The suprachiasmatic nucleus (SCN) encodes time of day through changes in daily firing; however, the molecular mechanisms by which the SCN times behavior are not fully understood. To identify factors that could encode day/night differences in activity, we combine patch-clamp recordings and single-cell sequencing of individual SCN neurons in mice. We identify PiT2, a phosphate transporter, as being upregulated in a population of Vip+Nms+ SCN neurons at night. Although nocturnal and typically showing a peak of activity at lights off, mice lacking PiT2 (PiT2-/-) do not reach the activity level seen in wild-type mice during the light/dark transition. PiT2 loss leads to increased SCN neuronal firing and broad changes in SCN protein phosphorylation. PiT2-/- mice display a deficit in seasonal entrainment when moving from a simulated short summer to longer winter nights. This suggests that PiT2 is responsible for timing activity and is a driver of SCN plasticity allowing seasonal entrainment.

Spinal cord injury (SCI) is a debilitating condition that results in significant impairment of motor function and sensation. Despite the ongoing efforts to develop effective treatments, there are currently very limited options available for patients with SCI. Celastrol, a natural anti-inflammatory compound extracted from Tripterygium wilfordii, has been shown to exhibit anti-inflammatory and anti-apoptotic properties. In this study, we aimed to explore the therapeutic potential of celastrol for SCI and elucidate the underlying molecular mechanisms involved. We found that local tissue often experiences a significant decrease in cAMP content and occurrs apoptosis after SCI. However, the treatment of celastrol could promote the production of cAMP by up-regulating the VIP-ADCYAP1R1-GNAS pathway. This could effectively inhibit the phosphorylation of JNK and prevent apoptosis, ultimately improving the exercise ability after SCI. Together, our results reveal celastrol may be a promising therapeutic agent for the treatment of SCI.

Many studies have reported obvious seasonal differences in the intestinal flora of rats, and this stable distribution of the seasonal flora helps in maintaining the normal physiological function of the host. However, the mechanism underlying these seasonal differences in intestinal flora remains unclear. To explore the correlation among seasonal factors and intestinal water metabolism and intestinal flora, 20 Sprague Dawley (SD) rats were divided into spring, summer, autumn, and winter groups. The environment for the four seasons was simulated using the Balanced Temperature and Humidity Control system. The intestinal water metabolism was evaluated by determining the intestinal transmission function, fecal water content, water content of colonic tissue, and the colonic expression levels of AQP3, AQP4, and AQP8. The composition and relative abundance of intestinal microflora in rats in each season were assessed through 16S rDNA amplifier sequencing, and the relationship between the dominant flora and intestinal water metabolism in each season was analyzed using Spearman correlation analysis. The high temperature and humidity season could lead to an increase in intestinal water metabolism and intestinal water content in rats, whereas the low temperature and humidity season could lead to a decrease, which was closely related to the change in microflora. To explore the molecular mechanism of seasonal changes in intestinal water metabolism, the concentration of colonic 5-HT, VIP, cAMP, and PKA associated with intestinal water metabolism in rats were also examined. Seasonal changes could affect the concentration of colonic 5-HT and VIP in rats, and then regulate AQPs through cAMP/PKA pathway to affect the intestinal water metabolism. These results suggest that seasonal factors affect the level of intestinal water metabolism in rats and result in seasonal differences in intestinal flora.

