This study investigated the therapeutic effect of Shegan Mahuang Decoction(SGMHD) on cold-induced asthma in rats and explored its underlying mechanism. Seventy-two healthy male SD rats of specific pathogen free(SPF) grade were randomly divided into a blank group, a model group, a positive control group(dexamethasone, 0.4 mg·kg~(-1)), and low-, medium-, and high-dose SGMHD groups(3.2, 6.4, and 12.8 g·kg~(-1)). The blank group received saline, while the other groups were sensitized by intraperitoneal injection of ovalbumin(OVA) solution. Subsequently, the rats were placed in a cold chamber adjustable to 0-2 ℃, and OVA solution was ultrasonically nebulized to induce cold-induced asthma in rats. After three weeks of treatment, the general behaviors of rats were observed. Hematoxylin-eosin(HE) staining was used to evaluate pathological changes in lung tissues, periodic acid-Schiff(PAS) staining assessed mucin changes, and Masson staining was performed to examine collagen deposition. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of the inflammatory factors interleukin-4(IL-4) and vascular endothelial growth factor(VEGF) in serum and bronchoalveolar lavage fluid(BALF). Real-time quantitative polymerase chain reaction(RT-PCR) was employed to assess the mRNA expression levels of transient receptor potential vanilloid subfamily member 1(TRPV1), nuclear respiratory factor 1(NRF-1), and mitochondrial transcription factor A(mtTFA) in lung tissues. Western blot was used to measure the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues. Compared with the blank group, the model group exhibited signs of rapid respiration, increased frequency of defecation with looser stools, and disheveled and dull fur. Pathological results showed significant infiltration of inflammatory cells in lung tissues, narrowing of bronchial lumens, increased mucin secretion, and enhanced collagen deposition in the model group. Additionally, the levels of IL-4 and VEGF in serum and BALF were significantly elevated, and the mRNA and protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were significantly increased. Compared with the model group, SGMHD improved the behaviors of rats, alleviated pathological changes in lung tissues, mucin production, and collagen deposition, significantly decreased the levels of IL-4 and VEGF in serum and BALF, and reduced the mRNA expression levels of TRPV1, NRF-1, and mtTFA in lung tissues, with the medium-dose SGMHD group showing the most significant effect. Moreover, the protein expression levels of TRPV1, NRF-1, and mtTFA in lung tissues were also reduced, with the medium-dose SGMHD group exhibiting the most significant effect. In conclusion, this study demonstrates that SGMHD can alleviate airway inflammation and inhibit airway remodeling in cold-induced asthma rats. These effects may be associated with the modulation of the TRPV1/NRF-1/mtTFA signaling pathway.
Rats ; Male ; Animals ; Mice ; Interleukin-4/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Rats, Sprague-Dawley ; Asthma/genetics* ; Lung ; Bronchoalveolar Lavage Fluid ; RNA, Messenger/metabolism* ; Collagen/metabolism* ; Mucins/therapeutic use* ; Ovalbumin ; Disease Models, Animal ; Mice, Inbred BALB C ; TRPV Cation Channels/metabolism* ; Drugs, Chinese Herbal

OBJECTIVE: To explore and verify that transient receptor potential vanilloid 4(TRPV4) affects chondrocyte degeneration. METHODS: Neonatal SD rats were selected, primary chondrocytes were extracted, and identified by toluidine blue staining and alcian blue staining;an in vitro chondrocyte inflammation model was constructed by IL-1β, and TRPV4 inhibitor was used to treat chondrocytes under inflammatory conditions, and the chondrocytes were treated by RT-PCR method was used to detect matrix metallopeptidase 13(MMP-13), a disintegrin and metalloproteinase with thrombospondin 5, (ADAMTS-5)、nitric oxide synthase 2(NOS2)、Collagen, type II alpha 1(Col2α1)and aggrecan (Acan) mRNA in chondrocytes; primary chondrocytes were treated with different concentrations of TRPV4 overexpression plasmid, and the optimal overexpression dose was screened. The mRNA expressions of TRPV4, MMP-13, ADAMTS-5, NOS2, Col2α1 and Acan in chondrocytes under the optimal TRPV4 overexpression dose were detected. RESULTS: Toluidine blue staining and Alcian blue staining identified the extracted cells as primary chondrocytes;RT-PCR showed that TRPV4, MMP-13, ADAMTS-5, NOS2 mRNA in chondrocytes treated with TRPV4 inhibitor under inflammatory conditions. The expression of Col2α1 mRNA was significantly decreased (P<0.05), and the expression of Col2α1 mRNA was increased (P<0.05). Although there was no significant difference in the expression of Acan mRNA, the overall trend was also increasing. The expression of Col2α1 and Acan mRNA in chondrocytes was significantly decreased (P<0.05), and the expression of NOS2 mRNA was increased(P<0.05), but there was no significant difference in MMP-13 and ADAMTS-5 (P>0.05). CONCLUSION Inhibiting the expression of TRPV4 can down-regulate the expression of genes related to chondrocyte degeneration.
