Cognitive dysfunction in schizophrenia patients caused by downregulation of γ-aminobutyric acid receptor subunits

BACKGROUND The expression pattern of gamma aminobutyric acid(GABA)receptor subunits are commonly altered in patients with schizophrenia,which may lead to nerve excitation/inhibition problems,affecting cognition,emotion,and behavior.AIM To explore GABA receptor expression and its relationship with schizophrenia and to provide insights into more effective treatments.METHODS This case-control study enrolled 126 patients with schizophrenia treated at our hospital and 126 healthy volunteers who underwent physical examinations at our hospital during the same period.The expression levels of the GABA receptor subunits were detected using 1H-magnetic resonance spectroscopy.The recognized cognitive battery tool,the MATRICS Consensus Cognitive Battery,was used to evaluate the scores for various dimensions of cognitive function.The correlation between GABA receptor subunit downregulation and schizophrenia was also analyzed.RESULTS Significant differences in GABA receptor subunit levels were found between the case and control groups(P<0.05).A significant difference was also found between the case and control groups in terms of cognitive function measures,including attention/alertness and learning ability(P<0.05).Specifically,as the expression levels of GABRA1(α1 subunit gene),GABRB2(β2 subunit gene),GABRD(δsubunit),and GABRE(εsubunit)decreased,the severity of the patients’condition increased gradually,indicating a positive correlation between the downregulation of these 4 receptor subunits and schizophrenia(P<0.05).However,the expression levels of GABRA5(α5 subunit gene)and GABRA6(α6 subunit gene)showed no significant correlation with schizophrenia(P>0.05).CONCLUSION Downregulation of the GABA receptor subunits is positively correlated with schizophrenia.In other words,when GABA receptor subunits are downregulated in patients,cognitive impairment becomes more severe.

Bile acids inhibit ferroptosis sensitivity through activating farnesoid X receptor in gastric cancer cells

BACKGROUND Gastric cancer(GC)is associated with high mortality rates.Bile acids(BAs)reflux is a well-known risk factor for GC,but the specific mechanism remains unclear.During GC development in both humans and animals,BAs serve as signaling molecules that induce metabolic reprogramming.This confers additional cancer phenotypes,including ferroptosis sensitivity.Ferroptosis is a novel mode of cell death characterized by lipid peroxidation that contributes universally to malignant progression.However,it is not fully defined if BAs can influence GC progression by modulating ferroptosis.AIM To reveal the mechanism of BAs regulation in ferroptosis of GC cells.METHODS In this study,we treated GC cells with various stimuli and evaluated the effect of BAs on the sensitivity to ferroptosis.We used gain and loss of function assays to examine the impacts of farnesoid X receptor(FXR)and BTB and CNC homology 1(BACH1)overexpression and knockdown to obtain further insights into the molecular mechanism involved.RESULTS Our data suggested that BAs could reverse erastin-induced ferroptosis in GC cells.This effect correlated with increased glutathione(GSH)concentrations,a reduced GSH to oxidized GSH ratio,and higher GSH peroxidase 4(GPX4)expression levels.Subsequently,we confirmed that BAs exerted these effects by activating FXR,which markedly increased the expression of GSH synthetase and GPX4.Notably,BACH1 was detected as an essential intermediate molecule in the promotion of GSH synthesis by BAs and FXR.Finally,our results suggested that FXR could significantly promote GC cell proliferation,which may be closely related to its anti-ferroptosis effect.CONCLUSION This study revealed for the first time that BAs could inhibit ferroptosis sensitivity through the FXR-BACH1-GSHGPX4 axis in GC cells.This work provided new insights into the mechanism associated with BA-mediated promotion of GC and may help identify potential therapeutic targets for GC patients with BAs reflux.

