Up-regulation of MTHFD2 is associated with clinicopathological characteristics and poor survival in ovarian cancer, possibly by regulating MOB1A signaling

Background

MTHFD2 is a folate-coupled metabolic enzyme, which has been proved to participant in the metabolic reprogramming and tumor cell-sustaining proliferative capacity. However, the function of MTHFD2 in the development of ovarian cancer and its potential molecular mechanisms is still unclear.

Materials and methods

The expression, various mutations, prognosis, and related network signaling pathways of MTHFD2 were analyzed using bioinformatics-related websites, including Oncomine, GEPIA, UCSC, cBioPortal, KM Plotter, TISIDB and TIMER. The prognostic value of MTHFD2 expression was validated by our own ovarian cancer samples using RT-qPCR. The migration ad invasion of ovarian cancer cells were further analyzed by CCK-8 and transwell assay. The Western-blot assay was performed to explore the protein levels of MTHFD2 and MOB1A.

Results

We obtained the following important results. (1) MTHFD2 expression was markedly up-regulated in ovarian cancer than normal samples. (2) Among patients with ovarian cancer, those with higher MTHFD2 expression was associated with lower survival rate. (3) The major mutation type of MTHFD2 in ovarian cancer samples was missense mutation. (4) MTHFD2 knockdown inhibited proliferation, migration, invasion, as well as the expression of MOB1A in vitro.

Conclusion

MTHFD2, as a NAD + -dependent enzyme, accelerated tumor progression by up-regulating MBO1A, suggesting that this protein may be an independent prognostic factor and a potential therapeutic target for future ovarian cancer treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00954-w.

Iterative mutagenesis induced by atmospheric and room temperature plasma treatment under multiple selection pressures for the improvement of coenzyme Q10 production by Rhodobacter sphaeroides

CoQ10, which has been widely applied in medicine by dietary supplement, possesses important functions in antioxidant process and bioenergy generation. Iterative mutagenesis introduced by atmospheric and room temperature plasma (ARTP) treatment was studied to improve the coenzyme Q10 (CoQ10) production of Rhodobacter sphaeroides (R. sphaeroides), and multiple selection pressures including vitamin K3 (VK3), Na2S and benzoic acid (BA) were adopted for the first time. After two rounds of mutation and screening, a mutant strain R.S 17 was obtained, and the product titer was increased by 80.37%. The CoQ10 titer and cell density reached 236.7 mg L-1 and 57.09 g L-1, respectively, in the fed-batch fermentation, and the CoQ10 content was 22.1% higher than that of the parent strain. In addition, the spectral scanning results indicated the metabolic flux improvement contributing to the CoQ10 production in R.S 17, and the genetic stability was validated. Based on the iterative mutagenesis introduced by ARTP under multiple selection pressures, the promotion of CoQ10 production by R. sphaeroides was achieved. The significant improvement in fermentation performances and the good genetic stability of R.S 17 indicate a potential way for the efficient biosynthesis of CoQ10.

Antioxidant activity of yeast mannans and their growth-promoting effect on Lactobacillus strains

Yeast mannans from Saccharomyces cerevisiae (123.2 kDa, 40.5 kDa and 21.3 kDa) were prepared. The scavenging abilities of Fe²⁺, OH˙, and O₂˙^- and protective capacities against lipid peroxidation and oxidative DNA damage increased with the reduction of the molecular weights of yeast mannans. The highest scavenging abilities of Fe²⁺, OH˙ and O₂˙^- (25.32%, 70.8%, and 61.5%) were observed with YM-90, and it showed an anti-lipid peroxidation capacity of 65.82%, which was much stronger than that of vitamin C (VC), with a thiobarbituric acid-reactive substance (TBARS) inhibition rate of 80.41%. However, the highest DPPH scavenging rate (88.7%) was exhibited by YM-30. In addition, the growth-promoting effect of yeast mannans on Lactobacillus strains was further confirmed, and a 54.2% increment of Lactobacillus plantarum ZWR5 cell viability was achieved by YM-90. The results indicated the potential industrial applications of this yeast mannan technology in therapeutic and nutraceutical production.

