To investigate the effect of Rehmanniae Radix on depression-like behavior and monoamine neurotransmitters of chronic unpredictable mild stress(CUMS) model rats. CUMS combined with isolated feeding was used to induce the depression model of rats. The depression-like behavior of rats was evaluated by sucrose preference test, open field test, and forced swim test. Hematoxylin-Eosin(HE) staining was used to investigate the pathological changes of neurons in the CA1 and CA3 area of hippocampus. Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) was used to detect the contents of 5-hydroxytryptamine(5-HT), 5-hydroxyindoleacetic acid(5-HIAA), dopamine(DA), 3,4-dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA), norepinephrine(NE), and 3-methoxy-4-hydroxyphenyl glycol(MHPG) in rats. Western blot was used to detect the protein expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), and monoamine oxidase A(MAO-A) in the hippocampus of rats. Compared with the normal group, depressive-like behavior of rats was obvious in the model group. The arrangements of neurons in the CA1 and CA3 area of hippocampus were loose and disorderly. The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in the hippocampal area were decreased(P<0.01). The protein expression of TPH2 was decreased(P<0.01), but those of SERT and MAO-A were increased(P<0.01). In the Rehmanniae Radix groups with 1.8 g·kg~(-1) and 7.2 g·kg~(-1), the depression-like behavior of CUMS rats and pathological changes of neurons in CA1, CA3 area of hippocampus were improved. The protein expression of TPH2(P<0.05, P<0.01) was increased, and those of SERT and MAO-A were down-regulated(P<0.05, P<0.01). The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in hippocampus were increased(P<0.05, P<0.01). The changes in DA, DOPAC, HVA, DA/(DOPAC +HVA), NE, DHPG, and NE/DHPG were not statistically significant. The results suggested that Rehmanniae Radix improved depression-like behavior of CUMS rats, and the mechanism might be related to the regulation of synthesis, transportation, and metabolism of 5-HT neurotransmitter in the hippocampus.
3,4-Dihydroxyphenylacetic Acid/pharmacology* ; Animals ; Antidepressive Agents/therapeutic use* ; Chromatography, Liquid ; Depression/drug therapy* ; Disease Models, Animal ; Dopamine ; Eosine Yellowish-(YS)/pharmacology* ; Hematoxylin/pharmacology* ; Hippocampus/metabolism* ; Homovanillic Acid/pharmacology* ; Hydroxyindoleacetic Acid/metabolism* ; Methoxyhydroxyphenylglycol/pharmacology* ; Monoamine Oxidase/metabolism* ; Neurotransmitter Agents/metabolism* ; Norepinephrine/pharmacology* ; Plant Extracts ; Rats ; Rehmannia/chemistry* ; Serotonin/metabolism* ; Serotonin Plasma Membrane Transport Proteins/pharmacology* ; Stress, Psychological/metabolism* ; Tandem Mass Spectrometry ; Tryptophan Hydroxylase/metabolism*

The current study was aimed to investigate the potential effects of perinatal exposure to therapeutic dose of penicillin and cefixime on the cognitive behaviors, gastrointestinal (GI) motility and serum 5-hydroxytryptamine (5-HT) level in the offspring. Pregnant rats were continuously treated with cefixime or penicillin in the period between 1 week before and 1 week after labor. Behavior tests, including social preference, self-grooming and elevated plus maze tests, and intestinal motility tests were carried out on the offspring at age of 4 to 10 weeks. Serum 5-HT levels were detected with ELISA, and potassium/sodium hyperpolarization activated cyclic nucleotide-gated channel 2 (HCN2) and tryptophan hydroxylase 1 (TPH1) expression levels in colon epithelium of offspring were detected by Western blot and RT-qPCR. The results showed that, compared with the naive group, cefixime increased social behavior in the female offspring, but did not affect the male offspring. Compared with the naive group, cefixime significantly decreased colonic and intestinal transits, and increased cecum net weight and standardized cecum net weight in the male offspring, but did not affect the female offspring. The serum 5-HT levels in the male offspring, rather than the female offspring, in cefixime and penicillin groups were significantly increased compared with that in the naive group. The protein expression level of HCN2 in colon epithelium of the offspring in cefixime group was significantly down-regulated, and the TPH1 expression level was not significantly changed, compared with that in the naive group. These results suggest that perinatal antibiotics exposure may affect neural development and GI functions of the offspring, and the mechanism may involve peripheral 5-HT and gender-dependent factor.
Animals ; Anti-Bacterial Agents ; pharmacology ; Colon ; Female ; Gastrointestinal Motility ; Male ; Mice ; Pregnancy ; Rats ; Serotonin ; Tryptophan Hydroxylase

