Effect of vasoactive intestinal peptide on defecation and VIP-cAMP-PKA-AQP3 signaling pathway in rats with constipation / 中南大学学报(医学版)

To observe the effect of vasoactive intestinal peptide (VIP) on the metabolism of intestinal fluid and cyclic AMP protein kinase A signaling pathway (cAMP-PKA) and water channel protein 3 (AQP3) in rats with constipation, and to explore the mechanism of VIP in the treatment of constipation.
 Methods: A total of 45 healthy adult rats were randomly divided into a control group, a model group, a model +VIP group. After 4 weeks of VIP treatment, the first black stool time were examined with the ink gastric method; the water content in feces was calculated; the morphological changes in colonic tissues were observed by HE staining. The expression of VIP and AQP3 protein levels in colon tissues were detected by Western blot; and the cAMP, PKA, AQP3 mRNA expression levels were detected by quantitative real time polymerase chain reaction (qPCR). 
 Results: Compared with the control group, the first black stool time was prolonged, the water content of fecal decreased significantly (both P<0.01); part of the colon mucosa epithelial cells were destructed; the goblet cell volume decreased and quantity was reduced; the contents of AQP3 and VIP in colon tissues were significantly decreased, and the cAMP, PKA and AQP3 mRNA levels were decreased in the model group (all P<0.05). Compared with the model group, the first black stool time in the model +VIP group was shortened, the fecal water content increased significantly (both P<0.05); the mucosal epithelium integrity improved, the number of goblet cells increased; the content of AQP3 and VIP in colon tissues was increased, and the cAMP, PKA, and AQP3 mRNA levels were elevated (all P<0.05).
 Conclusion: Intravenous injection of VIP can regulate intestinal fluid metabolism and improve the symptoms of constipation in rats, which might be related to the regulation of VIP-cAMP-PKA-AQP3 signaling pathway.

Compound danshen injection regulated the expression of AQP3 in the human amnion epithelium cells through JNK signal pathway / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the role of Compound Danshen Injection (CDI) in regulating the expression of aquaporin 3 (AQP3) in human amnion epithelium cells (hAECs), and to study the relation between c-Jun N-terminal kinase (JNK) signal pathway and AQP3.</p><p><b>METHODS</b>hAECs were isolated and primarily cultured from term pregnancy with normal amniotic fluid volume and from term pregnancy with oligohydramnios, and then hAECs were further divided into four groups, i.e., the blank control group (A), the SP600125 group (B), the CDI group (C), and the SP600125 +CDI group (D). The cell viability was measured by cell counting kit-8 assay (CCK-8). The expression of total JNK, phosphorylated JNK, and AQP3 were determined by Western blot.</p><p><b>RESULTS</b>(1) In hAECs with normal AFV or with oligohydramnios: There was no statistical difference in the cell viability or the expression of total JNK among the 4 groups (P > 0.05). But there was statistical difference in the expression of p-JNK (P < 0.05). Compared with A group, the expression of p-JNK was obviously down-regulated in B group, but obviously up-regulated in C group (P < 0.05). The expression of p-JNK was significantly lower in D group than in C group, but higher than that in A group or B group (P < 0.05).The AQP3 expression in the hAECs with normal amniotic fluid volume of C group and D group were higher than that in the A group (P < 0.05). However, there was no statistical difference in the AQP3 expression between C group and D group (P > 0.05). In hAECs with oligohydramnios, the expression of AQP3 obviously decreased in B group, but up-regulated in C group (both P < 0.05). The expression of AQP3 was lower in D group than in C group, but higher than in B group (P < 0.05).</p><p><b>CONCLUSION</b>CDI could regulate the AQP3 expression in hAECs with oligohydramnios via activating the JNK signal pathway.</p>

