Alpha 2-adrenoceptor participates in anti-hyperalgesia by regulating metabolic demand.

The α2-adrenoceptor agonist dexmedetomidine is a commonly used drug for sedatives in clinics and has analgesic effects; however, its mechanism of analgesia in the spine remains unclear. In this study, we systematically used behavioural and transcriptomic sequencing, pharmacological intervention, electrophysiological recording and ultrasound imaging to explore the analgesic effects of the α2-adrenoceptor and its molecular mechanism. Firstly, we found that spinal nerve injury changed the spinal transcriptome expression, and the differential genes were mainly related to calcium signalling and tissue metabolic pathways. In addition, α2-adrenoceptor mRNA expression was significantly upregulated, and α2-adrenoceptor was significantly colocalised with markers, particularly neuronal markers. Intrathecal dexmedetomidine suppressed neuropathic pain and acute inflammatory pain in a dose-dependent manner. The transcriptome results demonstrated that the analgesic effect of dexmedetomidine may be related to the modulation of neuronal metabolism. Weighted gene correlation network analysis indicated that turquoise, brown, yellow and grey modules were the most correlated with dexmedetomidine-induced analgesic effects. Bioinformatics also annotated the involvement of metabolic processes and neural plasticity. A cardiovascular-mitochondrial interaction was found, and ultrasound imaging revealed that injection of dexmedetomidine significantly enhanced spinal cord perfusion in rats with neuropathic pain, which might be regulated by pyruvate dehydrogenase kinase 4 (pdk4), cholesterol 25-hydroxylase (ch25 h) and GTP cyclohydrolase 1 (gch1). Increasing the perfusion doses of dexmedetomidine significantly suppressed the frequency and amplitude of spinal nerve ligation-induced miniature excitatory postsynaptic currents. Overall, dexmedetomidine exerts analgesic effects by restoring neuronal metabolic processes through agonism of the α2-adrenoceptor and subsequently inhibiting changes in synaptic plasticity.

Posttraumatic stress disorder symptoms among healthcare workers during the Omicron era.

Background: The COVID-19 pandemic has caused significant psychological stress among healthcare workers. This study aimed to clarify the factors that influenced health workers' posttraumatic stress disorder (PTSD) symptoms. Method: A total of 443 healthcare workers from eight Mental Health Centers in Shandong were recruited to attend an online survey. Participants completed self-evaluation measures of exposure to the COVID-19 environment and PTSD symptoms, as well as measures of potential protective factors such as euthymia and perceived social support. Results: About 45.37% of healthcare workers had severe symptoms of PTSD symptoms. Healthcare workers with more serious PTSD symptoms were significantly related to higher exposure to COVID-19 (r = 0.177, p < 0.001), as well as lower levels of euthymia (r = -0.287, p < 0.001) and perceived social support (r = -0.236, p < 0.001). The structural equation model (SEM) further revealed that the impact of exposure to COVID-19 on PTSD symptoms was partially mediated by euthymia, and moderated by perceived social support, especially from others (e.g., friends, leaders, relatives and colleagues). Conclusion: These findings suggested that improving the state of euthymia, getting social support from others could alleviate PTSD symptoms among healthcare workers during the COVID-19.

Splenectomy does not affect mouse behaviors.

The spleen is critical for immunity. It is the largest immune organ and immune center in the peripheral system. While the relationship between behavior and immunity has been demonstrated in physiology and diseases, the role of the spleen in behavior is not clear. To investigate the effects of the spleen on behaviors, we performed a refined splenectomy procedure on C57BL/6J mice and performed an open field test, circadian rhythm test, elevated plus maze, sucrose preference test, and Barnes maze test. Splenectomy did not induce changes in general locomotion, circadian rhythms, learning and memory, or depression/anxiety-related behaviors. To further investigate the effects of spleen on stress susceptibility, we established mouse models of depression through chronic unpredictable mild stress. The behavioral performances of mice subjected to splenectomy showed no differences from control animals. These findings suggest that splenectomy does not cause changes in baseline behavioral performance in mice.

