Effect of chemogenetic manipulation of PVN corticotropin-releasing factor-expressing neurons on excitability of presympathetic neurons in SHR / 中国药理学通报

Aim To observe the effect of corticotropin-releasing factor ( CRF) -expressing neurons on presympathetic neurons in hypothalamic paraventricular nucleus ( PVN) of normotensive Wistar Kyoto ( WKY) rats or spontaneously hypertensive rats (SHR) , and to elucidate the underlying neuronal circuit mechanism of central sympathetic hyperexcitability. Methods The expression levels of CRF protein in WKY rats and SHR PVN were determined by Western blot. Meanwhile, the WKY and SHR PVN CRF-expressing neurons and presympathetic neurons were observed by immunofluo-rescent staining. Adult WKY rats and SHR were used in this study. By microinjection of Cre-dependent ade-no-associated viruses ( AAV) that specifically recognized the CRF promoter and AAV of chemogenetics into the PVN, CRF-expressing neurons expressed designer receptors exclusively activated by designer drugs (DREADDs). Human M3 muscarinic DREADD coupled to Gq receptor ( hM3 Dq) was specifically expressed in PVN CRF-expressing neurons in WKY rats, while human M4 muscarinic DREADD coupled to Gi receptor ( hM4Di) was specifically expressed in PVN CRF-expressing neurons in SHR. Clozapine-N-oxide (CNO) , as a designer ligand, would couple to excitatory hM3Dq or inhibitory hM4Di to regulate the excitability of PVN CRF-expressing neurons. Then the PVN presympathetic neurons were retrogradely labeled by microinjection of fluosecent tracer into the intermedio-lateral column (IML) of spinal cord. Lastly, whole cell patch clamp was used to determine the effect of CNO (10 jjumol L~ ) on spontaneous excitatory postsynaptic currents ( sEPSCs) and current-evoked firing of PVN presympathtic neurons of WKY rats and SHR. Results The expression of CRF protein in the PVN of SHR was significantly higher than that of WKY rats, and the activity and number of CRF-expressing neurons in the PVN of SHR were increased. PVN CRF-expressing neurons were expressed with chemogenetic DREADDs and PVN presympathetic neurons were retrogradely labeled with fluorescent tracer in WKY rats and SHR. In SHR expressed with chemogenetic inhibitory hM4Di-mCherry of PVN CRF-expressing neurons, bath application of CNO to the brain slices resulted in a significant decrease in sEPSCs frequency, but no change in their amplitude of labeled PVN presympathetic neurons. In contrast, in WKY rats expressed with excitatory hM3Dq-eGFP of PVN CRF-expressing neurons, CNO had no obvious effect on the sEPSCs frequency and amplitude in PVN presympathetic neurons. Furthermore, bath application of CNO had no significant effect on current-evoked firing of PVN presympathetic neurons of either WKY rats with hM3Dq-eGFP expression in CRF neurons or SHR with hM4Di-mCherry expression in CRF neurons. Conclusions The activity and number of PVN CRF-expressing neurons are increased in SHR, and CRF-expressing neurons enhance the excitability of presympathetic neurons, which acts as a regulatory neuronal microcircuit between CRF neurons and presympathetic neurons in the PVN.

Endogenous corticotropin-releasing factor potentiates the excitability of presympathetic neurons in paraventricular nucleus via activation of its receptor 1 in spontaneously hypertensive rats / 生理学报

It is well established that increased excitability of the presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) during hypertension leads to heightened sympathetic outflow and hypertension. However, the mechanism underlying the overactivation of PVN presympathetic neurons remains unclear. This study aimed to investigate the role of endogenous corticotropin-releasing factor (CRF) on the excitability of presympathetic neurons in PVN using Western blot, arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) recording, CRISPR/Cas9 technique and patch-clamp technique. The results showed that CRF protein expression in PVN was significantly upregulated in spontaneously hypertensive rats (SHRs) compared with normotensive Wistar-Kyoto (WKY) rats. Besides, PVN administration of exogenous CRF significantly increased RSNA, heart rate and ABP in WKY rats. In contrast, knockdown of upregulated CRF in PVN of SHRs inhibited CRF expression, led to membrane potential hyperpolarization, and decreased the frequency of current-evoked firings of PVN presympathetic neurons, which were reversed by incubation of exogenous CRF. Perfusion of rat brain slices with artificial cerebrospinal fluid containing CRF receptor 1 (CRFR1) blocker, NBI-35965, or CRF receptor 2 (CRFR2) blocker, Antisauvagine-30, showed that blocking CRFR1, but not CRFR2, hyperpolarized the membrane potential and inhibited the current-evoked firing of PVN presympathetic neurons in SHRs. However, blocking CRFR1 or CRFR2 did not affect the membrane potential and current-evoked firing of presympathetic neurons in WKY rats. Overall, these findings indicate that increased endogenous CRF release from PVN CRF neurons enhances the excitability of presympathetic neurons via activation of CRFR1 in SHRs.

