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Toll‐like receptors (TLRs) are essential immunoreceptors involved in host defence against invading microbes. Recent studies indicate that certain TLRs activate immunological autophagy to eliminate microbes. It remains unknown whether TLRs regulate autophagy to play a role in the heart. This study examined this question. The activation of TLR3 in cultured cardiomyocytes was observed to increase protein levels of autophagic components, including LC3‐II, a specific marker for autophagy induction, and p62/SQSTM1, an autophagy receptor normally degraded in the final step of autophagy. The results of transfection with a tandem mRFP‐GFP‐LC3 adenovirus and use of an autophagic flux inhibitor chloroquine both suggested that TLR3 in cardiomyocytes promotes autophagy induction without affecting autophagic flux. Gene‐knockdown experiments showed that the TRIF‐dependent pathway mediated the autophagic effect of TLR3. In the mouse model of chronic myocardial infarction, persistent autophagy was observed, concomitant with up‐regulated TLR3 expression and increased TLR3‐Trif signalling. Germline knockout (KO) of TLR3 inhibited autophagy, reduced infarct size, attenuated heart failure and improved survival. These protective effects were abolished by in vivo administration of an autophagy inducer rapamycin. Similar to the results obtained in cultured cardiomyocytes, TLR3‐KO did not prevent autophagic flux in mouse heart. Additionally, this study failed to detect the involvement of inflammation in TLR3‐KO‐derived protection, as wild‐type and TLR3‐KO hearts were comparable in inflammatory activity. It is concluded that up‐regulated TLR3 expression and signalling contributes to persistent autophagy following MI, which promotes heart failure and lethality.

In this paper, we discuss the normality and shared values of meromorphic functions with differential polynomial. We obtain the main result: Let \(\mathcal {F}\) be a family of meromorphic functions in a domain D and k, q be two positive integers. Let \(P(z,w)=w^{q}+a_{q-1}(z)w^{q-1}+\cdots +a_{1}(z)w \) and \(H(f,f',\ldots ,f^{(k)})\) be a differential polynomial with \(\frac{\varGamma }{\gamma }|_H

Objective Centrally acting antihypertensive action of moxonidine is a result of activation of Imidazoline-1 receptor (I1R) in the rostral ventrolateral medulla (RVLM). Hypertension shows an increase in reactive oxygen species (ROS) in the RVLM. The present objective was to determine the phosphoinositide-3 kinase (PI3K) signaling pathway involved in the effect of moxonidine on ROS generation in the RVLM of spontaneously hypertensive rat (SHR). Methods Wistar-Kyoto rats and SHR received intracisternal infusion (2 weeks) of tested agents which were subjected to subsequent experiments. In-situ ROS in the RVLM was evaluated by the oxidative fluorescence dye. Western blot and PCR analysis were performed to detect the expression levels of PI3K signaling pathway. Lentivirus was injected bilaterally into the RVLM for silencing PI3K signaling. Results ROS production in the RVLM was dose-dependently reduced in SHRs treated with infusion of moxonidine (20 nmol/day), which was prevented by the I1R antagonist efaroxan but not by the α2-adrenoceptor antagonist yohimbine. Moxonidine pretreatment significantly blunted cardiovascular sensitivity to injection of tempol (5 nmol) or angiotensin II (10 pmol) into the RVLM in SHR. Expression levels of PI3K/Akt, nuclear factor kappa-B (NFκB), NADPHase (NOX4), and angiotensin type I receptor (AT1R) in the RVLM were markedly decreased in SHR treated with moxonidine. Infection of lentivirus containing PI3K shRNA in the RVLM effectively prevented effects of moxonidine on cardiovascular activity and expression levels of Akt, NFκB, NOX4, and AT1R. Conclusion The centrally antihypertensive drug moxonidine decreases ROS production in the RVLM through inactivation of the PI3K/Akt signaling pathway in hypertension.

Myocardial ischaemia (MI) remains a major cause of death and disability worldwide. Accumulating evidence suggests a significant role for innate immunity, in which the family of toll‐like receptors (TLRs) acts as an essential player. We previously reported and reviewed the changes of Tlr expression in models of MI. However, the underlying mechanisms regulating Tlr expression in MI remain unclear. The present study first screened transcription factors (TFs) that potentially regulate Tlr gene transcription based on in silico analyses followed by experimental verification, using both in vivo and in vitro models. Forkhead box C1 (FOXC1) was identified as a putative TF, which was highly responsive to MI. Next, by focusing on two representative TLR subtypes, an intracellular subtype TLR3 and a cell‐surface subtype TLR4, the regulation of FOXC1 on Tlr expression was investigated. The overexpression or knockdown of FoxC1 was observed to up‐ or down‐regulate Tlr3/4 mRNA and protein levels, respectively. A dual‐luciferase assay showed that FOXC1 trans‐activated Tlr3/4 promoter, and a ChIP assay showed direct binding of FOXC1 to Tlr3/4 promoter. Last, a functional study of FOXC1 was performed, which revealed the pro‐inflammatory effects of FOXC1 and its destructive effects on infarct size and heart function in a mouse model of MI. The present study for the first time identified FOXC1 as a novel regulator of Tlr expression and described its function in MI.

Shenfu Injection (SFI) is a classical Chinese medicine used to treat heart failure. Our previous study demonstrated that miRNAs underwent changes in rats with myocardial hypertrophy induced by abdominal aortic constriction. Interestingly, there was a significant change in miR-19a-3p, whose target gene is known to be associated with MEF2 signaling. However, whether and how SFI regulates miR-19a-3p in the treatment of myocardial hypertrophy has not been investigated. The purpose of the present study was to investigate the regulatory effect of SFI on miR-19a-3p in MEF2 signaling in the rat hypertrophic myocardium. We found that the miR-19a-3p expression level was significantly decreased in the hypertrophic myocardium, and MEF2A was the target gene of miR-19a-3p. The protein expressions of MEF2A, β-MHC, BNP and TRPC1 were significantly increased in hypertrophic cardiomyocytes. MiR-19a-3p was up-regulated after SFI treatment, and the protein expressions of these genes were significantly decreased. In addition, miR-19a-3p over-expression in hypertrophic cardiomyocytes could decrease MEF2A mRNA and protein expressions, and anti-miR-19a-3p showed the opposite result. Our study provided substantial evidence that miR-19a-3p played a functional role in MEF2 signaling in myocardial hypertrophy. SFI attenuated cardiomyocyte hypertrophy probably through up-regulating or maintaining the miR-19a-3p levels and regulating the MEF2 signaling pathway.