Oleanolic acid improved intestinal immune function by activating and potentiating bile acids receptor signaling in E. coli-challenged piglets

Background Infection with pathogenic bacteria during nonantibiotic breeding is one of the main causes of animal intestinal diseases.Oleanolic acid(OA)is a pentacyclic triterpene that is ubiquitous in plants.Our previous work demonstrated the protective effect of OA on intestinal health,but the underlying molecular mechanisms remain unclear.This study investigated whether dietary supplementation with OA can prevent diarrhea and intestinal immune dysregulation caused by enterotoxigenic Escherichia coli(ETEC)in piglets.The key molecular role of bile acid receptor signaling in this process has also been explored.Results Our results demonstrated that OA supplementation alleviated the disturbance of bile acid metabolism in ETEC-infected piglets(P<0.05).OA supplementation stabilized the composition of the bile acid pool in piglets by regulating the enterohepatic circulation of bile acids and significantly increased the contents of UDCA and CDCA in the ileum and cecum(P<0.05).This may also explain why OA can maintain the stability of the intestinal microbiota structure in ETEC-challenged piglets.In addition,as a natural ligand of bile acid receptors,OA can reduce the severity of intestinal inflammation and enhance the strength of intestinal epithelial cell antimicrobial programs through the bile acid receptors TGR5 and FXR(P<0.05).Specifically,OA inhibited NF-κB-mediated intestinal inflammation by directly activating TGR5 and its downstream c AMP-PKA-CREB signaling pathway(P<0.05).Furthermore,OA enhanced CDCA-mediated MEK-ERK signaling in intestinal epithelial cells by upregulating the expression of FXR(P<0.05),thereby upregulating the expression of endogenous defense molecules in intestinal epithelial cells.Conclusions In conclusion,our findings suggest that OA-mediated regulation of bile acid metabolism plays an important role in the innate immune response,which provides a new diet-based intervention for intestinal diseases caused by pathogenic bacterial infections in piglets.

Gamma-aminobutyric acid promotes human hepatocellular carcinoma growth through overexpressed gamma-aminobutyric acid A receptor α3 subunit

AIM:To investigate the expression pattern of gamma-aminobutyric acid A(GABAA) receptors in hepatocellular carcinoma(HCC) and indicate the relationship among gamma-aminobutyric acid(GABA),gamma-aminobutyric acid A receptor α3 subunit(GABRA3) and HCC.METHODS:HCC cell line Chang,HepG2,normal liver cell line L-02 and 8 samples of HCC tissues and paired non-cancerous tissues were analyzed with semiquantitative polymerase chain reaction(PCR) for the expression of GABAA receptors.HepG2 cells were treated with gamma-aminobutyric acid(GABA) at serial concentrations(0,1,10,20,40 and 60 μmol/L),and their proliferating abilities were analyzed with the 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay,cell doubling time test,colon formation assay,cell cycle analysis and tumor planted in nude mice.Small interfering RNA was used for knocking down the endogenous GABRA3 in HepG2.Proliferating abilities of these cells treated with or without GABA were analyzed.RESULTS:We identified the overexpression of GABRA3 in HCC cells.Knockdown of endogenous GABRA3 expression in HepG2 attenuated HCC cell growth,suggesting its role in HCC cell viability.We determined the in vitro and in vivo effect of GABA in the proliferation of GABRA3-positive cell lines,and found that GABA increased HCC growth in a dose-dependent manner.Notably,the addition of GABA into the cell culture medium promoted the proliferation of GABRA3-expressing HepG2 cells,but not GABRA3-knockdown HepG2 cells.This means that GABA stimulates HepG2 cell growth through GABRA3.CONCLUSION:GABA and GABRA3 play important roles in HCC development and progression and can be a promising molecular target for the development of new diagnostic and therapeutic strategies for HCC.

Effects of Rhizoma Acori Tatarinowii extracts on gamma-aminobutyric acid type A receptor alpha 1 subunit brain expression during development in a recurrent seizure rat model

Extracts from Rhizoma Acori Tatarinowii （Grassleaf Sweetflag Rhizome, Shichangpu） have been shown to improve learning and memory, reduce anxiety, allay excitement, and suppress seizures. Rhizoma Acori Tatarinowii extracts interact with y-aminobutyric acid and activate the y-aminobutyric acid type A receptor, although few studies have addressed the precise effects of v-aminobutyric acid type A receptor al subunit. In the present study, y-aminobutyric acid type A receptor al subunit protein expression in the cerebral cortex and hippocampus, and pathological scores of brain injury, were significantly greater following recurrent seizures, but significantly decreased following treatment with Rhizoma Acori Tatarinowii extracts. These results indicated that Rhizoma Acori Tatarinowii extracts down-regulated y-aminobutyric acid type A receptor al subunit protein expression in the cerebral cortex and hippocampus and protected seizure-induced brain injury during development.