Increased expression of KPNA2 predicts unfavorable prognosis in ovarian cancer patients, possibly by targeting KIF4A signaling

Background

Karyopherin α-2 (KPNA2) is a member of karyopherin family, which is proved to be responsible for the import or export of cargo proteins. Studies have determined that KPNA2 is associated with the development and prognosis of various cancers, yet the role of KPNA2 in ovarian carcinoma and its potential molecular mechanisms remains unclear.

Materials and methods

The expression and prognosis of KPNA2 in ovarian cancer was investigated using GEPIA and Oncomine analyses. Mutations of KPNA2 in ovarian cancer were analyzed by cBioPortal database. The prognostic value of KPNA2 expression was evaluated by our own ovarian carcinoma samples using RT-qPCR. Subsequently, the cell growth, migration and invasion of ovarian cancer cells were investigated by CCK-8 and transwell assay, respectively. The protein levels of KPNA2 and KIF4A were determined by western blot.

Results

We obtained the following important results. (1) KPNA2 and KIF4A wereoverexpressed in ovairan cancer tissues and cells. (2) Among patients with ovarian cancer, overexpressed KPNA2 was associated with lower survival rate. (3) Mutations (R197* and S140F) in KPNA2 will have some influences on protein structure, and then may cause protein function abnormal. (4) KPNA2 konckdown inhibited proliferation, migration, invasion, as well as the expression of KIF4A.

Conclusion

KPNA2, as a tumorigenic gene in ovarian cancer, accelerated tumor progression by up-regulating KIF4A, suggesting that KPNA2 might be a hopeful indicator of treatment and poor prognosis.

Open simultaneous saccharification and fermentation of l-lactic acid by complete utilization of sweet sorghum stalk: a water-saving process

A complete and efficient utilization of sweet sorghum stalk including sweet sorghum juice (SSJ) and sweet sorghum bagasse (SSB) was achieved via the open simultaneous saccharification and fermentation (SSF) of l-lactic acid. To simplify the pretreatment process and reduce water consumption, a combined hydrolysis approach was applied and the NaOH-pretreated liquor (SL) was utilized as a partial neutralizing agent. In order to further enhance the product titer, the acid hydrolysate of SSJ (SSJAH) was fed, and MgO was used as a neutralizing agent. A product titer of 94 g L-1 was obtained with a productivity of 1.55 g L-1 h-1, and the yield reached 98.31%. Totally, 274.79 g l-lactic acid was produced from 1 kg sweet sorghum stalk, and 83.22% water was saved compared with the previous study based on alkali pretreatment of SSB. This study provides an effective process for l-lactic acid biosynthesis from lignocellulosic substrates.

Analyses of DNA Methylation Involved in the Activation of Nuclear Karyopherin Alpha 2 Leading to Identify the Progression and Prognostic Significance Across Human Breast Cancer

Background

Karyopherin alpha 2 (KPNA2) is a nuclear import factor that plays a crucial role in nucleocytoplasmic transport, as well as cell proliferation, migration, and invasion in several cancers. However, the roles of KPNA2 in breast cancer as well as the underlying molecular mechanisms have not been elucidated.

Materials and Methods

To evaluate gene expression alterations during breast carcinogenesis, KPNA2 expression was analyzed using the Gene Expression Profiling Interactive Analysis and Oncomine analyses. The correlation between methylation and expression was analyzed using the MEXPRESS tool, UALCAN cancer database, and cBioPortal browser. Then, the expression and prognostic value of KPNA2 were investigated by our own breast cancer samples using RT-PCR. KPNA2 methylation level was detected by methylation-specific PCR.

Results

We obtained the following important results. (1) KPNA2 expression was significantly higher in breast cancer than normal samples and regulated by aberrant DNA hypomethylation of promoter region. (2) Among patients with breast cancer, those with higher KPNA2 expression had a lower survival rate. (3) The major mutation type of KPNA2 in breast cancer samples was missense mutation. (4) Homer1 was able to promote breast cancer progression may be through upregulating TPX2 expression.

Conclusion

Our findings suggest that aberrant DNA hypomethylation of promoter regions contributes to the aberrant expression of KPNA2 in breast cancer, which might be a potential indicator of poor prognosis.