It remains unclear whether and how cardiomyocytes contribute to the inflammation in chronic heart failure (CHF). We recently reviewed the capacity of cardiomyocytes to initiate inflammation, by means of expressing certain immune receptors such as toll‐like receptors (TLRs) that respond to pathogen‐ and damage‐associated molecular patterns (PAMP and DAMP). Previous studies observed TLR4‐mediated inflammation within days of myocardial infarction (MI). This study examined TLR4 expression and function in cardiomyocytes of failing hearts after 4 weeks of MI in rats. The increases of TLR4 mRNA and proteins, as well as inflammatory cytokine production, were observed in both the infarct and remote myocardium. Enhanced immunostaining for TLR4 was observed in cardiomyocytes but not infiltrating leucocytes. The injection of lentivirus shRNA against TLR4 into the infarcted heart decreased inflammatory cytokine production and improved heart function in vivo. Accordingly, in cardiomyocytes isolated from CHF hearts, increases of TLR4 mRNA and proteins were detected. More robust binding of TLR4 with lipopolysaccharide (LPS), a PAMP ligand for TLR4, and heat shock protein 60 (HSP60), a DAMP ligand for TLR4, was observed in CHF cardiomyocytes under a confocal microscope. The maximum binding capacity (Bmax) of TLR4 was increased for LPS and HSP60, whereas the binding affinity (Kd) was not significantly changed. Furthermore, both LPS and HSP60 induced more robust production of inflammatory cytokines in CHF cardiomyocytes, which was reduced by TLR4‐blocking antibodies. We conclude that the expression, ligand‐binding capacity and pro‐inflammatory function of cardiomyocyte TLR4 are up‐regulated after long‐term MI, which promote inflammation and exacerbate heart failure.

Three new isoprenylated 2-arylbenzofurans, namely artostyracins A–C (1–3, resp.), together with a known one (4), were isolated from the root of Artocarpus styracifolius Pierre. Their structures were determined by spectroscopic methods (1D and 2D NMR, UV, IR, and HR-ESI-MS). All of the compounds were evaluated for the anti-respiratory burst properties using a cellular model reproduced by chemical stimulation of rat neutrophils. Compounds 1 and 3 offered the potently inhibitory effects on respiratory burst of rat neutrophils with IC50 values of 1.42 and 1.91 μM, while compounds 2 and 4 revealed moderate suppression activity with IC50 values of 11.56 and 46.91 μM.

The rostral ventrolateral medulla (RVLM) plays a key role in cardiovascular regulation. It has been reported that tonically active glutamatergic input to the RVLM is increased in hypertensive rats, whereas angiotensin-converting enzyme 2 (ACE2) in the brain has been suggested to be beneficial to hypertension. This study was designed to determine the effect of ACE2 gene transfer into the RVLM on tonically active glutamatergic input in spontaneously hypertensive rats (SHRs). Lentiviral particles containing enhanced green fluorescent protein (lenti-GFP) or ACE2 (lenti-ACE2) were injected bilaterally into the RVLM. Both protein expression and activity of ACE2 in the RVLM were increased in SHRs after overexpression of ACE2. A significant reduction in blood pressure and heart rate in SHRs was observed 6 wk after lenti-ACE2 injected into the RVLM. The concentration of glutamate in microdialysis fluid from the RVLM was significantly reduced by an average of 61% in SHRs with lenti-ACE2 compared with lenti-GFP. ACE2 overexpression significantly attenuated the decrease in blood pressure and renal sympathetic nerve activity evoked by bilateral injection of the glutamate receptor antagonist kynurenic acid (2.7 nmol in 100 nl) into the RVLM in SHRs. Therefore, we suggest that ACE2 overexpression in the RVLM attenuates the enhanced tonically active glutamatergic input in SHRs, which may be an important mechanism underlying the beneficial effect of central ACE2 to hypertension.

In the present paper, we consider the floating problem of river-crossing shield tunnel in the process of construction. Firstly, based on the theoretical analysis of equilibrium states of excavation face and shield segments away from shield tail, we obtain the equation for calculating the minimum thickness of overlying soil in the associated equilibrium states. Secondly, the above derived formula are applied in the Fuhe bridge project, which is a sub-project of No.1 Nanchang metro; at the same time, numerical simulation is carried out to further evaluate the safety with the change of overlying soil thickness. Lastly, some useful conclusions are drawn through comparative study, which is helpful to similar projects.

Aims The molecular events leading from cardiomyocyte ischaemia to inflammatory cytokine production are not well understood. We previously found that heat shock protein 60 (HSP60) appeared in extracellular space after cardiomyocyte ischaemia. This study examined the activation and regulation of toll-like receptors (TLRs) by HSP60 in cardiomyocytes. Methods and results Cytokine production and TLRs regulation mediated by TLRs signalling were examined in response to exogenous HSP60 (exHSP60) and endogenous HSP60 (enHSP60) released extracellularly under ischaemia. The results showed that exHSP60 induced inflammatory cytokine production in adult rat cardiomyocytes and H9c2 cells (a standard cardiac cell line derived from embryonic cells), through a pathway dependent on TLR4, myeloid differentiation factor 88 (MyD88), p38, and nuclear factor-κB (NF-κB). Further study revealed up-regulated expression of both TLR2 and TLR4 by exHSP60, which was dependent on the activation of TLR4, MyD88, c-Jun NH2-terminal kinase (JNK), and NF-κB, but not on p38. In myocytes exposed to ischaemia, enHSP60 was released into the media, and triggered cytokine production and TLR2/4 overexpression, through the same pathways as exHSP60. In rats subjected to LAD ligation, the released enHSP60 contributed to cytokine production and TLR2/4 overexpression in the ischaemic myocardium. Conclusion Extracellular HSP60 induces cytokine production via TLR4-MyD88-p38/NF-κB pathway, and up-regulates TLR2/4 expression via TLR4-MyD88-JNK/NF-κB pathway. Both pathways contribute to myocardial inflammation induced by ischaemia.

In this article, we prove the following normality criterion: let n ≥ 2, m, k be three positive integers, and a be a non-zero complex number. Let ℱ be a family of meromorphic functions in a domain D such that each f ∈ ℱ has only zeros of multiplicity at least max{k, 2}. If for each pair of f and g in ℱ, f m (f (k)) n and g m (g (k)) n share the value a IM, then ℱ is normal in D. This extends Hu and Meng's result.

Four new flavonoids, artoheteroids A-D (1–4), together with six known ones (5–10), were isolated from the roots of Artocarpus heterophyllus. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR, UV, IR, CD, and HR-ESI-MS. All isolated compounds were screened for their inhibitory abilities against cathepsin K (CatK). Among them, compounds 1–2, 4–6, and 10 were found to have suppression capabilities against CatK with IC50 values ranging from 1.4 to 93.9 μM.

