnancy; dry OAB had no negative effect on QoL, whereas wet OAB compromised QoL both during and after pregnancy, mainly in the ‘mobility’ and ‘embarrassment’ domains. The urge urinary incontinence symptom in wet OAB seems to profoundly compromise QoL. Apparently, in young mothers with wet OAB, limitations in mobility are especially stressful and these symptoms can be embarrassing.

     

Does a microfluidic chip for sperm sorting have a positive add‐on effect on laboratory and clinical outcomes of intracytoplasmic sperm injection cycles? A sibling oocyte study

The most recent technologies for sperm sorting involve microfluidics. However, the most important question whether their use is of any advantage in terms of laboratory and clinical IVF/ICSI outcomes still remains controversy. In this study, we aimed to investigate whether a microfluidic sperm sorting device (Fertile Plus^®) has a positive add‐on effect on laboratory and clinical outcomes. Sibling oocytes of 81 patients were assigned to two sperm sorting groups including swim up and Fertile Plus^®. All embryos were cultured until day 5/6. Fertilisation, embryo quality and blastocyst development were assessed as primary outcomes among 81 patients; clinical pregnancy, implantation and live birth rates were analysed as secondary outcomes as a subgroup analysis due to transfer cancellations. No statistically significant differences were found between groups in terms of all outcomes analysed in laboratory and clinical terms (p > .05 for all). The results of this study suggest that sorting spermatozoa through Fertile chip does not improve laboratory outcomes significantly and does not seem to have a positive contribution to clinical outcomes.     

Calcium supplementation and weight bearing physical activity--do they have a combined effect on the bone density of pre-pubertal children?

The adaptation of bone to exercise has been shown to be modified by dietary calcium intake. The aim of this randomised controlled trial was to investigate whether there was a differential response to calcium supplementation in elite gymnasts and school children controls. The primary hypothesis was that gymnasts who took calcium supplements would have greater increases in cortical and trabecular volumetric bone mineral density (vBMD) at the radius and tibia. Secondary outcomes studied were changes in bone geometry at the radius and tibia and lumbar spine and whole body measurements. Children were randomised to 12 months daily supplementation of 500 mg elemental calcium (1250 mg (in the form of calcium carbonate salt)) or placebo. Outcome measures were assessed using peripheral quantitative computed tomography (pQCT) (distal and diaphyseal radius and tibia) and dual energy X-ray absorptiometry (DXA) (lumbar spine and whole body). Eighty-six subjects participated in the trial (44 gymnasts, 42 controls) and 75 subjects completed the trial (39 gymnasts, 36 controls). Data were analysed by analysis of covariance adjusting for baseline value of bone parameters, age, height, gender and puberty, and delay between baseline measurement and start of intervention. The primary analysis was for a calcium-exercise interaction; a pooled calcium effect with no interaction was also tested. Results are presented as ratios (95% confidence intervals). At the distal tibia, trabecular vBMD showed a significant interaction (p=0.04), with controls (1.00: 0.99, 1.09) responding more than gymnasts (0.98: 0.94, 1.02) to supplementation. At the distal radius, change in trabecular vBMD was not significant (p=0.05). There were no differences in change in cortical vBMD at either site between the gymnasts and controls (tibia: p=0.82, radius: p=0.88). For all other secondary outcomes at radius, tibia, spine and whole body no significant interactions were found. In conclusion, there was no beneficial effect of additional calcium in gymnasts who already consume their recommended nutrient intake (888 mg/day; United Kingdom reference nutrient intake for 8- to 11-year-olds is 555-800 mg/day) for calcium. We speculate that gymnasts have already adapted their bones (geometry and vBMD) to the demands imposed upon them by the loading they are subjected to during gymnastics and do not benefit from additional calcium supplementation.     

