Transcriptomics and UHPLC-QQQ-MS analyses reveal the dysregulation of branched chain amino acids metabolism in renal fibrotic rats.

The dysregulated levels of branched chain amino acids (BCAA) contribute to renal fibrosis in chronic kidney disease (CKD), yet specific analysis of BCAA contents and how they are regulated still remain unclear. It is therefore of great scientific interest to understand BCAA catabolism in CKD and develop a sensitive method for simultaneous determination of individual BCAA and their metabolites branched chain α-ketoacids (BCKA). In this work, the important role of BCAA metabolism that drives renal fibrosis in the process of CKD was first revealed by using transcriptomics. The key target genes controlling BCAA metabolism were then validated, that is, mRNA levels of BCKDHA and BCKDHB, the regulating rate-limiting enzymes during BCAA metabolism were abnormally reduced by quantitative PCR (qPCR), and a similar drop-off trend of protein expression of BCKDH, HIBCH and MCCC2 that are closely related to BCAA metabolism was also confirmed by western blotting. Furthermore, we established a novel strategy that simultaneously determines 6 individual BCAA and BCKA in serum and tissue. The method based on dansylhydrazine derivatization and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry (UHPLC-QQQ-MS) achieved to simultaneously determine the contents of BCAA and BCKA, which is efficient and stable. Compared with normal rats, levels of BCAA including leucine, isoleucine and valine in serum and kidney of CKD rats was decreased, while BCKA including α-ketoisocaproic acid, α-ketomethylvaleric acid and α-ketoisovaleric acid was increased. Together, these findings revealed the abnormality of BCAA metabolism in driving the course of kidney fibrosis and CKD. Our current study sheds new light on changes in BCAA metabolism during CKD, and may facilitate development of drugs to treat CKD and renal fibrosis.

Marine glycoproteins: a mine of their structures, functions and potential applications.

Many bioactive compounds are reported from marine organisms, which are significantly different from those found in terrestrial organisms regarding their chemical structures and pharmacological activities. Marine glycoproteins (MGs) have aroused increasing attention as a good nutrient source owing to their potential applications in medicine, cosmetics and food. However, there is a lack of a comprehensive study on MGs to help readers understand the current state of research on marine-derived glycoproteins. The current review compiles the recent progress made on the structures and functions of MGs with future perspectives to maximize their value and applications via bibliometric analysis methods for the first time. The current research on MGs appears mostly limited to the laboratory, with no large-scale production of marine glycoproteins developed. The sugar chains are bound to proteins through covalent bonds that can readily be cleaved leading to difficultly in their separation and purification. Health effects attributed to MGs include treatment of inflammatory diseases, as well as anti-oxidant, immune modulation, anti-tumor, hypolipidemic, hypoglycemic, anti-bacterial and anti-freeze activities. This review can not only deepen the understanding of the functions of MGs, but also lay an important foundation for the further development and utilization of marine resources.

Overview on isolation, structural and functional properties of marine glycoproteins (MGs) via bibliometric analysis methods for the first time.Marine glycoproteins (MGs) have various biological activities and potential health applications.glycoproteins from marine organisms (MGs) significantly enhanced anti-oxidant and anti-inflammatory activities.

The Anti-Fatigue Effect of Glycoprotein from Hairtail Fish (Trichiurus lepturus) on BALB/c Mice.

Fatigue is related to a variety of chronic diseases and has become a hot research topic in recent years. Various bioactive components have been extracted from hairtail fish (Trichiurus lepturus); however, none of these studies involved the anti-fatigue activity of hairtail fish glycoprotein (HGP). Thus, antioxidant experiments were conducted in vitro, and the anti-fatigue activity of HGP was further evaluated in BALB/c mice. The effects of HGP on the behavior of BALB/c mice were verified by classical behavioral experiments, and the indicators related to anti-fatigue activity were detected. The results showed that the antioxidant capacity in vitro of HGP increased gradually in the concentration range of 10 to 100 mg/mL. HGP improved the exercise ability of the mice. HGP was also found to significantly (p < 0.05) reduce the serum levels of lactate dehydrogenase (LDH), blood lactic acid (BLA), blood urea nitrogen (BUN), and creatine kinase (CK). The contents of liver glycogen (LG) and muscle glycogen (MG) were also significantly (p < 0.05) increased by HGP. Malondialdehyde (MDA) content in the serum and brains of the mice was significantly (p < 0.05) reduced and catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD) were significantly (p < 0.05) increased by HGP, especially in the middle- and high-dose groups. These results enhance our understanding of the anti-fatigue function of HGP and lay an important foundation for the further development and utilization of hairtail fish resources.