Background Increasing evidence suggests that miR-126 participates in the glucose homeostasis through its target molecules. Although bioinformatics analysis predicts that miR-126 can bind with the insulin receptor substrate-2(IRS-2) mRNA at the “seed sequence”, but there are still no definitely reports to support it. In this study, we provided evidences that IRS-2 was one of the target genes of miR-126. And miR-126 has a proliferation inhibiting effects in INS-1 β cells, mainly through the suppression of IRS-2. Methods The 3’-UTR of IRS-2 regulated by miR-126 was analyzed by the luciferase assay and western blot. Furthermore, proliferation of INS-1 β cells stimulated by glucose was tested, and the association between IRS-2 and miR-126 were analyzed. Results We found that mutation of only three of the 6 “seed sequences” can eliminate the inhibition effect of miR-126. In INS-1 β cells, administration of miR-126 suppresses the proliferation, together with the unbalanced down-regulation of IRS-2 and IRS-1. Over-expression of IRS-2 can reverse the proliferation effect of miR-126, while not of IRS-1. These results suggested that miR-126 inhibited the β-cell proliferation via the inhibition of IRS-2 instead of IRS-1.Additionally, we also found that high glucose and insulin could stimulate the rapid production of endogenous miR-126 within 6 hours, together with the short term suppression of IRS-1 and IRS-2 expression, and intensify the unbalanced expression of IRS-1 and IRS-2. Conclusions IRS-2 was one of the targets of miR-126. MiR-126 inhibited the β-cell proliferation through IRS-2 instead of IRS-1. MiR-126 may take part in the glucose homeostasis both through its target IRS-2 and IRS-1. The unbalance between IRS-1 and IRS-2 caused by miR-126 may play an important role in type 2 diabetes.

To study the chemical constituents from root of Artocarpus styracifolius.Tne constituents were isolated from the root of Artocarpus styracifolius by column chromatography over silica gel, RP-18 silica gel, MCI GEL CHP-20P, macroporous resin HP-20, Sephadex LH-20, Toyopearl HW-40C and by preparative HPLC. Their structures were elucidated by analysis of physical and chemical properties and spectral data.Nine compounds were isolated and their structures were identified as p-hydroxy benzoic acid (1), syringic acid (2), 2,4-dihydroxy benzaldehyde (3), (+)-lyoniresinol (4), 5,5'-dimethoxysecoisolariciresinol (5), (+)- syringaresinol (6), scopoletin (7), xylarolide (8) and trans-oxyresveratrol (9).Compounds 2, 5, 6 and 8 are isolated from Moraceae for the first time. Compounds 1, 4 and 7 are firstly characterized in the genus Artocarpus, compounds 3 and 9 are characterized in Artocarpus styracifolius for the first time.

MicroRNAs (miRNAs) are a novel class of powerful, endogenous regulators of gene expression. In an intact rat model of myocardial ischemia caused by coronary artery ligation, this study identified 17 miRNAs that changed more than 1.5-fold in the myocardium subjected to 4-h ischemia. Using miRNA microarray analysis, most of these aberrantly expressed miRNAs were confirmed by quantitative RT-PCR. MiR-378, a significantly down-regulated miRNA, was selected for further function study. In serum deprived rat H9c2 cardiomyocytes exposed to hypoxia (1% O(2)), miR-378 expression was down-regulated as well. The overexpression of miR-378 resulting from miR-378 mimic transfection significantly enhanced cell viability, reduced lactate dehydrogenase release, and inhibited apoptosis and necrosis. By contrast, miR-378 deficiency resulting from miR-378 inhibitor transfection aggravated the hypoxia-induced apoptosis and cell injury. In accordance, miR-378 inhibitor caused significant apoptosis and cell injury to cardiomyocytes cultured under normoxia. Using bioinformatic algorithms, caspase-3, a key apoptosis executioner, was predicted as a putative target of miR-378. The quantitative RT-PCR showed no effects of miR-378 mimic or inhibitor on caspase-3 mRNA level. However, the amount of caspase-3 proteins was reduced by miR-378 mimic, whereas increased by miR-378 inhibitor. Furthermore, the luciferase reporter assay confirmed caspase-3 to be a target of miR-378, and the apoptosis and cell injury caused by miR-378 inhibitor in both normoxic and hypoxic cells were abolished by a caspase-3 inhibitor. This study first showed that miR-378 inhibited caspase-3 expression and attenuated ischemic injury in cardiomyocytes. It may represent a potential novel treatment for apoptosis and ischemic heart disease.

Hydrogen sulfide (H(2)S), an endogenous "gasotransmitter", exists in the central nervous system. However, the central cardiovascular effects of endogenous H(2)S are not fully determined. The present study was designed to investigate the central cardiovascular effects and its possible mechanism in anesthetized rats. Intracerebroventricular (icv) injection of NaHS (0.17~17 microg) produced a significant and dose-dependent decrease in blood pressure (BP) and heart rate (HR) (P0.05) compared to control. The higher dose of NaHS (17 microg, n = 6) decreased BP and HR quickly of rats and 2 of them died of respiratory paralyse. Icv injection of the cystathionine beta-synthetase (CBS) activator s-adenosyl-L-methionine (SAM, 26 microg) also produced a significant hypotension and bradycardia, which were similar to the results of icv injection of NaHS. Furthermore, the hypotension and bradycardia induced by icv NaHS were effectively attenuated by pretreatment with the K(ATP) channel blocker glibenclamide but not with the CBS inhibitor hydroxylamine. The present study suggests that icv injection of NaHS produces hypotension and bradycardia, which is dependent on the K(ATP) channel activation.

Non-technical summary Elevated blood glucose is generally regarded as one of the risk factors that lead to coronary heart disease in patients with type 2 diabetes. However, our studies show that after inducing short-term damage, high blood glucose subsequently provides paradoxical protection for vessel function of animals with high blood pressure. Vessels can adapt to sustained high blood glucose and produce different stress proteins to counteract, to some extent, the damage brought about by hypertension. The results help us understand part of the basis for vessel adaptation in diabetes. The implication for treatment of diabetes is that if the patients have long-standing diabetes and established cardiovascular disease, the target of blood glucose lowering should be less stringent and reached gradually to avoid abrupt cancellation of the pre-existing adaptations., Although both diabetes and hypertension are risk factors for cardiovascular disease, the role of hyperglycaemia per se in endothelial dysfunction is controversial. This study was designed to examine whether hyperglycaemia, or streptozotocin-induced diabetes, could aggravate endothelial dysfunction in stroke-prone spontaneously hypertensive rats (SHRSP). Hyperglycaemia was induced by streptozotocin in 2-month-old SHRSP and age-matched normotensive Wistar–Kyoto (WKY) rats. The aorta was isolated 8 weeks after induction of hyperglycaemia to record its function and to examine its morphology with transmission electron microscopy. Endothelial/inducible nitric oxide synthase (eNOS/iNOS) and inducible/constitutive haem oxygenase (HO-1/HO-2) levels were determined with Western blotting. Aortic endothelial function and production of reactive oxygen species and nitric oxide were assayed after incubation in vitro in hyperglycaemic, hyperosmolar solution. Streptozotocin-induced diabetes of 8 weeks duration did not result in endothelial dysfunction in normotensive WKY rats. In contrast, hyperglycaemic WKY rats showed significantly enhanced endothelium-dependent vasodilatation, which was abrogated by simultaneous blocking of NOS and HO. The enhanced vasodilatation was associated with elevation of vascular eNOS and HO-1. Significant endothelial dysfunction and massive macrophage–monocyte infiltration were found in SHRSP aorta (the ratio of the number of macrophages to endothelial cells in the intima, expressed as a percentage, was 20.9 ± 2.8% in SHRSP versus 1.9 ± 0.5% in WKY rats, P < 0.01), which was attenuated significantly in hyperglycaemic SHRSP (11.3 ± 1.6%, P < 0.01 versus SHRSP). Acute hyperglycaemia (10 min) aggravated endothelial dysfunction in SHRSP, with a marked increase in intracellular reactive oxygen species and NO production. Sustained in vitro incubation in hyperglycaemic/hyperosmolar conditions (addition of an extra 50 mmol L−1 of glucose or mannitol to the usual buffer, to produce a final osmolarity of 350 mosmol L−1) for 5 h enhanced endothelium-dependent vasodilatation, with elevated vessel NO production and upregulation of eNOS/HO-1 proteins. Sustained hyperglycaemia does not aggravate endothelial dysfunction and macrophage infiltration in SHRSP. Hyperglycaemia/hyperosmolarity-induced upregulation of eNOS and HO-1 may play a role in this paradoxical adaptation of endothelial function.

