Objective:To investigate the role and molecular mechanisms of signal transducer and activator of tran-scription 3(STAT3)in the paraventricular nucleus(PVN)of the hypothalamus in regulating body weight and energy metabolism in mice.Methods:AAV2/9-hSyn-Cre-EGFP virus was stereotactically injected into the PVN of STAT3Flox/Flox mice to conditionally knock out(CKO)STAT3 in the PVN.STAT3 expression was verified via immunoflu-orescence staining and Western blot.Body weight and temperature were monitored,glucose tolerance was assessed using glucose tolerance tests in mice,and morphological changes in the liver,interscapular brown adipose tissue(IBAT),in-guinal white adipose tissue(IWAT),and quadriceps muscle were evaluated via hematoxylin-eosin(HE)staining.RT-qPCR was used to measure mRNA levels of platelet-derived growth factor receptor α(PDGFRα),peroxisome prolifera-tor-activated receptor γ(PPARγ),hormone-sensitive lipase(HSL),and adipose triglyceride lipase(ATGL)in these tissues.Results:STAT3 protein expression in the PVN of CKO mice was significantly reduced,and the number of STAT3-positive neurons was also decreased.Compared to wild-type(WT)mice,CKO mice exhibited increased body weight,impaired thermogenesis in IBAT,and reduced glucose tolerance.HE staining revealed lipid droplet accumula-tion in hepatocytes of the liver,enlarged adipocytes with hypertrophic lipid droplets and leukocyte infiltration in adipose tissues,and intermuscular fat deposition in the quadriceps muscle.RT-qPCR analysis showed decreased mRNA levels of PDGFRα,HSL,and ATGL in the liver;upregulated PPARγ mRNA but downregulated HSL and ATGL mRNA in IBAT and IWAT;and reduced PPARγ and HSL mRNA levels in the quadriceps muscle of CKO mice.Conclusion:The STAT3 signaling pathway in the PVN is critical for maintaining systemic energy balance and serves as a key node in met-abolic regulation.

Objective:To investigate the role and molecular mechanisms of signal transducer and activator of tran-scription 3(STAT3)in the paraventricular nucleus(PVN)of the hypothalamus in regulating body weight and energy metabolism in mice.Methods:AAV2/9-hSyn-Cre-EGFP virus was stereotactically injected into the PVN of STAT3Flox/Flox mice to conditionally knock out(CKO)STAT3 in the PVN.STAT3 expression was verified via immunoflu-orescence staining and Western blot.Body weight and temperature were monitored,glucose tolerance was assessed using glucose tolerance tests in mice,and morphological changes in the liver,interscapular brown adipose tissue(IBAT),in-guinal white adipose tissue(IWAT),and quadriceps muscle were evaluated via hematoxylin-eosin(HE)staining.RT-qPCR was used to measure mRNA levels of platelet-derived growth factor receptor α(PDGFRα),peroxisome prolifera-tor-activated receptor γ(PPARγ),hormone-sensitive lipase(HSL),and adipose triglyceride lipase(ATGL)in these tissues.Results:STAT3 protein expression in the PVN of CKO mice was significantly reduced,and the number of STAT3-positive neurons was also decreased.Compared to wild-type(WT)mice,CKO mice exhibited increased body weight,impaired thermogenesis in IBAT,and reduced glucose tolerance.HE staining revealed lipid droplet accumula-tion in hepatocytes of the liver,enlarged adipocytes with hypertrophic lipid droplets and leukocyte infiltration in adipose tissues,and intermuscular fat deposition in the quadriceps muscle.RT-qPCR analysis showed decreased mRNA levels of PDGFRα,HSL,and ATGL in the liver;upregulated PPARγ mRNA but downregulated HSL and ATGL mRNA in IBAT and IWAT;and reduced PPARγ and HSL mRNA levels in the quadriceps muscle of CKO mice.Conclusion:The STAT3 signaling pathway in the PVN is critical for maintaining systemic energy balance and serves as a key node in met-abolic regulation.