Animals ; Rats ; Aggrecans/metabolism* ; Cartilage, Articular ; Cells, Cultured ; Chondrocytes ; Interleukin-1beta/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; RNA, Messenger/metabolism* ; TRPV Cation Channels/metabolism*

OBJECTIVE: Exposure to high intensity, low frequency noise (HI-LFN) causes vibroacoustic disease (VAD), with memory deficit as a primary non-auditory symptomatic effect of VAD. However, the underlying mechanism of the memory deficit is unknown. This study aimed to characterize potential mechanisms involving morphological changes of neurons and nerve fibers in the hippocampus, after exposure to HI-LFN. METHODS: Adult wild-type and transient receptor potential vanilloid subtype 4 knockout (TRPV4^-/-) mice were used for construction of the HI-LFN injury model. The new object recognition task and the Morris water maze test were used to measure the memory of these animals. Hemoxylin and eosin and immunofluorescence staining were used to examine morphological changes of the hippocampus after exposure to HI-LFN. RESULTS: The expression of TRPV4 was significantly upregulated in the hippocampus after HI-LFN exposure. Furthermore, memory deficits correlated with lower densities of neurons and neurofilament-positive nerve fibers in the cornu ammonis 1 (CA1) and dentate gyrus (DG) hippocampal areas in wild-type mice. However, TRPV4^-/- mice showed better performance in memory tests and more integrated neurofilament-positive nerve fibers in the CA1 and DG areas after HI-LFN exposure. CONCLUSION TRPV4 up-regulation induced neurofilament positive nerve fiber injury in the hippocampus, which was a possible mechanism for memory impairment and cognitive decline resulting from HI-LFN exposure. Together, these results identified a promising therapeutic target for treating cognitive dysfunction in VAD patients.
