Actin cytoskeleton and plasma membrane aquaporins are involved in different drought response of Arabidopsis rhd2 and der1 root hair mutants.

Actin cytoskeleton and reactive oxygen species are principal determinants of root hair polarity and tip growth. Loss of function in RESPIRATORY BURST OXIDASE HOMOLOG C/ROOT HAIR DEFECTIVE 2 (AtRBOHC/RHD2), an NADPH oxidase emitting superoxide to the apoplast, and in ACTIN 2, a vegetative actin isovariant, in rhd2-1 and der1-3 mutants, respectively, lead to similar defects in root hair formation and elongation Since early endosome-mediated polar localization of AtRBOHC/RHD2 depends on actin cytoskeleton, comparing the proteome-wide consequences of both mutations might be of eminent interest. Therefore, we employed a differential proteomic analysis of Arabidopsis rhd2-1 and der1-3 mutants. Both mutants exhibited substantial alterations in abundances of stress-related proteins. Notably, plasma membrane (PM)-localized PIP aquaporins showed contrasting abundance patterns in the mutants compared to wild-types. Drought-responsive proteins were mostly downregulated in rhd2-1 but upregulated in der1-3. Proteomic data suggest that opposite to der1-3, altered vesicular transport in rhd2-1 mutant likely contributes to the deregulation of PM-localized proteins, including PIPs. Moreover, lattice light sheet microscopy revealed reduced actin dynamics in rhd2-1 roots, a finding contrasting with previous reports on der1-3 mutant. Phenotypic experiments demonstrated a drought stress susceptibility in rhd2-1 and resistance in der1-3. Thus, mutations in AtRBOHC/RHD2 and ACTIN2 cause similar root hair defects, but they differently affect the actin cytoskeleton and vesicular transport. Reduced actin dynamics in rhd2-1 mutant is accompanied by alteration of vesicular transport proteins abundance, likely leading to altered protein delivery to PM, including aquaporins, thereby significantly affecting drought stress responses.

The involvement of aquaporin 5 in the inflammatory response of primary Sjogren's syndrome dry eye: potential therapeutic targets exploration.

Sjogren's syndrome (SS) is a chronic autoimmune disease. Mainly due to the infiltration of lymphoplasmic cells into the exocrine glands, especially the salivary glands and lacrimal glands, resulting in reduced tear and saliva secretion. Reduced tear flow can trigger Sjogren's syndrome dry eye (SSDE). Although the pathophysiology of SSDE xerosis remains incompletely understood, recent advances have identified aquaporin-5 (AQP5) as a critical factor in dysregulation of the exocrine gland and epithelium, influencing the clinical presentation of SSDE through modulation of inflammatory microenvironment and tear secretion processes. This review aims to explore AQP5 regulatory mechanisms in SSDE and analyze its potential as a therapeutic target, providing new directions for SSDE treatment.

Aquaporin-1 Facilitates Macrophage M1 Polarization by Enhancing Glycolysis Through the Activation of HIF1α in Lipopolysaccharide-Induced Acute Kidney Injury.

This study aimed to investigate how aquaporin 1 (AQP1) modulates hypoxia-inducible factor-1α (HIF1α) to promote glycolysis and drive the M1 polarization of macrophages. Within 12 h post-treatment with LPS to induce acute kidney injury in rats, a significant upregulation of AQP1 and HIF1α protein levels was noted in serum and kidney tissues. This elevation corresponded with a decrease in blood glucose concentrations and an enhancement of glycolytic activity relative to the control group. Furthermore, there was a pronounced reduction in the circulating levels of the anti-inflammatory cytokine IL-10, accompanied by an upregulation in the levels of the pro-inflammatory cytokines IL-6 and TNF-α. The administration of an HIF1α inhibitor reversed these effects, which did not affect the production of AQP1 protein. In cellular assays, AQP1 knockdown mitigated the increase in HIF1α expression induced by LPS. Furthermore, the suppression of HIF1α with PX-478 led to decreased expression levels of Hexokinase 2 (HK2) and Lactate Dehydrogenase A (LDHA), indicating that AQP1 regulates glycolysis through HIF1α. M1 polarization of macrophages was reduced by AQP1 knockdown and was further diminished by the addition of an HIF1α inhibitor. Inhibition of the glycolytic process not only weakened M1 polarization but also promoted M2 polarization, thereby reducing the release of inflammatory cytokines. These findings provide a novel perspective for developing therapeutic strategies that target AQP1 and HIF1α, potentially improving the treatment of sepsis-associated AKI.

