Dopamine D1 receptor in medial prefrontal cortex mediates the effects of TAAR1 activation on chronic stress-induced cognitive and social deficits.

Trace amine-associated receptor 1 (TAAR1) is an intracellular expressed G-protein-coupled receptor that is widely expressed in major dopaminergic areas and plays a crucial role in modulation of central dopaminergic neurotransmission and function. Pharmacological studies have clarified the roles of dopamine D1 receptor (D1R) in the medial prefrontal cortex (mPFC) in cognitive function and social behaviors, and chronic stress can inhibit D1R expression due to its susceptibility. Recently, we identified TAAR1 in the mPFC as a potential target for treating chronic stress-induced cognitive and social dysfunction, but whether D1R is involved in mediating the effects of TAAR1 agonist remains unclear. Combined genomics and transcriptomic studies revealed downregulation of D1R in the mPFC of TAAR1-/- mice. Molecular dynamics simulation showed that hydrogen bond, salt bridge, and Pi-Pi stacking interactions were formed between TAAR1 and D1R indicating a stable TAAR1-D1R complex structure. Using pharmacological interventions, we found that D1R antagonist disrupted therapeutic effect of TAAR1 partial agonist RO5263397 on stress-related cognitive and social dysfunction. Knockout TAAR1 in D1-type dopamine receptor-expressing neurons reproduced adverse effects of chronic stress, and TAAR1 conditional knockout in the mPFC led to similar deficits, along with downregulation of D1R expression, all of these effects were ameliorated by viral overexpression of D1R in the mPFC, suggesting the functional interaction between TAAR1 and D1R. Collectively, our data elucidate the possible molecular mechanism that D1R in the mPFC mediates the effects of TAAR1 activation on chronic stress-induced cognitive and social deficits.

TAAR1 in dentate gyrus is involved in chronic stress-induced impairments in hippocampal plasticity and cognitive function.

Multiple lines of evidence suggest that the trace amine-associated receptor 1 (TAAR1) holds promise as a potential target for stress-related disorders, such as treating major depressive disorder (MDD). The role of TAAR1 in the regulation of adult neurogenesis is recently supported by transcriptomic data. However, it remains unknown whether TAAR1 in dentate gyrus (DG) mediate chronic stress-induced negative effects on hippocampal plasticity and related behavior in mice. The present study consisted of a series of experiments using RNAscope, genetic approaches, behavioral tests, immunohistochemical staining, Golgi-Cox technique to unravel the effects of TAAR1 on alterations of dentate neuronal plasticity and cognitive function in the chronic social defeat stress model. The mice subjected to chronic defeat stress exhibited a noteworthy decrease in the mRNA level of TAAR1 in DG. Additionally, they exhibited compromised social memory and spatial object recognition memory, as well as impaired proliferation and maturation of adult-born dentate granule cells. Moreover, the selective knockout TAAR1 in DG mostly mimicked the cognitive function deficits and neurogenesis impairment induced by chronic stress. Importantly, the administration of the selective TAAR1 partial agonist RO5263397 during stress exposure attenuated the adverse effects of chronic stress on cognitive function, adult neurogenesis, dendritic arborization, and the synapse number of dentate neurons in DG. In summary, our findings suggest that TAAR1 plays a crucial role in mediating the detrimental effects of chronic stress on hippocampal plasticity and cognition. TAAR1 agonists exhibit therapeutic potential for individuals suffering from cognitive impairments associated with MDD.

The causal involvement of the BDNF-TrkB pathway in dentate gyrus in early-life stress-induced cognitive deficits in male mice.