An Anti-FOD Method Based on CA-CM-CFAR for MMW Radar in Complex Clutter Background

Traditional constant false alarm rate (CFAR) methods have shown their potential for foreign object debris (FOD) indication. However, the performance of these methods would deteriorate under the complex clutter background in airport scenes. This paper presents a threshold-improved approach based on the cell-averaging clutter-map (CA-CM-) CFAR and tests it on a millimeter-wave (MMW) radar system. Clutter cases are first classified with variability indexes (VIs). In homogeneous background, the threshold is calculated by the student-t-distributed test statistic; under the discontinuous clutter conditions, the threshold is modified according to current VI conditions, in order to address the performance decrease caused by extended clutter edges. Experimental results verify that the chosen targets can be indicated by the t-distributed threshold in homogeneous background. Moreover, effective detection of the obscured targets could also be achieved with significant detectability improvement at extended clutter edges.

Excess copper inhibits the growth of rice seedlings by decreasing uptake of nitrate

Copper (Cu) toxicity has a deleterious effect on plant growth, and different nitrogen (N) forms have significantly different impacts on the uptake and accumulation of heavy metals by plants. However, it remains unclear how excess Cu inhibits the growth of rice seedlings under different N forms. Here, we examined the mechanism of Cu toxicity inhibiting the growth of rice supplied with different N forms. Rice seedlings were grown in a nutrient solution with 0.81 mmol L^-1 N, as ammonium (NH₄⁺), nitrate (NO₃^-) and NH₄⁺ + NO₃^-, or without N (0 N) in the presence of 0.2 μmol L^-1 CuSO₄ or 10 μmol L^-1 CuSO₄. The inhibition of shoot growth under excess Cu was more pronounced in plants that were supplied with NO₃^- than NH₄⁺; such inhibition was not induced by higher Cu concentration in shoots. Applied with NO₃^- alone increased solution pH value up to 6.2, but supplied with NH₄⁺ alone and NH₄⁺ + NO₃^- decreased solution pH value to 4.0 and 4.2, respectively. The increment of solution pH reduced Cu concentration in shoots of rice supplied with NO₃^- alone. Copper toxicity decreased NO₃^- concentrations in rice seedlings that were supplied with NO₃^- alone but increased the NH₄⁺ concentrations in plants that were supplied with NH₄⁺ or NH₄⁺ + NO₃^-. High Cu levels reduced the uptake of NO₃^- in roots by the analysis of net NO₃^- flux and NO₃^- assimilation enzymes activity. Under excess Cu, the transcript levels of OsNPF6.5, OsNPF2.2 and OsNPF2.4 genes were suppressed, while OsNRT2.1, OsNRT2.2 and OsNAR2.1 were raised in roots. In conclusion, Cu toxicity inhibits NO₃^- uptake and upward translocation by modulating the expression level of NO₃^- transporter genes. The reduction in the concentrations of NO₃^- and total N decreased shoot growth of rice seedlings when N was supplied as NO₃^-. Hence, rice seedlings supplied with NO₃^- had lower shoot biomass than those with NH₄⁺ under Cu stress.

A Clutter-Analysis-Based STAP for Moving FOD Detection on Runways

Security risks and economic losses of civil aviation caused by Foreign Object Debris (FOD) have increased rapidly. Synthetic Aperture Radars (SARs) with high resolutions potentially have the capability to detect FODs on the runways, but the target echo is hard to be distinguished from strong clutter. This paper proposes a clutter-analysis-based Space-time Adaptive Processing (STAP) method in order to obtain effective clutter suppression and moving FOD indication, under inhomogeneous clutter background. Specifically, we first divide the radar coverage into equal scattering cells in the rectangular coordinates system rather than the polar ones. We then measure normalized RCSs within the X-band and employ the acquired results to modify the parameters of traditional models. Finally, we describe the clutter expressions as responses of the scattering cells in space and time domain to obtain the theoretical clutter covariance. Experimental results at 10 GHz show that FODs with a reflection higher than -30 dBsm can be effectively detected by a Linear Constraint Minimum Variance (LCMV) filter in azimuth when the noise is -60 dBm. It is also validated to indicate a -40 dBsm target in Doppler. Our approach can obtain effective clutter suppression 60dB deeper than the training-sample-coupled STAP under the same conditions.

