Acupuncture Alleviates Chronic Ischemic White Matter Injury in SHR Rats via JNK-NMDAR Circuit

To study the protective mechanism of acupuncture at "Jiangya Recipe" on chronic ischemic white matter injury in spontaneously hypertensive rats (SHR) and the regulation of Jun N-terminal kinase-N-methyl-D-aspartate receptor (JNK-NMDAR) loop. A hypertensive white matter injury model was established in 46 male SHR rats aged 11 weeks by bilateral common carotid artery tapering (SHR-2VGO). In the SHR sham operation group, only bilateral common carotid arteries were isolated and in the SHR-2VGO modeling group, 36 rats were used for microcoil spring clip implantation to narrow the common carotid arteries and then, after 2 weeks of modeling, rats with impaired motor function were removed, and SHR-2VGO rats with successful final models were randomly divided into the model group, JNK blocking group, and acupuncture group. The sham operation group, model group, and JNK blocking group underwent the same grasping fixation, and the acupuncture group received acupuncture at acupoints "Jiangya Fang" once daily. In the JNK blocker group, an injection cannula was implanted into the lateral ventricle and sp600125 was injected into the lateral ventricle at 4.5 ul/day for 4 weeks. One week after the end of the intervention, white matter lesions were detected by MRI DWI and T2 imaging, and the learning and memory ability of rats was tested by Y-Maze and Passive Avoidance. Myelin density was detected by luxol fast blue (LFB) staining, also axon arrangement, myelin integrity, and thickness of neurons were detected by electron microscopy; neuronal morphology and the number of Nissl bodies in the hippocampus were detected by Nissl staining, dendritic spine density changes were detected by Golgi staining, and JNK, NMDAR1, and N-methyl-D-receptor 2B (NMDAR2B) in DG, CA3 region of hippocampus were detected by immunohistochemistry, protein expression of p-JNK/JNK, p-NMDAR1/NMDAR1, NMDAR2B, GSK3β protein expression in the fimbria of hippocampus was detected by Western blot. The Y maze test of SHR-2VGO+Acu and SHR-2VGO+ sp600125 group showed that the spontaneous alternating reaction rate increased significantly. At the same time, the incubation period increased significantly and the number of errors decreased significantly in Passive Avoidance. MRI T2WI showed that the white matter high signal of the corpus callosum, internal capsule and hippocampal fimbria in the SHR-2VGO+ sp600125 and SHR-2VGO+Acu groups was significantly lower than that in the SHR-2VGO model group, and the striatum and anterior commissure were not obvious. DWI showed that the SHR-2VGO model group had scattered high signal and limited diffusion movement in both the internal capsule and striatum, but the difference between groups was not obvious. Compared with SHR-2VGO rats, LFB staining of SHR-2VGO + sp600125 and SHR-2VGO +Acu groups showed significant relaxation of myelin porosity in corpus callosum, striatum, inner capsule, anterior commissure and hippocampal fimbria, and electron microscopy showed improved axonal myelin integrity and thickness in corpus callosum region. Also, the number of blue patchy Nissl bodies increased, and the number and complexity of dendritic spines increased significantly in Golgi staining. Immunohistochemical detection showed that JNK levels in DG and CA3 region were increased and NMDAR1 and NMDAR2B levels were decreased in SHR-2VGO+Acu and SHR-2VGO+ sp600125 groups. Meanwhile, protein expressions of GSK3β, NMDAR1/p-NMDAR1 and NMDAR2B in fimbria of hippocampus were increased, and JNK/P-JNK protein expression decreased. Acupuncture can increase the density and thickness of myelin sheath in white matter areas of corpus callosum, anterior commissure and hippocampal fimbria, increase the number and length of hippocampal neuronal dendrites, and improve hypertensive white matter injury and cognitive decline through JNK-NMDAR pathway.