The biogenic monoamine 5-hydroxytryptamine (5-HT) is an ancient intracellular signaling molecule widely distributed in all animals with nervous systems, and has been implicated in principal behaviors. Tryptophan hydroxylase (TRH) induces a highly specific catalytic reaction that converts L-tryptophan (tryptophan) to 5-hydroxy-L-tryptophan (5-HTP) that is subsequently used as a substrate by aromatic L-amino acid decarboxylase (DDC) to form 5-HT. Five-HT is an ancient intracellular signaling molecule that is widely distributed in the animal kingdom and has been implicated in regulating the behaviors of animals with nervous systems. However, the role of TRH in Lepidoptera is not well understood. In this study, we cloned 1 667 bp cDNAs of Bombyx mori TRH (BmTRH), which contains a 1 632 bp open reading frame (ORF). Homology analysis revealed that BmTRH shared high amino acid identity with Homo sapiens TPH and Drosophila TRH (DmTRH). The high homology (70%) of BmTRH with DmTRH suggested that BmTRH could have a function similar to DmTRH. Gene expression analysis revealed that BmTRH was mainly expressed in head and central nervous (CNS). Moreover, immunohistochemistry and Western blotting analyses showed that BmTRH was detected only in larval nervous tissues. Taken together, our results indicate that BmTRH could likely function in the regulation of neural activities in B. mori. The transcripts of B. mori decarboxylase (BmDDC) and B. mori phenylalanine hydroxylase (BmPAH) whose proteins had TRH activity, were also expressed in the CNS tissues, indicating that unlike in Drosophila, two distinct mechanisms likely regulate 5-HT synthesis in silkworm.
Amino Acid Sequence ; Animals ; Bombyx ; Cloning, Molecular ; DNA, Complementary ; Insect Proteins ; Phenylalanine Hydroxylase ; Tryptophan Hydroxylase

BACKGROUND/AIMS: Irritable bowel syndrome (IBS) is a multifaceted disorder that afflicts millions of individuals worldwide. IBS is currently diagnosed based on the presence/duration of symptoms and systematic exclusion of other conditions. A more direct manner to identify IBS is needed to reduce healthcare costs and the time required for accurate diagnosis. The overarching objective of this work is to identify gene expression-based biological signatures and biomarkers of IBS. METHODS: Gene transcripts from 24 tissue biopsy samples were hybridized to microarrays for gene expression profiling. A combination of multiple statistical analyses was utilized to narrow the raw microarray data to the top 200 differentially expressed genes between IBS versus control subjects. In addition, quantitative polymerase chain reaction was employed for validation of the DNA microarray data. Gene ontology/pathway enrichment analysis was performed to investigate gene expression patterns in biochemical pathways. Finally, since vitamin D has been shown to modulate serotonin production in some models, the relationship between serum vitamin D and IBS was investigated via 25-hydroxyvitamin D (25[OH]D) chemiluminescence immunoassay. RESULTS: A total of 858 genetic features were identified with differential expression levels between IBS and asymptomatic populations. Gene ontology enrichment analysis revealed the serotonergic pathway as most prevalent among the differentially expressed genes. Further analysis via real-time polymerase chain reaction suggested that IBS patient-derived RNA exhibited lower levels of tryptophan hydroxylase-1 expression, the enzyme that catalyzes the rate-limiting step in serotonin biosynthesis. Finally, mean values for 25(OH)D were lower in IBS patients relative to non-IBS controls. CONCLUSIONS: Values for serum 25(OH)D concentrations exhibited a trend towards lower vitamin D levels within the IBS cohort. In addition, the expression of select IBS genetic biomarkers, including tryptophan hydroxylase 1, was modulated by vitamin D. Strikingly, the direction of gene regulation elicited by vitamin D in colonic cells is “opposite” to the gene expression profile observed in IBS patients, suggesting that vitamin D may help “reverse” the pathological direction of biomarker gene expression in IBS. Thus, our results intimate that IBS pathogenesis and pathophysiology may involve dysregulated serotonin production and/or vitamin D insufficiency.
Biomarkers ; Biopsy ; Cohort Studies ; Colon ; Diagnosis ; Gene Expression Profiling ; Gene Expression ; Gene Ontology ; Health Care Costs ; Humans ; Immunoassay ; Irritable Bowel Syndrome ; Luminescence ; Oligonucleotide Array Sequence Analysis ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; RNA ; Serotonin ; Transcriptome ; Tryptophan ; Tryptophan Hydroxylase ; Vitamin D ; Vitamins