Effects of compound salvia miltiorrhiza injection on aquaporin 3 expression in human amniotic epithelial cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effects of Compound Salvia miltiorrhiza Injection (CSI) on aquaporin 3 (AQP3) expression in human amniotic epithelial cells (hAECs), and to explore its mechanisms for treating oligohydramnios.</p><p><b>METHODS</b>The hAECs selected from 8 human term pregnancies with oligohydramnios and no other complications (as the test group)and 8 human term pregnancies with normal amniotic fluid volume (as the control group) were primarily cultured. The mRNA and protein expressions of AQP3 in hAECs were detected using reverse transcription-polymerase chain reaction and Western blot with various concentrations of CSI (0.000, 0.001, 0.010, 0.020, 0.060, and 0.100 mg/mL, respectively) at different time points (0, 6, 12,24, and 48 h, respectively).</p><p><b>RESULTS</b>(1) Compared with the control group, the AQP3 expression was down-regulated in the test group (P < 0.05). (2) The AQP3 expression in the two groups reached the peak when the concentration of CSI was 0.010 mg/mL, showing statistical difference when compared with other concentrations (P < 0.05). (3) The AQP3 expression reached the peak when 0.010 mg/mL CSI acted for 12 h, showing statistical difference when compared with other concentrations (P < 0.05). (4) The AQP3 expression was up-regulated in the two groups when 0.010 mg/mL CSI acted for 12 h. But the up-regulated AQP3 expression was more obvious in the test group than in the control group (P < 0.05).</p><p><b>CONCLUSIONS</b>CSI could regulate the AQP3 expression in hAECs. CSI showed more obvious effects on the AQP3 expression in hAECs of oligohydramnios human term pregnancies.</p>

The role of MAPK signal pathway in the regulation of AQP3 expression induced by compound danshen injection in human amniotic epithelial cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the role of mitogen-activated protein kinases (MAPKs)-extracellular signal regulated kinase1/2 (ERK1/2) signal pathway in the regulation of Compound Danshen Injection (CDI) induced AQP3 expression in the human amniotic epithelial cells (hAECs).</p><p><b>METHODS</b>hAECs of term pregnancy with normal amniotic fluid volume (AFV) or isolated oligohydramnios were primarily cultured. And the cells were equally divided into four groups, i.e., the vehicle control group, the U0126 group, the CDI group, the CDI + U0126 group. The expressions of phosphorylated ERK1/2 (p-ERK1/2) and AQP3 in hAECs were detected using Western blot analysis.</p><p><b>RESULTS</b>(1) When compared with the control group, the expression level of p-ERK1/2 in hAECs in those with normal AFV and oligohydramnios obviously decreased in the U0126 group (P < 0.05). The expression level of p-ERK1/2 could be elevated in the CDI group (P < 0.05). The expression level of p-ERK1/2 in hAECs was higher in the CDI +U0126 group than in the U0126 group, but lower in the CDI + U0126 group than in the CDI group (P < 0.05). (2) There was no obvious change in AQP3 expression in hAECs with normal AFV between the U0126 group and the vehicle control group (P > 0.05). There was no statistical difference in the expression level of AQP3 between the CDI group and the U0126 +CDI group (P > 0.05), but they were higher than those in the vehicle control group (P < 0.05). (3) Compared with the vehicle control group, the expression level of AQP3 in hAECs with oligohydramnios significantly decreased in the U0126 group and increased in the CDI group (P < 0.05). The expression level of AQP3 was lower in the U0126 + CDI group than in the CDI group, but higher in the U0126 +CDI group than in the U0126 group (P < 0.05).</p><p><b>CONCLUSION</b>CDI could regulate AQP3 expression level in hAECs with oligohydramnios via activating the MAPK-ERK1/2 signal transduction pathway.</p>