Gene expression analysis of Aquaporin genes in ruminants during growth phase in response to heat stress.

Aquaporins (AQPs) are trans-membrane protein involved in water transport and different cellular functions such as cell adhesion, signalling and proliferation. These membrane proteins are essential for key physiological functions such as organ development, osmoregulation, tissue regeneration and metabolism. The regulation of AQP5 gene expression in ruminants during growth phase has not been analysed in-vivo. Therefore, the gene expression pattern was analysed in Jamunapari goats during 3 months to 12 month of age and adult age group in response to heat stress. The genotyping of the AQP5 gene was carried out by High-Resolution Melting (HRM) in four different goat breeds, which indicated four distinct genotypes in the population. The nucleotide diversity for the AQP5 gene ranged from 0.315 and 0.524 across the breeds. Additionally, a close evolutionary relationship between AQP5 and the HSP70 gene was observed, indicating a shared pathway for heat stress regulation. The m-RNA expression level of AQP5 at 3, 9, 12 month and adult age group exhibited 47.24, 1140, 43.17 and 12.55-fold higher expression than control. The m-RNA expression level of the AQP5 gene was up-regulated and significantly higher (P < 0.05) at 9-month age as compared to the other age groups. Heat stress phenotypes were classified based on respiration rate and heart rate, and the m-RNA expression of AQP5 was higher in heat stress-susceptible (HSS) individuals than heat stress-tolerant (HST) individuals at 3, 9, and 12 months of age. The AQP5 plays a significant role in thermoregulation during growth phases in response to heat stress in goats, however, it is required to understand the role of aquaporins at cellular level as well as to establish the association with production performance in ruminant system in-vivo.

Aquaporin proteins: A promising frontier for therapeutic intervention in cerebral ischemic injury.

Cerebral ischemic injury is characterized by reduced blood flow to the brain, remains a significant cause of morbidity and mortality worldwide. Despite improvements in therapeutic approaches, there is an urgent need to identify new targets to lessen the effects of ischemic stroke. Aquaporins, a family of water channel proteins, have recently come to light as promising candidates for therapeutic intervention in cerebral ischemic injury. There are 13 aquaporins identified, and AQP4 has been thoroughly involved with cerebral ischemia as it has been reported that modulation of AQP4 activity can offers a possible pathway for therapeutic intervention along with their role in pH, osmosis, ions, and the blood-brain barrier (BBB) as possible therapeutic targets for cerebral ischemia injury. The molecular pathways which can interacts with particular cellular pathways, participation in neuroinflammation, and possible interaction with additional proteins thought to be involved in the etiology of a stroke. Understanding these pathways offers crucial information on the diverse role of AQPs in cerebral ischemia, paving the door for the development of focused/targeted therapeutics.

Protective Effect of Protocatechuic Aldehyde on Cerebral Ischemia/Reperfusion Injury in Rats through Blood-Brain Barrier Protection.

Cerebral ischemia can lead to destruction of the blood-brain barrier (BBB), the main cause of cerebral edema and cerebral infarction. BBB damage is also one of the key factors affecting the result of drug therapy. We studied the protective effect of 5-day pretreatment with protocatechuic aldehyde (PAL) at doses of 10 and 20 mg/kg on BBB function and structure after middle cerebral artery occlusion/reperfusion (MCAO/R) in rats. The infarct volume, behavioral neurological deficit score, and Evans blue content in the brain were estimated. We also evaluated the content of nitric oxide (NO) and activities of inducible and neuronal NO synthases. Expression of aquaporin-4 (AQP-4), occludin, claudin-5, and MMP-3 in the brain tissues was estimated by Western blotting. The BBB ultrastructure was analyzed under an electron microscope. We revealed that PAL at both used doses significantly reduced the neurological deficit score, brain infarct volume, and Evans blue extravasation. Electron microscopy showed that PAL significantly improved the ultrastructure of BBB and alleviated its injury. Pretreatment with PAL increased expression of occludin and claudin-5 and reduced expression of AQP-4 and MMP-3. At the same time, the release of NO and activities of NO synthases were notably inhibited. Our results suggest that PAL can be a promising compound to attenuate cerebral ischemia resulting from occlusion/reperfusion injury via BBB protection.