Pretreatment effect of adenosine on activation of NF—κB and level of TNF—α during myocardial ischemia and reperfusion in rats

Ithasbeenshownthatischemiaandreperfusion(I/R)increasecytokinelevelsincludingTNF α ,IL 1,IL 6 ,IL 8,IF γ ,andintercellularadhesionmolecule 1(ICAM 1)inthemyocardium .1TNF αandIL 6arethoughttobeimportantintheprogressionofmyocardialdysfunction .2 AdenosineinhibitsmyocardialTNF αproductionin postischenmicrat ,reduceshumanmyocardialinjuryafterI/R ,3anddecreasesLipopolysaccharide (LPS )inducedcardiacandmacrophageTNF a production .4 However ,themolecularmechanismsofadenosineinthedown …     

The contents and effect of angiotensin Ⅱ on hCG release in human placental villi during the first trimester of gestation

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Safety and beneficial effect on body core temperature of a prewarmed plasma substitute—hydroxyethyl starch—during anesthesia

Purpose We investigated, first, the safety of use and stability of a plasma substitute—hydroxyethyl starch (HES)—kept in a warming cabinet for a long period, and then the effect on body core temperature of the prewarmed HES in patients during urological surgery.Methods In the first part of the study, HES colloid solutions (500ml per pack; Hespander) were kept in a warming cabinet (40°C) for 3 months and were tested for biological and chemical safety and stability. In the second part of the study, 1000ml of HES at room temperature (control group; n = 10) or kept in a warming cabinet for a few days (warmed group; n = 10) was infused via a central venous catheter for 30min in patients undergoing urological surgery under general anesthesia with lumbar epidural anesthesia. Esophageal temperature was monitored as the core temperature. HES fluid temperatures in the pack and at the end of a 1-m intravenous tube connected to the central venous catheter were also measured.Results The test of HES products warmed for 3 months passed all inspections performed during the study period. In the warmed group, the pack and intravenous tube temperatures of HES were still high at 15min after infusion (37.1° ± 1.5°C [mean ± SD] and 34.8° ± 2.2°C, respectively). Core temperature in the warmed group decreased significantly, by 0.34° ± 0.06°C, but was significantly higher than that in the control group (by 0.84° ± 0.13°C) after 30min of the infusion.Conclusions The use of HES products kept in a warming cabinet prior to surgery can maintain warm body temperature, easily, safely, and effectively.     

The effect of Shen-Fu on gastrointestinal tract injury and its potential mechanism during cardio-pulmonary bypass in patients undergoing cardiac surgery

Objective: To investigate the effect of Shen-Fu (SF) injection on gastrointestinal tract injury and its potential mechanism.Methods: Thirty-eight patients undergoing elective open heart surgery were assigned to Group C (control group, n = 18) and Group SF (n = 20) randomly. In Group SF, the patients received intravenous injection of SF (0.5 ml/kg) at the beginning of the surgery followed by a continuous infusion of 100 ml SF (1.0 ml/kg) solution diluted by saline at a rate of 0.004 ml · Kg-1 · min-1 with a Grasby pump. The control group was injected with normal saline in the same volume. Gastric intramucosal pH (pHi), activity of blood diamine oxidase ( DAO ), and concentrations of blood LPS and IL-6 were measured before CPB ( S0) and 1 h ( S1 ) and 2 h ( S2) after aortic declamping, respectively.Results: In Group C, pHi value was significantly lower at S1 and S2 than at S0 ( mean P <0.01) and blood DAO and concentrations of LPS and IL-6 were significantly higher at S1 and S2 than at S0 ( meanP < 0.01     

Does skin preparation alter suture strength characteristics? Assessing the effect of chlorhexidine and isopropyl alcohol on common skin closure suture material

Sutures are essential to approximate tissues and enable healing by first intention until a wound regains its original tensile strength. The mechanical properties of sutures are well documented, but the effects of exposing sutures to skin preparation solutions used in surgery are not. This study was performed to investigate whether 2% chlorhexidine and 70% isopropyl alcohol skin preparation, commonly used prior to incision and prior to closure, has any effect on the mechanical properties of several commonly used surgical suture types. Four suture types were soaked in either 2% chlorhexidine and 70% isopropyl alcohol or Hartmann''s solution for 5 minutes. All sutures were left to dry for 11 days before being tested to failure using an Instron 3367 tensile testing machine. Testing revealed significant differences in failure load, ultimate tensile stress, and Young''s modulus between suture types (P < .05). No significant differences in failure load (P = .98), ultimate tensile stress (P = .21), or Young''s modulus (P = .22) were observed between the test group and the control group when comparing sutures of the same type. This study demonstrates that chlorhexidine/isopropyl skin preparation solutions do not significantly change the mechanical properties of suture materials exposed to them.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.