Browsing by Author "Qiao, Guo-Fen"

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    Contribution of Baroreflex Afferent Pathway to NPY-Mediated Regulation of Blood Pressure in Rats
    (Springer, 2020-04) Liu, Yang; Zhao, Shu-Yang; Feng, Yan; Sun, Jie; Lu, Xiao-Long; Yan, Qiu-Xin; Li, Ying; Liu, Zhuo; Wang, Lu-Qi; Sun, Xun; Li, Shijun; Qiao, Guo-Fen; Li, Bai-Yan; Pediatrics, School of Medicine
    Neuropeptide Y (NPY), a metabolism-related cardiovascular factor, plays a crucial role in blood pressure (BP) regulation via peripheral and central pathways. The expression of NPY receptors (Y1R/Y2R) specific to baroreflex afferents impacts on the sexually dimorphic neural control of circulation. This study was designed to investigate the expression profiles of NPY receptors in the nodose ganglion (NG) and nucleus tractus solitary (NTS) under hypertensive conditions. To this end, rats with hypertension induced by NG-nitro-L-arginine methylester (L-NAME) or high fructose drinking (HFD), and spontaneously hypertensive rats (SHRs) were used to explore the effects/mechanisms of NPY on BP using functional, molecular, and electrophysiological approaches. The data showed that BP was elevated along with baroreceptor sensitivity dysfunction in model rats; Y1R was up- or down-regulated in the NG or NTS of male and female HFD/L-NAME groups, while Y2R was only down-regulated in the HFD groups as well as in the NG of the male L-NAME group. In SHRs, Y1R and Y2R were both down-regulated in the NTS, and not in the NG. In addition to NPY-mediated energy homeostasis, leptin-melanocortin activation may be essential for metabolic disturbance-related hypertension. We found that leptin and α-melanocyte stimulating hormone (α-MSH) receptors were aberrantly down-regulated in HFD rats. In addition, α-MSH concentrations were reduced and NPY concentrations were elevated in the serum and NTS at 60 and 90 min after acute leptin infusion. Electrophysiological recordings showed that the decay time-constant and area under the curve of excitatory post-synaptic currents were decreased by Y1R activation in A-types, whereas, both were increased by Y2R activation in Ah- or C-types. These results demonstrate that sex- and afferent-specific NPY receptor expression in the baroreflex afferent pathway is likely to be a novel target for the clinical management of metabolism-related and essential hypertension.
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    FGF21 ameliorates the neurocontrol of blood pressure in the high fructose-drinking rats
    (Nature Publishing Group, 2016-07-08) He, Jian-Li; Zhao, Miao; Xia, Jing-Jun; Guan, Jian; Liu, Yang; Wang, Lu-Qi; Song, Dong-Xue; Qu, Mei-Yu; Zuo, Meng; Wen, Xin; Yu, Xue; Huo, Rong; Pan, Zhen-Wei; Ban, Tao; Zhang, Yan; Zhu, Jiu-Xin; Shou, Weinian; Qiao, Guo-Fen; Li, Bai-Yan; Department of Pediatrics, IU School of Medicine
    Fibroblast growth factor-21 (FGF21) is closely related to various metabolic and cardiovascular disorders. However, the direct targets and mechanisms linking FGF21 to blood pressure control and hypertension are still elusive. Here we demonstrated a novel regulatory function of FGF21 in the baroreflex afferent pathway (the nucleus tractus solitarii, NTS; nodose ganglion, NG). As the critical co-receptor of FGF21, β-klotho (klb) significantly expressed on the NTS and NG. Furthermore, we evaluated the beneficial effects of chronic intraperitoneal infusion of recombinant human FGF21 (rhFGF21) on the dysregulated systolic blood pressure, cardiac parameters, baroreflex sensitivity (BRS) and hyperinsulinemia in the high fructose-drinking (HFD) rats. The BRS up-regulation is associated with Akt-eNOS-NO signaling activation in the NTS and NG induced by acute intravenous rhFGF21 administration in HFD and control rats. Moreover, the expressions of FGF21 receptors were aberrantly down-regulated in HFD rats. In addition, the up-regulated peroxisome proliferator-activated receptor-γ and -α (PPAR-γ/-α) in the NTS and NG in HFD rats were markedly reversed by chronic rhFGF21 infusion. Our study extends the work of the FGF21 actions on the neurocontrol of blood pressure regulations through baroreflex afferent pathway in HFD rats.