A bibliometric analysis on cohort study of liver cancer in China / 中华流行病学杂志

To retrospectively analyze the application trend of cohort study in the field of liver cancer in past 27 years and to look forward to the future development trend. Chinese and English papers reporting the cohort studies of liver cancer conducted in the mainland of China since 1991 were included. The literature management software was used to analyze the publication time, institution, type and objective of the studies and the follow-up performance. Statistical analysis was carried out by using SPSS 21.0. The number and quality of the papers reporting liver cancer-related cohort studies increased significantly in past 27 years and a core English journal group of this field has formed. The average annual growth rates of Chinese and English papers published were 20.4 and 35.2 respectively. About 52.3 of the Chinese papers and 73.5 of the English papers were published in past five years and the quality of these papers was high. The Chinese papers published on Chinese core journals accounted for 49.2, and the English papers published on SCI periodicals (IF>3) accounted for 47.3. For the study objective, those published on the domestic journals mainly focused on the pathogenesis of hepatoma (41.5), studies with large sample size was the common form. The SCI studies mainly focused on the prognosis of liver cancer (40.7). High-quality SCI papers are more interested in the studies of prognosis, and survival analysis was the common form. The application of cohort study in the field of liver cancer gradually increased in China. Large-scale study and prognosis analysis were conducted commonly. However, it is necessary to further improve the researchers' understanding of cohort study, improve the follow-up quality, and increase the application of scientific evaluation methods, such as survival analysis, for the better solving of clinical problems.

Amino acid compounds released by the giant freshwater prawn Macrobrachium rosenbergii during ecdysis: a factor attracting cannibalistic behaviour? / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Ecdysis is a common phenomenon that happens throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii. It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process. The objective of the present study was to determine the amino acid profile released by M. rosenbergii during the ecdysis process that promotes cannibalism. To accomplish this, changes in amino acid levels (total amino acid (TAA) and free amino acid (FAA)) of tissue muscle, exoskeleton, and sample water of culture medium from the moulting (E-stage) and non-moulting (C-stage) prawns were analysed using high-performance liquid chromatography (HPLC). Comparison study revealed that among the TAA compounds, proline and sarcosine of tissues from moulting prawn were found at the highest levels. The level of FAA from water that contains moulting prawns (E-stage) was dominated by tryptophan and proline. Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M. rosenbergii during ecdysis. The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism, and also for future dietary manipulation to improve feeding efficiencies and feeding management, which indirectly impacts productivity and profitability.

Investigation and risk factor analysis of hyperuricemia in pilots / 解放军医学杂志

Objective To investigate the incidence of hyperuricemia in military pilots and the relationship between hyperuricemia and other related risk factors of cardiovascular diseases. Methods A total of 2563 pilots, who had undergone a regular physical examination in the Air Force General Hospital from 2005 to 2010, participated in the current study. The participants were divided into high serum uric acid (UA) group (hyperuricemia group, UA >420μmol/L, n=294) and normal UA group (n=2269). The incidence rates of hypertension, hyperglycemia, and hyperlipemia were compared between these two groups. The dependent variable was serum UA level of the pilots. Other indices included the total cholesterol (CHO), triglycerides (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), fasting blood glucose (FBG), systolic blood pressure (SBP), diastolic blood pressure (DBP), smoking, body weight, and flight time as independent variable. Logistic multivariate regression analysis was conducted to determine the relationship between UA level and these indexes. Results The incidence rates of hypertension, hypercholesterolemia, hypertriglyceridemia, low HDL, and high LDL were significantly higher in hyperuricemia group than in normal UA group (P<0.01). The Multiple logistc-regression analysis suggested that high UA level was closely related to TG (OR=1.637, P<0.01), DBP (OR=1.025, P<0.01) and body weight (OR=1.046, P<0.01). Conclusion The serum UA of pilots is closely related to the risk factors of other cardiovascular diseases.

Protective effect of total glucosides of Picrorhiza scrophulariiflora against oxidative stress in glomerular mesangial cells induced by high glucose / 药学学报

Total glucosides of Picrorhiza scrophulariiflora (TGP) is the active principal in Picrorhiza scrophulariiflora which has antioxidant effect. Since oxidative stress plays a key role in diabetic nephropathy, we investigated the effects of TGP on oxidative stress in bovine glomerular mesangial cells (MC) induced by prolonged high glucose. Bovine glomerular mesangial cells were cultured and passages 2-3 were used for the experiment. Mesangial cells were cultured in high glucose medium, and treated with TGP for 3 weeks. Then collagen IV excreted by mesangial cells were detected, and the percentages of cell cycle were observed by flow cytometry technique. The levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and [Ca2+]i were measured by flow cytometry after loaded with fluorescent probe DCFH-DA, Rh123 and fluo-3-acetoxymethylest. TGP significantly decreased the excretion of collagen IV and cell hypertrophy induced by high glucose, reduced the levels of ROS and [Ca2+]i, and increased MMP. Therefore we conclude that TGP could protect mesangial cells against oxidative stress induced by high glucose.