The Arabidopsis PIP1;1 Aquaporin Represses Lateral Root Development and Nitrate Uptake Under Low Nitrate Availability.

Nitrate (NO3 -) deficiency decreases root water uptake and root hydraulic conductance. This adaptive response is correlated with reduced abundance and activity of plasma membrane intrinsic protein (PIP) aquaporins. We therefore screened changes in the root architecture of a complete set of Arabidopsis pip loss-of-function mutants grown under NO3 - deficiency to systematically approach the impact of PIPs under these conditions. NO3 - deprivation led to attenuated responses of specific pip single mutants compared to the strongly altered LR parameters of wild-type plants. In particular, pip1;1 exhibited a lower relative reduction in LR length and LR density, revealing that PIP1;1 represses LR development when NO3 - is scarce. Indeed, PIP1;1 compromises root and shoot NO3 - accumulation during early developmental stages. A fluorescent VENUS-PIP1;1 fusion revealed that PIP1;1 is specifically repressed in the pericycle, endodermis and at the flanks of emerging LRs upon NO3 - deficiency. Thus, LR plasticity and NO3 - uptake are affected by an interactive mechanism involving aquaporins (PIP1;1) and nitrate accumulation during seedling development under NO3 --deficient conditions.

Saccharomyces boulardii Mitigates Fructose-Induced Non-Alcoholic Fatty Liver in Rats.

Background and Objectives: Non-alcoholic fatty liver disease (NAFLD) is a growing global health concern closely linked to metabolic disorders, including obesity, insulin resistance, and dyslipidemia. Emerging evidence suggests that the gut-liver axis plays a critical role in the pathogenesis of NAFLD, with recent research highlighting the influence of gut microbiota, including fungal species such as Saccharomyces boulardii (S. boulardii). This study aimed to evaluate the effects of S. boulardii on lipid metabolism and oxidative stress in a rat model of fructose-induced NAFLD. Materials and Methods: Thirty Wistar rats were divided into three groups: a control group, a fatty liver group induced by 35% fructose supplementation, and a treatment group receiving S. boulardii (100 mg/kg/day) after fructose induction. Results: Biochemical analyses revealed that the treatment group exhibited significantly lower plasma levels of malondialdehyde (MDA), alanine aminotransferase (ALT), total triglycerides, and cholesterol compared to the untreated fatty liver group (p < 0.05). Furthermore, liver tissue analysis showed a marked reduction in lipid accumulation and fatty infiltration in the treatment group, with no visible lipid vacuoles in hepatocytes. The expression of aquaporin-8 (AQP8) and sirtuin-1 (SIRT1), key markers associated with hepatocyte function and lipid metabolism, was significantly higher in the S. boulardii group compared to the fatty liver group (p < 0.001). Conclusions: These findings indicate that S. boulardii supplementation mitigates the metabolic and oxidative stress-related alterations associated with fructose-induced NAFLD. In conclusion, our study suggests that S. boulardii exerts protective effects on the liver by reducing lipid accumulation and oxidative stress, highlighting its potential as a therapeutic intervention for NAFLD.

Therapeutic Potential of Intermittent Hypoxia in Atrial Fibrillation.

Intermittent hypoxia (IH) has been extensively studied in recent years, demonstrating adverse and beneficial effects on several physiological systems. However, the precise mechanism underlying its cardiac effects on the heart remains unclear. This study aims to explore the effect of treatment on atrial fibrillation under IH conditions, providing data that can potentially be used in the treatment of heart disease. An atrial fibrillation (AF) model was induced by injecting monocrotaline (MCT, 60 mg/kg) into rats. The study included 32 rats divided into four groups: Control, Control + IH, AF, and AF + IH. We evaluated molecular changes associated with AF using ELISA and Western blot and performed electrophysiological experiments to evaluate AF. Arrhythmia-related calcium and fibrosis markers were investigated. Phosphorylation levels of CaMKII, Phospholamban, and RyR2 all increased in the AF group but decreased in the IH-exposed group. Additionally, fibrosis marker expressions such as SMA, MMP2, MMP9, and TGF-ß increased in the AF group but were significantly downregulated with IH treatment. Connexin 43 and AQP4 expression were restored in the IH-treated group. These findings suggest that IH may prevent AF by downregulating the expression of calcium-handling proteins and fibrosis-associated proteins in an AF-induced rat model.

Omega-3 Polyunsaturated Fatty Acids and Blood-Brain Barrier Integrity in Major Depressive Disorder: Restoring Balance for Neuroinflammation and Neuroprotection.