Cognitive dysfunction is a significant, untreated clinical need in patients with psychiatric disorders, for which preclinical studies are needed to understand the underlying mechanisms and to identify potential therapeutic targets. Early-life stress (ELS) leads to long-lasting deficits of hippocampus-dependent learning and memory in adult mice, which may be associated with the hypofunction of the brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin receptor kinase B (TrkB). In this study, we carried out eight experiments using male mice to examine the causal involvement of the BDNF-TrkB pathway in dentate gyrus (DG) and the therapeutic effects of the TrkB agonist (7,8-DHF) in ELS-induced cognitive deficits. Adopting the limited nesting and bedding material paradigm, we first demonstrated that ELS impaired spatial memory, suppressed BDNF expression and neurogenesis in the DG in adult mice. Downregulating BDNF expression (conditional BDNF knockdown) or inhibition of the TrkB receptor (using its antagonist ANA-12) in the DG mimicked the cognitive deficits of ELS. Acute upregulation of BDNF (exogenous human recombinant BDNF microinjection) levels or activation of TrkB receptor (using its agonist, 7,8-DHF) in the DG restored ELS-induced spatial memory loss. Finally, acute and subchronic systemic administration of 7,8-DHF successfully restored spatial memory loss in stressed mice. Subchronic 7,8-DHF treatment also reversed ELS-induced neurogenesis reduction. Our findings highlight BDNF-TrkB system as the molecular target of ELS-induced spatial memory deficits and provide translational evidence for the intervention at this system in the treatment of cognitive deficits in stress-related psychiatric disorders, such as major depressive disorder.

(2R,6R)-hydroxynorketamine improves PTSD-associated behaviors and structural plasticity via modulating BDNF-mTOR signaling in the nucleus accumbens.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a mental illness caused by either experiencing or observing a traumatic event that is perceived to pose a serious risk to one's life. (2R,6R)-HNK has an alleviating effect on negative emotions, nevertheless, the mechanism of (2R,6R)-HNK action is unclear. METHODS: In this study, the single prolonged stress and electric foot shock (SPS&S) method was used to establish a rat model of PTSD. After determining the validity of the model, (2R,6R)-HNK was administered to the NAc by microinjection using a concentration gradient of 10, 50, and 100 µM, and the effects of the drug in the SPS&S rat model were evaluated. Moreover, our study measured changes in related proteins in the NAc (BDNF, p-mTOR/mTOR, and PSD95) and synaptic ultrastructure. RESULTS: In the SPS&S group, the protein expression of brain-derived neurotrophic factor (BDNF), mammalian target of rapamycin (mTOR), and PSD95 was reduced and synaptic morphology was damaged in the NAc. In contrast, after the administration of 50 µM (2R,6R)-HNK, SPS&S-treated rats improved their exploration and depression-linked behavior, while protein levels and synaptic ultrastructure were also restored in the NAc. With the administration of 100 µM (2R,6R)-HNK, locomotor behavior, and social interaction improved in the PTSD model. LIMITATIONS: The mechanism of BDNF-mTOR signaling after (2R,6R)-HNK administration was not explored. CONCLUSION: (2R,6R)-HNK may ameliorate negative mood and social avoidance symptoms in PTSD rats by regulating BDNF/mTOR-mediated synaptic structural plasticity in the NAc, providing new targets for the development of anti-PTSD drugs.

[Research progress on the immunomodulatory effects and mechanisms of trace amine-associated receptor 1].

Trace amines are endogenous molecules distributed in the central nervous system and peripheral tissues that resemble common biogenic amines in terms of subcellular localization, chemical structure, and metabolism. Trace amine-associated receptor (TAAR) is a kind of evolutionarily conserved G-protein-coupled receptors in vertebrates, in which TAAR1 is a functional regulator of monoamine transmitters such as dopamine and serotonin. TAAR1 is widely considered as a potential therapeutic target for schizophrenia, depression and drug addiction. Moreover, TAAR1 is also expressed in peripheral tissues. The homeostasis imbalance of trace aminergic system can induce over-activation of peripheral immune system and central immune inflammatory response. TAAR1 modulators are becoming potential emerging drugs for the treatment of immune-related illnesses, because they may play a major role in the activation or modulation of immune response.

(2R,6R)-hydroxynorketamine acts through GluA1-induced synaptic plasticity to alleviate PTSD-like effects in rat models.