Gamma-aminobutyric acid A receptor and N-methyl-D-aspartate receptor subunit expression in rat spiral ganglion neurons

BACKGROUND： Gamma-aminobutyric acid A （GABAA） and N-methyl-D-aspartate （NMDA） receptors are significant receptors in the central nervous system. An understanding of GABAA and NMDA receptor expression in spiral ganglion neurons （SGN） provides information for the functional role of these receptors in the auditory system. OBJECTIVE： To investigate mRNA expression of GABAA receptor （GABAAR） and NMDA receptor （NMDAR） subunits in the rat SGN. DESIGN, TIME AND SETTING： This in vitro, molecular biological study was performed at the Laboratory of Otolaryngology-Head and Neck Surgery, Guangxi Medical University, China from July 2007 to May 2008. MATERIALS： Reverse Transcriptase Kit and Taq DNA polymerase were purchased from Fermentas Burlington, ON, Canada; GABAAR and NMDAR primers were purchased from Shanghai Sangon, Shanghai, China. METHODS： SGN from 3-5 day postnatal Wistar rats was collected for primary cultures, mRNA expression of GABAAR and NMDAR subunits in the SGN was determined by reverse transcription polymerase chain reaction. MAIN OUTCOME MEASURES： Expression levels of GABAAR and NMDAR subunits were determined by quantitative analysis. RESULTS： GABAAR subunits （αl 6, β1 3, and y1 3） and NMDAR subunits （NR1, NR2A, NR2B, NR2C, NR2D, NR3A, and NR3B） were detected in the SGN. In α subunit genes of GABAAR, α1 and α3 expression was similar （P 〉 0.05） and greater than the other subunits. Of the β subunit genes, β1 subunit mRNA levels were greater than β2 and β3. Of the y subunit genes, y2 subunit mRNA levels were greater than y1 and y3. NR1 mRNA expression was the greatest of NMDAR subunits. CONCLUSION： GABAAR subunits （α1 6, β1-3, and y1-3） and NMDAR subunits （NR1, NR2A, NR2B, NR2C, NR2D, NR3A, and NR3B） were expressed in the rat SGN. Through comparison of GABAAR and NMDAR subunit expression, possible GABAAR combinations, as well as highly expressed subunit combinations, were estimated, which provided information for pharmacological and electrophysiological characteristics of GABAAR in the auditory system.

Bile acids and their receptors: Potential therapeutic targets in inflammatory bowel disease

Chronic and recurrent inflammatory disorders of the gastrointestinal tract caused by a complex interplay between genetics and intestinal dysbiosis are called inflammatory bowel disease.As a result of the interaction between the liver and the gut microbiota,bile acids are an atypical class of steroids produced in mammals and traditionally known for their function in food absorption.With the development of genomics and metabolomics,more and more data suggest that the pathophysiological mechanisms of inflammatory bowel disease are regulated by bile acids and their receptors.Bile acids operate as signalling molecules by activating a variety of bile acid receptors that impact intestinal flora,epithelial barrier function,and intestinal immunology.Inflammatory bowel disease can be treated in new ways by using these potential molecules.This paper mainly discusses the increasing function of bile acids and their receptors in inflammatory bowel disease and their prospective therapeutic applications.In addition,we explore bile acid metabolism and the interaction of bile acids and the gut microbiota.

Evolution of neurotransmitter gamma-aminobutyric acid,glutamate and their receptors

Gamma-aminobutyric acid(GABA)and glutamate are two important amino acid neurotransmitters widely present in the nervous systems of mammals,insects,round worm,and platyhelminths,while their receptors are quite diversified across different animal phyla.However,the evolutionary mechanisms between the two conserved neurotransmitters and their diversified receptors remain elusive,and antagonistic interactions between GABA and glutamate signal transduction systems,in particular,have begun to attract significant attention.In this review,we summarize the extant results on the origin and evolution of GABA and glutamate,as well as their receptors,and analyze possible evolutionary processes and phylogenetic relationships of various GABAs and glutamate receptors.We further discuss the evolutionary history of Excitatory/Neutral Amino Acid Transporter(EAAT),a transport protein,which plays an important role in the GABA-glutamate“yin and yang”balanced regulation.Finally,based on current advances,we propose several potential directions of future research.