Animals ; Mice ; TRPV Cation Channels/metabolism* ; Intermediate Filaments/metabolism* ; Hippocampus/metabolism* ; Neurons/metabolism* ; Memory Disorders/metabolism*

This study aims to explore the pharmacodynamic effect of baicalin on rat brain edema induced by cerebral ischemia reperfusion injury and discuss the mechanism from the perspective of inhibiting astrocyte swelling, which is expected to serve as a refe-rence for the treatment of cerebral ischemia with Chinese medicine. To be specific, middle cerebral artery occlusion(suture method) was used to induce cerebral ischemia in rats. Rats were randomized into normal group, model group, high-dose baicalin(20 mg·kg~(-1)) group, and low-dose baicalin(10 mg·kg~(-1)) group. The neurobehavior, brain index, brain water content, and cerebral infarction area of rats were measured 6 h and 24 h after cerebral ischemia. Brain slices were stained with hematoxylin and eosin(HE) for the observation of pathological morphology of cerebral cortex after baicalin treatment. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of total L-glutathione(GSH) and glutamic acid(Glu) in brain tissue, Western blot to measure the content of glial fibrillary acidic protein(GFAP), aquaporin-4(AQP4), and transient receptor potential vanilloid type 4(TRPV4), and immunohistochemical staining to observe the expression of GFAP. The low-dose baicalin was used for exploring the mechanism. The experimental results showed that the neurobehavioral scores(6 h and 24 h of cerebral ischemia), brain water content, and cerebral infarction area of the model group were increased, and both high-dose and low-dose baicalin can lower the above three indexes. The content of GSH dropped but the content of Glu raised in brain tissue of rats in the model group. Low-dose baicalin can elevate the content of GSH and lower the content of Glu. According to the immunohistochemical staining result, the model group demonstrated the increase in GFAP expression, and swelling and proliferation of astrocytes, and the low-dose baicalin can significantly improve this situation. The results of Western blot showed that the expression of GFAP, TRPV4, and AQP4 in the cerebral cortex of the model group increased, and the low-dose baicalin reduce their expression. The cerebral cortex of rats in the model group was severely damaged, and the low-dose baicalin can significantly alleviate the damage. The above results indicate that baicalin can effectively relieve the brain edema caused by cerebral ischemia reperfusion injury in rats, possibly by suppressing astrocyte swelling and TRPV4 and AQP4.
Animals ; Aquaporin 4/genetics* ; Astrocytes ; Brain Edema/drug therapy* ; Brain Ischemia/metabolism* ; Flavonoids ; Infarction, Middle Cerebral Artery/drug therapy* ; Rats ; Rats, Sprague-Dawley ; Reperfusion ; TRPV Cation Channels/therapeutic use*

Atrial Ca²⁺ handling abnormalities, mainly involving the dysfunction of ryanodine receptor (RyR) and sarcoplasmic reticulum Ca²⁺-ATPase (SERCA), play a role in the pathogenesis of atrial fibrillation (AF). Previously, we found that the expression and function of transient receptor potential vanilloid subtype 4 (TRPV4) are upregulated in a sterile pericarditis (SP) rat model of AF, and oral administration of TRPV4 inhibitor GSK2193874 alleviates AF in this animal model. The aim of this study was to investigate whether oral administration of GSK2193874 could alleviate atrial Ca²⁺ handling abnormalities in SP rats. A SP rat model of AF was established by daubing sterile talcum powder on both atria of Sprague-Dawley (SD) rats after a pericardiotomy, to simulate the pathogenesis of postoperative atrial fibrillation (POAF). On the 3rd postoperative day, Ca²⁺ signals of atria were collected in isolated perfused hearts by optical mapping. Ca²⁺ transient duration (CaD), alternan, and the recovery properties of Ca²⁺ transient (CaT) were quantified and analyzed. GSK2193874 treatment reversed the abnormal prolongation of time to peak (determined mainly by RyR activity) and CaD (determined mainly by SERCA activity), as well as the regional heterogeneity of CaD in SP rats. Furthermore, GSK2193874 treatment relieved alternan in SP rats, and reduced its incidence of discordant alternan (DIS-ALT). More importantly, GSK2193874 treatment prevented the reduction of the S2/S1 CaT ratio (determined mainly by RyR refractoriness) in SP rats, and decreased its regional heterogeneity. Taken together, oral administration of TRPV4 inhibitor alleviates Ca²⁺ handling abnormalities in SP rats primarily by blocking the TRPV4-Ca²⁺-RyR pathway, and thus exerts therapeutic effect on POAF.