Major depressive disorder (MDD), affecting over 264 million individuals globally, is associated with immune system dysregulation and chronic neuroinflammation, potentially linked to neurodegenerative processes. This review examines blood-brain barrier (BBB) dysfunction in MDD, focusing on key regulators like matrix metalloproteinase 9 (MMP9), aquaporin-4 (AQP4), and ATP-binding cassette subfamily B member 1 (ABCB1). We explore potential mechanisms by which compromised BBB integrity in MDD may contribute to neuroinflammation and discuss the therapeutic potential of omega-3 polyunsaturated fatty acids (n-3 PUFAs). n-3 PUFAs have demonstrated anti-inflammatory and neuroprotective effects, and potential ability to modulate MMP9, AQP4, and ABCB1, thereby restoring BBB integrity in MDD. This review aims to elucidate these potential mechanisms and evaluate the evidence for n-3 PUFAs as a strategy to mitigate BBB dysfunction and neuroinflammation in MDD.

Crucial role of Aquaporin-4 extended isoform in brain water Homeostasis and Amyloid-ß clearance: implications for Edema and neurodegenerative diseases.

The water channel aquaporin-4 (AQP4) is crucial for water balance in the mammalian brain. AQP4 has two main canonical isoforms, M23, which forms supramolecular structures called Orthogonal Arrays of Particles (OAP) and M1, which does not, along with two extended isoforms (M23ex and M1ex). This study examines these isoforms' roles, particularly AQP4ex, which influences water channel activity and localization at the blood-brain barrier. Using mice lacking both AQP4ex isoforms (AQP4ex-KO) and lacking both AQP4M23 isoforms (OAP-null) mice, we explored brain water dynamics under osmotic stress induced by an acute water intoxication (AWI) model. AQP4ex-KO mice had lower basal brain water content than WT and OAP-null mice. During AWI, brain water content increased rapidly in WT and AQP4ex-KO mice, but was delayed in OAP-null mice. AQP4ex-KO mice had the highest water content increase at 20 min. Immunoblot analysis showed stable total AQP4 in WT mice initially, with increases at 30 min. AQP4ex and its phosphorylated form (p-AQP4ex) levels rose quickly, but the p-AQP4ex/AQP4ex ratio dropped at 20 min. AQP4ex-KO mice showed a compensatory rise in canonical AQP4 at 20 min post-AWI. These findings highlight the important role of AQP4ex in water content dynamics in both normal and pathological states. To evaluate brain waste clearance, amyloid-ß (Aß) removal was assessed using a fluorescent Aß intra-parenchyma injection model. AQP4ex-KO mice demonstrated markedly impaired Aß clearance, with extended diffusion distances and reduced fluorescence in cervical lymph nodes, indicating inefficient drainage from the brain parenchyma. Mechanistically, the polarization of AQP4 at astrocytic endfeet is essential for efficient clearance flow, aiding interstitial fluid movement into the CSF and lymphatic system. In AQP4ex-KO mice, disrupted polarization forces reliance on slower, passive diffusion for solute clearance, significantly reducing Aß removal efficiency and altering extracellular space dynamics. Our results underscore the importance of AQP4ex in both brain water homeostasis and solute clearance, particularly Aß. These findings highlight AQP4ex as a potential therapeutic target for enhancing waste clearance mechanisms in the brain, which could have significant implications for treating brain edema and neurodegenerative diseases like Alzheimer's.

Pyometra alters uterine aquaporins related with lipopolysaccharide concentrations and antioxidant enzyme activities in bitches.