PURPOSE: Sleep deprivation induces depressive symptoms. Dexmedetomidine is a α2-adrenoreceptor agonist and this drug possesses sedative, anxiolytic, analgesic, and anesthetic-sparing effect. In this study, the action of dexmedetomidine on sleep deprivation-induced depressive behaviors was investigated using mice. METHODS: For the inducing of sleep deprivation, the mice were placed inside a water cage containing 15 platforms and filled with water up to 1 cm below the platform surface for 7 days. One day after sleep deprivation, dexmedetomidine at the respective dosage (0.5, 1, and 2 μg/kg) was intraperitoneally treated into the mice, one time per a day during 6 days. Then, forced swimming test and tail suspension test were conducted. Immunohistochemistry for tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT; serotonin), tryptophan hydroxylase (TPH) and western blot for D1 dopamine receptor were also performed. RESULTS: Sleep deprivation increased the immobility latency in the forced swimming test and tail suspension test. The expressions of TPH, 5-HT, and D1 dopamine receptor were decreased, whereas, TH expression was increased by sleep deprivation. Dexmedetomidine decreased the immobility latency and increased the expressions of TPH, 5-HT, and D1 dopamine receptor, whereas, HT expression was decreased by dexmedetomidine treatment. CONCLUSIONS: In our results, dexmedetomidine alleviated sleep deprivation-induced depressive behaviors by increasing 5-HT synthesis and by decreasing dopamine production with up-regulation of D1 dopamine receptor.
Animals ; Blotting, Western ; Depression ; Dexmedetomidine* ; Dopamine ; Hindlimb Suspension ; Immunohistochemistry ; Mice* ; Physical Exertion ; Receptors, Dopamine ; Serotonin ; Sleep Deprivation ; Tryptophan Hydroxylase ; Tyrosine 3-Monooxygenase ; Up-Regulation ; Water

Serotonin (5-hydroxytryptamine [5-HT]) is a monoamine that has various functions in both neuronal and non-neuronal systems. In the central nervous system, 5-HT regulates mood and feeding behaviors as a neurotransmitter. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. Unfortunately, some drugs were withdrawn due to the development of unwanted peripheral side effects, such as valvular heart disease and pulmonary hypertension. Recent studies revealed that peripheral 5-HT plays an important role in metabolic regulation in peripheral tissues, where it suppresses adaptive thermogenesis in brown adipose tissue. Inhibition of 5-HT synthesis reduced the weight gain and improved the metabolic dysfunction in a diet-induced obesity mouse model. Genome-wide association studies also revealed genetic associations between the serotonergic system and obesity. Several genetic polymorphisms in tryptophan hydroxylase and 5-HT receptors were shown to have strong associations with obesity. These results support the clinical significance of the peripheral serotonergic system as a therapeutic target for obesity and diabetes.
Adipose Tissue, Brown ; Animals ; Anti-Obesity Agents ; Central Nervous System ; Diabetes Mellitus* ; Feeding Behavior ; Genome-Wide Association Study ; Heart Valve Diseases ; Hypertension, Pulmonary ; Mice ; Neurons ; Neurotransmitter Agents ; Obesity* ; Polymorphism, Genetic ; Receptors, Serotonin ; Serotonin* ; Thermogenesis ; Tryptophan Hydroxylase ; Weight Gain

PURPOSE: Stress is associated with depression, which induces many psychiatric disorders. Serotonin, also known as 5-hydroxy-tryptamine (5-HT), acts as a biochemical messenger and regulator in the brain. It also mediates several important physiological functions. Depression is closely associated with an overactive bladder. In the present study, we investigated the effect of treadmill exercise on stress-induced depression while focusing on the expression of 5-HT 1A (5-H(1A)) receptors in the dorsal raphe. METHODS: Stress was induced by applying a 0.2-mA electric foot shock to rats. Each set of electric foot shocks comprised a 6-second shock duration that was repeated 10 times with a 30-second interval. Three sets of electric foot shocks were applied each day for 7 days. For the confirmation of depressive state, a forced swimming test was performed. To visualize the expression of 5-HT and tryptophan hydroxylase (TPH), immunohistochemistry for 5-HT and TPH in the dorsal raphe was performed. Expression of 5-H(1A) receptors was determined by western blot analysis. RESULTS: A depressive state was induced by stress, and treadmill exercise alleviated the depression symptoms in the stress-induced rats. Expressions of 5-HT, TPH, and HT 1A in the dorsal raphe were reduced by the induction of stress. Treadmill exercise increased 5-HT, TPH, and HT 1A expressions in the stress-induced rats. CONCLUSIONS: Treadmill exercise enhanced 5-HT synthesis through the up-regulation of 5-HT(1A) receptors, and improved the stress-induced depression. In the present study, treadmill exercise improved depression symptoms by enhancing 5-HT(1A) receptor expression. The present results suggest that treadmill exercise might be helpful for the alleviation of overactive bladder and improve sexual function.
Animals ; Blotting, Western ; Brain ; Depression* ; Exercise Test ; Exercise* ; Foot ; Immunohistochemistry ; Physical Exertion ; Rats* ; Receptor, Serotonin, 5-HT1A* ; Serotonin ; Shock ; Stress, Psychological ; Tryptophan Hydroxylase ; Up-Regulation* ; Urinary Bladder, Overactive