Post-traumatic stress disorder (PTSD) is a debilitating mental disorder with high morbidity and great social and economic relevance. However, extant pharmacotherapies of PTSD require long-term use to maintain effectiveness and have enormous side effects. The glutamatergic system, especially the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), is an important target of current research on the mechanism of PTSD. Postsynaptic AMPAR function and expression are known to be increased by (2R, 6R)-hydronorketamine (HNK), the primary metabolite of ketamine. However, whether (2R,6R)-HNK alleviates PTSD-like effects via AMPAR upregulation is yet to be known. In the present study, rats were exposed to single prolonged stress and electric foot shock (SPS&S). Afterwards, gradient concentrations of (2R,6R)-HNK (20, 50, and 100 µM) were administered by intracerebroventricular (i.c.v.) injection. Open field, elevated plus maze, freezing behavior, and forced swimming tests were used to examine PTSD-like symptoms. In addition, the protein levels of GluA1, BDNF and PSD-95 were analyzed using western blotting and immunofluorescence, and the synaptic ultrastructure of the prefrontal cortex (PFC) was observed by transmission electron microscopy. We found that (2R,6R)-HNK changed SPS&S-induced behavioral expression, such as increasing autonomous activity and residence time in the open arm and decreasing immobility time. Likewise, (2R,6R)-HNK (50 µM) increased GluA1, BDNF, and PSD-95 protein expression in the PFC. Changes in synaptic ultrastructure induced by SPS&S were reversed by administration of (2R,6R)-HNK. Overall, we find that (2R,6R)-HNK can ameliorate SPS&S-induced fear avoidance in rats, as well as rat cognates of anxiety and depression. This may be related to GluA1-mediated synaptic plasticity in the PFC.

The GluA1-Related BDNF Pathway Is Involved in PTSD-Induced Cognitive Flexibility Deficit in Attentional Set-Shifting Tasks of Rats.

Background: Post-Traumatic Stress Disorder (PTSD) is a severe psychological disorder characterized by intrusive thoughts, heightened arousal, avoidance, and flashbacks. Cognitive flexibility dysfunction has been linked with the emergence of PTSD, including response inhibition deficits and impaired attentional switching, which results in difficulties for PTSD patients when disengaging attention from trauma-related stimuli. However, the molecular mechanisms of cognitive flexibility deficits remain unclear. Methods: The animals were exposed to a single prolonged stress and electric foot shock (SPS&S) procedure to induce PTSD-like features. Once the model was established, the changes in cognitive flexibility were assessed using an attentional set-shifting task (ASST) in order to investigate the effects of traumatic stress on cognitive flexibility. Additionally, the molecular alterations of certain proteins (AMPA Receptor 1 (GluA1), brain-derived neurotrophic factor (BDNF), and Postsynaptic density protein 95 (PSD95) in the medial prefrontal cortex (mPFC) were measured using Western blot and immunofluorescence. Results: The SPS&S model exhibited PTSD-like behaviors and induced reversal learning and set-shifting ability deficit in the ASST. These behavioral changes are accompanied by decreased GluA1, BDNF, and PSD95 protein expression in the mPFC. Further analysis showed a correlative relationship between the behavioral and molecular alterations. Conclusions: The SPS&S model induced cognitive flexibility deficits, and the potential underlying mechanism could be mediated by GluA1-related BDNF signaling in the mPFC.

A Real-World Study of Optimal Treatment with Anlotinib First-Line Therapy in Advanced Hepatocellular Carcinoma.

