Modeling of progesterone-induced intracellular calcium signaling in human spermatozoa.

Calcium ion is a secondary messenger of mammalian spermatozoa. The dynamic change of its concentration plays a vital role in the process of sperm motility, capacitation, acrosome and fertilization. Progesterone released by the cumulus cells, as a potent stimulator of fertilization, can activate the calcium channels on the plasma membrane, which in turn triggers the dynamic change of intracellular calcium concentration. In this paper, a mathematical model of calcium dynamic response in mammalian spermatozoa induced by progesterone is proposed and numerical simulation of the dynamic model is conducted. The results show that the dynamic response of calcium concentration predicted by the model is in accordance with experimental evidence. The proposed dynamic model can be used to explain the phenomena observed in the experiments and predict new phenomena to be revealed by experimental investigations, which will provide the basis to quantitatively investigate the fluid mechanics and biochemistry for the sperm motility induced by progesterone.

Inhaled neutrophil elastase inhibitor reduces oleic acid-induced acute lung injury in rats.

RATIONALE: Neutrophil elastases (NE) play an important role in the pathogenesis of acute lung injury (ALI). NE activities are significantly increased in serums and lungs of patients or animals with ALI. Intravenous infusion (IV) of Sivelestat, an NE inhibitor, can reduce ALI. Through inhalation, drugs reach lungs directly and in high concentration. We hypothesized that inhaled Sivelestat would alleviate oleic acid (OA)-induced ALI in rats. METHODS: Rats were anesthetized and mechanically ventilated, and then ALI was induced by OA injection. One hour later, the animals were randomized to receive either Sivelestat (3 mg/kg/h) or saline inhalation. The effect of Sivelestat IV (3 mg/kg/h) was also investigated. All animals were ventilated and observed for 6 h. RESULTS: OA injection increased NE activities in lung tissues and serums. The increase of NE activities in lung tissues and serums markedly reduced by 77%, and 29%, respectively, by the inhalation of Sivelestat; and 53.8%, and 80%, respectively, by Sivelestat IV. Additionally, inhaled Sivelestat resulted in ameliorated lung injury by reducing edema and infiltration of neutrophils in the lung, improved oxygenation and survival. CONCLUSIONS: An over increased NE activity in lungs may play a vital effect in the pathogenesis of OA-induced ALI in rats. Topical application of nebulized Sivelestat, an NE inhibitor, may reduce OA-induced ALI in rats. Sivelestat inhalation can be developed as a novel treatment for ALI.

Modulation of itch and pain signals processing in ventrobasal thalamus by thalamic reticular nucleus.

Thalamic reticular nucleus (TRN) is known to be crucial for dynamically modulating sensory processing. Recently, the functional role of TRN in itch and pain sensation processing has drawn much attention. We found that ventrobasal thalamus (VB) neurons exhibited scratching behavior-related and nociceptive behavior-related neuronal activity changes, and most of VB neurons responsive to pruritic stimulus were also activated by nociceptive stimulus. Inhibition of VB could relieve itch-induced scratching behaviors and pathological pain without affecting basal nociceptive thresholds, and activation of VB could facilitate scratching behaviors. Tracing and electrophysiology recording results showed that VB mainly received inhibitory inputs from ventral TRN. Furthermore, optogenetic activation of TRN-VB projections suppressed scratching behaviors, and ablation of TRN enhanced scratching behaviors. In addition, activation of TRN-VB projections relieved the pathological pain without affecting basal nociceptive thresholds. Thus, our study indicates that TRN modulates itch and pain signals processing via TRN-VB inhibitory projections.

PBN-PVT projections modulate negative affective states in mice.

Long-lasting negative affections dampen enthusiasm for life, and dealing with negative affective states is essential for individual survival. The parabrachial nucleus (PBN) and thalamic paraventricular nucleus (PVT) are critical for modulating affective states in mice. However, the functional roles of PBN-PVT projections in modulating affective states remain elusive. Here, we show that PBN neurons send dense projection fibers to the PVT and form direct excitatory synapses with PVT neurons. Activation of the PBN-PVT pathway induces robust behaviors associated with negative affective states without affecting nociceptive behaviors. Inhibition of the PBN-PVT pathway reduces aversion-like and fear-like behaviors. Furthermore, the PVT neurons innervated by the PBN are activated by aversive stimulation, and activation of PBN-PVT projections enhances the neuronal activity of PVT neurons in response to the aversive stimulus. Consistently, activation of PVT neurons that received PBN-PVT projections induces anxiety-like behaviors. Thus, our study indicates that PBN-PVT projections modulate negative affective states in mice.