Expression of aquaporin 3 and aquaporin 9 is regulated by oleic acid through the PI3K/Akt and p38 MAPK signaling pathways / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the effect of oleic acid (OA) on expression of aquaglyceroporin genes, AQP3 and AQP9, in hepatocyte steatosis and to investigate the underlying molecular mechanisms using an in vitro system.</p><p><b>METHODS</b>HepG2 cells were treated with OA at different concentration to establish in vitro models of nonalcoholic hepatocyte steatosis. The corresponding extents of hepatic steatosis modeling were assessed by oil red O staining and optical density (OD) measurements of the intracellular fat content. The model lines were then treated with inhibitors of the PI3K/Akt and p38 MAPK signaling pathway factors and effects on AQP3/9 expression was measured by real time RT-PCR and western blotting.</p><p><b>RESULTS</b>The fat concentration, indicative of hepatic steatosis, increased in conjunction with increased concentrations of OA (0 less than 250 less than 500 mumol/L). OA exposure also down-regulated AQP3 mRNA and up-regulated AQP9 mRNA levels in a concentration-dependent manner. The most robust changes in expression occurred in response to the 500 mumol/L concentration of OA for both AQP3 (0.47+/-0.18; t = 4.5450, P less than 0.05) and AQP9 (1.57+/-0.21; t = 3.0306, P less than 0.05). Treatment with OA + PI3K pathway inhibitor (LY294004) significantly decreased AQP9 mRNA expression (4.55+/-0.62) as compared to the control group (1.00+/-0.10; t = 9.7909, P less than 0.01), that 500 mumol/L OA group (2.43+/-0.53; t = 4.5018, P less than 0.05), and the LY294002 group (1.90+/-0.16; t = 7.1683, P less than 0.01). Treatment with p38 MAPK pathway inhibitor (SB230580) significantly increased the OA-suppressed level of AQP3 mRNA to the level detected in the control group (1.27+/-0.11; t = 5.7455, P less than 0.01) and decreased the OA-stimulated AQP9 mRNA (0.38+/-0.09; t = 6.5727, P less than 0.01). No significant changes in mRNA expression of AQP3/9 were observed with inhibition of the ERK1/2 and JNK signal transduction pathways. The OA-induced changes in protein expression levels of AQR3 and AQP9 followed a similar trend of the genes. Finally, OA suppressed the level of phosphorylated Akt (from 0.21+/-0.02 to 0.13+/-0.03; t = 3.8431, P less than 0.05) but elevated the level of phosphorylated p38 (from 0.58+/-0.06 to 1.02+/-0.10; t = 12.5289, P less than 0.01). Again, OA treatment produced no significant affect on ERK1/2 and JNK phosphorylation.</p><p><b>CONCLUSION</b>OA down-regulates AQP3 expression by stimulating the p38 MAPK signaling pathway, and up-regulates the AQP9 by blocking the PI3K/Akt pathway and activating the p38 MAPK signaling pathway.</p>

Expression of Aquaporin-3 in Ipsilateral Rat Kidney With Unilateral Partial Ureteral Obstruction

PURPOSE: Aquaporin (AQP), a protein located in the cellular membrane, allows rapid passage of water across the cell membrane. Various AQP subtypes have been associated with ureteral obstruction. In particular, AQP3 has two functions: water and glycerol transport. The aim of this study was to investigate the expression of AQP3 in the ipsilateral rat kidney in unilateral partial ureteral obstruction (UPUO). MATERIALS AND METHODS: Sprague-Dawley rats (n=30, 200-250 g) were divided into two groups. A sham operation was performed in the control group (n=10) and UPUO of the left upper ureter with a silicone tube was induced in the UPUO group (n=20). The left kidney was obtained from both groups 7 days after the operations. The kidney specimens underwent immunofluorescent staining with AQP3 monoclonal antibody, and the density of AQP3 in the tissue was measured with an image analyzer. RESULTS: In the UPUO group, thinning of the epithelial layer and infiltration of inflammatory cells was seen along with the localized expression of AQP3 in the basolateral aspect of the principal collecting duct cells. The mean optical density of AQP3 was significantly lower in the UPUO group than in the control group (100.9+/-17.5 compared with 131.7+/-16.9; p<0.001). CONCLUSIONS: These results suggest that a decrease in the expression of AQP3 may be the result of a urinary stasis reaction caused by UPUO in response to local and intrarenal factors. These changes suggest that AQP3 may have a pathophysiological role in UPUO.

Effect of curing-injury Cataplasma on expression of AQP-3 in skeletal muscle of rat model with acute injury in soft tissues / 中南大学学报(医学版)