Pyometra is a common life-threatening inflammatory disease with a complex etiopathogenesis that develops during the diestrus stage and can be observed in elderly intact bitches. The present study evaluated five aquaporin (AQP1, AQP2, AQP3, AQP5, and AQP9) transcript abundances and immunolocalization in the uterine tissue, and investigated their relationship with uterine tissue and blood lipopolysaccharide (LPS) concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, and nitric oxide (NO) production in dogs suffering from pyometra. The study sampled 36 client-owned intact bitches from different breeds, of which 24 cases were diagnosed with pyometra. Twelve of these bitches in the diestrus stage that presented for elective ovariohysterectomy were used as the control group. Blood samples were collected into tubes without anticoagulant for serum progesterone, LPS concentration, and antioxidant activities at the time of diagnosis. Bacteriological and tissue samples from the uteri were collected after the ovariohysterectomy. The tissue samples were used to determine antioxidant activity, and hormone and toxin concentrations. Transcript abundance of uterine AQPs were determined by qPCR, and their presence and localization were determined by by immunohistochemistry. For all pyometra samples, the bacteria isolated from the uterine swabs were Escherichia coli. Compared to the control group, AQP1, AQP2, and AQP5 were downregulated more than 2-fold, whereas AQP9 was upregulated nearly 3-fold and AQP3 was upregulated more than 4-fold in the pyometra affected uteri (P<0.05). Uterine AQP1 was moderately negatively correlated with serum LPS concentration (r=-0.568, P<0.01) and tissue NO production (r=-0.407, P<0.05). AQP5 was positively correlated with serum SOD activity (r=0.485, P<0.05) and negatively correlated with serum LPS concentration (r=-0.512, P<0.05). AQP9 was negatively correlated with tissue SOD and serum GPx activity. This is the first study to identify AQP9 transcript abundance and immunolocalization in canine uterine tissue. Uterine AQP1, AQP2, AQP3, AQP5, and AQP9 transcript abundances were altered in spontaneously developed canine pyometra while AQP transcript abundance was negatively related to serum toxin concentration, NO production, and antioxidant enzyme activity. Further studies should be conducted to determine the role of altered abundances of AQPs transcripts in pyometra pathogenesis.

Melatonin Improves Vasogenic Edema via Inhibition to Water Channel Aquaporin-4 (AQP4) and Metalloproteinase-9 (MMP-9) Following Permanent Focal Cerebral Ischemia.

Background: The efficacy of melatonin in reducing vasogenic and cytotoxic edema was investigated using a model of permanent middle cerebral artery occlusion (pMCAO). Methods: Rats underwent pMCAO, followed by intravenous administration of either melatonin (5 mg/kg) or a vehicle 10 min post-insult. Brain infarction and edema were assessed, and Western blot analyses were conducted to examine the expression levels of aquaporin-4 (AQP4), metalloproteinase-9 (MMP-9), and the neurovascular tight-junction protein ZO-1 upon sacrifice. The permeability of the blood-brain barrier (BBB) was measured using spectrophotometric quantification of Evans blue dye leakage. Results: Compared to controls, melatonin-treated rats exhibited a significant reduction in infarct volume by 26.9% and showed improved neurobehavioral outcomes (p < 0.05 for both). Melatonin treatment also led to decreased Evans blue dye extravasation and brain edema (p < 0.05 for both), along with lower expression levels of AQP4 and MMP-9 proteins and better preservation of ZO-1 protein (p < 0.05 for all). Conclusions: Therefore, melatonin offers neuroprotection against brain swelling induced by ischemia, possibly through its modulation of AQP4 and MMP-9 activities in glial cells and the extracellular matrix (ECM) during the early phase of ischemic injury.

Astragaloside IV and cycloastragenol promote liver regeneration through regulation of hepatic oxidative homeostasis and glucose/lipid metabolism.