Posterior Thalamic Nucleus Mediates Facial Histaminergic Itch.

Itch induces a desire to scratch and leads to skin damage in some severe conditions. Much progress has been made in the peripheral and spinal level, and recent findings suggested that we need to focus on the central circuitry mechanism. However, the functional role of the thalamus in itch signal processing remains largely unknown. We showed that the posterior thalamic nucleus (Po) played a vital role in modulating facial histaminergic itch signal processing. We found that the calcium signal of Po neurons was increased during the histaminergic itch-induced scratching behavior in the cheek model, and pharmacogenetic suppression of Po neurons reduced the scratching behaviors. Retrograde mapping results suggested that the Po receives information from the somatosensory cortex, motor cortex, parabrachial nucleus (PBN), the principal sensory trigeminal nucleus (PrV) and the spinal trigeminal nucleus (SpV), which participate in itch signal transmission from head and body. Thus, our study indicates that the Po is critical in modulating facial histaminergic itch signal processing.

Activation of CaMKII and GluR1 by the PSD-95-GluN2B Coupling-Dependent Phosphorylation of GluN2B in the Spinal Cord in a Rat Model of Type-2 Diabetic Neuropathic Pain.

The mechanisms underlying type-2 diabetic neuropathic pain (DNP) are unclear. This study investigates the coupling of postsynaptic density-95 (PSD-95) to N-methyl-D-aspartate receptor subunit 2B (GluN2B), and the subsequent phosphorylation of GluN2B (Tyr1472-GluN2B) in the spinal cord in a rat model of type-2 DNP. Expression levels of PSD-95, Tyr1472-GluN2B, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and its phosphorylated counterpart (Thr286-CaMKII), and α-amino-3-hydroxy-5-methyl-4-soxazole propionic acid receptor subtype 1 (GluR1) and its phosphorylated counterpart (Ser831-GluR1) were significantly increased versus controls in the spinal cord of type-2 DNP rats whereas the expression of total spinal GluN2B did not change. The intrathecal injection of Ro25-6981 (a specific antagonist of GluN2B) or Tat-NR2B9c (a mimetic peptide disrupting the interaction between PSD-95 and GluN2B) induced an antihyperalgesic effect and blocked the increased expression of Tyr1472-GluN2B, CaMKII, GluR1, Thr286-CaMKII, and Ser831-GluR1 in the spinal cords; the increase in spinal cord PSD-95 was not affected. These findings indicate that the PSD-95-GluN2B interaction may increase phosphorylation of GluN2B, and subsequently induce the expression of phosphorylation of CaMKII and GluR1 in the spinal cord of type-2 DNP rats. Targeting the interaction of PSD-95 with GluN2B may provide a new therapeutic strategy for type-2 DNP.

[The relationship between autophagy activation in spinal cord and type 2 diabetic neuropathic pain in rats].

OBJECTIVE: To investigate the relationship between autophagy function in spinal cord and type 2 diabetic neuropathic pain in rats. METHODS: Forty-two male Sprague-Dawley rats were fed with a high-sugar, high-fat diet for 8 weeks to induce the insulin resistance, and then received a single intraperitoneal streptozocin (STZ) injection to establish type 2 diabetes rat model. Two weeks after STZ injection, mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of rats were detected, the rats with MWT and TWL decreasing to below 80% compared to baseline were chosen as type 2 diabetic neuropathic pain rats (group DNP, n=24), the rest of the rats were chosen as type 2 diabetic non-neuropathic pain rats (group DA, n=18). And another 18 normal rats randomly selected from the total were classified as control group (group C) and fed with common forage for 8 weeks. The MWT and TWL were measured again on the 3rd, 7th and 14th day after determining the grouping of DA and DNP, and then, the lumbar segments 4~6 of the spinal cord were removed from the executed rats for determination of the expressions of microtubule-associated protein light chain 3 (LC3)、Beclin-1and P62 by Western blot. The co-expressions of P62 with GFAP or OX-42 or NeuN in spinal dorsal horn were detected in another 6 lumbar segments of diabetic neuropathic pain (DNP) rats on the 7th day by immunofluorescence double dye method. RESULTS: Compared with group C, the insulin level was increased and ISI decreased in SD rats fed with high-sugar, high-fat diet, that meant the rats in insulin-resistance. After STZ injection, blood glucose rose to the standard of type 2 diabetes mellitus, i.e. ≥ 16.7 mmol/L. Compared with group C and group DA, MWT was significantly decreased, TWL shortened and the expression of LC3-Ⅱ and Beclin-1 in the spinal dorsal horn up-regulated, P62 expression down-regulated on the 3rd, 7th and 14th day in group DNP (P<0.05). P62 was mainly localized in spinal dorsal horn and coexisted with neurons, and spots of P62 immunoreactivity could be detected in a few microglia but not observed in astrocyte. CONCLUSIONS: The changes in expression of LC3-Ⅱ、Beclin-1 and P62 in spinal cord of type 2 diabetes neuropathic pain rats means autophagy activation of spinal, up-regulated autophagy of neurons in spinal dorsal horn mainly involves in the formation and development of type 2 diabetic neuropathic pain in rats.