Vector flow imaging(VFI)is an innovative ultrasound flow measurement technology.Compared with the traditional color Doppler and spectral Doppler,VFI has the advantages of independence of angle correction and direct acquisition of real-time amplitude and direction of flow.Transverse oscillation(TO)method is one of the effective methods for vector flow imaging.However,a complete and detailed algorithm validation process based on commercial ultrasound machines is still lacking due to more complex convex probes.This study starts with introducing the imaging process and principle of transverse oscillation vector flow technique,and calculates the error between the set velocity value and the measured velocity value through the simulation experiment,and verifies the error between the set velocity value and the measured velocity value through the Doppler flow phantom experiment.Among them,the velocity value measured by the TO vector flow technique in the simulation experiment is 0.48 m/s and the preset value is 0.50 m/s,the error between them is-4％.The velocity values are 8.33,11.14,14.44 and 16.67 cm/s measured by the Doppler flow phantom experiment,the actual velocity values are 7.97,10.78,14.06 and 17.34 cm/s,the errors between them are all within±5％.Both experiments verify the feasibility of using vector flow technique on abdominal convex probe.

Ghrelin is a hormone produced by the stomach that regulates energy metabolism after acting on the central nervous system.Cocaine amphetamine-regulated transcriptional peptide(CART)neurons participate in the regulation of feeding behavior and energy balance.It is known that CART neurons are influenced by hormones to regulate energy homeostasis,but whether ghre-lin exerts its pro-appetite function by influencing CART neurons is unknown.Therefore,this study focuses on the role of VMHCART neurons in the regulation of feeding and relative body weight by ghrelin.Firstly,the whole brain expression of CART was determined by immunofluorescence.Then the effect of intraperitoneal injection of ghrelin on the expression of DMHCART neurons was evalua-ted.Finally,the ghrelin was delivered to DMH and the changes of food intake and relative body weight of mice were measured.CART immunoreactive neurons were detected in medial preoptic nucleus(MPA),arcuate nucleus(ARC),dorsomedial hypothalamic nucleus(DMH),thalamic pa-raventricular nucleus(PVT)and raphe nucleus(ROb).Compared with the control group,periph-eral injection of ghrelin significantly increased the expression of DMHC ART immunoreactive neurons(P=0.037 3).DMH long-term injection of ghrelin resulted in an increase in body weight(P=0.004 0)and feed intake(P=0.023 1).The results provide anatomical evidence for the whole brain distribution of CART,which proves that ghrelin affects feed intake and body weight of mice through CART neurons in DMH,suggesting that specific neuron types and regional specificity are involved in ghrelin regulation of feed intake and energy homeostasis.

Vesicular glutamate transporter 2(VGlut2)is expressed in the PVN of the hypothalamic paraventricular nucleus(PVNVG1ut2)as an excitatory neurotransmitter,which regulates food intake and energy metabolism and plays an important role in maintaining homeostasis.However,it is not clear that the upstream and downstream projection network of PVNVGut2 neurons hinders the anal-ysis of glutamatergic neuron circuit function.Anterograde and retrograde tracer viruses were injec-ted into the PVN of VGlut2 mice by stereotactic brain injection technique to find the input and output nuclei of PVNVGlut2 neurons.Anterograde tracing results showed that PVNVGlut2 neurons pro-jected to the downstream medial amygdala(MeAD)and arcuate nucleus(ARC).Retrograde trac-ing results showed that PVNVGlut2 received input from the prefrontal nucleus(Pr),the reticular tegmental nucleus(RtTg),and the hypoglossal nucleus(12N).In addition,VGlut2 was found to be co-expressed with neuronal nitric oxide synthase(nNOS)neurons in the PVN.The anatomical net-work of PVNVG1ut2 neurons was analyzed by virus tracking tool,which laid the anatomical founda-tion for further study on the functional regulation of PVNVGlut2.

Amylin exerts a satiety-limiting effect on food intake by influencing the regulation of en-ergy metabolism in the central nucleus.However,the binding sites of amylin are widely distributed throughout the central nervous system,and it remains unclear whether the locus coeruleus(LC)responds to amylin stimulation.Therefore,this experiment aims to confirm whether amylin exerts its inhibitory effect on food intake through the LC following localized damage to the LC nucleus.The results indicate that amylin,while suppressing appetite,activates c-Fos neurons and tyrosine hydroxylase(TH)within the LC,leading to increased heat production in the interscapular brown adipose tissue(IBAT)of mice.However,after LC damage,the central feeding inhibition mediated by amylin is alleviated,although it is weaker compared to the group with solely LC damage,and the thermogenic capacity of IBAT is reduced.Thus,the study demonstrates that the LC is also one of the sites of action for exogenous amylin and is crucial for maintaining amylin-induced thermo-genesis.These findings expand the understanding of amylin's central actions and ultimately provide potential targets for obesity treatment.