Therapeutic application of Asarum, a herbal medicine that has been used for centuries, reportedly causes acute respiratory disturbance. The responsible constituents, the sites of action, and the mechanisms involved in this side effect are unclear. We investigated the effects of β-asarone, a volatile constituent of Asarum, on neurotransmission in the medullary respiratory neuronal network using extracellular recording of the rhythmic hypoglossal activity and voltage clamp recordings of the postsynaptic activity of the airway preganglionic parasympathetic motoneurons (APPMs) in vitro. β-Asarone caused progressive decreases in the duration and area of the hypoglossal bursts in a concentration-dependent manner. The frequency and amplitude of the bursts were initially unaltered or temporarily increased, but were then inhibited progressively after prolonged exposure. As with the inhibition of the hypoglossal bursts, the tonic and the phasic excitatory and inhibitory postsynaptic currents in the APPMs were attenuated. These data suggest that the Asarum-caused acute respiratory disturbance involves β-asarone-induced inhibition of neurotransmission in the medullary respiratory neuronal network.

The biosecurity of transgenic organism has been widely concerned and extremely restricted its application. Recently, many technological strategies have been developed to ensure its biosecurity. Thus, transgene containment technologies have become one of the hotspots in current transgenic research. In this paper, several transgene containment technologies, such as marker-free transgenic technology, safety marker transgenic technology, chloroplast transgenic technologies, terminator technology, male sterility technology, and 'GM-gene-deletor'technology were reviewed and evaluated. 'GM-gene-deletor' technology, as one of these technologies, demonstrated a prosperous future for safe application of transgenic organisms. Finally, the strategies for developing new transgene containment technologies have been suggested.

Inflammation is observed at all stages of atherosclerosis. The initial stage of atherosclerosis is characterized by recruitment of leukocytes to activated endothelial cells (ECs). MicroRNAs (miRNAs) are a class of 19-25 nucleotides, non-protein-coding RNAs that repress target gene expression by translational inhibition or mRNA degradation. The link between miRNA and endothelial functions is largely unknown. Northern blot showed that miR-155 and miR-221 were highly expressed in human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs). Bioinformatics analysis proposed Ets-1, a key endothelial transcription factor for inflammation and tube formation, as a candidate target for miR-155 and miR-221/222 cluster. The effect was demonstrated by luciferase reporter assay and Western blot. By using Western blot, we also confirmed that angiotensin II type 1 receptor (AT1R) is a target of miR-155 in HUVECs. Quantitative PCR showed that Ets-1 and its downstream genes, including VCAM1, MCP1 and FLT1, were upregulated in angiotensin II-stimulated HUVECs, and this effect was partially reversed by overexpression of miR-155 and miR-221/222. In addition, cell adhesion assay revealed overexpression of miR-155 and miR-221/222 effectively decreased the adhesion of Jurkat T cells to Ang II-stimulated HUVECs. Besides, by targeting AT1R, miR-155 can also decrease the HUVECs migration in response to Ang II. In summary, HUVECs highly expressed miR-155 may co-target AT1R and Ets-1 while miR-221/222 targets Ets-1, which indirectly regulate the expression of several inflammatory molecules of ECs, and therefore attenuate the adhesion of Jurkat T cells to activated HUVECs and reduce HUVECs migration. These findings present possible therapeutic targets in atherosclerosis.

Aims The depressor action of the centrally antihypertensive drug moxonidine has been attributed to activation of I1-imidazoline receptor in the rostral ventrolateral medulla (RVLM). The objective of this study was to determine the role of the γ-aminobutyric acid (GABA) mechanisms in the RVLM in mediating the effect of moxonidine in anaesthetized normotensive rats. Methods and results The relationship between the effects of microinjection or picoinjection of moxonidine and the functional state of GABA receptors at the level of the RVLM or pre-sympathetic neuron was determined. Microdialysis was performed to detect the effect of moxonidine on the release of GABA in the RVLM. Western blot analysis was carried out to test the effect of chronic intracerebroventricular injection of moxonidine on the protein expression of GABA receptors in the RVLM. Pre-treatment with the GABAA or GABAB receptor antagonist bicuculline (5 pmol) or CGP35348 (200 pmol), respectively, microinjected into the RVLM significantly attenuated the decrease in blood pressure and renal sympathetic nerve activity induced by moxonidine. In 22 moxonidine-sensitive pre-sympathetic neurons in the RVLM, picoinjection of bicuculline (100 fmol/5 nL) significantly attenuated the neuronal inhibition evoked by moxonidine (100 pmol/5 nL). The release of GABA in the RVLM was increased after intravenous moxonidine (50 μg/kg). Central infusion of moxonidine upregulated the protein expression of both GABAA and GABAB receptors in the RVLM. Conclusion The current data demonstrate that GABAergic mechanisms in the RVLM are responsible for the hypotension and sympathoinhibition of moxonidine.

1. Leptin, an important adipose-derived hormone, can be associated with cardiac pathophysiology; however, the role of leptin in cardiomyocyte apoptosis is poorly understood. The present study examines serum-deprivation-induced apoptosis in primary cultured cardiomyocytes treated with leptin. 2. Cardiomyocytes were subjected to serum deprivation in the presence or absence of leptin (5 or 50 nmol/L) for 48 h. Apoptosis was determined by Hoechst 33258 and Annexin V-FITC/propidium iodide dual staining. Cell viability, malondialdehyde (MDA) content, caspase 3 activation, and the expression and enzyme activity of superoxide dismutase (SOD) were measured. Small interference RNA (siRNA) targeting SOD1 and SOD2 were used to knockdown their expression and measure apoptosis. 3. Serum deprivation caused nearly 30% of apoptosis in cardiomyocytes, and an approximately 60% decrease in cell viability. The mRNA levels and the activated form of caspase 3 were greatly increased. In the presence of leptin, the apoptotic rate was reduced to approximately 15%, cell viability was increased and the activation of caspase 3 was partially inhibited. Additionally, the augmented lipid peroxidation (MDA formation) was abolished, and the impaired activities of SOD1 and SOD2 were restored by leptin. The mRNA expression of SOD2, but not SOD1, was stimulated by leptin. Transfection with siRNA that cause deficiency of either SOD1 or SOD2 attenuated the anti-apoptotic effects of leptin. 4. The results suggest that leptin inhibits serum-deprivation-induced apoptosis in cardiomyocytes by activating SOD. The present study outlines the direct actions of leptin in cardiac disorders that are related to elevated leptin levels.