The role of Th1/Th2 cytokines played in regulation of specific CD4 + Th1 cell conversion and activation during inflammatory reaction of chronic obstructive pulmonary disease

CD4 ⁺ Th1-CXCR3 signalling pathway may play a key role in chronic obstructive pulmonary disease (COPD). The aim of this study was to explore Th1/Th2 cytokines ratio differences in patients in different stages of COPD and to confirm the hypothesis that elastin exposure might serve as an antigen to initiate the stimulation of CD4 ⁺ Th1-CXCR3 immune inflammation pathway. Patients of COPD in different stages and normal individuals were enrolled. Ten millilitres of peripheral blood was drawn from patients. The concentration of CXCR3, IFN-γ, IL-2, IL-4 and IL-13 in plasma was detected by ELISA. The Naïve CD4⁺ T cells were isolated from the peripheral blood mononuclear cells, which were stimulated by elastin and collagen before determining the level of IFN-γ secretion by ELISPOT. Compared with control group, the concentration of CXCR3 in the acute exacerbation COPD (AECOPD) group was higher (P < .05). The concentration of IFN-γ and IL-2 in AECOPD group was lower than that in remission (P < .05). The concentration of IFN-γ in the AECOPD and remission was higher than that in controls (P < .05), while IL-2 was opposite (P < .01). The concentration of IL-4 and IL-13 in AECOPD group was higher than that in the controls (P < .05). The CD4⁺ Th1 cells stimulated by the elastin as antigen secreted more IFN-γ than that by collagen (P < .01). CXCR3 was highly expressed in patients with COPD. There were different Th1/Th2 cytokines in different stages of COPD. The CD4+Th1-specific conversion and activation may be an initiator of COPD immune inflammatory response.

[Application of 3D virtual reality technology with multi-modality fusion in resection of glioma located in central sulcus region]

Objective: To explore the clinical and teaching application value of virtual reality technology in preoperative planning and intraoperative guide of glioma located in central sulcus region. Method: Ten patients with glioma in the central sulcus region were proposed to surgical treatment. The neuro-imaging data, including CT, CTA, DSA, MRI, fMRI were input to 3dgo sczhry workstation for image fusion and 3D reconstruction. Spatial relationships between the lesions and the surrounding structures on the virtual reality image were obtained. These images were applied to the operative approach design, operation process simulation, intraoperative auxiliary decision and the training of specialist physician. Results: Intraoperative founding of 10 patients were highly consistent with preoperative simulation with virtual reality technology. Preoperative 3D reconstruction virtual reality images improved the feasibility of operation planning and operation accuracy. This technology had not only shown the advantages for neurological function protection and lesion resection during surgery, but also improved the training efficiency and effectiveness of dedicated physician by turning the abstract comprehension to virtual reality. Conclusion: Image fusion and 3D reconstruction based virtual reality technology in glioma resection is helpful for formulating the operation plan, improving the operation safety, increasing the total resection rate, and facilitating the teaching and training of the specialist physician.

Abnormal expression levels of BMP15/Smad1 are associated with granulosa cell apoptosis in patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects reproductive dysfunction and metabolism in women of childbearing age. An increasing number of studies have suggested that the bone morphogenetic protein 15 (BMP15) signalling pathway serves an important role in the pathogenesis of PCOS; however, the full mechanism remains unknown. The present study revealed that intrinsic follicular dysplasia may be associated with regulation disorders of ovarian granulosa cell apoptosis. Compared with the control group, body mass index, luteinising hormone and testosterone levels were significantly increased (P<0.05). The percentage of S phase cells was significantly higher, cells in G2/M phase cells was significantly lower, and cells undergoing apoptosis was significantly higher in the PCOS group compared with the control group (P<0.05). The expression levels of B‑cell lymphoma 2 was significantly decreased in granulosa cells of PCOS group, whereas the expression of caspase‑3 was higher than the control group (P<0.05). The rate of apoptosis of granulosa cells was measured by a terminal deoxynucleotide transferase dUTP nick‑end labelling assay. The relative mRNA expression levels of BMP receptor 2 and SMAD1 were significantly decreased in granulosa cells in the PCOS group compared with the control (P<0.05). In addition, the expression of BMP15 in follicular fluid and Smad1 in granulosa cells was significantly decreased in the PCOS group compared with the control (P<0.05). The data suggested that the BMP15/Smad1 signalling pathway may be involved in granulosa cell apoptosis, and may be a target for clinical treatment for PCOS.