Inhibition of the STIM1/Orai1 Signaling Pathway by Glycine Betaine Mitigates Myocardial Hypertrophy in Spontaneous Hypertension Rats

Background

Spontaneous hypertension is a leading risk factor for cardiovascular diseases morbidity and mortality. Glycine betaine (GB) is a natural vitamin that has the potential to lower blood pressure. This work attempted to investigate the role and mechanisms of GB in spontaneous hypertension.

Methods

Spontaneously hypertensive rats (SHRs) were administrated with 100, 200, or 400 mg/kg of GB by gavage or combined with by injection of lentivirus-mediated STIM1 overexpression vector. The heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart weight/body weight (HW/BW) of rats were monitored. The pathological changes in myocardium were examined by hematoxylin and eosin staining and Masson staining. The expression of genes and proteins was detected by quantitative real-time PCR, western blotting, and immunohistochemistry.

Results

GB at 200 and 400 mg/kg reduced the HR, SBP, DBP and HW/BW in SHRs. GB decreased the cross-sectional area and fibrotic area in the myocardium and downregulated the expression of atrial natriuretic peptide (ANP) and β-myosin heavy chain (β-MHC) in the myocardium of SHRs. It indicated that GB treatment effectively alleviated myocardial hypertrophy in SHRs. Additionally, GB treatment repressed the expression of stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein 1 (Orai1) in the myocardium of SHRs. STIM1 overexpression reversed GB treatment-mediated inhibition of myocardial hypertrophy in SHRs.

Conclusions

In conclusion, GB repressed STIM1/Orai1 signaling pathway, which contributed to alleviating myocardial hypertrophy in SHRs. Thus, our study provides a theoretical basis for GB as an antihypertensive drug.

[Effect of electroacupuncture on transforming growth factor-β1 and renal tubular epithelial mesenchymal transformation in renal tissue of spontaneously hypertensive rats]

OBJECTIVE

To observe the effects of electroacupuncture (EA) on renal fibrosis, the expression of transforming growth factor-β1 (TGF-β1) and epithelial mesenchymal transition (EMT) marker proteins in renal tissue of spontaneously hypertensive rats (SHR), so as to explore the underlying mechanism on EA alleviating hypertensive renal impairment.

METHODS

Twenty-four male SHR were randomly divided into model group, losartan group and EA group, with 8 rats in each group, and eight male Wistar-Kyoto rats were taken as the normal group. Rats in the losartan group received gavage of losartan potassium solution (3 mg/mL, 30 mg·kg^-1·d^-1),once every other day for 12 weeks. Rats in the EA group received EA stimulation at bilateral "Shenshu" (BL23) and "Geshu" (BL17) (2 Hz/15 Hz, 1.0 mA), 15 min each time, once every other day for 12 weeks. The systolic blood pressure of caudal artery was measured before, and 4, 8 and 12 weeks after the intervention. The 24-hour urinary protein was measured before, and 6 and 12 weeks after the intervention. Histopathological changes of the left renal tissue were observed under light mircoscope after H.E. stain. Extracellular matrix (ECM) in renal tissues was observed after periodate Schiff staining. Basement membrane and collagen fibers were observed after Masson staining with collagen volume fraction (CVF) evaluated. The expression of TGF-β1 mRNA in the right renal was detected by real-time fluorescence quantitative PCR. The expression of TGF-β1 and EMT marker E-cadherin, α-SMA and fibronectin (FN) proteins in the left renal tissue was measured by immunohistochemistry.