Purpose: To observe the efficacy and safety of anlotinib as a first-line treatment for patients with advanced hepatocellular carcinoma (aHCC) in a real-word environment, explore the optimal treatment regimen for patients with aHCC using anlotinib as a first-line treatment. Patients and Methods: Data from 62 patients with aHCC who received anlotinib single-drug first-line therapy between February 2019 and November 2021. Patients received anlotinib monotherapy, which may be interrupted or discontinued or changed in the event of unacceptable or severe adverse events (AEs) or failure to inhibit tumor progression. The primary endpoint was progression-free survival (PFS) and the secondary endpoints were objective response rate(ORR), disease control rate (DCR), overall survival (OS), and safety. Results: Among the 62 patients, in the best overall response assessment, there were 12 with complete response (CR; 19.4%), 17 with partial response (PR; 27.4%), 25 with stable disease (SD; 40.3%), and 8 with progressive disease (PD; 14.5%). The ORR and DCR were 46.8% and 87.1%, respectively. Among the 11 patients who received tyrosine kinase inhibitors (TKIs) combined with programmed death 1 (PD-1) inhibitors after disease progression, three (27.3%) had CR, one (9.1%) had PR, three (27.3%) had SD, and four (36.4%) had PD. Therefore, the ORR and DCR were 36.4% and 63.6%, respectively. The median PFS for anlotinib monotherapy was 7.37 months (95% confidence interval [CI]: 5.88-8.86) and the median OS did not reach. AEs occurred in 95.2% of patients during anlotinib monotherapy, with the most common being thrombocytopenia (51.6%). The incidence of grade ≥3 AEs was 38.7%. Conclusion: Anlotinib is effective and well-tolerated as a first-line treatment for patients with aHCC. Treatment with TKIs and PD-1 inhibitors after disease progression has also shown preliminary efficacy and safety; therefore, sequential therapy with anlotinib-TKIs and PD-1 inhibitors may be an effective treatment for patients with aHCC.

Effect of ketamine on mood dysfunction and spatial cognition deficits in PTSD mouse models via HCN1-BDNF signaling.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a debilitating mental disease with high morbidity and major social and economic relevance. No efficient treatment for PTSD has thus far been identified. Clinical research has shown that ketamine can rapidly alleviate symptoms in patients with chronic PTSD; however, its pharmacological mechanism has yet to be determined. METHODS: This study aimed to identify a model of single prolonged stress (SPS), which induced PTSD-like features in adult mice. Once the model was established, stress-related behavioral changes in the mouse model were evaluated after intraperitoneal injection of ketamine (10 mg/kg). Alterations in certain proteins (HCN1, BDNF, and PSD95) and synaptic ultrastructure in the prefrontal cortex (PFC) and hippocampus (HIP) were measured. RESULTS: The mice under the SPS model exhibited anxiety- and depression-like behaviors and induced spatial cognitive deficits, accompanied by elevated HCN1 protein expression in the PFC and HIP, reduced brain-derived neurotrophic factor (BDNF) and PSD95 proteins, and alterations in synaptic morphology. After ketamine administration, the SPS-treated mice restored their protein levels and synaptic ultrastructure in the PFC, and their PTSD-like behaviors improved. However, learning and memory in the SPS-treated mice did not improve in the water maze test, and no significant changes in protein level and synaptic ultrastructure in the HIP were shown. LIMITATIONS: The electrophysiological mechanism of the HCN1 ion channel after ketamine administration was not explored. CONCLUSION: Ketamine could generally improve SPS-induced mood dysfunction in mice but exerted no effect on the spatial cognitive function, which could be related to the alterations in synaptic morphology and function mediated by HCN1-related BDNF signaling in the PFC and HIP.

Vortioxetine attenuates the effects of early-life stress on depression-like behaviors and monoamine transporters in female mice.

Major depressive disorder is a major psychiatric disorder and a leading cause of disability around the world. Females have about twice as high an incidence of depression as males. However, preclinical animal models of depression have seldom investigated the molecular alterations associated with higher depression risk in females. In this study, adopting the early-life stress (ELS) paradigm of limited bedding and nesting material, we found that ELS induced depression-like behaviors only in adult female mice, as evaluated by sucrose preference and tail suspension tests. We then examined the ELS effects on monoamine neurotransmission (transporters for monoamine reuptake and release) in depression-related brain regions in female mice. We found that ELS resulted in widespread changes of the expression levels of these transporters in four brain regions. Moreover, systemic 21-day treatment with vortioxetine, a novel multimodal antidepressant, successfully reversed depression-like behaviors and normalized some molecular changes, including that of the norepinephrine transporter in the medial prefrontal cortex, vesicular monoamine transporter 2 in nucleus accumbens core, and serotonin transporter in amygdala. Collectively, these results provide evidence for the validity of using the limited bedding and nesting material paradigm to investigate sex differences in depression and demonstrate that the region-specific alterations of monoamine neurotransmission may be associated with depression-like behaviors in female mice. This article is part of the special issue on 'Stress, Addiction and Plasticity'.