Cardiac hypertrophy, which is characterized by an increase in cell size and reactivation of fetal genes, occurs as an adaptive response to diverse forms of stress and often results in heart failure and sudden death. Growing evidence indicates that microRNAs (miRNAs) are involved in cardiac hypertrophy, but the function of these miRNAs remains elusive. Here, using real time PCR analysis, we showed that several miRNAs were dynamically regulated in the rat hypertrophic hearts and miR-199a was up-regulated by 10-fold in hypertrophic hearts after abdominal aorta constriction for 12 weeks. With tissue profiling analysis, we showed that miR-199a was predominantly expressed in cardiomyocytes, but was also faintly detected in cardiac fibroblasts. To investigate whether miR-199a was involved in cardiac hypertrophy, both over-expression and knockdown of miR-199a were performed in cultured cardiomyocytes. Over-expression of miR-199a in cardiomyocytes increased the cell size as measured by cell surface area, and also reduced the mRNA expression level of alpha-myosin heavy chain. In accordance, knockdown of endogenous miR-199a in cardiomyocytes reduced the cell size. Down-regulation of miR-199a also attenuated the phenylephrine-induced increase of cell size. Furthermore, bioinformatic algorithms were used to predict the potential targets of miR-199a in cardiac hypertrophy, and hypoxia-inducible factor 1 alpha was confirmed by the luciferase reporter assay to be a potential target of miR-199a. Taken together, our results demonstrated that miR-199a, which was predominantly expressed in cardiomyocytes, was essential for the maintenance of cell size of cardiomyocytes and might play a role in the regulation of cardiac hypertrophy.

Plasma ghrelin was elevated in chronic heart failure (CHF) patients with cachexia. Obestatin, a sibling of ghrelin, opposes several actions of ghrelin. We, therefore, investigated plasma obestatin and ghrelin levels in patients with CHF. Total plasma ghrelin and obestatin levels were measured in 65 patients with CHF (22 with cardiac cachexia) and 15 controls. Ghrelin levels were significantly higher in patients with cachexia (1237.8 ± 47.9 pg/ml) than those without cachexia (P = 0.041) and controls (P < 0.01). Obestatin levels correlated positively with ghrelin levels, and obestatin levels were significantly increased in patients with cachexia (282.3 ± 13.0 pg/ml) than patients without cachexia and controls (both P < 0.01). However, the ghrelin to obestatin ratios (4.5 ± 0.2) were significantly lower in CHF patients with cachexia than controls (P < 0.01). Ghrelin and ratio of ghrelin to obestatin were independent predictors of the development of cardiac cachexia. No association was found between ghrelin, obestatin and New York Heart Association functional class, brain natriuretic peptide. There was disturbance of circulating ghrelin and obestatin in the CHF patients especially those with cachexia, which may have a role in the pathogenesis of cardiac cachexia in CHF.

Obestatin is a recently discovered 23-amino acid peptide encoded by the same gene that encodes ghrelin. It has been reported that there is a significant negative correlation between the plasma ghrelin concentration and systemic blood pressure in patients with pregnancy-induced hypertension. We investigated the plasma concentration of obestatin in 18 non-pregnant women, 18 normal pregnant women, and 15 patients with pregnancy-induced hypertension. The plasma concentrations of obestatin in these 3 groups of women were 63.4 ± 9.5 pg/ml, 38.1 ± 6.3 pg/ml, and 46.0 ± 9.3 pg/ml, respectively. In non-pregnant women, there was no correlation between the plasma obestatin concentration and the mean arterial pressure. However, there was a positive correlation between the plasma obestatin concentration and the mean arterial pressure in normal pregnant women and pregnant women with pregnancy-induced hypertension. These results suggest that obestatin may have some potential role in the regulation of blood pressure in normal pregnant women and women with pregnancy-induced hypertension.

Aims The central antihypertensive drug moxonidine lowers blood pressure (BP) through stimulating an imidazoline receptor within the rostral ventrolateral medulla (RVLM). Nitric oxide (NO) generated by the inducible NO synthase (iNOS) in the RVLM has been suggested to be involved in tonic sympathetic inhibition. The aim of this study was to determine the role of NO generated by iNOS in mediating moxonidine-induced cardiovascular inhibition in rats. Methods and results In anaesthetized rats, the cardiovascular response to local or systemic injection of moxonidine was observed after treatment with the selective iNOS inhibitor S -methylisothiourea (SMT) in the brain. Using immunohistochemical staining and western blot techniques, the protein expression of iNOS in the RVLM was measured in the moxonidine-infused rats. Intracerebroventricular (ICV) injection of SMT (1–100 nmol) dose-dependently attenuated the moxonidine (20 nmol, ICV)-induced decrease in BP and heart rate. Prior injection of SMT (20 and 200 pmol) into the RVLM also dose-dependently prevented the decrease in BP and renal sympathetic nerve activity evoked by RVLM microinjection of moxonidine (5 nmol) or intravenous injection of moxonidine (50 µg/kg). We further found that expression of iNOS protein following chronic ICV infusion of moxonidine (20 nmol, 2 weeks) is selectively upregulated in the RVLM but not in the nucleus tractus solitarius. Conclusion The present data suggest that an NO mechanism generated by iNOS in the RVLM plays an important role in mediating the sympathetic inhibition of the centrally acting drug moxonidine.

Hypoxic preconditioning (HPC) has been well demonstrated to have potent protective effects in many cell types; however, the mechanisms responsible for this phenomenon are not fully understood. Recently, glucose-regulated protein 78 (GRP78), an inducible molecular chaperon, was indicated to be associated with ischemic preconditioning. We hypothesized that HPC protects cardiomyocytes against hypoxia by inducing GRP78 in cultured neonatal rat cardiomyocytes. HPC was induced by exposing cardiomyocytes to brief hypoxia (1% O 2 , 30 min) followed by reoxygenation. GRP78 was expressed constitutively in cultured cardiomyocytes and its expression was enhanced at 12 h, peaked at 24 h (207.3 ±23.6% of the baseline), and was sustained for up to 72 h after HPC. Twenty-four hours after HPC, the myocytes were subjected to prolonged hypoxia (1% O 2 , 12 h). The lactic dehydrogenase (LDH) release and malondialdehyde (MDA) content were reduced, while cell viability and superoxide dismutase (SOD) activity were increased in the preconditioned cells compared with the non-HPC cells. The GRP78 protein level was higher in cells exposed to both HPC and hypoxia than in the cells exposed to HPC alone or hypoxia alone. Heat shock protein 70 (HSP70) was induced in parallel by late HPC. Transfection of GRP78 antisense oligonucleotides blocked GRP78 expression but not HSP70, resulting in attenuated cardioprotection afforded by late HPC. Furthermore, inducing GRP78 by gene transfer protected cardiomyocytes from hypoxic injury. These findings demonstrate that the induction of GRP78 partially mediates the late HPC, suggesting that GRP78 is a novel mechanism responsible for the late cytoprotection of HPC.