Dual-stimuli responsive smart nanoprobe for precise diagnosis and synergistic multi-modalities therapy of superficial squamous cell carcinoma.

BACKGROUND: Although the promising advancements of current therapeutic approaches is available for the squamous cell carcinoma (SCC) patients, the clinical treatment of SCC still faces many difficulties. The surgical irreparable disfigurement and the postoperative wound infection largely hamper the recovery, and the chemo/radiotherapy leads to toxic side effects. RESULTS: Herein, a novel pH/Hyaluronidase (HAase) dual-stimuli triggered smart nanoprobe FeIIITA@HA has been designed through the biomineralization of Fe3+ and polyphenol tannic acid (TA) under the control of hyaluronic acid (HA) matrix. With the HA residues on the outer surface, FeIIITA@HA nanoprobes can specifically target the SCC cells through the over-expressed CD44, and accumulate in the carcinoma region after intravenously administration. The abundant HAase in carcinoma microenvironment will trigger the degradation of HA molecules, thereby exposing the FeIIITA complex. After ingesting by tumor cells via CD44 mediated endocytosis, the acidic lysosomal condition will further trigger the protonation of TA molecules, finally leading to the Fe3+ release of nanoprobe, and inducing a hybrid ferroptosis/apoptosis of tumor cells through peroxidase activity and glutathione depletion. In addition, Owing to the outstanding T1 magnetic resonance imaging (MRI) performance and phototermal conversion efficiency of nanoprobes, the MRI-guided photothermal therapy (PTT) can be also combined to complement the Fe3+-induced cancer therapy. Meanwhile, it was also found that the nanoprobes can promote the recruitment of CD4+ and CD8+ T cells to inhibit the tumor growth through the cytokines secretion. In addition, the FeIIITA@HA nanoprobes can be eliminated from the body and no obvious adverse side effect can be found in histological analysis, which confirmed the biosafety of them. CONCLUSION: The current FeIIITA@HA nanoprobe has huge potential in clinical translation in the field of precise diagnosis and intelligent synergistic therapy of superficial SCC. This strategy will promisingly avoid the surgical defects, and reduce the systemic side effect of traditional chemotherapy, paving a new way for the future SCC treatment.

Red Blood Cell Membrane-Coated Ultrasmall NaGdF4 Nanoprobes for High-Resolution 3D Magnetic Resonance Angiography.

Enhanced angiography based on magnetic resonance imaging (MRI) has emerged as a noninvasive, robust, and high-resolution imaging technique for the clinical evaluation of vascular diseases. However, the effects of clinical Gd-chelating contrast agents are unsatisfactory for MRI contrast enhancement owing to their short blood half-life caused by rapid vascular extravasation, especially in microvessels. To address these issues, nanoprobes based on red blood cell membrane-coated ultrasmall NaGdF4 nanoparticles that exhibit much higher longitudinal molar relaxivity (r1) than the clinically used contrast agent gadolinium diethylenetriaminepentaacetic acid have been developed. Furthermore, the appropriate hydrodynamic diameter and stealth nature aid the nanoprobes to reside longer within the blood vessels without extravasation, thereby increasing the contrast between the blood vessels and surrounding tissues. Through probe-enhanced three-dimensional (3D) dynamic contrast-enhanced MR angiography, the main arteries and veins of the mouse were readily discernible, and even tiny vessels with sub-millimeter diameters could be clearly depicted. With this level of outstanding MR angiography performance, the embolization and recanalization processes of the carotid artery can be serially monitored with high imaging resolution using only a single injection. Additionally, the results of clearance studies and the toxicity tests further highlight the safety features of the nanoprobe. To summarize, the nanoprobes used in this study exhibit less extravascular leakage and a longer blood half-life, thus successfully overcoming the defects of the conventional low-molecular-weight Gd-based contrast agents and demonstrating their potential usefulness in enhanced MR angiography.