OBJECTIVE@#To observe the effect of curing-injury cataplasma on the expression of aquaporin protein 3 (AQP-3) in skeletal muscle of rat model with acute injury in soft tissues.@*METHODS@#A total of 54 SD rats were randomly divided into 3 groups, and by using 10% sodium sulfide the depilating treatment was made in the thigh lateral of each left hind leg 1 day before modeling. The depilatory area in the control group was merely marked with striking range, not attacked for modeling. In the depilatory area of the modeling group, the blowing apparatus was used to attack the marked range to establish the model of soft tissue swelling with acute injury, to which none medication was given. In the drug treatment group, immediately after establishing the model of soft tissue swelling with acute injury, curing-injury cataplasma was scattered on the stricken area, and fixed with bandage. After the modeling, the rats were killed at 1 h, 6 h, 1 d, 3 d, 5 d, and 7 d, 3 rats in each group at each time point. In the marked area some tissue was taken, and the dry/wet proportion method was used to detect the water content in the skeletal muscle. Western blot and qPCR method were used for the AQP-3 protein and the level of gene expression.@*RESULTS@#At the six time points, for the modeling and drug treatment groups, the water content of skeletal muscle was higher than that of the control group (P<0.05). At 3 d, 5 d and 7 d, the water content in the drug treatment group was lower than that of the modeling group (P<0.01); for the modeling and drug treatment groups, AQP-3 protein and the level of gene expression were higher than those of the control group. There was significant difference between the drug treatment group and the modeling group (P<0.01).@*CONCLUSION@#Curing-injury cataplasma can relieve soft tissue swelling with acute injury, and accelerate the repair process after the injury.

Role of Keratinocytes in the Development of Vitiligo

Vitiligo is an acquired depigmentary disorder of the skin that results from the loss of functioning epidermal melanocytes. Most studies on vitiligo have concentrated on the abnormality of melanocytes rather than the abnormality of keratinocytes; however, epidermal melanocytes form a functional and structural unit with neighboring keratinocytes. In fact, direct cell-to cell contact stimulates in vitro proliferation of melanocytes, and growth factors produced by adjacent keratinocytes regulate the proliferation and differentiation of melanocytes. The potential role of keratinocyte-derived cytokines has also been presented. We focused on the structural changes in vitiliginous keratinocytes, which may result in loss of melanocytes, to examine the pathomechanism of vitiligo. The results of a comparison between depigmented and normally pigmented epidermis in patients with vitiligo showed that the keratinocytes in the depigmented epidermis were more vulnerable to apoptosis. Impaired Phosphatidylinositol 3-kinase (PI3K)/serine/threonine protein kinase (Akt) activation followed by reduced nuclear factor-kappaB activation under increased tumor necrosis factor-alpha levels was demonstrated as a mechanism for keratinocyte apoptosis. The role of aquaporin 3 in keratinocyte apoptosis was addressed based on the relationship between the PI3K/AKT pathway and the E-cadherin-catenin complex. Apoptotic keratinocytes induced a lower expression of keratinocyte-derived factors, including stem cell factor, in depigmented epidermis, resulting in passive melanocyte death.

Changes in Transepidermal Water Loss and Skin Hydration according to Expression of Aquaporin-3 in Psoriasis

BACKGROUND: Aquaporins (AQPs) are a family of water transporting proteins present in many mammalian epithelial and endothelial cell types. Among the AQPs, AQP3 is known to be a water/glycerol transporter expressed in human skin. OBJECTIVE: The relationship between the expression level of AQP3 and transpidermal water loss (TEWL) in the lesional and peri-lesional skin of psoriasis-affected patients, and skin hydration in the lesional and peri-lesional skin of psoriasis patients, was investigated. METHODS: The expression of AQP3 in psoriasis-affected and healthy control skin was determined using immunohistochemical and immunofluroscence staining. TEWL and skin hydration were measured using a Tewameter(R) TM210 (Courage & Khazaka, Cologne, Germany) and a Corneometer(R) CM 820 (Courage & Khazaka), respectively. RESULTS: AQP3 was mainly expressed in the plasma membrane of stratum corneum and the stratum spinosum in normal epidermis. Unlike the normal epidermis, AQP3 showed decreased expression in the lesional and peri-lesional epidermis of psoriasis. TEWL was increased, and skin hydration was decreased, in the lesional and peri-lesional skin of psoriasis patients, compared with the healthy control sample. CONCLUSION: Although various factors contribute to reduced skin hydration in the lesional and peri-lesional skin of psoriasis, AQP3 appears to be a key factor in the skin dehydration of psoriasis-affected skin.