BACKGROUND: The regenerative capacity of the liver is pivotal for mitigating various forms of liver injury and requires the rapid proliferation of hepatocytes. Aquaporin-9 (AQP9) provides vital support for hepatocyte proliferation by preserving hydrogen peroxide (H2O2) oxidative balance and glucose/lipid metabolism equilibrium within hepatocytes. Our previous study demonstrated that Radix Astragali (RA) decoction promotes liver regeneration by upregulating hepatic expression of AQP9, possibly via two major active constituents: astragaloside IV (AS-IV) and cycloastragenol (CAG). PURPOSE: To verify that upregulated AQP9 expression in hepatocytes maintains liver oxidative balance and glucose/lipid metabolism homeostasis, and is the main pharmacological mechanism by which AS-IV and CAG promote liver regeneration. STUDY DESIGN/METHODS: Effects of AS-IV and CAG on liver regeneration were scrutinized using a mouse model of 70 % partial hepatectomy (PHx). AQP9-targeted liver regeneration mediated by AS-IV and CAG was verified using AQP9 gene knockout mice (AQP9-/-). The AQP9 protein expression pattern in hepatocytes was determined using tdTomato-tagged AQP9 transgenic mice (AQP9-RFP). Potential mechanisms of AS-IV and CAG on liver regeneration were studied using real-time quantitative PCR, immunoblotting, staining with hematoxylin and eosin, oil red O, and periodic acid-Schiff, and immunofluorescence, immunohistochemistry, HyPerRed fluorescence, and biochemical analyses. RESULTS: AS-IV and CAG promoted substantial liver regeneration and increased hepatic AQP9 expression in wild-type mice (AQP9+/+) following 70 % PHx, but had no discernible benefits in AQP9-/- mice. Both saponin compounds also helped maintain oxidative homeostasis by reducing levels of oxidative stress markers (reactive oxygen species [ROS], H2O2, and malondialdehyde) and elevating levels of ROS scavengers (glutathione and superoxide dismutase) in AQP9+/+ mice post-70 % PHx. This further activated the PI3K-AKT and insulin signaling pathways, thereby fostering liver regeneration. Furthermore, AS-IV and CAG both promoted hepatocyte glycerol uptake, increased gluconeogenesis, facilitated lipolysis, reduced glycolysis, and inhibited glycogen deposition, thus ensuring the energy supply required for liver regeneration. CONCLUSION: This research is the first to demonstrate AS-IV and CAG as major active ingredients of RA that promote liver regeneration by upregulating hepatocyte AQP9 expression, improving hepatocyte glucose/lipid metabolism, and reducing oxidative stress damage, constituting a crucial pharmacological mechanism underlying the liver-protective effects of RA. The augmentation of hepatocyte AQP9 expression underscores an important aspect of the Qi-tonifying effect of RA. This study establishes AQP9 as an effective target for regulation of liver regeneration and provides a universal strategy for clinical drug intervention aimed at enhancing liver regeneration.

Case report: Autoimmune glial fibrillary acidic protein astrocytopathy with overlapping autoimmune syndrome.

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a rare autoimmune disease, which is characterized by the immune system attacking astrocytes in the central nervous system, resulting in inflammation and damage to the nervous system. We reported a 41-year-old female patient with only drowsiness for 3 months, who was, otherwise, healthy with no other signs of meningoencephalitis or myelitis. There were no obvious abnormalities in her neurological and ophthalmic tests. Brain magnetic resonance imaging (MRI) plain scan + enhancement with the gadolinium contrast agent revealed patchy hypointensity on T1-weighted imaging, hyperintensity on T2-weighted imaging, hyperintensity on T2-weighted fluid-attenuated inversion recovery in the left basal ganglia, corona radiata, and local septum pellucida, with no enhancement in the enhanced lesions. Cerebrospinal fluid (CSF) revealed white blood cell count of 5.00 × 106/L, CSF protein of 828.53 mg/L, and glucose of 2.83 mmol/L. Aquaporin-4 (AQP4) antibody, N-methyl-D-aspartate receptor (NMDAR) antibody and GFAP antibody were all positive, whereas the remaining autoimmune encephalitis antibody tests were negative. Oncology screening [including head, chest, and whole-abdomen (involving the pelvic cavity) CT and tumor markers] did not reveal any obvious evidence of tumor presence. The patient received systemic treatment with high-dose intravenous injection of steroids combined with immunosuppressive agents, and the clinical and imaging features of the patients improved. To the best of our knowledge, reports on overlapping positivity of AQP4 antibody and NMDAR antibody in patients with GFAP astrocytopathy were still very rare. We hope to supplement the existing literature on this topic, review the relevant literature, and strive to increase the understanding toward GFAP astrocytopathy with overlapping autoimmune syndrome so as to enable early diagnosis and early treatment and to improve the clinical outcome of patients.

Autoantibody against aquaporin-5 may be a new diagnostic biomarker for primary Sjögren's syndrome.