Complete genome characterization of the 2018 dengue outbreak in Hunan, an inland province in central South China.

In 2018, a small-scale dengue epidemic broke out in Hunan Province, an inland province in central South China, with 172 people infected. To verify the causative agent, complete genome information was obtained by PCR and sequencing based on the viral RNAs extracted from patient serum samples. Mutation and evolutionary analysis were performed by MEGA7.0 software. The online softwares "Predict protein" and "Mfold" were used to predict the secondary structure of proteins and untranslated regions, respectively. Phylogenetic analysis showed that all five isolates in this study were DENV type 2, which is most closely related to the Zhejiang strain (2017-MH110588). Compared with the DENV-2 standard strain, 773 nucleotide mutations occurred in the isolated strain, of which 666 were nonsense mutations. Of the 80 mutated amino acids, 22 occurred in the structural protein region (2 in C region, 8 in PrM/M region, 12 in E region), and 58 in the non-structural (NS) protein region (9 in NS1 region, 10 in NS2 region, 12 in NS3 region, 7 in NS4 region, 20 in NS5 region). The prM/M region had the highest AA mutation rate, while NS4B was conservative. Three amino acid mutations (E: N390thS, and NS5: S676thN, K800thT) may important for the replication and virulence of the DENV. Secondary structure prediction observed 28 changes in polynucleotide binding regions and 110 changes in protein binding sites of coding sequence. 2 and 4 base substitutions resulted in 2 and 6 significant changes in the RNA secondary structure of 5' UTR and 3' UTR, respectively. Two significant positive selection sites were observed in NS5. To our knowledge, this research is the first complete genome analysis of the epidemic strain of the 2018 dengue outbreak in Hunan and will benefit further research for virus traceability and vaccine development.

Molecular characterization of the viral structural protein genes in the first outbreak of dengue virus type 2 in Hunan Province, inland China in 2018.

BACKGROUND: An unexpected dengue outbreak occurred in Hunan Province in 2018. This was the first dengue outbreak in this area of inland China, and 172 cases were reported. METHODS: To verify the causative agent of this outbreak and characterise the viral genes, the genes encoding the structural proteins C/prM/E of viruses isolated from local residents were sequenced followed by mutation and phylogenetic analysis. Recombination, selection pressure, potential secondary structure and three-dimensional structure analyses were also performed. RESULTS: Phylogenetic analysis revealed that all epidemic strains were of the cosmopolitan DENV-2 genotype and were most closely related to the Zhejiang strain (MH010629, 2017) and then the Malaysia strain (KJ806803, 2013). Compared with the sequence of DENV-2SS, 151 base substitutions were found in the sequences of 89 isolates; these substitutions resulted in 20 non-synonymous mutations, of which 17 mutations existed in all samples (two in the capsid protein, six in the prM/M proteins, and nine in the envelope proteins). Moreover, amino acid substitutions at the 602nd (E322:Q → H) and 670th (E390: N → S) amino acids may have enhanced the virulence of the epidemic strains. One new DNA binding site and five new protein binding sites were observed. Two polynucleotide binding sites and seven protein binding sites were lost in the epidemic strains compared with DENV-2SS. Meanwhile, five changes were found in helical regions. Minor changes were observed in helical transmembrane and disordered regions. The 429th amino acid of the E protein switched from a histamine (positively charged) to an asparagine (neutral) in all 89 isolated strains. No recombination events or positive selection pressure sites were observed. To our knowledge, this study is the first to analyse the genetic characteristics of epidemic strains in the first dengue outbreak in Hunan Province in inland China. CONCLUSIONS: The causative agent is likely to come from Zhejiang Province, a neighbouring province where dengue fever broke out in 2017. This study may help clarify the intrinsic geographical relatedness of DENV-2 and contribute to further research on pathogenicity and vaccine development.

Efficient Delivery of Nerve Growth Factors to the Central Nervous System for Neural Regeneration.