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    KCa1.1 β4-subunits is not responsible for iberiotoxin-resistance in baroreceptor neurons in adult male rats
    (Elsevier, 2015) Xu, Wen-Xiao; Ban, Tao; Wang, Lu-Qi; Zhao, Miao; Yin, Lei; Li, Guo; Chen, Hanying; Schild, John H.; Qiao, Guo-Fen; Yan, Jing-Long; Li, Bai-Yan; Biomedical Engineering, School of Engineering and Technology
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    Neuropeptide Y-mediated sex- and afferent-specific neurotransmissions contribute to sexual dimorphism of baroreflex afferent function
    (Impact Journals, 2016-10-04) Liu, Yang; Wu, Di; Qu, Mei-Yu; He, Jian-Li; Yuan, Mei; Zhao, Miao; Wang, Jian-Xin; He, Jian; Wang, Lu-Qi; Guo, Xin-Jing; Zuo, Meng; Zhao, Shu-Yang; Ma, Mei-Na; Li, Jun-Nan; Shou, Weinian; Qiao, Guo-Fen; Li, Bai-Yan; Department of Pediatrics, IU School of Medicine
    BACKGROUND: Molecular and cellular mechanisms of neuropeptide-Y (NPY)-mediated gender-difference in blood pressure (BP) regulation are largely unknown. METHODS: Baroreceptor sensitivity (BRS) was evaluated by measuring the response of BP to phenylephrine/nitroprusside. Serum NPY concentration was determined using ELISA. The mRNA and protein expression of NPY receptors were assessed in tissue and single-cell by RT-PCR, immunoblot, and immunohistochemistry. NPY was injected into the nodose while arterial pressure was monitored. Electrophysiological recordings were performed on nodose neurons from rats by patch-clamp technique. RESULTS: The BRS was higher in female than male and ovariectomized rats, while serum NPY concentration was similar among groups. The sex-difference was detected in Y1R, not Y2R protein expression, however, both were upregulated upon ovariectomy and canceled by estrogen replacement. Immunostaining confirmed Y1R and Y2R expression in myelinated and unmyelinated afferents. Single-cell PCR demonstrated that Y1R expression/distribution was identical between A- and C-types, whereas, expressed level of Y2R was ~15 and ~7 folds higher in Ah- and C-types than A-types despite similar distribution. Activation of Y1R in nodose elevated BP, while activation of Y2R did the opposite. Activation of Y1R did not alter action potential duration (APD) of A-types, but activation of Y2R- and Y1R/Y2R in Ah- and C-types frequency-dependently prolonged APD. N-type ICa was reduced in A-, Ah- and C-types when either Y1R, Y2R, or both were activated. The sex-difference in Y1R expression was also observed in NTS. CONCLUSIONS: Sex- and afferent-specific expression of Neuropeptide-Y receptors in baroreflex afferent pathway may contribute to sexual-dimorphic neurocontrol of BP regulation.
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    Parkinson‐like early autonomic dysfunction induced by vagal application of DOPAL in rats
    (Wiley, 2021) Sun, Jie; He, Chao; Yan, Qiu-Xin; Wang, Hong-Dan; Li, Ke-Xin; Sun, Xun; Feng, Yan; Zha, Rong-Rong; Cui, Chang-Peng; Xiong, Xue; Gao, Shan; Wang, Xue; Yin, Rui-Xue; Qiao, Guo-Fen; Li, Bai-Yan; Biomedical Engineering, School of Engineering and Technology
    Aim: To understand why autonomic failures, a common non-motor symptom of Parkinson's disease (PD), occur earlier than typical motor disorders. Methods: Vagal application of DOPAL (3,4-dihydroxyphenylacetaldehyde) to simulate PD-like autonomic dysfunction and understand the connection between PD and cardiovascular dysfunction. Molecular and morphological approaches were employed to test the time-dependent alternation of α-synuclein aggregation and the ultrastructure changes in the heart and nodose (NG)/nucleus tractus solitarius (NTS). Results: Blood pressure (BP) and baroreflex sensitivity of DOPAL-treated rats were significantly reduced accompanied with a time-dependent change in orthostatic BP, consistent with altered echocardiography and cardiomyocyte mitochondrial ultrastructure. Notably, time-dependent and collaborated changes in Mon-/Tri-α-synuclein were paralleled with morphological alternation in the NG and NTS. Conclusion: These all demonstrate that early autonomic dysfunction mediated by vagal application of DOPAL highly suggests the plausible etiology of PD initiated from peripheral, rather than central site. It will provide a scientific basis for the prevention and early diagnosis of PD.
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    Spontaneous activities in baroreflex afferent pathway contribute dominant role in parasympathetic neurocontrol of blood pressure regulation
    (Wiley, 2018-12) Xu, Wen-Xiao; Yu, Jin-Ling; Feng, Yan; Yan, Qiu-Xin; Li, Xin-yu; Li, Ying; Liu, Zhuo; Wang, Di; Sun, Xun; Li, Ke-Xin; Wang, Lu-Qi; Qiao, Guo-Fen; Li, Bai-Yan; Biomedical Engineering, School of Engineering and Technology
    Aim To study the dominant role of parasympathetic inputs at cellular level of baroreflex afferent pathway and underlying mechanism in neurocontrol of blood pressure regulation. Methods Whole‐cell patch‐clamp and animal study were conducted. Results For the first time, we demonstrated the spontaneous activities from resting membrane potential in myelinated A‐ and Ah‐type baroreceptor neurons (BRNs, the 1st‐order), but not in unmyelinated C‐types, using vagus‐nodose slice of adult female rats. These data were further supported by the notion that the spontaneous synaptic currents could only be seen in the pharmacologically and electrophysiologically defined myelinated A‐ and Ah‐type baroreceptive neurons (the 2nd‐order) of NTS using brainstem slice of adult female rats. The greater frequency and the larger amplitude of the spontaneous excitatory postsynaptic currents (EPSCs) compared with the inhibitory postsynaptic currents (IPSCs) were only observed in Ah‐types. The ratio of EPSCs:IPSCs was estimated at 3:1 and higher. These results confirmed that the afferent‐specific spontaneous activities were generated from baroreflex afferent pathway in female‐specific subpopulation of myelinated Ah‐type BRNs in nodose and baroreceptive neurons in NTS, which provided a novel insight into the dominant role of sex‐specific baroreflex‐evoked parasympathetic drives in retaining a stable and lower blood pressure status in healthy subjects, particularly in females. Conclusion The data from current investigations establish a new concept for the role of Ah‐type baroreceptor/baroreceptive neurons in controlling blood pressure stability and provide a new pathway for pharmacological intervention for hypertension and cardiovascular diseases.