Quantitative Proteomics Provided Insights into the Protective Effects of Heat Acclimation on the Rat Hypothalamus after Exertional Heatstroke.

BACKGROUND: The effects of heat acclimation (HA) on the hypothalamus after exertional heatstroke (EHS) and the specific mechanism have not been fully elucidated, and this study aimed to address these questions. METHODS: In the present study, rats were randomly assigned to the control, EHS, HA, or HA + EHS groups (n = 9). Hematoxylin and eosin (H&E) staining was used to examine pathology. Tandem mass tag (TMT)-based proteomic analysis was utilized to explore the impact of HA on the protein expression profile of the hypothalamus after EHS. Bioinformatics analysis was used to predict the functions of the differentially expressed proteins. The differential proteins were validated by western blotting. An enzyme-linked immunosorbent assay was used to measure the expression levels of inflammatory cytokines in the serum. RESULTS: The H&E staining (n = 5) results revealed that there were less structural changes in hypothalamus in the HA + EHS group compared with the EHS group. Proteomic analysis (n = 4) revealed that proinflammatory proteins such as argininosuccinate synthetase (ASS1), high mobility group protein B2 (HMGB2) and vimentin were evidently downregulated in the HA + EHS group. The levels of interleukin (IL)-1ß, IL-1, and IL-8 were decreased in the serum samples (n = 3) from HA + EHS rats. CONCLUSIONS: HA may alleviate hypothalamic damage caused by heat attack by inhibiting inflammatory activities, and ASS1, HMGB2 and vimentin could be candidate factors involved in the exact mechanism.

Acquired heat acclimation in rats subjected to physical exercise under environmental heat stress alleviates brain injury caused by exertional heat stroke.

BACKGROUND: Exertional heatstroke (EHS) is an emergency with a high mortality rate, characterized by central nervous system dysfunctions. This study aims to establish a Heat acclimation/acclimatization (HA) rat model in locomotion to recapitulate the physical state of human in severe environment of high temperature and humidity, and investigate the mechanism of organism protection in HA. (2) Methods: Wistar rats were exposed to 36 °C and ran 2 h/d for 21 days, acquired thermal tolerance test was conducted to assess the thermotolerance and exercise ability. Core temperature and consumption of water and food were observed. Expression of HSP70 and HSP90 of different tissues were determined by WB. Pathological structure of brain tissue was detected with HE staining. Proteomics was used to identify the differently expressed proteins in cerebral cortex of different groups. And key molecules were identified by RT-PCR and WB. (3) Results: HA rats displayed stronger thermotolerance and exercised ability on acquired thermal tolerance test. Brain water content of HA + EHS group reduced compared with EHS group. HE staining revealed slighter brain injuries of HA + EHS group than that of EHS. Proteomics focused on cell death-related pathways and key molecules Aquaporin 4 (AQP4) related to cell edema. Identification results showed HA increased AQP4, Bcl-xl, ratio of p-Akt/AKT and Bcl-xl/Bax, down-regulated Cleaved Caspase-3. (4) Conclusions: This HA model can ameliorate brain injury of EHS by reducing cerebral edema and cell apoptosis, offering experimental evidence for EHS prophylaxis.

Low p-SYN1 (Ser-553) Expression Leads to Abnormal Neurotransmitter Release of GABA Induced by Up-Regulated Cdk5 after Microwave Exposure: Insights on Protection and Treatment of Microwave-Induced Cognitive Dysfunction.

With the wide application of microwave technology, concerns about its health impact have arisen. The signal transmission mode of the central nervous system and neurons make it particularly sensitive to electromagnetic exposure. It has been reported that abnormal release of amino acid neurotransmitters is mediated by alteration of p-SYN1 after microwave exposure, which results in cognitive dysfunction. As the phosphorylation of SYN1 is regulated by different kinases, in this study we explored the regulatory mechanisms of SYN1 fluctuations following microwave exposure and its subsequent effect on GABA release, aiming to provide clues on the mechanism of cognitive impairment caused by microwave exposure. In vivo studies with Timm and H&E staining were adopted and the results showed abnormality in synapse formation and neuronal structure, explaining the previously-described deficiency in cognitive ability caused by microwave exposure. The observed alterations in SYN1 level, combined with the results of earlier studies, indicate that SYN1 and its phosphorylation status (ser-553 and ser62/67) may play a role in the abnormal release of neurotransmitters. Thus, the role of Cdk5, the upstream kinase regulating the formation of p-SYN1 (ser-553), as well as that of MEK, the regulator of p-SYN1 (ser-62/67), were investigated both in vivo and in vitro. The results showed that Cdk5 was a negative regulator of p-SYN1 (ser-553) and that its up-regulation caused a decrease in GABA release by reducing p-SYN1 (ser-553). While further exploration still needed to elaborate the role of p-SYN1 (ser-62/67) for neurotransmitter release, MEK inhibition had was no impact on p-Erk or p-SYN1 (ser-62/67) after microwave exposure. In conclusion, the decrease of p-SYN1 (ser-553) may result in abnormalities in vesicular anchoring and GABA release, which is caused by increased Cdk5 regulated through Calpain-p25 pathway after 30 mW/cm2 microwave exposure. This study provided a potential new strategy for the prevention and treatment of microwave-induced cognitive dysfunction.