The central nervous system (CNS) plays a central role in the control of sensory and motor functions, and the disruption of its barriers can result in severe and debilitating neurological disorders. Neurotrophins are promising therapeutic agents for neural regeneration in the damaged CNS. However, their penetration across the blood-brain barrier remains a formidable challenge, representing a bottleneck for brain and spinal cord therapy. Herein, a nanocapsule-based delivery system is reported that enables intravenously injected nerve growth factor (NGF) to enter the CNS in healthy mice and nonhuman primates. Under pathological conditions, the delivery of NGF enables neural regeneration, tissue remodeling, and functional recovery in mice with spinal cord injury. This technology can be utilized to deliver other neurotrophins and growth factors to the CNS, opening a new avenue for tissue engineering and the treatment of CNS disorders and neurodegenerative diseases.

Enhanced Delivery of Rituximab Into Brain and Lymph Nodes Using Timed-Release Nanocapsules in Non-Human Primates.

Tumor metastasis into the central nervous system (CNS) and lymph nodes (LNs) is a major obstacle for effective therapies. Therapeutic monoclonal antibodies (mAb) have revolutionized tumor treatment; however, their efficacy for treating metastatic tumors-particularly, CNS and LN metastases-is poor due to inefficient penetration into the CNS and LNs following intravenous injection. We recently reported an effective delivery of mAb to the CNS by encapsulating the anti-CD20 mAb rituximab (RTX) within a thin shell of polymer that contains the analogs of choline and acetylcholine receptors. This encapsulated RTX, denoted as n-RTX, eliminated lymphoma cells systemically in a xenografted humanized mouse model using an immunodeficient mouse as a recipient of human hematopoietic stem/progenitor cells and fetal thymus more effectively than native RTX; importantly, n-RTX showed notable anti-tumor effect on CNS metastases which is unable to show by native RTX. As an important step toward future clinical translation of this technology, we further analyzed the properties of n-RTX in immunocompetent animals, rats, and non-human primates (NHPs). Our results show that a single intravenous injection of n-RTX resulted in 10-fold greater levels in the CNS and 2-3-fold greater levels in the LNs of RTX, respectively, than the injection of native RTX in both rats and NHPs. In addition, we demonstrate the enhanced delivery and efficient B-cell depletion in lymphoid organs of NHPs with n-RTX. Moreover, detailed hematological analysis and liver enzyme activity tests indicate n-RTX treatment is safe in NHPs. As this nanocapsule platform can be universally applied to other therapeutic mAbs, it holds great promise for extending mAb therapy to poorly accessible body compartments.

Comparison analysis of microRNAs in response to dengue virus type 2 infection between the Vero cell-adapted strain and its source, the clinical C6/36 isolated strain.

To elucidate the differences in microRNAs during dengue virus infection between Vero cell-adapted strain (DENV-2-Vero) and its source, the clinical C6/36 isolated strain (DENV-2-C6/36), a comparison analysis was performed in Vero cells by high throughput sequencing. The results showed that the expression of 16 known and 3 novel miRNAs exhibited marked differences. 5 known miRNAs were up-regulated in DENV-2-C6/36 group, while 11 known microRNAs were down-regulated in DENV-2-Vero group. The GO enrichment and KEGG pathway analysis showed that there was a distinct difference in regulating viral replication between two strains. In DENV-2-Vero infection group, significantly enriched GO terms included virion attachment to host cells, viral structural protein/genome processing and packaging. Meanwhile, the regulation of cell death and apoptosis between two groups were different in the early stage of infection. KEGG enrichment analysis showed that DENV-2-C6/36 infection induced more intense regulation of immune-related pathways, including Fc gamma R-mediated phagocytosis, etc. DENV-2-Vero infection could partially alleviate the immune defense of Vero cells compared with DENV-2-C6/36. The results indicated that the distinct microRNA changes induced by two DENV-2 strains may be partly related to their infective abilities. Our data provide useful insights that help elucidate the host-pathogen interactions following DENV infection.