RESULTS

In the model group, irregular arrangement of nephrocytes, renal tubule atrophy, lumen stenosis, ECM hyperplasia and deposition, scar and sclerosis were observed, which were relatively milder in the EA and losartan groups. Compared with the normal group, tubulointerstitium CVF, systolic blood pressure of caudal artery before, and at 4, 8 and 12 weeks after the intervention, 24-hour urinary protein before, and at 6 and 12 weeks after the intervention, the expression of TGF-β1 mRNA, area of TGF-β1, α-SMA and FN positive staining in renal tissues were significantly increased (P<0.01), while the area of E-cadherin positive staining was significantly decreased (P<0.01) in the model group. Compared with the model group, tubulointerstitium CVF, systolic blood pressure of caudal artery at 4, 8 and 12 weeks after the intervention, 24-hour urinary protein at 6 and 12 weeks after the intervention, the expression of TGF-β1 mRNA, area of TGF-β1, α-SMA and FN positive staining in renal tissues were significantly decreased (P<0.01，P<0.05), while area of E-cadherin positive staining was significantly increased (P<0.01) in the losartan and EA groups. Compared with the losartan group, the area of E-cadherin was conside-rately increased (P<0.01), while the area of α-SMA protein decreased (P<0.01) in the EA group.

CONCLUSION

EA could effectively alleviate hypertension and renal interstitial fibrosis in SHR, the mechanism of which may be related to its function in reducing the expression of TGF-β1 and inhibiting EMT in renal tissue.

Signature microRNA expression profile is associated with spontaneous hypertension in African green monkey

Chlorocebus aethiops sabaeus, the African Green monkey (AGM), has been proved to exhibit renal vascular remodeling and spontaneous hypertension. However, little is known about the roles of microRNAs (miRNAs) in this process.Using small RNA deep sequencing, we compared the plasma miRNA expression patterns between hypertensive (HT) AGMs and normotensive (NT) AGMs. Expression of miRNAs (miR-122, miR-339, miR-296-5p) was validated independently in plasma samples from 10 HT AGMs and 10 NT AGMs (fold changes are 2.0, 1.6, 2.7 respectively; all P< 0.001). Potential BP (blood pressure)-regulating mRNA targets were predicted by TargetScan and confirmed in the Vero cells. We report for the first time a circulating miRNA profile for AGM. miRNAs, such as miR-122, miR-339, miR-296-5p, may be involved in renal pathologies and spontaneous hypertension of AGM.

Spontaneous Elevation of Blood Pressure After SAH: An Epiphenomenon of Disease Severity and Demand, But Not a Surrogate for Outcome?

BACKGROUND

Spontaneous blood pressure increase is frequently observed after aneurysmal subarachnoid hemorrhage (aSAH). These episodes of spontaneous blood pressure alterations are usually tolerated under the assumption of an endogenous response to maintain cerebral perfusion. The relevance of blood pressure variability and its relationship to disease severity and outcome, however, remain obscure.

METHODS

A total of 115 consecutive patients with aSAH were included for this retrospective analysis of a continuously collected data pool. Demographics, initial clinical severity of aSAH (HH°, mFS), treatment modality, clinical course, and outcome (development of DCI, cerebral infarction, and GOS after 3 months) were recorded. Hemodynamic information-recorded automatically with a frequency of 1/15 min-was analyzed for spontaneous blood pressure increase (SBI) and endogenous persistent hypertension (EPH) after exclusion of iatrogenic factors and relevant co-medication. Subgroup analysis included stratification for day 0-3, 4-14, and 14-21.

RESULTS

SBI and EPH incidence varied from 17 to 84% depending on detection threshold (15-35 mmHg) and time period under scrutiny. Incidence of blood pressure increase correlated with disease severity upon admission (p < 0.05), but the anticipated association with outcome was not observed. SBI and EPH were more likely to occur between day 4 and 14 (p < 0.001), but only early occurrence (day 0-3) was associated with higher incidence of DCI (p < 0.05). Persistent blood pressure elevation between day 4 and 21 was associated with fewer DCI. However, no influence of spontaneous upregulation on clinical outcome after three months was observed.

CONCLUSIONS

Spontaneous hemodynamic upregulation is a frequent phenomenon after aSAH. Our data support the hypothesis that spontaneous blood pressure alterations reflect an endogenous, demand-driven response correlating with disease severity. Early alterations may indicate an aggravated clinical course, while later upregulation in particular-if permitted-does not translate into a higher risk of unfavorable outcome.