Administration, Oral ; Animals ; Atrial Fibrillation/etiology* ; Calcium/metabolism* ; Myocytes, Cardiac/metabolism* ; Pericarditis/pathology* ; Rats ; Rats, Sprague-Dawley ; Ryanodine Receptor Calcium Release Channel/pharmacology* ; Sarcoplasmic Reticulum/pathology* ; TRPV Cation Channels

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Ciliao" (BL 32) and "Huiyang" (BL 35) on the pain, urodynamic and the expressions of transient receptor poteintial vanilloid 1 (TRPV1) and P2X3 receptors in bladder of rats with interstitial bladder (IC), and to explore the possible mechanism on EA for IC. METHODS: A total of 24 Wistar female rats were randomly divided into a blank group, a model group and an EA group, 8 rats in each group. In the model group and the EA group, IC model was established by intraperitoneal injection of cyclophosphamide by 150 mg/kg at once. EA was applied at "Ciliao" (BL 32) and "Huiyang" (BL 35) in the EA group for 20 min, with continuous wave, 30 Hz in frequency, once a day for 3 consecutive days. Mechanical pain threshold of bladder and urodynamic indexes (first urination time, bladder effective volume and urination pressure) were observed after model establishment and after intervention, the expressions of TRPV1 and P2X3 receptors in the bladder were detected by Western blot. RESULTS: After model establishment, the mechanical pain threshold of bladder was decreased in the model group and the EA group compared with that in the blank group (P<0.01). After intervention, the mechanical pain threshold of bladder in the model group was lower than the blank group (P<0.01), and that in the EA group was higher than the model group (P<0.01). The urodynamic of the rats in the blank group was normal, obvious abnormal contraction during the filling period of bladder was found in the rats of the model group, while no abnormal contraction during the filling period was found in the rats of the EA group. After model establishment, in the model group and the EA group, the first urination time was earlier than the blank group (P<0.01), while bladder effective volume and urination pressure were lower than the blank group (P<0.01). After intervention, in the model group, the first urination time was earlier than the blank group (P<0.01), while bladder effective volume and urination pressure were lower than the blank group (P<0.05); in the EA group, the first urination time was later than the model group (P<0.05), while bladder effective volume and urination pressure were higher than the model group (P<0.05). Compared with the blank group, the protein expressions of TRPV1 and P2X3 receptors in bladder were up-regulated in the model group (P<0.01); compared with the model group, the protein expressions of TRPV1 and P2X3 receptors in bladder were down-regulated in the EA group (P<0.05). CONCLUSION EA can relieve bladder pain and improve urodynamic in IC rats. The mechanism may be related to the down-regulation on the expressions of TRPV1 and P2X3 receptors and the further inhibition on the abnormal input of bladder signal.
Rats ; Female ; Animals ; Cystitis, Interstitial/therapy* ; Electroacupuncture ; Urinary Bladder ; Receptors, Purinergic P2X3/metabolism* ; Rats, Sprague-Dawley ; Rats, Wistar ; Pain ; Antineoplastic Agents ; TRPV Cation Channels/metabolism*

This study aims to explore the effect of Jinzhen Oral Liquid(JOL) on cough after infection in rats and the mechanism. To be specific, a total of 60 male SD rats were classified into 6 groups: normal group(equivalent volume of distilled water, ig), model group(equivalent volume of distilled water, ig), Dextromethorphan Hydrobromide Oral Solution group(3.67 mL·kg~(-1), ig), high-, medium-, and low-dose JOL groups(11.34, 5.67, and 2.84 mL·kg~(-1), respectively, ig). Lipopolysaccharide(LPS, nasal drip), smoking, and capsaicin(nebulization) were employed to induce cough after infection in rats except the normal group. Administration began on the 19 th day and lasted 7 days. Capsaicin(nebulization) was used to stimulate cough 1 h after the last administration and the cough frequency and cough incubation period in rats were recorded. The pathological morphology of lung tissue was observed based on hematoxylin-eosin(HE) staining. Immunohistochemistry(IHC) was used to detect the specific expression of transient receptor potential vanilloid 1(Trpv1), nerve growth factor(NGF), tropomyosin receptor kinase A(TrkA), and phosphorylated-p38 mitogen-activated protein kinase(p-p38 MAPK) in lung tissue, Western blot the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and real-time fluorescent quantitative polymerase chain reaction(real-time PCR) the mRNA expression of Trpv1, NGF, and TrkA. The results showed that model group demonstrated significantly high cough frequency, obvious proliferation and inflammatory cell infiltration in lung tissue, significantly enhanced positive protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue and significant increase in the mRNA expression of Trpv1, NGF, and TrkA compared with the normal group. Compared with the model group, JOL can significantly reduce the cough frequency, alleviate the pathological changes of lung tissue, and decrease the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and high-dose and medium-dose JOL can significantly lower the mRNA expression of Trpv1, NGF, and TrkA. This study revealed that JOL can effectively inhibit Trpv1 pathway-related proteins and improve cough after infection. The mechanism is that it reduces the expression of NGF, TrkA, and p-p38 MAPK in lung tissue, thereby decreasing the expression of Trpv1 and cough sensitivity.