Effective Preservation of Chilled Pork Using Photodynamic Antibacterial Film Based on Curcumin-ß-Cyclodextrin Complex.

A biodegradable photodynamic antibacterial film (PS-CF) was prepared using the casting method, with κ-Carrageenan (κ-Car) as the film-forming substrate and curcumin-ß-cyclodextrin (Cur-ß-CD) complex as photosensitizer. Chilled pork samples were coated with PS-CF and stored at 4 °C to investigate the effects of PS-CF combined with LED light irradiation (425 nm, 45 min) (PS+L+) on pork preservation during 10 days of storage. The total viable count (TVC) of bacteria, total volatile basic nitrogen value (TVB-N) and the pH of pork treated with PS+L+ were all lower than the control, and the water-holding capacity (WHC) was higher. Ten days later, the TVB-N value was 12.35 ± 0.57 mg/100 g and the TVC value was 5.78 ± 0.17 log CFU/g, which was within the acceptable range. Sensory evaluation determined that the color, odor, and overall acceptability of pork treated with PS+L+ were significantly better than the control. These findings suggest that PS+L+ treatment effectively extended the shelf life of chilled pork from ~4-5 to 10 days. Correlation analysis showed that the sensory quality of the chilled pork significantly correlated with total bacterial counts, TVB-N and thiobarbituric acid reactive substances (TBARS) (p < 0.05), suggesting that these biomarkers could be used as standard indicators for evaluating the freshness of chilled pork. These findings demonstrate the effectiveness of Cur-ß-CD photodynamic antibacterial film for the preservation of chilled pork and provide a theoretical basis for the application of the film for the preservation of fresh food in general.

Intervention Effects of Okra Extract on Brain-Gut Peptides and Intestinal Microorganisms in Sleep Deprivation Rats.

Objective: Okra, possessing various bioactive components, is used to treat different diseases. This study sought to estimate the intervention effects of okra extract (OE) on brain-gut peptides (BGPs) and intestinal microorganisms in sleep deprivation (SD) rats. Methods: SD rat models were established using the modified multiple platform method and then treated with normal saline, diazepam tablets, or different doses of OE. Body weight and average daily water consumption of rats were recorded. Depressive behaviors of rats were assessed by the open field test and sucrose preference test. Serum levels of noradrenaline, melatonin, inflammatory factors (IL-1ß/IL-6/TNF-α/IL-4/IL-10), and BGP indexes, including gastrin (GAS), motilin (MTL), 5-hydroxytryptamine (5-HT), cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were measured by ELISA. Additionally, the DNA relative contents of representative intestinal microorganisms in the collected rat feces were determined using RT-qPCR. Results: SD decreased body weight and average daily water consumption and induced depressive behaviors as well as stress and inflammatory responses in rats. SD rats exhibited lowered GAS, MTL, 5-HT, and VIP but elevated CCK and showed diminished DNA relative contents of Bacteroidetes and probiotics (Bifidobacteria and Lactobacilli) but increased Clostridium perfringens. OE at different doses ameliorated the depressive behaviors and mitigated the stress and inflammatory responses in SD rats, raised the serum contents of GAS, MTL, 5-HT, and VIP, reduced CCK level, elevated the DNA relative contents of Bacteroidetes and probiotics, but diminished Clostridium perfringens. OE exhibited similar intervention effects to diazepam tablets (positive control). Conclusion: OE exerts intervention effects on BGPs and intestinal microorganisms in SD rats.

Essential oil of Magnolia denudata is an effective anesthetic for spotted seabass (Lateolabrax maculatus): a test of its effect on blood biochemistry, physiology, and gill morphology.