Effect of propofol on the reactivity of acetylcholinesterase,N-methyl-D-aspartate receptors,and gamma-aminobutyric acid receptors in the hippocampus of aged rats after chronic cerebral ischemia

We induced ischemic brain injury in aging rats to examine the effects of varying doses of propofol on hippocampal activities of acetylcholinesterase, N-methyI-D-aspartate receptors, and y-aminobutyric acid receptors. Propofol exhibited no obvious impact on acetylcholinesterase activity, but directly activated the y-aminobutyric acid receptor. The neuroprotective function of propofol on the hippocampus of aging rats following cerebral ischemic injury may be related to altered activities of y-aminobutyric acid receptors and N-methyI-D-aspartate receptors.

Expression of gamma-aminobutyric acid A receptor subunits aα_1,β_1,γ_2 mRNA in rats with hepatic encephalopathy

AIM To investigate the mRNA expression of gammaaminobutyric acid A (GABAA) receptor subunits α1,β1, γ2in different parts of the brain of rats with hepaticencephalopathy.METHODS: Twelve adult male Sprague-Dawley rats were randomly divided into two groups: (1) hepatic encephalopathy model group (n = 6), which was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg/kg) for threeconsecutive days; (2) control group (n = 6), in which the rats were treated with same dose of normal saline solution. After the freeze slice of cerebrum was made,in situ hybridization was used to detect the mRNA of GABAA receptor subunits α1, β1, and γ2 in rat cerebral cortex, basal nuclei, substantia nigra and hippocampi. Image data were collected and analyzed quantitatively by QWin550CWmodel image signal gather and analysis system. RESULTS: In rats with hepatic encephalopathy, mRNA expression levels of GABAA receptor subunits α1, β1 increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis and hippocampi (144.7±15.67/184.14±4.41, 60.61±33.66/113.07±32.44,87.71± 21.25/128.40±18.85, 122.34±5.56/161.60±4.56,123.29±5.21/140.65±4.15, 123.40±4.42/140.09±4.52,124.76±4.18/140.09±4.12, 141.62±15.09/182.80 ±5.20,69.13±30.74/134.21±43.76, 87.87±25.16/151.01±19.49,122.14±6.30/162.33±3.92, 122.81±5.09/137.19±7.12,123.00±4.63/138.11±5.92, 125.75 ±2.43/138.81±6.10,P＜0.01), but did not change in the cerebral cortex compared to the control group. Similar changes were found in the mRNA expression levels of GABAA receptor subunit γ2,which increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis (136.81±26.41/167.97±16.23, 51.00±36.14/113.18±36.52, 86.35±20.30/126.90±19.74, P＜0.01), CA1 of hippocampal (162.15±9.05/178.62±6.45, P＜0.05), and no changes were found in the cerebral cortex and CA2, CA3, CA4 of hippocampi.CONCLUSION: In rats with hepatic encephalopathy, mRNA expression levels of GABAA receptor subunits α1,β1, γ2 increase significantly in basal nuclei, substantia nigra and hippocampi, suggesting that the changes of mRNA expression levels in GABAA receptor subunits may contribute to the pathogenesis of hepatic encephalopathy.

Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

Expression of gamma-aminobutyric acid type A receptor α_2 subunit in the dorsal root ganglion of rats with sciatic nerve injury

The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the y-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.

Gamma-aminobutyric acid A receptors in Alzheimer＇s disease： highly localized remodeling of a complex and diverse signaling pathway

Alzheimer＇s disease （AD）, the predominant form of dementia, is a chronic, incurable neurodegenerative disorder presenting with symptoms includ- ing progressive memory loss and disturbed emotional state. It has been estimated that dementia affects over 47 million people worldwide （Prince et al., 2015）, and with 60-80% of cases attributable to AD.

