BACKGROUND AND PURPOSE: The detection of aquaporin 4-IgG (AQP4-IgG) is now a critical diagnostic criterion for neuromyelitis optica spectrum disorder (NMOSD). To evaluate the serostatus of NMOSD patients based on the 2015 new diagnostic criteria using a new in-house cell-based assay (CBA). METHODS: We generated a stable cell line using internal ribosome entry site-containing bicistronic vectors, which allow the simultaneous expression of two proteins (AQP4 and green fluorescent protein) separately from the same RNA transcript. We performed in-house CBA using serum from 386 patients: 178 NMOSD patients diagnosed according to the new diagnostic criteria without AQP4-IgG, 63 high risk NMOSD patients presenting 1 of the 6 core clinical characteristics of NMOSD but not fulfilling dissemination in space, and 145 patients with other neurological diseases, including 66 with multiple sclerosis. The serostatus of 111 definite and high risk NMOSD patients were also tested using a commercial CBA kit with identical serum to evaluate the correlation between the 2 methods. All assays were performed by two independent and blinded investigators. RESULTS: Our in-house assay yielded a specificity of 100% and sensitivities of 80% (142 of 178) and 76% (48 of 63) when detecting definite- and high risk NMOSD patients, respectively. The comparison with the commercial CBA kit revealed a correlation for 102 of the 111 patients: no correlation was present in 7 patients who were seronegative using the commercial method but seropositive using the in-house method, and in 2 patients who were seropositive using the commercial method but seronegative using the in-house method. CONCLUSIONS: These results demonstrate that our in-house CBA is a highly specific and sensitive method for detecting AQP4-IgG in NMOSD patients.
Aquaporin 4 ; Cell Line ; Humans ; Methods ; Multiple Sclerosis ; Neuromyelitis Optica* ; Research Personnel ; Ribosomes ; RNA ; Sensitivity and Specificity

OBJECTIVETo investigate the expression of aquaporin 4 (AQP4) after microwave exposure and the correlation with the brain injury by radiation.

METHODS70 male rats were exposed to microwave whose average power density was 0, 10, 30 and 100 mW/cm(2) respectively. Rats were sacrificed at 6 h, 1 d, 3 d and 7 d after exposure. Immunohistochemistry and Western blot were used to detect the expression of AQP4 in protein level in rat hippocampus, and the expression of AQP4 in gene level was measured by in situ hybridization and RT-PCR.

RESULTSThe expression of AQP4 in rat hippocampus was abnormal after 10, 30, 100 mW/cm(2) microwave exposure. The protein level showed increased at first and then recovered at 10 and 30 mW/cm(2) groups, while increased progressively in 100 mW/cm(2) group within 14 d (P < 0.01). The gene expression of AQP4 was increased (0.51 +/- 0.02) at the beginning (6 h) and then regained after 10 mW/cm(2) microwave exposure, while in 30 and 100 mW/cm(2) groups, it rose to the peak at 7 d (0.46 +/- 0.02 and 0.43 +/- 0.08) and didn't get back (P = 0.004; P = 0.012).

CONCLUSIONMicrowave radiation can increase the expression of AQP4 in rat hippocampus. The change might participate in the process of increasing permeability of blood-brain barrier and lead to the brain edema after microwave radiation.

Animals ; Aquaporin 4 ; genetics ; metabolism ; Hippocampus ; metabolism ; radiation effects ; Male ; Microwaves ; adverse effects ; Rats ; Rats, Wistar

OBJECTIVETo evaluate the effect of water channel aquaporin 4 (AQP4) on bleomycin-induced lung fibrosis in mice.

METHODSIn wild type and AQP4 gene knockout (AQP4-/-) mice, lung fibrosis was induced by injection of bleomycin (3 mg/kg) into the trachea and saline injection was used as a control. At d3, 7, 14, 28 after bleomycin-treatment, mice were randomly sacrificed in batch and the lung coefficient was determined. Serum levels of TGF-β1 and TNF-α were measured by ELISA and hydroxyproline contents in lung tissue were determined by Alkaline hydrolysis method. H-E staining and Masson's staining were performed to examine the pathological changes of lung tissues after bleomycin-treatment.