Magnolia denudata is a well-known ornamental tree in China due to its beautiful blossoms, and it has been used as an analgesic to treat human headaches. This study investigated the anesthetic potential and physiological response of the essential oil of M. denudata flowers on spotted seabass Lateolabrax maculatus. Fish (mean ± SD, 164.16 ± 15.40 g) were individually exposed to different concentrations of M. denudata essential oil (MDO, 10, 20, 40, 60, 80, 100, and 120 mg/L) and eugenol (10, 20, 30, 40, 50, 60, and 70 mg/L) to investigate anesthetic efficacy. Based on the ideal time criterion for anesthetic induction (< 3 min) and recovery (< 10 min), the lowest effective concentration for spotted seabass was 100 mg/L for MDO and 60 mg/L for eugenol. The physiological and histopathological damage in the gill of L. maculatus after using MDO and eugenol was also evaluated at the minimum dose inducing deep anesthesia, and at 0, 6, and 24 h after recovery. The results showed that MDO and eugenol anesthesia alleviated the levels of cortisol and glucose and the lactic dehydrogenase activity induced by handling. Compared with eugenol, MDO also caused secondary stress to the body, but MDO caused minor physiological responses and histological changes in the gills. This study suggests that MDO is an effective anesthetic for spotted seabass.

Isoquercetin alleviates sleep deprivation dependent hippocampal neurons damage by suppressing NLRP3-induced pyroptosis.

Purpose: Sleep deprivation (SD) leads to memory and cognitive impairment due to damage to the hippocampus. Isoquercetin possesses neuron-protective properties. Our study aimed to investigate the effects of isoquercetin on SD-induced hippocampal neurons damage and the underlying mechanism.Materials and methods: Herein, the cognitive competence was evaluated by Morris water maze test after SD. The morphology of the hippocampus was observed after Nissl staining. Moreover, the level of NLRP3 was detected by Immunofluorescent staining and western blot. In vitro study, pyroptosis was tested by TUNEL assay and flow cytometry. The levels of pyroptosis-related factors were measured by western blot.Results: The results indicated that isoquercetin improved spatial memory and prevented change of hippocampal neurons of SD mice. Moreover, SD upregulated NLRP3 level, which was downregulated by isoquercetin. Additionally, isoquercetin rescued the increase of pyroptosis and the upregulation of NLRP3, caspase-1, ASC, IL-1ß, IL-18, and GSDMD levels induced by LPS.Conclusions: In conclusion, isoquercetin improved learning and cognitive capability of SD mice via suppressing NLRP3-induced pyroptosis of hippocampal neurons cells, suggesting that isoquercetin might be an efficacious drug for memory disorders caused by SD.

An increase in VGF expression through a rapid, transcription-independent, autofeedback mechanism improves cognitive function.

The release of neuropeptides from dense core vesicles (DCVs) modulates neuronal activity and plays a critical role in cognitive function and emotion. The granin family is considered a master regulator of DCV biogenesis and the release of DCV cargo molecules. The expression of the VGF protein (nonacronymic), a secreted neuropeptide precursor that also belongs to the extended granin family, has been previously shown to be induced in the brain by hippocampus-dependent learning, and its downregulation is mechanistically linked to neurodegenerative diseases such as Alzheimer's disease and other mood disorders. Currently, whether changes in translational efficiency of Vgf and other granin mRNAs may be associated and regulated with learning associated neural activity remains largely unknown. Here, we show that either contextual fear memory training or the administration of TLQP-62, a peptide derived from the C-terminal region of the VGF precursor, acutely increases the translation of VGF and other granin proteins, such as CgB and Scg2, via an mTOR-dependent signaling pathway in the absence of measurable increases in mRNA expression. Luciferase-based reporter assays confirmed that the 3'-untranslated region (3'UTR) of the Vgf mRNA represses VGF translation. Consistently, the truncation of the endogenous Vgf mRNA 3'UTR results in substantial increases in VGF protein expression both in cultured primary neurons and in brain tissues from knock in mice expressing a 3'UTR-truncation mutant encoded by the modified Vgf gene. Importantly, Vgf 3'UTR-truncated mice exhibit enhanced memory performance and reduced anxiety- and depression-like behaviors. Our results therefore reveal a rapid, transcription-independent induction of VGF and other granin proteins after learning that are triggered by the VGF-derived peptide TLQP-62. Our findings suggest that the rapid, positive feedforward increase in the synthesis of granin family proteins might be a general mechanism to replenish DCV cargo molecules that have been released in response to neuronal activation and is crucial for memory function and mood stability.