Maternal Separation-Induced Histone Acetylation Correlates with BDNF-Programmed Synaptic Changes in an Animal Model of PTSD with Sex Differences.

Maternal separation (MS) causes long-lasting epigenetic changes in the brain and increases vulnerability to traumatic events in adulthood. Of interest, there may be sex-specific differences in these epigenetic changes. In this study, the extent of histone acetylation in the hippocampus (HIP) and the expression of BDNF were measured to determine whether BDNF influences risk of PTSD following MS in early life. Rat offspring were separated from their dams (3 h/day or 6 h/day from PND2~PND14). Then, pups were treated with a single prolonged stress (SPS) procedure when they reached adulthood (PND80). In animals stressed with the SPS procedure in adulthood, those that had increased MS intensity in childhood demonstrated more significant changes in performance on tests of anxiety, depression, and contextual fear memory. Reduced levels of total BDNF mRNA and protein were observed after SPS treatment and further declined in groups with greater MS time in childhood. Interestingly, these changes were correlated with decreased H3K9ac levels and increased HDAC2 levels. Additional MS also led to more severe ultrastructural synaptic damage in rats that experienced the SPS procedure, particularly in the CA1 and CA3 region of the HIP, reflecting impaired synaptic plasticity in these regions. Interestingly, male rats in the MS3h-PTSD group showed decreased anxiety, but no similar changes were found in female rats, suggesting a degree of gender specificity in coping with stress after mild MS. In summary, this study suggests that the epigenetic signatures of the BDNF genes can be linked to HIP responses to stress, providing insights that may be relevant for people at risk of stress-related psychopathologies.

Effects of BDNF Signaling on Anxiety-Related Behavior and Spatial Memory of Adolescent Rats in Different Length of Maternal Separation.

As an adverse form of early-life stress (ELS), maternal separation (MS) can interfere with the development of cognition and behaviors of adolescent rodents. Brain-derived neurotrophic factor (BDNF) is involved in the regulation of brain development and function, but the molecular mechanisms by which BDNF regulates brain function and behavior in MS with different stressor strengths remain unclear. This descriptive study characterized the levels of BDNF in the prefrontal cortex (PFC) and plasma corticosterone (CORT) from the offspring of rats exposed to early handling (EH, 15-min separation per day) and prolonged MS (PMS, 180-min separation per day), during postnatal days (PND) 1­21. The behavioral and biochemical analyses were performed during adolescence (PND 42­56). PMS resulted in reduced weight and decreased locomotor activity in the open field test and Y-maze task compared to control (CON) group, with EH showing an intermediate phenotype. BDNF protein levels in the PFC were lower in PMS compared to EH and further reduced in CON male rats. Plasma CORT levels were higher in PMS compared to CON with EH again showing intermediate levels. Neither PMS or EH affected spatial learning in the Y-maze task. These findings indicate that longer periods of maternal separation are necessary to increase anxiety-like behavior, elevate CORT levels, and further suppress BDNF levels in the PFC, providing a possible mechanism to explain why more severe forms of ELS lead to more significant psychiatric and medical consequences later in life.

The effects of histone deacetylase inhibitors on the attentional set-shifting task performance of alcohol-dependent rats.