OBJECTIVE: To observe the effect of electroacupuncture (EA) of bilateral \"Tianshu\"(ST25) at different frequencies on the first black stool discharge time, colonic electromyography (EMG) and immunoactivity of vasoactive intestinal peptide (VIP) and substance P (SP) in the colon tissue in rats with slow transit constipation (STC), so as to choose a better stimulating frequency in the treatment of STC.
METHODS: A total of 50 male Wistar rats were randomized into control, model, 2 Hz-EA, 100 Hz- EA, and 2 Hz/100 Hz-EA groups, with 10 rats in each group. The STC model was established by intraperitoneal injection of compound diphenoxylate suspension fluid (10 mg/kg). EA was applied to bilateral ST25 for 30 min, once a day for 14 consecutive days. The discharge time for the first black stool was recorded after gavage of mixed suspension fluid of active carbon (2 mL) for assessing the gastrointestinal motility. The colonic EMG was recorded by using a pair of silver electrodes and bioelectric amplifier. The expression of SP and VIP in the colonic tissue was detected by immunohistochemistry.
RESULTS: Following mode-ling, the colonic EMG amplitude, the discharge time for the first black stool and VIP immunoactivity were significantly increased (P<0.01), and the EMG frequency and SP immunoactivity were significantly decreased （P<0.01） in the model group compared with the control group. Compared with the model group, the increase of the discharge time for the first black stool, EMG amplitude and VIP immunoactivity, the decrease of EMG frequency and SP immunoactivity were reversed in the 3 EA groups (P<0.01, P<0.05). The therapeutic effect of 100 Hz-EA was notably weaker than that of both 2 Hz-EA and 2 Hz/100 Hz-EA in up-regulating EMG frequency and SP immunoactivity and in down-regulating the discharge time for the first black stool, EMG amplitude and VIP immunoactivity (P<0.05, P<0.01). There was no significant difference between the 2 Hz/100 Hz-EA and 2 Hz-EA groups (P>0.05).
CONCLUSIONS: EA can accelerate colonic EMG activities, which may be associated with its functions in down-regulating VIP immunoactivity and up-regulating SP immunoactivity in the colonic tissues. The therapeutic effects of 2 Hz/100 Hz-EA and 2 Hz-EA are better than that of 100 Hz-EA.
目的：观察不同频率电针“天枢”对慢传输型便秘（STC）大鼠的首粒黑便排出时间、结肠肌电、结肠血管活性肠肽(VIP)、结肠P物质(SP)的影响, 探讨不同频率电针治疗STC的机制。方法： Wistar大鼠随机分为对照组、模型组、低频电针组、高频电针组和变频电针组, 每组10只。采用复方地芬诺酯混悬液灌胃法复制STC大鼠模型。各电针组分别给予2 Hz低频、100 Hz高频和2 Hz/100 Hz变频电针刺激“天枢”, 每次15 min, 每日1次, 连续14 d。观察大鼠首粒黑便排出时间延长、结肠肌电, 免疫组织化学法观察结肠SP、VIP阳性表达情况。结果：与对照组相比, 模型组的首粒黑便排出时间延长（P<0.01）, 结肠肌电振幅、结肠VIP表达显著升高(P<0.01), 结肠肌电频率、结肠SP表达显著降低(P<0.01)；与模型组相比, 各电针组首粒黑便排出时间缩短（P<0.01）, 结肠肌电振幅、结肠VIP表达显著降低(P<0.01, P<0.05), 结肠肌电频率、结肠SP表达显著升高(P<0.01, P<0.05)；与高频电针组比较, 变频电针组和低频电针组首粒黑便排出时间缩短, 结肠肌电振幅、结肠VIP表达显著降低(P<0.05), 结肠肌电频率、结肠SP表达显著升高(P<0.01, P<0.05)。结论：电针“天枢”可通过改善大鼠结肠肌电, 降低结肠VIP表达, 增加结肠SP表达, 从而治疗STC, 且低频电针与变频电针效果优于高频电针。.

Chronic obstructive pulmonary disease (COPD) as an inflammatory respiratory system disease is caused by exposure to cigarette smoke and tobacco in long-term. Some anti-inflammatory peptides can control inflammation in COPD. N-acetyl-seryl-aspartyl-proline (Ac-SDKP) and vasoactive intestinal peptide (VIP) as peptide have anti-inflammatory effect, and, in this study, the effect of Ac-SDKP and VIP on COPD inflammation was studied. After producing cigarette smoke-induced COPD mice model, which were treated with VIP and Ac-SDKP, the levels of antioxidant-related factors (malondialdehyde (MDA) and superoxide dismutase (SOD)), fibrotic factors (hydroxyproline (HP) and TGF-β), pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and inflammation in histopathological examination were studied. MDA, Remodeling factors, pro-inflammatory cytokines, and inflammation in lung tissue were controlled by VIP and Ac-SDKP treatment. These treatments could enhance SOD. VIP and Ac-SDKP as immuno-regulatory factors had benefit effect in treatment of COPD. The anti-inflammatory, anti-fibrosis, and anti-oxidant properties of VIP and Ac-SDKP may be effective therapy in COPD.

Cognitive dysfunction caused by sepsis-associated encephalopathy (SAE) is still poorly understood. It is reported that vasoactive intestinal peptide (VIP) exerts its anti-inflammatory effects in multiple diseases, while its biological function in SAE remains unclear. We aimed to figure out whether VIP has influence on sepsis-induced neuroinflammation and cognitive dysfunction. To induce sepsis, rats were subjected to cecal ligation and puncture (CLP) operation. Morris water maze test and fear conditioning test were conducted to reveal cognitive dysfunctions. TUNEL assay was performed to evaluate apoptosis. We found out that the expression of VIP was downregulated in the hippocampus of septic rats. VIP was verified to attenuate sepsis-induced memory impairment following CLP. Additionally, we examined apoptosis and inflammation in rats\' hippocampus. It is worth noting that VIP inhibited the apoptosis in the hippocampus and reduced the productions of proinflammatory cytokines TNF-α, IL-6 and IL-1β. Furthermore, our data confirmed that VIP was involved in regulating the TLR-4/NF-κB signaling. In conclusion, VIP inhibited neuroinflammation and cognitive impairment in hippocampus of septic rats through the TLR-4/NF-κB signaling pathway.