The study aims to assess the diagnostic and clinical significance of autoantibodies against aquaporin-1 (anti-AQP1) and aquaporin-5 (anti-AQP5) in primary Sjögren's syndrome (pSS). A total of 163 participants were categorized into three groups: pSS group, other connective tissue diseases (CTD) group, and healthy control (HC) group. The levels of anti-AQP1 and anti-AQP5 autoantibodies in serum were determined using enzyme-linked immunosorbent assay (ELISA), and clinical data from patients were collected for statistical analysis. Our results showed that the level of anti-AQP1 in the pSS group was higher than in the HC group (P < 0.05), and no significant difference was observed between the pSS group and the CTD group (P > 0.05). ROC showed that the anti-AQP1 had no diagnostic value for pSS (P > 0.05). The anti-AQP5 level of 39 healthy adults was all below the cut-off value (14.10 ng/ml) (P < 0.05). The level of anti-AQP5 in the pSS group was higher than the CTD group (P < 0.05), the AUC was 0.86 (95% CI 0.80-0.93), with a sensitivity of 0.95 (95% CI 0.87-0.99) and a specificity of 0.70 (95% CI 0.58-0.84). No correlation was found between anti-AQP5 levels and the EULAR primary Sjögren's syndrome disease activity index score, anti-SSA, anti-SSB, antinuclear antibodies, rheumatoid factor, anti-ds-DNA, salivary gland flow rate, complement 3, and lymphocyte count in pSS samples (P > 0.05), respectively. Therefore, the elevated anti-AQP5 may emerge as a novel diagnostic biomarker for pSS patients due to high sensitivity and specificity.

Expression of AQP8 in Serum of Patients With Meniere's Disease and Its Value in Evaluating the Degree of Hydrolabyrinth and Predicting Prognosis.

OBJECTIVE: This study aims to explore the role of serum aquaporin 8 (AQP8) expression in evaluating the degree of hydrolabyrinth and predicting prognosis in patients with Meniere's disease. METHODS: One hundred and five patients diagnosed with Meniere's disease in our hospital were enrolled in the Meniere's disease group. Another 102 healthy subjects were enrolled as the control group. The expression of serum AQP8 mRNA was determined by the quantitative real-time PCR (qRT-PCR) method. Receiver operating characteristic (ROC) curve analysis was carried out to analyse the predictive value of serum AQP8 mRNA expression for poor prognosis in Meniere's disease patients. Multivariate logistic regression was used to analyse the influencing factors of poor prognosis in patients with Meniere's disease. RESULTS: The expression level of serum AQP8 mRNA in the Meniere's disease group was significantly higher than that in the control group (p < 0.05). In the severe hydrops group, serum AQP8 mRNA expression levels were higher than in the mild hydrops group and the no endolymphatic hydrops group. Additionally, the mild hydrops group had higher serum AQP8 mRNA levels than the no endolymphatic hydrops group (p < 0.05). The disease course, proportion of severe hydrops and serum AQP8 mRNA expression were all higher in the poor prognosis group compared to the good prognosis group (p < 0.05). The area under the curve (AUC) for serum AQP8 mRNA in predicting poor prognosis in Meniere's disease patients was 0.812 (95%CI: 0.702-0.922). CONCLUSION: AQP8 mRNA is associated with the degree of hydrolabyrinth in patients with Meniere's disease and plays an important role in predicting prognosis.

Electrolytic-reduction ion water protects keratinocytes from hydrogen peroxide through radical scavenging activity and induction of AQP3 expression.

Skin exposed to ultraviolet light produces hydrogen peroxide (H2O2) and reactive oxygen species (ROS) that cause protein denaturation and other disorders. We investigated whether electrolytic-reduction ion water (ERI), which has reducing properties and has been reported to protect skin, exhibits antioxidant activity in skin keratinocytes. The antioxidant activity of ERI was first examined using DPPH assay and Electron Spin Resonance to test for radicals, and using the Amplex Red method to test for H2O2. Concentration-dependent scavenging of hydroxyl radical but no H2O2 depletion were detected. An investigation of the expression of heme oxygenase-1, which is upregulated by oxidative response in cells, showed an increase through H2O2 oxidation, which was inhibited by ERI in a concentration-dependent manner. This suggests that ERI directly removes ROS. Quantitative real-time polymerase chain reaction analysis was performed to determine whether ERI regulates the expression of aquaporin 3 (AQP3), a known H2O2 transporter. This analysis revealed that ERI enhances AQP3 expression in a concentration-dependent manner and is involved in the transport of intracellular H2O2 to the extracellular space. In addition, ERI inhibited H2O2-induced cytotoxicity in a concentration-dependent manner. These results suggest that ERI protects keratinocytes from ROS by directly scavenging them and indirectly by eliminating them through the promotion of the efflux of intracellular H2O2.

A Plasma Membrane Intrinsic Protein Gene OfPIP2 Involved in Promoting Petal Expansion and Drought Resistance in Osmanthus fragrans.