Long noncoding RNA CCAT2 can predict metastasis and a poor prognosis: A meta-analysis

BACKGROUND

Colon cancer associated transcript 2 (CCAT2), a novel long non-coding RNA (lncRNA), plays a key role in tumorigenesis. This meta-analysis systematically summarizes the relationship between CCAT2 and cancers.

METHODS

A comprehensive, computerized literature search was conducted in PubMed, Cochrane library, Chinese National Knowledge Infrastructure, and Chinese Wan Fang database. Odds ratios (ORs), hazard ratios (HRs) and their 95% confidence interval (95% CI) were calculated to assess the effect size. A total of 9 studies were enrolled in this meta-analysis, which was performed by Revman5.3 software and Stata12.0.

RESULTS

Our meta-analysis indicates that patients with elevated expression of CCAT2 are prone to developing distant metastasis (DM) (OR=12.42; 95% CI=5.77-26.74; P < 0.00001), which is associated with a tendency for lymph nodes metastasis (LNM) (OR=3.60 95% CI=1.65-7.87, P=0.001). Further analyses reveal that patients with high CCAT2 expression have poorer overall survival (OS) (HR=1.53, 95% CI=1.15-2.02, P=0.003, random-effects) and progression-free survival (PFS) (HR=2.88, 95% CI=1.81-4.56, P < 0.00001, fixed-effects).

CONCLUSIONS

Therefore, CCAT2 may be a potential novel biomarker for indicating clinical outcomes of human cancers.

Promotion of photosynthesis in transgenic rice over-expressing of maize C4 phosphoenolpyruvate carboxylase gene by nitric oxide donors

We determined the effects of exogenous nitric oxide on photosynthesis and gene expression in transgenic rice plants (PC) over-expressing the maize C4pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC). Seedlings were subjected to treatments with NO donors, an NO scavenger, phospholipase inhibitors, a Ca(2+) chelator, a Ca(2+) channel inhibitor, and a hydrogen peroxide (H2O2) inhibitor, individually and in various combinations. The NO donors significantly increased the net photosynthetic rate (PN) of PC and wild-type (WT), especially that of PC. Treatment with an NO scavenger did inhibit the PN of rice plants. The treatments with phospholipase inhibitors and a Ca(2+) chelator decreased the PN of WT and PC, and photosynthesis was more strongly inhibited in WT than in PC. Further analyses showed that the NO donors increased endogenous levels of NO and PLD activity, but decreased endogenous levels of Ca(2+) both WT and PC. However, there was a greater increase in NO in WT and a greater increase in PLD activity and Ca(2+) level in PC. The NO donors also increased both PEPC activity and pepc gene expression in PC. PEPC activity can be increased by SNP alone. But the expression of its encoding gene in PC might be regulated by SNP, together with PA and Ca(2+).

Protective effects of SKF-96365, a non-specific inhibitor of SOCE, against MPP+-induced cytotoxicity in PC12 cells: potential role of Homer1

Parkinson's disease (PD) is the most common neurodegenerative movement disorder, characterized by loss of dopominergic (DA) neurons in substantia nigra pars compacta (SNpc), and can be experimentally mimicked by the neurotoxin MPP⁺ in vitro models. In this study, we investigated the potential protective effect of SKF-96365, a non-specific inhibitor of SOCE (store-operated calcium entry), on MPP⁺ induced cytotoxicity in PC12 cells. We found that pretreatment with SKF-96365 (10 µM and 50 µM) 30 min before injury significantly increased cell viability, decreased LDH release, prevented nuclear damage, and inhibited apoptotic cell death in MPP⁺ stressed PC12 cells. The results of calcium image using the ratiometric calcium indicator Fura-2-AM also showed that SKF-96365 reduced the intracellular calcium overload induced by MPP⁺ in PC12 cells. In addition, SKF-96365 decreased the expression of Homer1, a more recently discovered postsynaptic scaffolding protein with calcium modulating function, following MPP⁺ administration in PC12 cells, while had no statistically significant effects on endoplasmic reticulum (ER) calcium concentration. Furthermore, overexpression of Homer1 by using recombinant lentivirus partly reversed protective effects of SKF-96365 against MPP⁺ injury. The ER Ca²⁺ release was further amplified and ER calcium recovery was delayed by Homer1 upregulation in PC12 cells following MPP⁺ insult. Taken together, these data suggest that SKF-96365 protects PC12 cells against MPP⁺ induced cytotoxicity, and this protection may be at least in part on the inhibition of intracellular calcium overload and suppression of Homer1-mediated ER Ca²⁺ release.