Amylin exerts a satiety-limiting effect on food intake by influencing the regulation of en-ergy metabolism in the central nucleus.However,the binding sites of amylin are widely distributed throughout the central nervous system,and it remains unclear whether the locus coeruleus(LC)responds to amylin stimulation.Therefore,this experiment aims to confirm whether amylin exerts its inhibitory effect on food intake through the LC following localized damage to the LC nucleus.The results indicate that amylin,while suppressing appetite,activates c-Fos neurons and tyrosine hydroxylase(TH)within the LC,leading to increased heat production in the interscapular brown adipose tissue(IBAT)of mice.However,after LC damage,the central feeding inhibition mediated by amylin is alleviated,although it is weaker compared to the group with solely LC damage,and the thermogenic capacity of IBAT is reduced.Thus,the study demonstrates that the LC is also one of the sites of action for exogenous amylin and is crucial for maintaining amylin-induced thermo-genesis.These findings expand the understanding of amylin's central actions and ultimately provide potential targets for obesity treatment.

Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines, the epidemic prevention and control are still challenging. Here, we employ a capsid and antigen structure engineering (CASE) strategy to manufacture an adeno-associated viral serotype 6-based vaccine (S663V-RBD), which expresses trimeric receptor binding domain (RBD) of spike protein fused with a biological adjuvant RS09. Impressively, the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months. Compared to the licensed BBIBP-CorV (Sinopharm, China), a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type, C.37 (Lambda) and B.1.617.2 (Delta). More interestingly, the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid. Given its effectiveness, the CASE-based S663V-RBD may provide a new solution for the current and next pandemic.

COVID-19/genetics* ; Genome, Viral/genetics* ; Humans ; RNA, Viral/genetics* ; RNA-Seq ; SARS-CoV-2/genetics* ; Whole Genome Sequencing

Objective:To explore the characteristics of T lymphocyte subsets and cytokines in hyperlipidemia-induced acute pancreatitis (HLAP) and its prognostic value.Methods:This study included 184 patients with acute pancreatitis (AP) admitted to the First Affiliated Hospital of Xiamen University from January 2018 to May 2021. Based on disease etiology, there were 92 HLAP cases and 92 non-hyperlipidemia-induced AP (NHLAP) cases. Stratified by disease severity according to 2012 Atlanta classification criteria, the patients were divided into the severe subgroup (SAP) and non-severe subgroup (NSAP). Peripheral venous blood samples were taken from all patients on day 1, 3, and 5 after admission. T lymphocyte subsets were determined by flow cytometry, and cytokines were detected by flow fluorometry. The number of CD4 +% and CD8 +% and the expression of cytokines were compared by Student’s t test or Mann-Whitney U analysis. Logistic regression analyses were performed to identify risk factors for severe AP, and a receiver operating characteristic (ROC) curve was constructed to predict severe AP. Statistical significance was taken as P<0.05. Results:Compared with the NHLAP group, patients in the HLAP group had lower CD4 +%, while higher levels of IL-2 on day 1 ( P<0.05), and had also lower CD4 +%, while higher levels of IL-4, IL-6, and IL-10 on day 3 ( P<0.05). Furthermore, IL-6 and IL-10 levels of the HLAP group were significantly increased compared to the NHLAP group on day 5 ( P<0.05). IL-10 levels in the SAP subgroup were significantly higher than those in the NSAP subgroup on day 1 ( P<0.05). Compared with the NSAP subgroup, the SAP subgroup had elevated levels of IL-2, IL-4, IL-6, IL-10 and IFN-γ on day 3 (all P<0.05), and had lower CD4 +%, while increased levels of IL-6 and IL-10 on day 5 (all P<0.05). Multivariate Logistic regression analysis showed that IL-10 was an immune indicator of independent risk factor for severe AP in the HLAP group on day 1 ( OR=1.139, 95% CI: 1.038-1.251, P<0.05). Finally, ROC analysis showed that the area under the curve of IL-10 to assess HLAP with severe AP was 0.772, and the best cut-off value for predicting severe AP was 5.6 pg/mL, with a sensitivity of 83.3% and a specificity of 68.8%. Conclusions:Changes of CD4 +% and cytokines are different between the HLAP and NHLAP groups. IL-10 can be used as a predictor of early disease severity in patients with HLAP.