Animals ; Capsaicin/adverse effects* ; Cough/drug therapy* ; Dextromethorphan/adverse effects* ; Eosine Yellowish-(YS)/adverse effects* ; Hematoxylin ; Lipopolysaccharides/adverse effects* ; Male ; Medicine, Chinese Traditional ; Nerve Growth Factor/metabolism* ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptor, trkA/metabolism* ; TRPV Cation Channels/metabolism* ; Tropomyosin/metabolism* ; Water/metabolism* ; p38 Mitogen-Activated Protein Kinases/metabolism*

This study investigated the effect of Maxing Shigan Decoction(MXSGD) and its disassembled prescriptions against the airway inflammation in respiratory syncytial virus(RSV)-aggravated asthma and the regulation of transient receptor potential vanilloid-1(TRPV1). To be specific, ovalbumin(OVA) and RSV were used to induce aggravated asthma in mice(female, C57BL/6). Then the model mice were intervened by MXSGD and the disassembled prescriptions. The eosinophil(EOS) in peripheral blood, inflammatory cells in bronchoalveolar lavage fluid(BALF), enhanced pause(Penh) variation, and lung pathological damage in each group were observed, and the changes of interleukin(IL)-4, IL-13, substance P(SP), and prostaglandin E2(PGE2) in BALF were mea-sured by enzyme-linked immunosorbent assay(ELISA). Quantitative real time polymerase chain reaction(qPCR) and Western blot were used to detect mRNA and protein of TRPV1 in mouse lung tissue. In the in vitro experiment, 16 HBE cells were stimulated with IL-4 and RSV. Then the changes of TRPV1 expression after the intervention with the serum containing MXSGD and its disassembled prescriptions were observed. Besides, the intracellular Ca~(2+) level after the stimulation with TRPV1 agonist was evaluated. The results showed that the mice in the model group had obvious asthma phenotype, the levels of various inflammatory cells in the peripheral blood and BALF and Penh were significantly increased(P<0.05, P<0.01), and the lung tissue was severely damaged compared with the control group. Compared with the model group, the levels of EOS in the peripheral blood and BALF were significantly decreased in the MXSGD group, the SG group and the MXC group(P<0.05, P<0.01). The levels of WBC and neutrophils in BALF were significantly decreased in the MXSGD group and SG group(P<0.01), the levels of neutrophils in BALF were decreased in the MXC group(P<0.05). The improvement effect of the MXGSD on the level of inflammatory cells in peripheral blood and BALF was better than that of two disassembled groups(P<0.05, P<0.01). After 50 mg·mL~(-1) acetylcholine chloride stimulation, the Penh values of the MXSGD group and the MXC group significantly decreased(P<0.01), and the Penh value of the SG group decreased(P<0.05). The levels of IL-4, IL-13, PGE2 and SP in BALF could be significantly decreased in the MXSGD group(P<0.05, P<0.01), the levels of IL-13 and PGE2 in BALF could be decreased in the MXC group(P<0.05, P<0.01), and the levels of IL-13, PGE2 and SP in BALF could be decreased in the SG group(P<0.05, P<0.01). MXSGD could down-regulate the protein and mRNA expression of TRPV1 in lung tissue(P<0.05, P<0.01). The serum containing MXSGD and its disassembled prescriptions could down-regulate TRPV1 expression in 16 HBE cells stimulated by IL-4 combined with RSV and inhibit the inward flow of Ca~(2+) induced by TRPV1 agonist, especially the serum containing MXSGD which showed better effect than the serum containing disassembled ones(P<0.05). In vivo and in vitro experiments verified the protective effect of MXSGD and its disassembled prescriptions against airway inflammation in RSV-exacerbated asthma, the whole decoction thus possessed synergy in treating asthma, with better performance than the dissembled prescriptions. Different groups of prescription had made contributions in improving airway hyperresponsiveness, anti-allergy and anti-inflammation. The mechanism is the likelihood that it regulates TRPV1 channel and levels of related inflammatory mediators.