Iduna protects HT22 cells from hydrogen peroxide-induced oxidative stress through interfering poly(ADP-ribose) polymerase-1-induced cell death (parthanatos)

Oxidative stress-induced cell death is common in many neurological diseases. However, the role of poly(ADP-ribose) polymerase-1-induced cell death (parthanatos) has not been fully elucidated. Here, we found that hydrogen peroxide (H2O2) could lead to PARP-1 activation and apoptosis-inducing factor nuclear translocation in a concentration dependent manner. Iduna, as a novel regulator of parthanatos, was also induced by H2O2. Down-regulation of Iduna by genetic ablation promoted H2O2-induced cell damage. Up-regulation of Iduna reduced the loss of mitochondrial potential and ATP and NAD+ production, but did not affect the mitochondrial dysfunction-induced cytochrome c release, increase of Bax/Bcl-2 ratio, and Caspase-9/Caspase-3 activity. In contrast, overexpression of Iduna inhibited activation of PARP-1 and nuclear translocation of AIF. Further study showed that PARP-1 specific inhibitor, DPQ, blocked the protective effect of Iduna against H2O2-induced oxidative stress. Moreover, in the presence of proteasome inhibitor (MG-132) or ubiquitin E1 inhibitor (PYR-41), protective effect of Iduna was significantly weaken. These results indicate that Iduna acts as a potential antioxidant by improving mitochondrial function and inhibiting oxidative stress-induced parthanatos, and these protective effects are dependent on the involvement of ubiquitin-proteasome system.

Protective effect of Homer 1a against hydrogen peroxide-induced oxidative stress in PC12 cells

Oxidative stress-induced cell damage is involved in many neurological diseases. Homer protein, as an important scaffold protein at postsynaptic density, regulates synaptic structure and function. Here, we reported that hydrogen peroxide (H(2)O(2)) induced the expression of Homer 1a. Down-regulation of Homer 1a with a specific small interfering RNA (siRNA) exacerbated H(2)O(2)-induced cell injury. Up-regulation of Homer 1a by lentivirus transfection did not affect the anti-oxidant activity, but significantly reduced the reactive oxygen species (ROS) production and lipid peroxidation after H(2)O(2)-induced oxidative stress. Overexpression of Homer 1a attenuated the loss of mitochondrial membrane potential (MMP) and ATP production induced by H(2)O(2), and subsequently inhibited mitochondrial dysfunction-induced cytochrome c release, increase of Bax/Bcl-2 ratio and caspase-9/caspase-3 activity. Furthermore, in the presence of BAPTA-AM, an intracellular free-calcium (Ca(2+)) chelator, overexpression of Homer 1a had no significant effects on H(2)O(2)-induced oxidative stress. These results suggest that Homer 1a has protective effects against H(2)O(2)-induced oxidative stress by reducing ROS accumulation and activation of mitochondrial apoptotic pathway, and these protective effects are dependent on the regulation of intracellular Ca(2+) homeostasis.