Bioinformatics analysis of the structure and linear B-cell epitopes of aquaporin-3 from Schistosoma japonicum

OBJECTIVE@#To analyze the structure of aquaporins-3(AQP-3) from Schistosoma japonicum(SJAQP-3) using bioinformatical methods, and to provid of references for vaccine targets research.@*METHODS@#Protparam, BepiPred, TMHMM Server, MLRC, Geno3d, DNA star software packages were used to predict the physical and chemical properties, hydrophilicity plot, flexibility regions, antigenic index, surface probability plot, secondary structure, and tertiary structure of amino acid sequence of SJAQP-3.@*RESULTS@#SJAQP-3 had six transmembrane regions and two half-spanning helices that form a central channel. The half-spanning helices fold into the centre of the channel. Either of the half-spanning helix had a conserved motif of NPA common to all aquaporins. Predicted linear B-Cell epitopes were most likely at the N-terminal amino acid residues of 5aa-7aa, 59aa-62aa, 225aa-230aa, 282aa -288aa, 294aa -298aa and 305aa -307aa area. 59aa- 62aa, 225aa-230aa located outside the membrane, the others located inside the cell.@*CONCLUSIONS@#SJAQP-3 is a integral membrane protein in Schistosoma japonicum tegument. There are six potential epitopes in SJAQP-3. It might be a potential molecular target for the development of vaccines.

Expression of aquaporin 3, 4, and 8 in colonic mucosa of rat models with slow transit constipation / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of aquaporin 3, 4, and 8 in the colonic mucosa of rat models with slow transit constipation (STC).</p><p><b>METHODS</b>STC rat model was established by giving the rats the compound solution of diphenoxylate. Real time polymerase chain reaction (RT-PCR) was used to measure the expression of aquaporin mRNA in colonic mucosa of STC rat models (study group,n=16) and normal rats (control group,n=16). Gray scale ratio of aquaporin to β-action (internal reference) was used for quantification.</p><p><b>RESULTS</b>RT-PCR revealed that the mean gray scale ratios of aquaporin 3 in the proximal colon of the study group and control group were 0.344 and 0.602 (P<0.05), and were 0.419 and 0.509 in the distal colon (P>0.05), respectively. The mean gray scale ratios of aquaporin 4 in the proximal and the distal colon were 0.764 and 0.759 in the study group (P>0.05), and were 0.776 and 0.736 in the control group (P>0.05), respectively. However, there was no expression of aquaporin 8 in the proximal and the distal colon in either the study group or the control groups.</p><p><b>CONCLUSIONS</b>Expression of aquaporin 3 in the proximal colon of STC rat models is down-regulated, which regulates water absorption. There are no significant changes in the expressions of aquaporin 4 and 8.</p>

Significance of aquaporin-1 and aquaporin-3 expression in colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the significance of aquaporin-1(AQP-1) and aquaporin-3(AQP-3) in the development of colorectal carcinoma.</p><p><b>METHODS</b>The expression of AQP-1 and AQP-3 was investigated using immunohistochemical staining with Streptavidin Peroxidase in tissues from colorectal adenoma (CRA, n=25), colorectal cancer (CRC, n=50), and adjacent mucosa (CRT, n=50).</p><p><b>RESULTS</b>The positive rate of AQP-1 was 64%(32/50) in CRC, significantly higher than that in CRT (38%, 19/50) and CRA(32%, 8/25)(P<0.05). The expression of AQP-1 was associated with depth of invasion and lymph node metastasis in CRC patients(P<0.05). The positive rate of AQP-3 was 56% in CRT, 44% in CRA, and 52% in CRC. There were no significant differences (P>0.05). The expression of AQP-3 was associated with age, tumor diameter, and depth of invasion (P<0.05). No significant correlation between the expression of AQP-1 and AQP-3 in CRC was shown by Spearman correlation analysis(P>0.05).</p><p><b>CONCLUSIONS</b>AQP-1 expression is increased in CRC while the expression of AQP-3 is not. There is no correlation between the expression of AQP-1 and AQP-3 in CRC.</p>

Expressions of aquaporins 1 and 3 in the mouse prostate and their significance / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the expressions of aquaporins (AQPs) in the mouse prostatic tissue and their significance, and to provide some evidence for a deeper insight into the physiological function and regulation of AQP expressions in normal and diseased prostatic tissues.</p><p><b>METHODS</b>The mRNA expressions of AQP0 - 4 in the mouse prostatic tissue were determined by RT-PCR, and the expressions and localizations of AQP1 and AQP3 proteins were characterized by Western blot and immunohistochemistry.</p><p><b>RESULTS</b>RT-PCR exhibited the mRNA expressions of AQP1 and AQP3, but not those of AQP0, AQP2 and AQP4 in the prostate tissue, while Western blot showed the expression of the AQP1 protein with the relative molecular mass (RMM) of 28 000 and those of the glycosylated and non-glycosylated AQP3 proteins with the RMM of 35 000 and 27 000, respectively. Immunohistochemistry indicated the strong expression of AQP1 in the cyst and plasma membrane of the secretary cells and that of AQP3 in the stroma cells of the prostate.</p><p><b>CONCLUSION</b>The AQP1 and AQP3 genes were expressed in the secretary epithelia of the mouse prostate tissue, which suggests that AQP1 and AQP3 may play an important role in the secretion of prostatic fluid.</p>