Hydroalcoholic extract from Abelmoschus manihot (Linn.) Medicus flower reverses sleep deprivation-evoked learning and memory deficit.

Previous researches have indicated that sleep plays a vital role in cognitive functions. Sleep deprivation (SD) causes learning and memory damage, which is associated with oxidative stress. This study was performed to investigate the neuroprotective effects of an extract of Abelmoschus manihot flower (EAM) against memory deficit induced by SD in mice. The SD model was evoked by multiple platform method for 5 days, successively. The learning and memory-improving effects of EAM were assessed by behavioral trials and the underlying mechanism was investigated by measuring the oxidative stress alteration. Our findings indicated that the SD-induced memory deficit and the EAM treatment improved the cognitive functions of mice in the object location recognition test and passive avoidance task. In addition, EAM effectively improved the activities of the antioxidant enzyme, decreased the content of malondialdehyde (MDA), and restored the protein expression of the brain-derived neurotrophic factor (BDNF), tyrosine kinase B (TrkB) and glutamate receptor 1 (GluR1) in brain tissues. In conclusion, EAM could improve the SD-evoked learning and memory impairments. The possible underlying mechanisms of EAM may be related to its antioxidant capacity and enhanced BDNF/TrkB/GluR1 levels in the hippocampal memory.

Local injection to sciatic nerve of dexmedetomidine reduces pain behaviors, SGCs activation, NGF expression and sympathetic sprouting in CCI rats.

Neuropathic pain has become an intractable health threat, with its profound effect on quality of life. Dorsal root ganglia (DRG) is evidenced to play a crucial role in neuropathic pain. The peripheral nociceptive afferents seem to be essential not only to initiate the process of neuropathic pain, but also to maintain and modulate it. Dexmedetomidine (DEX), a highly selective agonist of α2-adrenergic receptor (α2-AR), has provided significant analgesia in neuropathic pain. In the present study, we found that local injection to sciatic nerve of DEX alleviated heat hypersensitivity induced by chronic constriction injury (CCI). Western blotting revealed that DEX inhibited the over-expression of nerve growth factor (NGF) significantly. Immunohistofluorescence results showed that DEX inhibited glia cells activation and sympathetic sprouting simultaneously in DRG. Our study suggests that DEX attenuates neuropathic pain in CCI rats by down-regulation of satellite glial cells (SGCs) activation, NGF expression and sympathetic sprouting.

Necrostatin-1 protection of dopaminergic neurons.

Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson's disease. We hypothesized that necrostatin-1 could block necroptosis and give protection to dopaminergic neurons. There is likely to be crosstalk between necroptosis and other cell death pathways, such as apoptosis and autophagy. PC12 cells were pretreated with necroststin-1 1 hour before exposure to 6-hydroxydopamine. We examined cell viability, mitochondrial membrane potential and expression patterns of apoptotic and necroptotic death signaling proteins. The results showed that the autophagy/lysosomal pathway is involved in the 6-hydroxydopamine-induced death process of PC12 cells. Mitochondrial disability induced overactive autophagy, increased cathepsin B expression, and diminished Bcl-2 expression. Necrostatin-1 within a certain concentration range (5-30 µM) elevated the viability of PC12 cells, stabilized mitochondrial membrane potential, inhibited excessive autophagy, reduced the expression of LC3-II and cathepsin B, and increased Bcl-2 expression. These findings suggest that necrostatin-1 exerted a protective effect against injury on dopaminergic neurons. Necrostatin-1 interacts with the apoptosis signaling pathway during this process. This pathway could be a new neuroprotective and therapeutic target in Parkinson's disease.