OBJECTIVES: Alcohol dependence causes extensive damage to the central nervous system, resulting in impaired brain structure and behavioral changes. Moreover, histone deacetylase (HDAC) inhibitors restrain the activity of HDAC and cause increased histone acetylation, which may be related to alcohol dependence. METHODS: Ethanol dependence was modelled in animals by persistent alcohol exposure and tested in the conditioned place preference (CPP) paradigm. To induce CPP, the alcohol-treated rats were given orally gradient concentration (3%, 6%, and 9% v/v) alcohol administration for 20 consecutive days. The sodium butyrate (NaB)-treated rats were injected daily. Cognitive flexibility was evaluated using an attentional set-shifting task (ASST) in which the rats performed a series of seven consecutive discriminations after the final CPP paradigm. RESULTS: Ethanol administration induced alcohol dependence behaviors, with more time spent in the ethanol-paired compartment. Compared with the CPP scores of the control group, the scores of the ethanol- and NaB-treated groups were significantly higher. In the ASST, alcohol-treated rats had significantly increased number of trials to reach criteria (TTC) in most phases, higher error rate, and lower cognitive levels compared to the control group. Moreover, the present findings demonstrated that NaB combined with ethanol caused cognitive deficits as the result of an increased number of TTC during the ASST. CONCLUSIONS: The attentional/cognitive flexibility of the prefrontal cortex of alcohol-dependent rats was damaged and the NaB administration procedure itself did not produce cognitive deficits, but instead exacerbated cognitive impairment in alcohol-dependent rats.

Long non-coding RNA UC001kfo promotes hepatocellular carcinoma proliferation and metastasis by targeting α-SMA.

Several long non-coding RNAs (lncRNAs) have been investigated and found to be correlated with the behaviours and prognosis of hepatocellular carcinoma (HCC); Specifically, we revealed that the lncRNA UC001kfo was differentially expressed in HCC tissues compared with normal liver tissues using lncRNA microarrays, but its functional role in cancers, including HCC, has not yet been elucidated. The present study found that the expression of UC001kfo was upregulated in HCC tissues and cell lines in comparison with tumour-adjacent tissues and normal hepatocytes, respectively. In addition, a high UC001kfo level was determined to be correlated with macro-vascular invasion and TNM stage of HCC. Specifically, patients with high UC001kfo expression displayed a significantly lower overall survival rate and progression-free survival rate. Moreover, both univariate and multivariate COX regression analyses identified TNM stage and high UC001kfo expression as risk factors for poor prognosis in HCC patients. In addition, UC001kfo was verified to promote the proliferation, metastasis and epithelial-mesenchymal transition (EMT) in HCC cells in both in vitro and in vivo assays. Mechanistically, α-SMA was indicated as a potential target gene of UC001kfo in mediating HCC metastasis. In conclusion, UC001kfo promotes HCC proliferation and metastasis by targeting α-SMA, and UC001kfo may potentially serve as a prognostic marker and a therapeutic target for treatment of HCC.

[Scopolamine and hyoscyamine synthesis in hair roots culture of Datura metel].

OBJECTIVE: To establish the hair roots culture system of Datura metel and study the hair roots growth and biosynthesis of scopolamine and hyoscyamine in hair roots culturing system. METHOD: Direct degermed cotyledon of wild D. metel was infected by Agrobacterium tumefaciens strain C58C1 to obtain hair roots. Growth curves and scopolamine and hyoscyamine biosynthesis curves were determined. The scopolamine and hyoscyamine from different hair roots lines were examined by HPLC. RESULT: Hair roots induction rate reached 70%. After 25 days cultured in 1/2 MS liquid nutrient medium, the hair roots weight, content of scopolamine and hyoscyamine reached maximum, tow high efficient accumulation hyoscyamine and scopolamine hair roots lines M1 and M2 were obtained. The medial accumulation coefficient of hyoscyamine and scopolamine were 2.53 times and 5.37 times compared with the leaves of wild D. metel respectively. CONCLUSION: The established hair roots induction and culture system of D. metel provided a foundation for further obtaining scopolamine and hyoscyamine.

Role of long non-coding RNAs in gene regulation and oncogenesis.