Female ; Mice ; Animals ; Interleukin-13/metabolism* ; Interleukin-4/metabolism* ; Dinoprostone ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Asthma/chemically induced* ; Lung ; Bronchoalveolar Lavage Fluid ; Ovalbumin/adverse effects* ; Inflammation/metabolism* ; RNA, Messenger/metabolism* ; Prescriptions ; Disease Models, Animal ; TRPV Cation Channels/metabolism*

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron-glia interaction mediated by the C3-TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3-TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.
Animals ; Astrocytes/metabolism* ; Complement C3/metabolism* ; Epilepsy ; Mice ; Neurons/pathology* ; Status Epilepticus ; TRPV Cation Channels/metabolism*

To explore the role of vascular endothelial growth factor (VEGF) in diabetic peripheral neuropathic pain in rats.
 Methods: Twenty-four adult male Sprague-Dawley rats aged 8 weeks were randomly divided into 3 groups (n=8 per group). The control group (C group): rats were intraperitoneally injected with sodium citrate solution at 10 mL/kg; the model group (M group): rats were intraperitoneally injected with streptozotocin at 65 mg/kg; the treatment group (T group): rats received intraperitoneal injection of anti-VEGF antibody (10 mg/kg) at the 1st, 3rd, 7th, 10th day after STZ treatment. Meanwhile, rats of C and M group were received with the same volume of sodium citrate solution. Blood glucose was measured before 1 day or at the 1st, 3rd, 7th or 14th day after receiving STZ. Body weight, paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured before 1 day or at the 1st, 3rd, 5th, 7th, 10th or 14th day after receiving STZ. All lumbar spinal cords were dissected to examine the p-protein kinase B (p-Akt) and transient receptor potential vanilloid 1 (TRPV1) expression by Western blot.
 Results: After injection with STZ, the body weight showed significant differences at some time point between the M, T or C group (P<0.01); body weight of rat in the C group were increased gradually. Compared with the C group, the fast blood glucose in the M or the T Group at the same time points were increased significantly (P<0.01). The PWMT and PWTL of the M, T or C group were significant difference among various time points (P<0.01). The PWMT and PWTL in the M or T group were obviously reduced compared with those in the C group (P<0.01). Compared with the M group, the PWMT and PWTL in the T group were increased at the 10th or 14th day (P<0.01 or P<0.05). Compared with the C group, the p-Akt and TRPV1 levels in the M and T group were increased (P<0.01). Compared with the M group, p-Akt and TRPV1 levels in T group were decreased (P<0.01).
 Conclusion: VEGF is able to regulate the expression of TRPV1 through PI3K/Akt pathway, which contributes to diabetic peripheral neuropathic pain in rats. Anti-VEGF treatment may be useful for alleviation of diabetic peripheral neuropathic pain.
Animals ; Antibodies ; pharmacology ; therapeutic use ; Diabetes Mellitus, Experimental ; chemically induced ; Diabetic Neuropathies ; chemically induced ; drug therapy ; Gene Expression Regulation ; drug effects ; Male ; Phosphatidylinositol 3-Kinases ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; TRPV Cation Channels ; genetics ; Vascular Endothelial Growth Factor A ; metabolism