The depressor mechanism of imidazoline-like drugs is believed to result from activation of I(1)-imidazoline receptors (I(1)R) and/or alpha(2)-adrenoceptors within the central nervous system, which are associated with the glutamatergic system. The rostral ventrolateral medulla (RVLM) has been recognized as a specific target area that mediates the depressor action of imidazoline-like drugs. The objective of this study was to determine the comparative effects of blockade of the central glutamate receptor subtypes N-methyl-d-aspartate (NMDA) or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate on the cardiovascular actions of imidazoline-like drugs (clonidine and moxonidine) in anaesthetized rats. Intracerebroventricular (i.c.v.) injection of the NMDA receptor antagonist MK801 or the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) produced similar reductions in blood pressure (BP) and heart rate (HR) to those induced by I.C.V. injection of clonidine. Intracerebroventricular injection of the glutamate receptor antagonist kynurenic acid not only abolished clonidine-induced hypotension and bradycardia but converted the responses to a pressor action and tachycardia. Unilateral injection of MK801 or CNQX into RVLM significantly attenuated intra-RVLM clonidine-induced decreases in BP and HR. We also found that unilateral injection of a selective I(1)R agonist, moxonidine, significantly decreased BP and HR, which were also attenuated to a similar extent by prior injection of MK801 or CNQX. In conclusion, these data show that blockade of central (RVLM) NMDA and AMPA/kainate receptors produces similar attenuation of the decrease in BP and HR induced by clonidine or moxonidine. It is suggested that both NMDA and AMPA/kainate receptors are involved in the cardiovascular inhibition produced by imidazoline-like drugs, which is probably at least partly dependent on an I(1)R mechanism in the RVLM.

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by an autoimmune-mediated loss of insulin secreting β-cells. Each B lymphocyte clone that escapes immune tolerance produces a specific antibody. No specific treatment against autoantibodies is available for autoimmune diseases. We have developed a strategy to produce an antiserum against autoantibodies for the treatment of T1DM. Non-obese diabetic (NOD) but not Balb/c mouse serum contains autoantibodies. Antisera were produced by immunizing Balb/c mice with affinity-purified IgG from NOD or BALB/c mice along with the immune adjuvant (hereafter, NIgG or BIgG, respectively). A bolus administration of NIgG significantly reduced serum autoantibodies, autoantibody-positive B lymphocytes in the spleens of NOD mice, mortality and morbidity of diabetes, blood glucose and islet immune infiltration, whereas it increased islet mass in NOD mice for at least 26 weeks. NIgG antiserum treatment has no significant effect on CD3(+), CD4(+) or CD8(+) T cells and B220(+) or CD19(+) B cells. BIgG also imparted a moderate therapeutic effect, although it was considerably lower than that of NIgG. NIgG did not cross-react with allogeneic serum. NIgG showed no effect on Balb/c mice. The results show the feasibility of producing antiserum against autoantibodies to prevent and treat autoimmune-induced T1DM with a single bolus administration.

Phosphorylated heat shock protein 27 is involved in enhanced heart tolerance to ischemia in short-term type 1 diabetic rats

Cardioprotection by intermittent high-altitude (IHA) hypoxia against ischemia-reperfusion (I/R) injury is associated with Ca2+overload reduction. Phospholamban (PLB) phosphorylation relieves cardiac sarcoplasmic reticulum (SR) Ca2+-pump ATPase, a critical regulator in intracellular Ca2+cycling, from inhibition. To test the hypothesis that IHA hypoxia increases PLB phosphorylation and that such an effect plays a role in cardioprotection, we compared the time-dependent changes in the PLB phosphorylation at Ser16(PKA site) and Thr17(CaMKII site) in perfused normoxic rat hearts with those in IHA hypoxic rat hearts submitted to 30-min ischemia (I30) followed by 30-min reperfusion (R30). IHA hypoxia improved postischemic contractile recovery, reduced the maximum extent of ischemic contracture, and attenuated I/R-induced depression in Ca2+-pump ATPase activity. Although the PLB protein levels remained constant during I/R in both groups, Ser16phosphorylation increased at I30 and 1 min of reperfusion (R1) but decreased at R30 in normoxic hearts. IHA hypoxia upregulated the increase further at I30 and R1. Thr17phosphorylation decreased at I30, R1, and R30 in normoxic hearts, but IHA hypoxia attenuated the depression at R1 and R30. Moreover, PKA inhibitor H89 abolished IHA hypoxia-induced increase in Ser16phosphorylation, Ca2+-pump ATPase activity, and the recovery of cardiac performance after ischemia. CaMKII inhibitor KN-93 also abolished the beneficial effects of IHA hypoxia on Thr17phosphorylation, Ca2+-pump ATPase activity, and the postischemic contractile recovery. These findings indicate that IHA hypoxia mitigates I/R-induced depression in SR Ca2+-pump ATPase activity by upregulating dual-site PLB phosphorylation, which may consequently contribute to IHA hypoxia-induced cardioprotection against I/R injury.

The main objective of this study is to test the hypothesis that N-methyl-D-aspartate (NMDA) receptors within the rostral ventrolateral medulla (RVLM) are involved in the inhibition of clonidine on the RVLM presympathetic neurons. Totally, 22 presympathetic neurons were recorded in anesthetized and paralyzed rats. The majority of these neurons (n=16 of 22) were significantly inhibited by iontophoretic (30 nA) clonidine, the other 6 neurons were insensitive to clonidine. In seven clonidine-sensitive neurons, iontophoretic clonidine (30 nA) antagonized the neuronal excitation of iontophoretic NMDA receptor agonist NMDA (20 nA). In remaining nine clonidine-sensitive neurons, iontophoretic NMDA receptor antagonist MK801 (60 nA) significantly attenuated the neuronal inhibition of iontophoretic (30 nA) clonidine. In conclusion, these results suggest that NMDA receptors contribute to the inhibition of clonidine on the RVLM presympathetic neurons.