BACKGROUND: Acute lung injury (ALI) is an acute multifactorial infectious disease induced by trauma, pneumonia, shock, and sepsis. This study aimed to investigate the protective effects of pseudoephedrine and emodin combined treatment in experimental ALI, as well as the mechanisms underlying the regulation of inflammation and pulmonary edema via the VIP/cAMP/PKA pathway.
METHODS: The wistar rats were randomly divided into fifteen groups (n = 5). Rats in each group were given intragastric administration 1 h before LPS injection. Those in the control and LPS groups were given intragastric administrations of physiological saline, rats in other groups were given intragastrically administered of differential dose therapeutic agents. The rats in the LPS and treatment groups were then injected intraperitoneally with LPS (7.5 mg/kg) to induce ALI. After being treated with pseudoephedrine and emodin for 12 h, all animals were sacrifice. Anal temperatures were taken on an hourly basis for 8 h after LPS injection. Pathological examination of lung specimen was performed by H&E staining. Cytokines (IL-1β, TNF-α, IL-6, iNOS, IL-10, Arg-1, CD86, CD206, F4/80, VIP) in lung tissue were assayed by ELISA and immunofluorescence. The expression of VIP, CAMP, AQP-1, AQP-5, p-PKA, PKA, p-IκBα, IκBα, p-p65, p65, p-P38, P38, p-ERK1/2, ERK1/2, p-JNK1/2, JNK1/2 protein in lung was determined by western blotting.
RESULTS: After rats being treated with pseudoephedrine + emodin, reduced of fever symptoms. The contents of inflammatory cytokines (IL-1β, TNF-α, IL-6, iNOS) were decreased and anti-inflammatory cytokines (IL-10, Arg-1) were significantly increased in serum. Pseudoephedrine + emodin treatment effectively promoted VIP cAMP and p-PKA protein expression in lung tissues, and significantly inhibited NF-κB, MAPK phosphorylation, Pseudoephedrine + emodin treatment can inhibit M1 polarization and promoted M2 polarization via the VIP/cAMP/PKA signaling pathway.
CONCLUSIONS: The combination of Pseudoephedrine and emodin was effective in ameliorating LPS-induced ALI in rats by inducing VIP/cAMP/PKA signaling. Inhibiting the NF-κB, MAPK inflammatory pathway, relief of pulmonary edema suppressing macrophage M1 polarization, and promoting macrophage M2 polarization.

暂无摘要。

Dopamine is required for working memory, but how it modulates the large-scale cortex is unknown. Here, we report that dopamine receptor density per neuron, measured by autoradiography, displays a macroscopic gradient along the macaque cortical hierarchy. This gradient is incorporated in a connectome-based large-scale cortex model endowed with multiple neuron types. The model captures an inverted U-shaped dependence of working memory on dopamine and spatial patterns of persistent activity observed in over 90 experimental studies. Moreover, we show that dopamine is crucial for filtering out irrelevant stimuli by enhancing inhibition from dendrite-targeting interneurons. Our model revealed that an activity-silent memory trace can be realized by facilitation of inter-areal connections and that adjusting cortical dopamine induces a switch from this internal memory state to distributed persistent activity. Our work represents a cross-level understanding from molecules and cell types to recurrent circuit dynamics underlying a core cognitive function distributed across the primate cortex.

BACKGROUND: Bone marrow mesenchymal stem cells are a potential resource for the clinical therapy of certain diseases. Canine, as a companion animal, living in the same space with human, is an ideal new model for human diseases research. Because of the high prevalence of diabetes, alternative transplantation islets resource (i.e. insulin producing cells) for diabetes treatment will be in urgent need, which makes our research on the transdifferentiation of Bone marrow mesenchymal stem cells into insulin producing cells become more important.
RESULTS: In this study, we completed the transdifferentiation process and achieved the transcriptome profiling of five samples with two biological duplicates, namely, \"BMSCs\", \"islets\", \"stage 1\", \"stage 2\" and \"stage 3\", and the latter three samples were achieved on the second, fifth and eighth day of induction. A total of 11,530 differentially expressed transcripts were revealed in the profiling data. The enrichment analysis of differentially expressed genes revealed several signaling pathways that are essential for regulating proliferation and transdifferentiation, including focal adhesion, ECM-receptor interaction, tight junction, protein digestion and absorption, and the Rap1 signaling pathway. Meanwhile, the obtained protein-protein interaction network and functional identification indicating involvement of three genes, SSTR2, RPS6KA6, and VIP could act as a foundation for further research.
CONCLUSIONS: In conclusion, to the best of our knowledge, this is the first survey of the transdifferentiation of canine BMSCs into insulin-producing cells according with the timeline using next-generation sequencing technology. The three key genes we pick out may regulate decisive genes during the development of transdifferentiation of insulin producing cells.