RESULTSOn d14 after bleomycin-treatment, the lung coefficients in wild type mice and AQP4-/- mice were 1.9-fold (12.69 ± 6.05 vs 6.80 ± 0.82, q=4.204, P<0.05) and 2.3-fold (14.05 ± 5.82 vs 6.05± 0.58, q=5.172, P<0.01) of that in control, respectively, but no significant difference was found between wild type and AQP4-/- mice in the lung coefficient value (P>0.05). The hydroxyproline contents in the lung increased after bleomycin-treatment; on d28, the lung hydroxyproline contents in wild type and in AQP4-/- mice were 1.55-fold (0.85 ± 0.22 g/mg vs 0.55 ± 0.14 μg/mg, q=4.313, P<0.05) and 1.4-fold (0.84 ± 0.13 μg/mg vs 0.60 ± 0.14μg/mg, q=4.595，P<0.05) of that in control, respectively, but no significant difference was noticed between wild type and AQP4-/- mice in lung hydroxyproline contents. There was a tendency that serum TGF-β1 and TNF-α levels increased in bleomycin-treated mice, but no significant difference was found between wild type and AQP4-/- mice. AQP4-knockout showed no effects on pathological changes of lung tissues with H-E staining and Masson's staining in mice with bleomycin-induced lung fibrosis.

CONCLUSIONAQP4 might not be involved in bleomycin-induced lung fibrosis in mice.

Animals ; Aquaporin 4 ; genetics ; Bleomycin ; toxicity ; Male ; Mice ; Mice, Knockout ; Pulmonary Fibrosis ; chemically induced ; genetics

Objective To investigate the clinical features of neuromyelitis optica spectrum disorders(NMOSD)with connective tissue diseases(CTD). Methods Clinical data of 16 NMOSD-CTD patients and 54 NMOSD patients admitted to the Second Affiliated Hospital of Fujian Medical University from January 2015 to February 2020 were collected.The initial symptom,intracranial lesion,spinal cord lesion,laboratory examination and treatment response were compared between the two groups. Results The incidence of Sjögren's syndrome(SS)was the highest(10/16,62.5%)in NMOSD-CTD group.The NMOSD-CTD group had significantly higher positive rate of aquaporin-4 immunoglobulin G(AQP4-IgG)in serum or cerebrospinal fluid(100% vs. 70.2%,P=0.009),higher positive rates of serum anti-nuclear antibodies,anti Sjögren's syndrome A antibodies and anti-Ro52 autoantibodies(P<0.001),as well as higher proportion of patients with the expanded disability status scale score ≥ 6(50.0% vs. 22.2%,P=0.035)than the NMOSD group.There was no significant difference between the two groups in the age of onset,visiting age,recurrence frequency,disease course,distribution of intracranial lesions,spinal cord involvement,or the effective rate of glucocorticoid pulse therapy(all P>0.05).Conclusions NMOSD is often complicated with CTD,and SS is the most common one.The positive rate of serum or cerebrospinal AQP4-IgG and the seropositivity of several other autoantibodies in NMOSD-CTD patients were higher than those in NMOSD patients.Neurological impairment in NMOSD-CTD patients were severer,which should arouse attention of clinicians.
Aquaporin 4 ; Autoantibodies ; Connective Tissue Diseases/epidemiology* ; Humans ; Immunoglobulin G ; Neuromyelitis Optica/epidemiology*