Objective The present study was designed to test the hypothesis that inflammation is involved in the end-organ damage (EOD) induced by sinoaortic denervation (SAD) in rats. Method SAD was performed in male Sprague-Dawley rats at the age of 10 weeks. Under anaesthesia, aortic nerves were cut and the sinus region of the carotid artery was stripped and painted with 10% phenol. Pathological evaluation of EOD and the determination of plasma or tissue levels of the factors related to inflammation, including thromboxane B2 (TXB2) interleukin-1 (IL-1), tumour necrosis factor alpha (TNF-alpha) and reactive oxygen species (ROS) were performed at 16 weeks after SAD. Pathological evaluation of EOD included heart weight ratio, myocardial and blood vessel hydroxyproline and collagen volume fraction, glomerular injury score and number of infiltrating inflammatory cells. Indomethacin (20 mg/kg per day, orally) or vitamin E (100 mg/kg per day, orally) was administered for 12 weeks, beginning from 4 weeks after SAD, to observe their effects on SAD-induced EOD. Results There were significant fibrosis and inflammatory infiltration in the myocardium and blood vessels, represented by higher hydroxyproline and collagen volume fraction, and a large amount of inflammatory cells in the tissues of SAD rats. Heart weight and kidney glomerular injury score were significantly higher in SAD than in sham-operated rats. Plasma TXB2, TNF-alpha, IL-1 and tissue ROS increased significantly after SAD. Indomethacin and vitamin E significantly decreased the contents of some factors related to inflammation in SAD rats. Both drugs also alleviated myocardial and vessel fibrosis, inflammatory infiltration and kidney damage. Conclusion Inflammation is involved in the organ damage induced by SAD in rats.

Although it is recognized that imidazoline receptors play an important role in the central regulation of cardiovascular activities, little is known about their role in the caudal ventrolateral medulla. In male Sprague-Dawley rats anesthetized with urethane, we used antagonists of I1-imidazoline receptor or alpha2-adrenoceptor to assess the function of these receptors in the caudal ventrolateral medulla in controlling the cardiovascular effects of clonidine. Unilateral microinjection of clonidine (6 nmol/50 nl) into the caudal ventrolateral medulla significantly (P

Background Both hypertension and high blood pressure variability (BPV) are involved in cardiovascular damage. This comparative study was designed to explore the possible effects of both of these phenomena on the cardiovascular system. Methods The high BPV model of 16-week sinoaortic denervated (SAD) rats and the hypertension model of spontaneously hypertensive rats (SHR) were used for comparison at the same age of 26 weeks. The comparison was focus on hemodynamics, cardiovascular hypertrophy, and hemodynamic responses to ketanserin. Linear regression analysis was performed to study the role of hemodynamics in cardiovascular hypertrophy. Results In SHR, hypertension was accompanied by a moderately high BPV, whereas in SAD rats, substantially high BPV existed alone, without hypertension. Left ventricular hypertrophy was severe in SHR but was mild in SAD rats. Aortic hypertrophy was present in SAD rats but was absent in SHR. In SAD rats, the hypertrophy was correlated with BPV but not with blood pressure (BP) level. However, in SHR, hypertrophy was correlated with both BP and BPV level. The BP-lowering effect of ketanserin was comparable in both models, whereas its BPV-lowering effect was greater in SAD rats than in SHR. This hypersensitivity was associated with basal BPV level in SAD rats. Conclusions These results indicate that hypertension may be more important than high BPV in causing left ventricular hypertrophy, and that the aorta may be more sensitive to substantially high BPV.

The role of endothelin-1 (ET-1) in acute ischemic arrhythmia is controversial. To illustrate the involvement of cardiac ET-1 in ischemic arrhythmia, the effects of ET-1 mRNA antisense oligodeoxynucleotides (AS-ODNs) on acute ischemic arrhythmia were observed. ET-1 AS-ODN was injected i.v. in rats 2 h before the experimental procedure and the ischemic arrhythmia caused by occlusion of the left anterior descending (LAD) coronary artery was observed in the isolated perfused heart. The results show that: 1) In normal perfused rat hearts, a small number of ventricular ectopic beats (VEBs) were observed and neither ventricular tachycardia (VT) nor heart arrest occurred. 2) LAD occlusion elicited various ischemic arrhythmias in isolated hearts. No differences in the incidences or numbers of the arrhythmias were found between isolated hearts which had received normal saline (NS) and those which had received ET-1 ODNs (sense-ODN and scrambled-ODNI in vivo. VT occurred in all hearts and the percentage of heart arrest was 33.3% in the NS group, 12.5% in the sense-ODN group, and 25% in the scrambled ODN group. 3) ET-1 AS-ODN dose-dependently decreased the incidence of VT, the arrhythmia score, the numbers of single VEBs and VT, and no heart arrest was observed in the hearts pretreated with ET-1 AS-ODN. These results demonstrated a contributory role for endogenous ET-1 in the genesis of ischemic arrhythmia in this rat heart model of arrhythmia.

Hypoxia is a strong stimulus for endothelin-1 (ET-1) synthesis, which is involved in myocardial ischemia. To shed light on the role and calcium mechanism of endogenous ET-1 in myocardial ischemia, the effects of the ET-1 antagonist BQ610 on hypoxia-induced injury and [Ca 2+ ] i changes were observed in cultured neonatal rat cardiomyocytes. Hypoxia-induced injury was assessed by determining supernatant activity of lactate dehydrogenase (LDH) and superoxide dismutase (SOD) in cardiomyocytes exposed to hypoxia produced by a 3% O 2 , 5% CO 2 atmosphere. [Ca 2+ ] i was measured with the Ca 2+ -sensitive dye Fluo-3 under a confocal microscope. The hypoxia model used for (Ca 2+ ] i measurement was prepared by perfusing cells with 95% N 2 , 5% CO 2 saturated DMEM solution containing 1 mM Na 2 S 2 O 4 . The results showed that: 1) Hypoxia significantly increased ET-1 content in culture supernatant. 2) The supernatant LDH was significantly increased after 12- or 24-h hypoxia. On the other hand, SOD activity was decreased significantly. BQ610 0.2-5 μM dose-dependently reduced LDH release and enhanced SOD activity. 3) [Ca 2+ ] i transient was observed in the normal cultured beating cardiomyocytes. Exposure to hypoxia caused termination of [Ca 2+ ] i transient in 3-5 min and a continuous rapid increase in [Ca 2+ ] i after about 20 min. In the presence of BQ610, the termination of [Ca 2+ ] i transient was postponed to 15-20 min into hypoxia; the [Ca 2+ ] i increase was rather slow until approximately 45 min into hypoxia. These results indicate that endogenous ET-1 contributed to hypoxia-induced injury in the cultured neonatal rat cardiomyocytes and that the injury was associated with a [Ca 2+ ] i mechanism partially mediated by ET-1.