Trigeminal neuralgia increases cerebral blood flow in a focal cerebral ischemic model in rats.

OBJECTIVE: To investigate the influences of trigeminal neuropathic pain on the cerebral blood flow in a ET-1 focal cerebral ischemia model. METHODS: Male Sprague-Dawley (SD) rats (220-260 g) were randomly divided into a model group (trigeminal neuralgia, TN group) and a sham operation group (sham group). The TN group received bilateral infraorbital nerve chronic constriction surgery, and the sham group only underwent exposure of the infraorbital nerve. The mechanical pain threshold of the rats was continuously monitored for 30 days post surgery. On postoperative day 30, the animals were anesthetized, and 3 µL (120 pM/µL) ET-1 was injected into the surroundings of the middle cerebral artery (MCA) to establish a cerebral focal ischemia-reperfusion injury model in rats. The changes in cerebral blood flow of these two groups were monitored 30 min after the injection of ET-1. RESULTS: The mechanic pain threshold values between rats in the two groups were not significantly different (P>0.05). The threshold value in the TN group on postoperative day 9 significantly decreased compared with that before surgery (P<0.01). Between postoperative days 9 and 30, the pain threshold values in the TN group were significantly lower than those in the sham group (P<0.01). From postoperative day 10, the mean arterial pressure in the TN group significantly increased compared with that before surgery (P<0.05), and the blood pressure (BP) in the TN group was higher than that in the sham group between postoperative days 10 and 30 (P<0.05). After 75 min of ET-1 microinjection, the cerebral blood flow in the rat frontal cortex exhibited reperfusion, and the cerebral blood flow in the TN group was significantly higher than that in the sham group (P<0.05). In addition, the content of calcitonin gene-related peptide (CGRP) in the blood of rats in the TN group was significantly higher than that in the sham group (P<0.05). CONCLUSIONS: Trigeminal neuropathic pain may increase the mean arterial pressure and the content of CGRP in the plasma of rats, thus increasing the cerebral blood flow in the frontal cortex of the ET-1 ischemia-reperfusion model.

Efficacy of dexmedetomidine on postoperative shivering: a meta-analysis of clinical trials.

PURPOSE: Shivering is a frequent complication in the postoperative period. The aim of the current meta-analysis was to assess the efficacy of dexmedetomidine on postoperative shivering. METHODS: Two researchers independently searched PubMed, EMBASE and the Cochrane Central Register of Controlled Trials for controlled clinical trials. The meta-analysis was performed by Review Manager. RESULTS: Thirty-nine trials with 2,478 patients were included in this meta-analysis. Dexmedetomidine reduced postoperative shivering compared with placebo (risk ratio [RR] = 0.26; 95% confidence interval [CI]: 0.20 to 0.34), with a minimum effective dose of 0.5 µg·kg(-1) (RR = 0.36; 95% CI: 0.21 to 0.60). The anti-shivering effect can be achieved both intravenously and epidurally when administered within two hours prior to the end of surgery. The efficacy of dexmedetomidine was similar to widely used anti-shivering agents, such as fentanyl, meperidine, tramadol, clonidine and so on; however, dexmedetomidine may increase the incidence of sedation, hypotension, bradycardia and dry mouth. CONCLUSIONS: The present meta-analysis indicates that dexmedetomidine shows superiority over placebo, but not over other anti-shivering agents. Therefore, considering its high price and potential adverse events, dexmedetomidine may not be appropriate solely for the purpose of the prevention of postoperative shivering.

Effects of dexmedetomidine on P2X4Rs, p38-MAPK and BDNF in spinal microglia in rats with spared nerve injury.