Expression and significance of aquaporin 3 and aquaporin 9 in colonic mucosa of patients with functional constipation / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the expression and distribution of aquaporin 3 (AQP3) and aquaporin 9 (AQP9) in colonic mucosa of patients with functional constipation, and to examine the relationship of constipation with AQP3 and AQP9.</p><p><b>METHODS</b>Immunohistochemistry and semi-quantitative Western blotting were used to detect the expression and distribution of AQP3 and AQP9 in colonic mucosa of 45 patients with functional constipation (trial group) and 21 cases without constipation (control group). Gray scale ratios of AQP3 and AQP9 to beta-actin protein as interior reference were relative amounts of AQP3 and AQP9.</p><p><b>RESULTS</b>Immunohistochemistry showed that AQP3 was distributed mainly in basement and cavosurface membrane of epithelial cell of colonic mucosa and AQP9 mainly in basement membrane of goblet cell in cavosurface colonic mucosa. Western blotting revealed that the average values of gray scale ratios of AQP3 in ascending colon of trial group and control group were 0.905 and 0.798 (P<0.05),while those of AQP9 were 0.544 and 0.543 (P>0.05), respectively. The average values of gray scale ratios of AQP3 in descending colon of trial group and control group were 0.697 and 0.701 (P>0.05), while those of AQP9 were 0.575 and 0.732 (P<0.05), respectively.</p><p><b>CONCLUSIONS</b>Up-regulated expression of AQP3 in ascending colon and down-regulated expression of AQP9 in descending colon are presented in patients with functional constipation as compared to patients without functional constipation. AQP3 and AQP9 may play a significant role in the onset and development of constipation.</p>

Study on correlation between aquaporin 3, 4 gene expression in gastric mucosa and severity of Pi-Wei damp-heat syndrome in patients with chronic superficial gastritis / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the relationship between aquaporin 3,4 (AQP3, AQP4) gene expression in gastric mucosa and severity of Pi-Wei damp-heat syndrome (PWDHS) in patients with chronic superficial gastritis (CSG).</p><p><b>METHODS</b>Gastric mucosa taken from the upper part of gastric corpus was collected under gastroscope and preserved in liquid nitrogen. The gene expression of AQP3 and AQP4 was determined quantitatively by fluorescent PCR.</p><p><b>RESULTS</b>The gene expression of AQP3 and AQP4 in patients with PWDHS of moderate and severe degree was higher than that in those of mild degree and in healthy persons respectively (P <0.05 and P <0.01); and the gene expression of AQP3 in patients with PWDHS of severe degree was higher than that in those of moderate degree (P<0.05).</p><p><b>CONCLUSION</b>The gene expression of AQP3 and AQP4 in gastric mucosa was correlative with the severity of PWDHS in patients with chronic superficial gastritis, the severer the syndrome, the higher the gene expression.</p>