The effects of four anti-sense oligodeoxynucleotides (AS-ODNs) against rat or human preproendothelin-1 mRNA on ischemic arrhythmias in anesthetized rats were studied. AS-ODN (60 nmol/kg) or control (normal saline; sense-ODN, and scrambled-ODN, 60 nmol/kg) was injected 2 h before acute myocardial ischemia elicited by the occlusion of the left anterior descending coronary artery. Arrhythmias during 60-min ischemia were assessed, and plasma endothelin-1 was determined with an endothelin-1-specific radioimmunoassay system. The results showed that anti-senses against human preproendothelin-1 mRNA were anti-arrhythmic without significant impact on hemodynamics, whereas two against rat preproendothelin-1 mRNA and the three controls failed to be anti-arrhythmic. In human antisense groups, both the incidence of reversible ventricular fibrillation and the mortality were decreased to zero. The incidences of ventricular tachycardia and salvos were significantly decreased from almost 100% in the controls to < or =30% (p < 0.01), the arrhythmia score from an average of approximately 3.6 to 0 and 0.7, respectively (p < 0.01 versus controls), and the total ventricular ectopic beats from an average of 307-338 to < 40 (p < 0.01). The human AS-ODNs led to less plasma endothelin-1, which was associated with suppressed ischemic arrhythmias in this rat model, indicating a contributory role of endothelin-1 in ischemic arrhythmias. Conversely, considering the two- or three-base mismatches between the human AS-ODNs and rat preproendothelin-1 mRNA, and the failure of the rat AS-ODNs in suppressing arrhythmias, the possibility could not be excluded that human endothelin-1 AS-ODNs acted via an undetermined pathway other than endothelin-1.

In mammals, pain sensation is initiated by the detection of noxious stimuli through specialized transduction ion channels and receptors in nociceptive sensory neurons. Transient receptor potential (TRP) channels are the key sensory transducers that confer nociceptors distinct sensory modalities. However, the regulatory mechanisms about their expression are poorly defined. Here we show that the zinc-finger protein ZBTB20 regulates TRP channels expression in nociceptors. ZBTB20 is highly expressed in nociceptive sensory neurons of dorsal root ganglia. Disruption of ZBTB20 in nociceptors led to a marked decrease in the expression levels of TRPV1, TRPA1 and TRPM8 and the response of calcium flux and whole-cell currents evoked by their respective specific agonists. Phenotypically, the mice lacking ZBTB20 specifically in nociceptors showed a defect in nociception and pain sensation in response to thermal, mechanical and inflammatory stimulation. Our findings point to ZBTB20 as a critical regulator of nociception and pain sensation by modulating TRP channels expression in nociceptors.

Salusin-beta is newly identified bioactive peptide of 20 amino acids, which is widely distributed in hematopoietic system, endocrine system, and the central nervous system (CNS). Although salusin-beta extensively expressed in the CNS, the central cardiovascular functions of salusin-beta are unclear. Our main objective was to determine the cardiovascular effect of microinjection of salusin-beta into the nucleus tractus solitarii (NTS) in anesthetized rats. Bilateral or unilateral microinjection of salusin-beta (0.94-94 microg/rat) into the NTS dose-dependently decreased blood pressure and heart rate. Bilateral NTS microinjection of salusin-beta (9.4 microg/rat) did not alter baroreflex sensitivity. Prior application of the glutamate receptor antagonist kynurenic acid (0.19 microg/rat, n=9) into the NTS did not alter the salusin-beta (9.4 microg/rat) induced hypotension and bradycardia. However, pretreatment with the GABA receptor agonist muscimol (0.5 ng/rat) within the rostral ventrolateral medulla (RVLM) completely abolished the hypotension (-14+/-5 vs. -3+/-5 mm Hg, P

The present study has explored possible fast actions of corticosteroid hormones on activity of cardiovascular neurons of the rostral ventrolateral medulla. Experiments were conducted in 60 urethane-anesthetized, artificially ventilated adult rats. Extracellular recordings of unitary firings were made from the RVLM with multi- or single-barreled microelectrodes. Barosensitive cardiovascular neurons were identified through activation of the baroreceptor reflex by electrical stimulation of the aortic nerve and by intravenous injection of phenylephrine. In 52 barosensitive cardiovascular neurons, iontophoretically applied corticosterone sulfate increased the ongoing activity of 30 (57.7%) neurons, the other 22 (42.3%) neurons being unaffected. In 16 bulbospinal pre-sympathetic neurons, iontophorized corticosterone increased the firing rate of 12 neurons. Intravenously applied corticosterone (0.2 mg) increased the firing rates of 5 out of 12 bulbospinal pre-sympathetic neurons. The average baseline activity of cardiovascular neurons sensitive to corticosterone was found to be significantly less than that of the cardiovascular neurons insensitive to corticosterone. In 64 non-cardiovascular neurons, the firing rate of 13 (20.3%) neurons increased, 23 (36.0%) decreased and 28 (43.7%) remained unchanged following local application of corticosterone. The changes in firing rates of RVLM neurons following application of corticosterone occurred rapidly and were dependent on the doses of the agent. RU-38486 was able to reduce or block the rapid effects of corticosterone on cardiovascular and non-cardiovascular neurons. The results demonstrated that corticosterone may fast, non-genomically, modulate the activity of central regulators of the cardiovascular system and suggested that fast non-genomic actions of corticosteroid hormones may be an important mechanism in the integration of the autonomic nervous and the cardiovascular systems during some conditions such as stress.

Experiments were performed in 25 urethane-anaesthetized male Sprague–Dawley rats. Forty-six RVLM neurons were identified as putative presympathetic neurons according to their arterial baroreceptor reflex related properties, i.e. they were inhibited by stimulation of the aortic nerve; silenced by elevation of blood pressure and had a cardiac cycle related rhythm of spontaneous discharge. Responses of these neurons to tripled square wave stimulation of vagal afferents was tested by means of peristimulus time histograms. In addition to a long-lasting inhibition (I2), some neurons had one (Po) or two excitatory peaks (P1 and P2), and there was a short-lasting inhibition (I1) between P1 and P2. After microinjection of CPP (0.1 μl, 50 mM) into the NTS, the inhibitory responses were blocked, but the excitatory peaks were not affected; in the CVLM, CPP microinjection of the same dose had a similar effect on the responses elicited by vagal afferent stimulation in 15 of the 24 neurons tested. No detectable effects were observed in 9 neurons. However, intravenously administered ketamine attenuated or abolished these responses, either inhibitory or excitatory, in a dose dependent way. These results suggest: (1) an NMDA mechanism is involved in both the inhibitory and the excitatory responses. For the inhibitory responses, the involvement is both in the NTS and in the CVLM; for the excitatory responses, it is probably in the RVLM. (2) There may be a direct excitatory amino acid (EAA) pathway from the NTS to the RVLM.

Salusins are newly discovered cardiovascular active peptides, including salusin-alpha and salusin-beta, which are peptides containing 28 and 20 amino acids respectively. Salusins are widely distributed in tissuse and organs of human and rat, and have a series of cardiovascular effects, including lowering blood pressure, slowing down the heart rate, inhibiting myocardial contraction, reducing cardiac ischemic injury, and promoting hypertrophy of cardiomyocytes and proliferation of vascular smooth muscle cells. It is noteworthy to mention that salusin-alpha and salusin-beta are polypeptides produced by the same precursor and play opposite roles in the development and progression of atherosclerosis.