Osmanthus fragrans, a native to China, is renowned as a highly popular gardening plant. However, this plant faces significant challenges from drought stress, which can adversely affect its flowering. In this study, we found that the plasma membrane-localized gene OfPIP2 exhibited a substantial upregulation during the flowering stages and in response to drought stress. GUS staining has illustrated that the OfPIP2 promoter can drive GUS activity under drought conditions. The overexpression of OfPIP2 was found to enhance petal size by modulating epidermal cell dimensions in Petunia and tobacco. Moreover, this overexpression also bolstered drought tolerance, as evidenced by a reduction in stomatal aperture in both species. Furthermore, yeast one-hybrid (Y1H) and dual-luciferase (Dual-LUC) assays have indicated that the transcription factor OfMYB28 directly binds to the OfPIP2 promoter, thereby regulating its expression. Together, we speculated that a module of OfMYB28-OfPIP2 was not only involved in the enhancement of petal size but also conferred the improvement of drought tolerance in O. fragrans. These results contribute valuable insights into the molecular function of the OfPIP2 gene and lay a foundation for molecular breeding strategies in O. fragrans.

Improvement effect and mechanism of XuanFuDaiZhe tang on rats with diarrheal irritable bowel syndrome induced by colorectal dilation.

ETHNOPHARMACOLOGICAL RELEVANCE: XuanFuDaiZhe Tang (XFDZT) is used in traditional Chinese medicine (TCM) to treat diarrhoea-predominant irritable bowel syndrome (IBS-D). Our laboratory has demonstrated that XFDZT remarkably improves various gastrointestinal motility disorders in animal models. However, previous studies have only focused on one or several protein targets without systematically investigating dynamic changes and protein interrelations. AIM OF THE STUDY: To explore the mechanisms underlying the therapeutic action of XFDZT in IBS-D using a network pharmacology approach and in vivo experiments. MATERIALS AND METHODS: The active compounds of XFDZT were selected from TCM Systems Pharmacology and TCM Integrated databases, and potential targets were identified using the Swiss Target Prediction databases. Targets related to IBS-D were mined from the DisGeNet, Drug Bank, and Therapeutic Target databases. The intersecting protein-protein interactions (PPIs) of the drug-disease crossover genes were analysed, and a central PPI network was constructed using the STRING database and Cytoscape 3.7.2. Following Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, a gene pathway network was constructed to identify key target genes and pathways. Using haematoxylin and eosin staining and western blotting, we validated how XFDZT controls water expression in the body to treat IBS-D infection. RESULTS: First, the results showed that XFDZT contained 1037 active ingredients and 1458 corresponding targets. After intersecting the 252 IBS targets, 108 targets were identified. The main targets of XFDZT were albumin, aquaporins such as AQP1 and AQP3, calmodulin, and the cellular enzyme CYP2C9. GO and KEGG enrichment predicted that the action pathways were the neuroactive ligand-receptor interaction, calcium signalling pathway, serotonergic synapse signalling pathway, cGMP-PKG signalling pathway, cAMP signalling pathway, and MLCK-MLC signalling pathway. Second, an IBS-D rat model was constructed using colorectal dilation (CRD). CRD can significantly induce IBS-D symptoms such as diarrhoea, abdominal pain, and anxiety and depression-like behaviour in rats. XFDZT (10, 20, and 40 g/kg) administered for 14, 21, and 28 days significantly reversed these changes in IBS-D rats in a time- and dose-dependent manner, suggesting that XFDZT significantly improved IBS-D. Finally, the mechanism by which XFDZT improves IBS-D was explored from the perspective of AQPs, tight junction proteins, and motility-related proteins in colon tissue. Compared with the control group, the protein expression of AQP1, AQP3, and AQP8 in the colon tissue of IBS-D rats was significantly downregulated, whereas the protein expression of AQP7 was significantly upregulated. The expression of tight junction-related proteins claudin-1, occludin, and ZO-1 in colon tissue was significantly downregulated, whereas the expression of motility-related proteins p-MLC, MLC, MLCK, and CaM in colon tissue was significantly upregulated, suggesting that IBS-D rats had AQP disorders, epithelial intercellular connections, and motility in colon tissue. The above changes were significantly reversed by XFDZT administration (5, 10, and 20 g/kg) for 14 days. CONCLUSION: XFDZT significantly improved diarrhoea, abdominal pain, anxiety, and depression in IBS-D rats, and its mechanism of action may be related to the regulation of AQPs, tight junction proteins, and the MLCK-MLC pathway. This study provided a pharmacological experimental basis for the development of XFDZT as a novel drug for the treatment of IBS-D.