[The mechanism of RvD1 alleviates type 2 diabetic neuropathic pain by influencing microglia polarization in rats].

OBJECTIVE: To study the relationship between microglia polarization in the spinal dorsal horn and type 2 diabetic neuropathic pain (DNP). And explore the mechanism of RvD1 alleviating type 2 diabetic neuropathic pain. METHODS: Type 2 diabetes mellitus (T2DM) rats came from the male SD rats which were fed by high-fat and high-sucrose diet and given intraperitoneal streptozotocin(STZ), then detected fa sting blood glucose level, the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL), which was to prepare the type 2 DNP model rats. And they were randomly divided into 3 groups:type 2 DNP group (group D), type 2 DNP and RvD1 group (group R), type 2 DNP and solvent control group (group S), 36 rats in each group. After being given STZ 14 days, the rats of group D, R, S were placed a catheter in subarachnoid cavity. Three days later, the RvD1 10µl (10 ng/µl) and 100% ethanol 10µl were injected into subarach-noid cavity through the catheter once a day for 14 consecutive days. Another 36 normal rats were served as normal control group (group N) and were fed with common forage. MWT and TWL were measured at 1, 3, 7, 14 days after Subarachnoid injection, then the nine rats'spinal cord of the lumbar segment 4~6 were removed to detect the expression of inducible nitric oxide synthase(iNOS) and arginase 1(Arg1) by Western blot, the marker of microglia M1 and M2 polarization. RESULTS: Compared with group N, MWT was decreased significantly and TWL was shortened, the expression of Arg1 was down-regulated and the expression of iNOS was up-regulated in spinal dorsal horn at the 1, 3, 7, 14 days in groups D and S (P < 0.05). Compared with group D, MWT was significantly increased and TWL was prolonged, the expression of Arg1 was up-regulated and the expression of iNOS was down-regulated in spinal dorsal horn at the 7, 14 days in group R (P < 0.05). There was no significant difference in the MWT, TWL and expression of Arg1 and iNOS between D and S groups. CONCLUSIONS: RvD1 promotes mi-croglia toward M2 polarization and alleviates type 2 diabetic neuropathic pain in rats.

Off-pump coronary artery bypass grafting versus on-pump coronary artery bypass grafting: which is better in patients with chronic obstructive pulmonary disease?

To evaluate the clinic outcome of off-pump coronary bypass grafting (OPCABG) of patients with coronary heart disease and chronic obstructive pulmonary disease, we collected and analyzed 1998-2002 data on 28 patients with these two diseases who had received off-pump coronary bypass operation in our hospital, and compared with data on those who also had the same two diseases but received on-pump coronary artery bypass at same time. There were no operation-related death; one died of respiratory failure 14 days after operation while staying in hospital; there were more respiratory complications in the conventional coronary artery bypass grafting group (CCABG) than in the OPCABG group; and the PaO2/FiO2 in the CCABG group was higher than that in the OPCABG group during operation because of CPB, but lower than that in the OPCABG group 6-12 hours after operation. OPCABG seemed more suitable than CCABG for coronary artery disease patients with chronic obstructive pulmonary disease due to less damage to their oxygen-exchange capability and the fewer respiratory complications.

Improvement of ventilation-induced lung injury in a rodent model by inhibition of inhibitory κB kinase.