Down-regulation of Homer1b/c attenuates glutamate-mediated excitotoxicity through endoplasmic reticulum and mitochondria pathways in rat cortical neurons

Glutamate-mediated excitotoxicity is involved in many acute and chronic brain diseases. Homer proteins, a new member of the postsynaptic scaffolding proteins, regulate glutamatergic signaling and intracellular calcium mobilization in the central nervous system. Here we investigated the effects of down-regulating Homer1b/c, a constitutively expressed long form of Homer proteins, on glutamate excitotoxicity-induced neuronal injury. In our in vitro excitotoxic models, we demonstrated that glutamate insults led to a dose-dependent neuronal injury, which was mediated by the intracellular calcium-dependent reactive oxygen species (ROS) production. We found that down-regulation of Homer1b/c with specific small interfering RNA (siRNA) improved neuronal survival, inhibited intracellular ROS production, and reduced apoptotic cell death after neurotoxicity. Homer1b/c knockdown decreased the intracellular calcium overload through inhibition of the group I metabotropic glutamate receptor (mGluR)/inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release from the endoplasmic reticulum (ER) in injured neurons. In addition, Homer1b/c siRNA transfection attenuated the activation of eukaryotic initiation factor 2α (eIF2α), RNA-dependent protein kinase-like ER kinase (PERK) and caspase-12, and inhibited the up-regulation of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) after glutamate treatment. Homer1b/c knockdown also preserved the mitochondrial membrane potential (MMP), reduced cytochrome c (Cyt. c) release, and partly blocked the increase of capase-9 activity and Bax/Bcl-2 ratio. Taken together, these results suggest that down-regulation of Homer1b/c protects cortical neurons against glutamate-induced excitatory damage, and this neuroprotection may be dependent at least in part on the inhibition of calcium-dependent ROS production and the preservation of the ER and mitochondrial function.

The selective mGluR5 agonist CHPG protects against traumatic brain injury in vitro and in vivo via ERK and Akt pathway

Group I metabotropic glutamate receptors (mGluRs) have been implicated in the pathophysiology of central nervous system injury, but the role of mGluR5 in traumatic brain injury (TBI) remains unclear. In the present study, we investigated the neuroprotective potency of (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG), a selective mGluR5 agonist, for protecting against TBI in both in vitro and in vivo models. Primary cortical neurons were treated with 1 mM CHPG in an in vitro preparation 30 min before TBI, and 250 nM CHPG was injected into the right lateral ventricle of rats 30 min before TBI was induced in in vivo studies. The results showed that CHPG significantly attenuated lactate dehydrogenase (LDH) release and neuronal apoptosis and reduced lesion volume. Compared to the control or vehicle group, the phosphorylation levels of extracellular signal-regulated kinase (ERK) and Akt were increased in the presence of CHPG, even following the induction of TBI. Furthermore, treatment with either the ERK inhibitor PD98059 or Akt inhibitor LY294002 partially reversed the CHPG's neuroprotective effects. These data suggest that CHPG minimizes brain damage after induction of TBI both in vitro and in vivo, and that these protective effects were possibly mediated by activation of the ERK and Akt signaling pathways. Thus, potentiating mGluR5 activity with selective agonists such as CHPG may be useful for the treatment of traumatic brain injury.

Cloning and characterization of a novel splicing variant of the ZADH1 gene

We report here the cloning and characterization of a novel splicing variant of the human zinc binding alcohol dehydrogenase, domain containing 1 (ZADH1) gene. ZADH1 is localized on chromosome 14q24.2. The cDNA of this splicing variant is 1613 base pairs in length, and encodes a 351-amino acid protein with a putative molecular weight of 38.5 kDa. We named the novel splicing variant ZADH1b. By MTC- panel PCR analysis, it was found that ZADH1b was widely expressed in human tissues. Computer analysis revealed ZADH1 had a potential ADH_zinc_N domain and it had considerable homology with some dehydrogenases. It was speculated that ZADH1 may have definite metabolic roles in vivo as a dehydrogenase.

Cloning of the KcURA3 gene and development of a transformation system for Kluyveromyces cicerisporus

KcURA3 was cloned from Kluyveromyces cicerisporus CBS4857 by complementation of the ura3 mutation in Saccharomyces cerevisiae. KcURA3 encodes a 267-amino-acid protein with 80% sequence identity to that of S. cerevisiae. An ura3 mutant strain from K. cicerisporus CBS4857, named Y179U, was obtained by selection on 5-fluoroorotic acid plates. Sequence analysis of this mutated gene revealed that it contained a point mutation at nucleotide position +277. Two vectors, pUK1 and pUKD, bearing KcURA3 were constructed. Either the lithium acetate method or electroporation could be used to transform pUK1 and pUKD intoY179U. The transformation efficiency using electroporation was higher than that using the lithium acetate method.