The aim of this paper was to investigate the effect of Schizonepetae Herba and Saposhnikoviae Radix(wind medicine) on the expression of AQP4 and AQP8 in colonic mucosa in rats with ulcerative colitis(UC). A total of 35 healthy SD male rats were randomly divided into normal group(gavaged with normal saline), DSS model group, as well as low, middle, and high dose wind medicine groups(Schizonepeta and Saposhnikovia 1∶1, gavaged at dosages of 6, 12, and 24 g·kg~(-1)·d~(-1)), with 7 in each group. UC rat model was established by free drinking of 3% dextran sulphate sodium(DSS) solution for 10 days. At the end of the 10 th day after the treatment, mice were put to death to collect colonic mucosa. The length of colon was measured; the colonic mucosal injury index(CMDI) and pathological changes of colon were observed. ELISA method was used for measuring the content of serum IL-1, IL-8, and immunohistochemical method was used to measure AQP4, AQP8 protein expressions in colon mucosa. The expressions of AQP4, AQP8 mRNA were measured by Real-time PCR. As compared with the normal group, the length of colon tissue was significantly reduced(P<0.01), CMDI scores and pathological scores were significantly increased(P<0.01), the levels of serum IL-1 and IL-8 were significantly increased(P<0.05) in model group; the immunohistochemical results showed that the protein expressions of AQP4, AQP8 were lower; the color was light yellow or brown; AQP4, AQP8 mRNA expressions in colon mucosa were significantly decreased in model group(P<0.01). CMDI scores, pathological scores, and the levels of serum IL-1, IL-8 in high, middle, low dose wind medicine groups were obvious lower than those in the model group(P<0.01 or P<0.05); the protein expressions of AQP4, AQP8 were higher; the color was chocolate brown or dark brown; the length of colon tissue, and the expressions of AQP4, AQP8 mRNA were obvious higher in wind medicine groups(P<0.01 or P<0.05). Schizonepetae Herba and Saposhnikoviae Radix could significantly improve the symptoms and histopathology of UC model rats and accelerate the intestinal mucosal healing. The mechanism may be related with up-regulating the expression level of AQP4 and AQP8 in colonic mucosa.
Animals ; Apiaceae ; Aquaporin 4 ; Colitis, Ulcerative ; Colon ; Intestinal Mucosa ; Male ; Mice ; Plant Roots ; Rats

OBJECTIVE: To observe the effects on neural function, living ability and mental state of the patients with acute intracerebral hemorrhage (ICH), as well as aquaporin 4 (AQP4) in the serum after treated with electroacupuncture (EA) on the base of routine therapy of western medicine. METHODS: Seventy-two acute ICH patients were randomized into an observation group (36 cases, 4 cases dropped off) and a control group (36 cases, 2 cases dropped off). In the control group, the conventional treatment was delivered such as stopping bleeding, preventing re-hemorrhage, controlling blood pressure, mitigating neural edema and reducing intracranial pressure. In the observation group, on the base of the treatment in the control group, EA was supplemented. Acupoints included Shuigou (GV 26), bilateral Neiguan (PC 6) and Sanyinjiao (SP 6) etc. Electric stimulation was operated at Neiguan (PC 6) and Sanyinjiao (SP 6) on the same side, with disperse-dense wave, and 2 Hz/100 Hz in frequency, tolerable current intensity. Electric stimulation was delivered for 30 min in each treatment, once daily and for 6 times per week. The duration of treatment was 2 weeks in the two groups. Before and after treatment, changes of the scores of National Institutes of Health stroke scale (NIHSS), modified Barthel index (MBI) and mini-mental state examination (MMSE), as well as AQP4 content in the serum were observed in the two groups; the efficacy and safety were compared between the two groups. RESULTS: The NIHSS scores and the serum AQP4 content decreased after treatment when compared with those before treatment in the two groups (P<0.05), while, MBI and MMSE scores increased (P<0.05). In the observation group, NIHSS score and serum AQP4 content were lower than those of the control group (P<0.05), and MBI and MMSE scores were higher (P<0.05). The total effective rate of the observation group was 93.8% (30/32), higher than that of the control group (73.5%, 25/34, P<0.05). The treatment in the two groups was safe, without adverse reactions and events occurring in the patients. CONCLUSION Electroacupuncture, on the base of conventional treatment of western medicine, can effectively improve the neural function, living ability, mental state and serum AQP4 content of the patients with acute ICH. It is suggested that the effective treatment by electroacupuncture may be related to the regulation of the serum AQP4 content.
Humans ; Electroacupuncture ; Aquaporin 4 ; Acupuncture Therapy ; Cerebral Hemorrhage/therapy* ; Treatment Outcome ; Acupuncture Points

OBJECTIVETo investigate the expression of aquaporin 3, 4, and 8 in the colonic mucosa of rat models with slow transit constipation (STC).

METHODSSTC 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.