OBJECTIVE: This article aims to review recent studies on the biological characteristics of long non-coding RNAs (lncRNAs), transcription regulation by lncRNAs, and the results of recent studies on the mechanism of action of lncRNAs in tumor development. DATA SOURCES: The data cited in this review were mainly obtained from the articles listed in PubMed and HighWire that were published from January 2002 to June 2010. The search terms were "long non-coding RNA", "gene regulation", and "tumor". STUDY SELECTION: The mechanism of lncRNAs in gene expression regulation, and tumors concerned with lncRNAs and the role of lncRNAs in oncogenesis. RESULTS: lncRNAs play an important role in transcription regulation by controlling chromatin remodeling, transcriptional control, and post-transcriptional controlling. lncRNAs are involved in many kinds of tumors and play key roles as both suppressing and promoting factors. CONCLUSION: lncRNAs could perfectly regulate the balance of gene expression system and play important roles in oncogenic cellular transformation.

[Culture in vitro and plant regeneration of Panax japonicus].

OBJECTIVE: To study the condition of culture in vitro and plant regeneration of Panax japonicus. METHODS: Embryos, stems and leaves of P. japonicus were used as explants, effects of different hormones for callus induction and plant regeneration were studied and optimized. RESULTS: The optimal way to obtain sterile explant for seeds was sterilized in 75% ethyl alcohol for 60 s then 0.1% HgCL2 for 12 min; Stems and leaves were sterilized in 75% ethyl alcohol for 15 s then 5% NaClO for 5 min. Used MS as basic medium, the optimal hormones combination for callus induction of embryos, stems and leaves were MS + 1.5 mg/L NAA + 1.5 mg/L 2, 4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.2 mg/L KT respectindy under the illumination. But under the darkness,the optimal callus induction hormones combination for embryos leaves were MS + 1.0 mg/L NAA + 1.5 mg/L 2,4-D +0.2 mg/L KT; 1.5 mg/L NAA + 1.5 mg/L 2,4-D + 0.1 mg/L KT; MS + 1.5 mg/L NAA + 1.0 mg/L 2,4-D + 0.1 mg/L KT respectivety. The optimal medium for germination was MS + 3.0 mg/L 6-BA + 1.0 mg/L GA3. The optimal medium for roots generation was MS + 1.0 mg/L 6-BA + 3.0 mg/L IBA. CONCLUSION: We establish the system of culture in vitro and plant regeneration for P. japonicus.

[Culture of hairy roots of Panax japonicus and ginsenoside re synthesis].

OBJECTIVE: To establish the induction method and culture system of hairy roots of Panax japonicus, and determine ginsenoside Re contents. METHOD: Hairy roots of P. japonicus was obtained through infecting pre-incubated terrestrial stem with the Agrobacterium tumefaciens strain C58C1; its enlarging culture was carried out on the 1/2MS medium, and growing characteristics were measured. The transformation of T-DNA was examined by PCR and ginsenoside Re content was determined by HPLC. RESULT: A. tumefaciens strain C58C1 could make terrestrial stem of P. japonicus bring about hairy roots, the max inductivity was 90% when infecting for 25 min. The PCR examination result showed that rolB genes could be inserted into the hair roots of P. japonicus. All hairy roots dould synthesize ginsenoside Re, among them, the max content was PJ8 with 60. 26 mg x g(-1). CONCLUSION: It was reported for the first time that the induction method and culture system of hairy roots of P. japonicus were established successfully, which provided a foundation for producing high content ginsenoside Re through culturing the hairy roots of P. japonicus.

[Study on the association between severe chronic hepatitis B and HLA-DRB1 gene polymorphism].

OBJECTIVE: To study the association between HLA-DRB1 gene polymorphism and severe chronic hepatitis B. METHODS: 26 patients with severe chronic hepatitis B were investigated for HLA-DRB1 gene polymorphism by polymerase chain reaction-sequence specific primers technique. The results were compared with those from 45 normal healthy people by use of chi2-test of Microsoft SPSS 13.0. RESULTS: The frequency of HLA-DRB1 * 1301/1302 allele in severe chronic hepatitis B group was significantly higher than the frequency in the control group, while the frequencies of HLA-DRB1 * 1201/1202, 1501/1502 allele were not significantly different. CONCLUSION: HLA-DRB1 * 1301,1302 is closely associated with the suseptibility to severe chronic hepatitis B, While HLA-DRB1 * 1201/1202, 1501/1502 have no association with severe chronic hepatitis B.