Evolution of neurotransmitter gamma-aminobutyric acid, glutamate and their receptors

Gamma-aminobutyric acid （GABA） and glutamate are two important amino acid neurotransmitters widely present in the nervous systems of mammals, insects, round worm, and platyhelminths, while their receptors are quite diversified across different animal phyla. However, the evolutionary mechanisms between the two conserved neurotransmitters and their diversified receptors remain elusive, and antagonistic interactions between GABA and glutamate signal transduction systems, in particular, have began to attract significant attention. In this review, we summarize the extant results on the origin and evolution of GABA and glutamate, as well as their receptors, and analyze possible evolutionary processes and phylogenetic relationships of various GABAs and glutamate receptors. We further discuss the evolutionary history of Excitatory/Neutral Amino Acid Transporter （EAAT）, a transport protein, which plays an important role in the GABA-glutamate ＂yin and yang＂ balanced regulation. Finally, based on current advances, we propose several potential directions of future research.

Electroacupuncture (EA) Speeds Up the Regulation of Hypothalamic Pituitary Adrenal Axis Dysfunction in Acute Surgical Trauma Rats: Mediated by Hypothalamic Gamma-Aminobutyric Acid (GABA)_AReceptors

Hypothalamic Corticotropin-releasing factor (CRF) directly activates the hypothalamic pituitary adrenal axis (HPA axis) during the surgical trauma induced stress response. Electroacupuncture (EA) has been demonstrated to have stress relieving effects in breast surgery, colorectal surgery, prostatectomy and craniotomy. This study was aimed to investigate the hypothesis that EA could regulate hypothalamic CRF in surgical trauma rats. In experiment one, Sprague-Dawley (SD) male rats were divided into intact, model (10% partial hepatectomy), sham EA and EA group. Rats from the Sham EA and EA group were stimulated at ST36-Zusanli and SP6-Sanyiniiao acupoints twice, 24 hours before the surgery and immediately after the surgery. Expressions of hypothalamic CRF and CRFR, GABA receptors, glutamate decarboxylase (GAD), serum adrenocorticotropic hormone (ACTH) and Corticosterone (CORT) were observed at 2, 4, 8 and 24 h after the surgery by radioimmunoassay (RIA), western blot, real-time PCR and immunohistochemistry. In the experiment two, SD male rats were divided into the intact, model, model + vehicle, model + L-838,417 EA and EA + L838,417 group. It was found that hypothalamus CRF, serum ACTH and CORT levels were increased in model group compared with the intact group, and those in the EA group decreased in comparison with the model group. Compared with the model group, hypothalamus-aminobutyric acid (GABA) receptor Aα3 mRNA and protein expressions of the EA group raised strikingly. In conclusion, EA alleviated surgical stress response by improving the GABA synthesis in hypothalamus, thus enhancing GABA receptors’ inhibitory regulation of the HPA axis dysfunction in rats with acute surgical trauma.

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.

Effects of gamma-aminobutyric acid receptors on muscarinic receptor-mediated free calcium ion levels in the facial nucleus following facial nerve injury

Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.

Folic Acid-Functionalized Nanocrystalline Cellulose as a Renewable and Biocompatible Nanomaterial for Cancer-Targeting Nanoparticles

The study focuses on the development of biocompatible and stable FA-functionalized nanocrystalline cellulose(NCC)as a potential drug delivery system for targeting folate receptor-positive cancer cells.The FA-functionalized NCCs were synthesized through a series of chemical reactions,resulting in nanoparticles with favorable properties for biomedical applications.The microstructural analysis revealed that the functionalized NCCs maintained their rod-shaped morphology and displayed hydrodynamic diameters suitable for evading the mononuclear phagocytic system while being large enough to target tumor tissues.Importantly,these nanoparticles possessed a negative surface charge,enhancing their stability and repelling potential aggregation.The binding specificity of FA-functionalized NCCs to folate receptor-positive cancer cells was demonstrated through various assays.The free folic acid inhibition assay showed approximately 30%decrease in the binding of functionalized NCCs in the presence of just 5 mM free FA,confirming their selectivity for folate receptor-positive cells.Confocal microscopy further validated this specificity,as only cancer cells displayed significant binding of functionalized NCCs.Crucially,biocompatibility tests revealed that both NCCs and FA-functionalized NCCs had minimal effects on red blood cells,and they did not induce erythrocyte aggregation.Furthermore,cell viability assays demonstrated functionalized NCCs have selective cytotoxicity against colorectal cancer cells HT-29 and SW-620(68%–88%cell viability)while sparing noncancerous colon cells CCD-18Co(81%–97%cell viability).In summary,FA-functionalized NCCs exhibit promising characteristics for targeted drug delivery in cancer therapy.Their biocompatibility,stability,and selective cytotoxicity make them an attractive option for delivering therapeutic agents to folate receptor-positive cancer cells,potentially improving the effectiveness of cancer treatments while minimizing harm to healthy tissues.