One of hypothesis is that sleep loss related to a decrease in serotonergic activity plays a significant role in attempted suicide. A growing evidence suggests that central serotonergic activity plays a key role in the etiology of suicide. It has been reported that the cerebrospinal fluid (CSF) levels of 5-hydroxyindoleacetic acid (5-HIAA), the main metabolite of serotonin, were reduced in suicide attempters. In addition, there is evidence that tryptophan hydroxylase is associated with suicide. The association between sleep and suicide was also suggested by some researchers. Several recent studies have showed the association between sleep disturbance and suicide rates in patients with mental disorders and in a general population. In addition, it has been suggested that serotonin plays a role in maintaining arousal and regulating muscle tone and in regulating some of the phasic events of REM sleep. Especially, it is well-known that 5-HT2 receptors are related to slow wave sleep. In conclusion, it is clear that sleep, serotonin activity, and suicide are linked, although the direction of causation needs clarification. In future, large population-based cohort studies are needed to demonstrate the direction of causation in the relationships between sleep, serotonin activity, and suicide.
Arousal ; Cohort Studies ; Humans ; Mental Disorders ; Muscles ; Serotonin ; Sleep, REM ; Suicide ; Suicide, Attempted ; Tryptophan Hydroxylase

OBJECTIVE: To investigate the genetic polymorphism in the 5' and 3' region of TPH2 gene of Northern Chinese Han population and to explore its application value in forensic medicine. METHODS: The sequence variants and the genetic polymorphisms of 6 SNP loci (rs4570625, rs11178997, rs11178998, rs41317118, rs17110747 and rs41317114) within a 905 bp 5' flanking region and a 1,104bp 3' flanking region of TPH2 gene were analyzed by DNA sequencing in a total of 244 unrelated healthy individuals in Northern Chinese Han population. The statistical analysis was carried out by Haploview v4.2 software. RESULTS: The genotypic distributions of the 6 SNP loci in the TPH2 gene were in accordance with Hardy-Weinberg equilibrium. One C/T variant in 92922 site was found. There was a high linkage disequilibrium among the 3 SNP loci (rs4570625, rs11178997 and rs11178998) in the 5' region and the 3 SNP loci (rs41317118, rs17110747 and rs41317114) in the 3' region of TPH2 gene, respectively. The parameters of population genetics of 6 SNP loci were obtained. CONCLUSION There are great polymorphisms in the 5' and 3' region of TPH2 gene in Northern Chinese Han population, which could be used as genetic indexes for association analysis of the related diseases, as well as for forensic individual identification and paternity testing.
3' Untranslated Regions ; 5' Untranslated Regions ; Asian People/genetics* ; China/ethnology* ; Forensic Genetics ; Gene Frequency ; Genetics, Population ; Genotype ; Humans ; Linkage Disequilibrium/genetics* ; Microsatellite Repeats ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Tryptophan Hydroxylase/genetics*

Lipoprotein receptor-related protein (LRP5) signaling is well correlated with the bone mass in both human and mice. Loss-of-function mutations of LRP5 result in osteopenia or osteoporosis. In contrast, gain-of-function mutations show high bone mass phenotype. To elucidate the molecular mechanism of the LRP5-mediated bone mass acquisition, several groups have genetically dissected the Wingless and Int-1 (Wnt)beta-catenin signaling pathway using osteoblast-lineage specific Cre mice. Key players for LRP5-mediated bone mass acquisition turn out to be different molecules with respect to the expressing tissue and action mode of these molecules. One is serotonin, a tryptophan metabolite that originates from duodenum, which acts as a negative regulator for bone formation. LRP5 suppresses serotonin biosynthesis by inhibiting the expression of tryptophan hydroxylase 1 in the gut. The other is sclerostin, an osteocyte-producing antagonist for LRP5 signaling. Here is a summary of recent findings about these two molecules, providing a chance to speculate new avenues in the LRP5-mediated bone mass acquisition.
Animals ; Bone Diseases, Metabolic ; Duodenum ; Humans ; Lipoproteins ; Mice ; Mitral Valve Prolapse ; Myopia ; Osteogenesis ; Osteoporosis ; Phenotype ; Serotonin ; Skin Diseases ; Tryptophan ; Tryptophan Hydroxylase