Molecular Detection and Phylogenetic Characterization of Bat and Human Adenoviruses in Southern China.

Several novel adenoviruses (AdVs) have recently been identified in humans and other animal species. In this study, we report the molecular detection of and phylogenetically characterize bat and human AdVs detected in fecal or rectal swab samples collected in southern China. To detect AdVs, a 252-261 bp fragment of the DNA polymerase (DPOL) gene was amplified using nested PCR. A total of 520 rectal swab samples were collected from eight bat species in four geographic regions of southern China (Guangzhou, Yunfu, Huizhou, and Haikou city). Thirty-six (6.9%) samples from the following species tested positive for AdVs: Myotis ricketti, Miniopterus schreibersii, Scotophilus kuhlii, Taphozous melanopogon, Rhinolophus blythi, and Cynopterus sphinx. Eight novel AdVs were detected in 13.3% of the samples from C. sphinx. Of 328 fecal samples from patients with diarrhea, 16 (4.9%) were positive for classical human AdVs. Phylogenetic analysis showed that human AdVs shared low similarity (57.1-69.3%) with bat AdVs in deduced amino acid sequences of the AdV DPOL region. Thus, our study indicated that bat AdVs and human AdVs are species specific. As such, there is no evidence of cross-species transmission of AdV between bats and humans based on current data.

High prevalence and diversity of viruses of the subfamily Gammaherpesvirinae, family Herpesviridae, in fecal specimens from bats of different species in southern China.

Several studies have reported the detection of herpesviruses (HVs) in bats. However, the prevalence and phylogenetic characteristics of HVs in bats are still poorly understood. To elucidate the epidemiological characteristics of bat HVs in southern China, 520 fecal samples from eight bat species were collected in four geographic regions of southern China. Of these samples, 73 (14.0 %) tested positive for HVs using nested polymerase chain reaction assay. Phylogenetic analysis revealed a high degree of molecular diversity of HVs in bats of different species from different geographic regions. Our study provides evidence for co-evolution of bats and HVs.

[Detection of High Molecular Weight Polycyclic Aromatic Hydrocarbons in Mixed Colloid Solution of Spherical Au and Urchin-Like Au-Ag Alloy with Surface-Enhanced Raman Scattering].

In this paper, Au nanosphere and Au-Ag alloy nanourchin were prepared by reducing the chloroauric acid. The mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin were used as surface-enhanced Raman scattering (SERS) substrate to detect polycyclic aromatic hydrocarbons (PAHs) in aqueous solution. The size of Au-Ag alloy nanourchin particle was about 300~400 nm and the thorn-like bulge covered on it was about 40~100 nm. The mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin which were optimized pH values and other parameters presented a better enhancement than Au nanosphere. The enhancement effect was about three times that of Au nanosphere colloid solution. Three kinds of high molecular weight PAHs, pyrene(4 rings), benzoanthracene(4 rings) and benzo[a]pyrene(5 rings), were detected. The results showed that there were good linear relationships between Raman intensity and concentration in the low concentration range and the mixed SERS substrate had a good reproducibility and stability. Their limits of detection (LODs) were 0.44, 2.92 and 1.64 nmol·L-1, respectively. The innovation of this paper was that the mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin are prepared as SERS substrate and the trace-level high molecular weight PAHs are detected. The results show that the detection of trace-level high molecular weight PAHs in aqueous can be realized using the mixed SERS substrate prepared in this study, which proposed an in-situ method for detecting the high molecular weight PAHs in aqueous.