Saikosaponin D improves nonalcoholic fatty liver disease via gut microbiota-bile acid metabolism pathway

Non-alcoholic fatty liver disease(NAFLD)is the main cause of chronic liver disease worldwide.Bupleurum is widely used in the treatment of non-alcoholic fatty liver,and saikosaponin D(SSD)is one of the main active components of Bupleurum.The purpose of this study was to investigate the efficacy of SSD in the treatment of NAFLD and to explore the mechanism of SSD in the improvement of NAFLD based on“gut-liver axis”.Our results showed that SSD dose-dependently alleviated high fat diet-induced weight gain in mice,improved insulin sensitivity,and also reduced liver lipid accumulation and injury-related biomarkers aspartate aminotransferase(AST)and alanine aminotransferase(ALT).Further exploration found that SSD inhibited the mRNA expression levels of farnesoid X receptor(Fxr),small heterodimer partner(Shp),recombinant fibroblast growth factor 15(Fgf15)and apical sodium dependent bile acid transporter(Asbt)in the intestine,suggesting that SSD improved liver lipid metabolism by inhibiting intestinal FXR signaling.SSD can significantly reduce the gut microbiota associated with bile salt hydrolase(BSH)expression,such as Clostridium.Decreased BSH expression reduced the ratio of unconjugated to conjugated bile acids,thereby inhibiting the intestinal FXR.These data demonstrated that SSD ameliorated NAFLD potentially through the gut microbiota-bile acidintestinal FXR pathway and suggested that SSD is a promising therapeutic agent for the treatment of NAFLD.

Gamma-aminobutyric acid A receptor gamma 2 subunit following Mg-free-induced seizures in cultured developing neurons

BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution culture. OBJECTIVE： To explore gammaminobutyric acid A receptor （GABAAR）γ 2 subunit expression following Mg^2＋-free-induced seizures in cultured developing neurons. DESIGN, TIME AND SETTING： Cellular and molecular biology. The in vitro experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central Southern University between January 2007 and February 2008. MATERIALS： Cortical neurons of Wistar rats on gestational days 16-17 were used. Normal extracellular solution （pH 7.3） consisted of NaCl 145 mmol/L, KCl 2.5 mmol/L, HEPES l0 mmol/L, MgC12 1 mmol/L, CaC12 2 mmol/L, glucose 10 mmol/L, and glycine 0.01 mmol/L. In addition, there was no MgCl2 in the Mg^2＋-free extracellular solution. METHODS： Cortical neurons cultured for 6 days were exposed to normal extracellular solution （control group） and Mg^2＋-free media （Mg^2＋-free group） respectively for 3 hours, followed by continuous culture in DMEM solution. MAIN OUTCOME MEASURES： On days 1, 7 and 12 after Mg^2＋-free treatment, real-time RT-PCR, immunochemistry, and flow cytometry were used to detect GABAAR 3/2 subunit expression. RESULTS： Compared with the control group, GABAAR γ-positive cells decreased significantly on days 1 and 7 after Mg^2＋-free treatment （P 〈 0.01）, but significantly increased on day 12 （P 〈 0.01 ）. GABAAR γ2 subunit mRNA expression decreased significantly at 7 days Mg^2＋-free treatment when measured by real-time RT-PCR compared with the control group （P 〈 0.05）. CONCLUSION： GABAAR γ2 subunit expression is modified following Mg-free-induced seizures in cultured developing neurons. This indicates the possibility that abnormal GABAA receptor expression might play an important role in development of neuronal injury.