BACKGROUND: Inhibition of nuclear factor κB (NF-κB) activation is a well-know strategy to ameliorate ventilation-induced lung injury (VILI). Inhibitory κB kinase (IKK) plays a key role in the regulation of NF-κB activation. In this study, we determined whether inhibition of IKK by an IKK inhibitor exerts lung protection in a rat model of VILI. METHODS: Anesthetized and mechanically ventilated Sprague-Dawley rats were randomly assigned to a standard (tidal volume, 8 mL/kg) or high-tidal volume (tidal volume, 25 mL/kg) ventilation group. An IKK inhibitor (IKK 16) or vehicle was administrated 1 hour before the induction of VILI. All groups were ventilated and observed for 5 hours. RESULTS: High-pressure ventilation caused activation of NF-κB, increased pulmonary inflammatory mediator levels, lung edema, and impairment of gas exchange. The IKK inhibitor treatment significantly reduced these changes and increased interleukin 10 levels, heme oxygenase 1 activity, protein kinase B (Akt) phosphorylation levels, and nuclear amounts of nuclear factor E2-related factor 2 protein. CONCLUSION: IKK may be a therapeutic target for VILI. An IKK inhibitor, IKK 16, can dampen VILI in rats. The beneficial effect of the IKK 16 may be mediated through the inhibition of NF-κB pathway and up-regulation of nuclear factor E2-related factor 2-regulated heme oxygenase 1 through the activation of the phosphatidylinositol 3 kinase/Akt.

Galangin dampens mice lipopolysaccharide-induced acute lung injury.

Galangin, an active ingredient of Alpinia galangal, has been shown to possess anti-inflammatory and antioxidant activities. Inflammation and oxidative stress are known to play vital effect in the pathogenesis of acute lung injury (ALI). In this study, we determined whether galangin exerts lung protection in lipopolysaccharide (LPS)-induced ALI. Male BALB/c mice were randomized to receive galangin or vehicle intraperitoneal injection 3 h after LPS challenge. Samples were harvested 24 h post LPS administration. Galangin administration decreased biochemical parameters of oxidative stress and inflammation, and improved oxygenation and lung edema in a dose-dependent manner. These protective effects of galangin were associated with inhibition of nuclear factor (NF)-κB and upregulation of heme oxygenase (HO)-1. Galangin reduces LPS-induced ALI by inhibition of inflammation and oxidative stress.

Genome of the Chinese tree shrew.

Chinese tree shrews (Tupaia belangeri chinensis) possess many features valuable in animals used as experimental models in biomedical research. Currently, there are numerous attempts to employ tree shrews as models for a variety of human disorders: depression, myopia, hepatitis B and C virus infections, and hepatocellular carcinoma, to name a few. Here we present a publicly available annotated genome sequence for the Chinese tree shrew. Phylogenomic analysis of the tree shrew and other mammalians highly support its close affinity to primates. By characterizing key factors and signalling pathways in nervous and immune systems, we demonstrate that tree shrews possess both shared common and unique features, and provide a genetic basis for the use of this animal as a potential model for biomedical research.

Attenuation of hyperoxia-induced lung injury in rats by adrenomedullin.

Oxidative stress and inflammation are involved in the pathogenesis of acute lung injury (ALI). Adrenomedullin (AM) is an endogenous peptide with anti-inflammatory and antioxidant properties. This study investigated that whether AM treatment may ameliorate hyperoxia-induced ALI in rats via inhibition of oxidative stress and inflammation. Rats were randomized to receive continuous intravenous infusion of AM or saline through a microosmotic pump, and then ALI was induced by exposing the animals in sealed cages >95% oxygen for 72 h. Exposure to hyperoxia caused lung injury as increased infiltration of inflammatory cells and disruption of lung architecture. AM administration markedly improved these changes. Additionally, AM administration significantly increased glutathione peroxidase and superoxide dismutase activities. Meanwhile, hyperoxia-induced increase of lipid hydroperoxide level was markedly reduced by AM treatment. Moreover, nuclear factor-kappa B-DNA-binding activity, and production of the inflammatory mediators interleukin-6, keratinocyte-derived chemokine, and matrix metalloproteinase 9, were significantly inhibited by AM treatment. AM ameliorates hyperoxia-induced ALI in rats by suppression of oxidative stress and inflammation.