RESULTSRT-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.

CONCLUSIONSExpression 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.

Animals ; Aquaporin 3 ; metabolism ; Aquaporin 4 ; metabolism ; Aquaporins ; metabolism ; Colon ; metabolism ; Constipation ; metabolism ; Disease Models, Animal ; Female ; Intestinal Mucosa ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVES: To observe the changes of expression of aquaporin-1（AQP-1） and AQP-4 in drowned and postmortem immersed rats' lungs. METHODS: Thirty healthy male Wistar rats were randomly divided into drowning group, postmortem immersion group and cervical dislocation group. The morphological changes of rats' lungs were observed using HE staining. The mRNA and protein expressions of AQP-1 and AQP-4 in rats' lungs were detected by real-time PCR, immunohistochemistry and Western blotting, respectively. RESULTS: The results of immunohistochemistry and the Western blotting showed that the protein expression of AQP-1 of the drowning group was higher than the postmortem immersion group and the cervical dislocation group （P<0.05）. The result of immunohistochemistry showed that the protein expression of AQP-4 of the drowning group was higher than the postmortem immersion group and the cervical dislocation group （P<0.05） while no difference were detected among the three of them by Western blotting （P>0.05）. The mRNA expressions of AQP-1 and AQP-4 in rats' lungs of the drowning group was significantly higher than the postmortem immersion group （P<0.05）. CONCLUSIONS The increase of mRNA and protein expressions of AQP-1 and AQP-4 in lungs of rats with cute lung injury of the drowning group would be useful for differentiating vital drowning from postmortem immersion.
Animals ; Aquaporin 1/metabolism* ; Aquaporin 4/metabolism* ; Autopsy ; Blotting, Western ; Drowning ; Immunohistochemistry ; Lung/metabolism* ; Male ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Real-Time Polymerase Chain Reaction

Aquaporins (AQPs) are expressed in myocardium and the implication of AQPs in myocardial water balance has been suggested. We investigated the expression patterns of AQP subtypes in normal myocardium and their changes in the process of edema formation and cardiac dysfunction following myocardial infarction (MI). Immunostaining demonstrated abundant expression of AQP1, AQP4, and AQP6 in normal mouse heart; AQP1 in blood vessels and cardiac myocytes, AQP4 exclusively on the intercalated discs between cardiac myocytes and AQP6 inside the myocytes. However, neither AQP7 nor AQP9 proteins were expressed in CD1 mouse myocardium. Echocardiography revealed that cardiac function was reduced at 1 week and recovered at 4 weeks after MI, whereas myocardial water content determined by wet-to-dry weight ratio increased at 1 week and rather reduced below the normal at 4 weeks. The expression of cardiac AQPs was up-regulated in MI-induced groups compared with sham-operated control group, but their time-dependent patterns were different. The time course of AQP4 expression coincided with that of myocardial edema and cardiac dysfunction following MI. However, expression of both AQP1 and AQP6 increased persistently up to 4 weeks. Our findings suggest a different role for cardiac AQPs in the formation and reabsorption of myocardial edema after MI.
Animals ; Aquaporin 1/metabolism ; Aquaporin 4/metabolism ; Aquaporin 6/metabolism ; Aquaporins/*metabolism ; Edema/pathology ; Immunohistochemistry ; Mice ; Muscle Cells/metabolism ; Myocardial Infarction/*metabolism/pathology/ultrasonography ; Myocardium/metabolism/pathology ; Time Factors

Water balance is one of the basic regulation mechanisms of homeostasis. There are 13 subtypes of aquaporins in mammals (AQP0-AQP12). In neural system, the AQP4 is mainly distributed in astrocytes. Phosphorylation and expression regulation of AQP4 is involved in the formation of brain edema, particularly in the clearance of vasogenic edema and the formation of cytotoxic edema. This article reviews regulations and functions of AQP4 in vasogenic edema and cytotoxic edema.
Animals ; Aquaporin 4 ; metabolism ; physiology ; Brain ; metabolism ; physiopathology ; Brain Edema ; metabolism ; physiopathology ; Homeostasis ; Humans ; Water-Electrolyte Balance ; physiology