Aquaporin-1 and aquaporin-3 expressions in the temporo-mandibular joint condylar cartilage after an experimentally induced osteoarthritis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Over 70% of the total tissue weight in the cartilage matrix consists of water, and the early-stage osteoarthritic cartilage is characterized by swelling. Water transport in the cartilage matrix and across the membranes of chondrocytes may be important in normal and pathological conditions of cartilage. The purpose of this study was to identify aquaporin-1 (AQP1) and aquaporin-3 (AQP3) expressions in the mandibular condylar cartilage after experimentally induced osteoarthritis (OA) in rats.</p><p><b>METHODS</b>An experimental temporomandibular joint OA was induced by partial discectomy in rats. The pathological characteristics of the normal, early-stage, and late-stage osteoarthritic TMJ cartilages were verified by histological techniques. The AQP1 and AQP3 gene expressions in the normal and osteoarthritic cartilages were measured using quantitative real-time reverse-transcription PCR analysis. The cartilage sections were incubated in primary polyclonal antibodies to AQP3; immunofluorescent microscopy was used to examine the AQP3 expression shown by its protein level.</p><p><b>RESULTS</b>The mRNA expression levels of AQP1 and AQP3, analyzed using quantitative PCR, revealed that AQP3 mRNA was highly up-regulated in the OA cartilage, which was considered significant. There was no notable difference in the expression of AQP1 mRNA between OA and normal controls. With the progressing of the OA, the localization of the AQP3 protein was quite different from that of the normal cartilage. Compared to the normal cartilage, the expressions of AQP3 protein were observed mainly in the proliferative zone and the upper mid-zone chondrocytes at the early-stage of OA, and were observed to appear frequently throughout the mid- and deep zone during the late-stage of OA.</p><p><b>CONCLUSIONS</b>The high expression of AQP3 mRNA in the OA cartilage and the different localization of the AQP3 protein suggest that it may play a particular role in OA pathogenesis. Further study of AQP3 function may provide new insight into the understanding of the molecular mechanisms underlying OA.</p>

Expression of aquaporins 1, 3, 8, 9 mRNA in human fetal membranes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of aquaporin (AQP)-1, 3, 8, 9 in human fetal membrane and their role in the human amniotic fluid circulation.</p><p><b>METHODS</b>RT-PCR was employed for detection of the expressions of AQP-1, 3, 8, 9 mRNA in human amnion and chorion from 20 women with normal term pregnancy.</p><p><b>RESULTS</b>AQP-1, 3, 8, 9 mRNA expression was detected in both human amnion and chorion, and no significant difference was found in their expression levels or between the amnion and chorion (P>0.05).</p><p><b>CONCLUSION</b>AQP-1, 3, 8, 9 can be associated with intramembranous transport and volume regulation of amniotic fluid.</p>

Expression of AQP3 gene in chronic atrophic and chronic superficial gastritis patients

Most studies about aquaporin 3 [AQP3] in the gastrointestinal tract were carried out on both in vivo and in vitro. The role of AQP3-mediated water transport in human gastrointestinal tract is still unclear. Our aim in this study was to explore the expression of AQP3 gene in chronic atrophic gastritis [CAG] and chronic superficial gastritis [CSG] atients and to determine its possible function in the development of gastritis. Twenty-two outpatients diagnosed as CSG and 12 outpatients diagnosed as CAG were selected randomly. Ten cases of healthy individuals were selected as normal control group. In all cases, AQP3 gene expression of gastric mucosa was detected by fluorescence quantitative polymerase chain reaction [FQ-PCR]. The AQP3 gene expression was significantly higher in gastric mucosa of CSG and healthy individuals than that in CAG [P < 0.01]. However, there was no significant difference in the AQP3 gene expression between helicobacter pylori positive patients and helicobacter pylori negative patients [P > 0.05]. AQP3 expression might play certain role in the occurrence and development of gastritis

Effects of Nitric Oxide Synthesis Inhibition on Indomethacin-Induced Downregulation of Renal Aquaporins in Rats / 대한신장학회잡지

BACKGROUND:The present study aimed to determine whether there is a regulatory mechanism exerted by endogenous nitric oxide (NO) in the regulation of aquaporin (AQP) water channels in the kidney. METHODS:Male Sprague-Dawley rats were used. They were divided into 4 groups: 1) L-NAME group was treated with N(G)-nitro-L-arginine methyl ester (L-NAME, 100 mg/L drinking water) for 1 week, 2) indomethacin group was treated with indomethacin (5 mg/kg, twice a day, i.p.) for 2 days, 3) L-NAME/ indomethacin group was treated with L-NAME for 1 week in which indomethacin was cotreated for the last two days, and 4) control group was kept untreated. The abundance of AQP2 and AQP3 proteins was determined in the inner medulla of the kidney. RESULTS:The expression of AQP2 and AQP3 proteins was significantly decreased by indomethacin. L-NAME abolished the indomethacin-induced decreases of AQP channels, although it did not significantly affect the expression of AQP channels by itself. CONCLUSION:These results suggest that endogenous NO system, when stimulated, may downregulate the expression of AQP2 and AQP3 channels in the kidney.