Microglia in the spinal cord is evidenced to play a crucial role in neuropathic pain. Spinal P2X4 receptors (P2X4Rs), which are mainly expressed in microglia, have been investigated for their roles in neuropathic pain. Dexmedetomidine (DEX), a highly selective agonist of α2-adrenergic receptors, is clinically applied to sedation and analgesia. Despite the proposed mechanisms underlying DEX-induced analgesia, the possible interactions between DEX and P2X4Rs at a molecular level have not been elucidated. We designated the spared nerve injury (SNI) to establish the neuropathic pain model. Mechanical paw withdrawal threshold (MWT) was measured to evaluate the sensitivity of neuropathic pain in rats. MWT was significantly decreased in SNI rats versus control rats. Expressions of spinal P2X4Rs, phosphorylated p38-mitogen-activated protein kinase (p-p38-MAPK) and brain-derived neurotrophic factor (BDNF) were upregulated in SNI rats. Immunofluorescence assay indicated higher densities of microglia and P2X4Rs, which appeared yellow in colour, suggesting they were co-labelled. Intraperitoneal injections of DEX 40µg/kg for 14 consecutive days markedly reversed the SNI-induced decline of MWT; the activation of microglia was markedly inhibited; in addition, the protein expressions of P2X4Rs, p-p38-MAPK and BDNF were significantly downregulated. Thus, DEX could attenuate the neuropathic pain in SNI rats, of which the mechanism might be related to the down-expressed P2X4Rs, p-p38 and BDNF in microglia of spinal dorsal horn.

[Effect of spontaneous firing of injured dorsal root ganglion neuron on excitability of wide dynamic range neuron in rat spinal dorsal horn].

The aim of the paper is to study the effect of spontaneous firing of injured dorsal root ganglion (DRG) neuron in chronic compression of DRG (CCD) model on excitability of wide dynamic range (WDR) neuron in rat spinal dorsal horn. In vivo intracellular recording was done in DRG neurons and in vivo extracellular recording was done in spinal WDR neurons. After CCD, incidence of spontaneous discharge and firing frequency enhanced to 59.46% and (4.30 ± 0.69) Hz respectively from 22.81% and (0.60 ± 0.08) Hz in normal control group (P < 0.05). Local administration of 50 nmol/L tetrodotoxin (TTX) on DRG neuron in CCD rats decreased the spontaneous activities of WDR neurons from (191.97 ± 45.20)/min to (92.50 ± 30.32)/min (P < 0.05). On the other side, local administration of 100 mmol/L KCl on DRG neuron evoked spontaneous firing in a reversible way (n = 5) in silent WDR neurons of normal rats. There was 36.36% (12/33) WDR neuron showing after-discharge in response to innocuous mechanical stimuli on cutaneous receptive field in CCD rats, while after-discharge was not seen in control rats. Local administration of TTX on DRG with a concentration of 50 nmol/L attenuated innocuous electric stimuli-evoked after-discharge of WDR neurons in CCD rats in a reversible manner, and the frequency was decreased from (263 ± 56.5) Hz to (117 ± 30) Hz (P < 0.05). The study suggests that the excitability of WDR neurons is influenced by spontaneous firings of DRG neurons after CCD.

Phosphatidylinositol 3-kinase mediates pain behaviors induced by activation of peripheral ephrinBs/EphBs signaling in mice.

EphBs receptors and their ephrinBs ligands are present in the adult brain and peripheral tissue and play a critical role in modulating multiple aspects of physiology and pathophysiology. Our recent evidence has shown that ephrinBs acted as a sensitizer to participate in peripheral sensitization and hyperalgesia induced by activation of peripheral ephrinBs/EphBs signaling. In the present study, we explored the role of phosphatidylinositol 3-kinase (PI3K) in ephrinB1-Fc-induced pain behaviors. Intraplantar injection of ephrinB1-Fc produced a time- and dose-dependent increase of PI3K-p110gamma expression and of phosphorylation of AKT in skin of injection site. Pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented activation of peripheral AKT by ephrinB1-Fc. The activated AKT expressed in peripheral nerve terminals and DRG peptide-containing and small non-peptide-containing neurons. Inhibition of peripheral PI3K signaling dose-dependently prevented and reversed pain behaviors and spinal Fos protein expression induced by intraplantar injection of ephrinB1-Fc. Furthermore, pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented ephrinB1-Fc-induced ERK activation in a dose-dependent manner. These data demonstrated that PI3K and PI3K crosstalk to ERK signaling mediated pain behaviors induced by activation of peripheral ephrinBs/EphBs signaling in mice.