A human homolog of the yeast gene encoding tRNA 2'-phosphotransferase: cloning, characterization and complementation analysis

The Saccharomyces cerevisiae TPT1 gene plays a role in removing the 2'-phosphate from ligated tRNA during the maturation of pre-tRNA. Here we reported the cloning and characterization of the human TRPT1 gene as a homolog of yeast TPT1. The TRPT1 gene is located at human chromosome 11q13 and encodes a polypeptide of 253 amino acids. BLAST searches with its amino acid sequence revealed the ubiquitous occurrence of TRPT1 homologs and their functional relationships with the presence of the DUF60/KptA domain. Northern analysis demonstrated that the gene is primarily expressed in heart and skeletal muscle, with lower or undetectable levels in other tissues studied. A plasmid-shuffling experiment showed that the human TRPT1 gene could complement the tpt1 mutation in S. cerevisiae

[Construction of Cryptococcus neoformans cap70 transformation system]

OBJECTIVE

To construct a transformation system of Cryptococcus neoformans capsule-deficient strain cap70.

METHODS

(1)Obtained ura5 mutants by screening the Cryptococcus neoformans cap70 using 5-fluoroorotic acid counter selection method, analyzed the obtaining strain by Southern blot and PCR; (2)Through the plasmid pCXJ18 and pCXJU which contained ura5 gene from Cryptococcus neoformans and ura3 from Kluyveromyces fragilils. as a selective marker, the ura5 strains were transformed by electrotransformation and chemical transformation.

RESULTS

Obtained ura5 mutants, they were detected as lack of ura function. The chemical transformation method was first be used in Cryptococcus neoformans transformation.

CONCLUSION

A transformation system of Cryptococcus neoformans cap70 has been established, which provides not only the basis for gene cloning from the species for studying gene function and gene expression.

[Factor analysis on the intelligence of patients with schizophrenia]

The authors made a factor analysis on the intelligence of patients with schizophrenia. 119 patients with schizophrenia were measured by Wechsler Adult Intelligence Scale-Revised China (WAIS-RC). The results revealed the average full intelligence quotient (IQ) of schizophrenia was 79.70, the verbal intelligence quotient(VIQ) 84.43, and the performance intelligence quotient(PIQ) 74.10. Multiple regression showed the regression coefficient of educational level for IQ was 8.6721. The regression coefficient of the course of disease for IQ was negative 0.1519. Factor analysis showed that the cumulative percent of three-factor solution of schizophrenia was 73.5. In conclusion, the IQ of most patients with schizophrenia was lower than norm, VIQ > PIQ(P = 0.0000). Educational level had greater influence on IQ. The longer the course of disease was, the worse the intelligence came to be. Factor analysis indicated that three-factor solution of schizophrenia was similar to that of norm, but each subtest value was lower than norm.

[Development of an expert system for assessment of criminal responsibility capacity of mentally ill offenders]

The objective of this study was to develop an expert system for the assessment of legal capacity (ESALC). Visual Basic for Windows 3.0 was employed in establishing ESALC, and 281 cases were assessed by the system. The results were in substantial agreement with those of expert assessment. Kappa = 0.68 (P < 0.01); accuracy 90.04%, sensitivity, 85.63% and specificity 96.49%. ESALC can be used as a supplementary instrument in forensic psychiatric assessment.

Cloning and expression of Kluyveromyces fragilis LAC4 gene

The genomic library of Kluyveromyces fragilis was constructed in E. coli TG1, and 5 beta-galactosidase gene (LAC4) clones have been obtained from the library by complementation of the Kluyveromyces lactis lac4-8 mutation. The studies on the structure and the function of the LAC4 gene revealed that (i) the gene can also complement E. coli lacZ mutation; (ii) the physical map of the K. fragilis LAC4 gene was very similar to that of K. lactis; (iii) the beta-galactosidase levels expressed by the clone strains were much higher than that expressed by the original strain; (iv) the variation of the beta-galactosidase level of different clone strains induced by lactose or galactose was related to the retained degree of the 5' flanking region of LAC4 gene, suggesting that there might be a lactose specific transcription activating element in the region.

[Survey of suicidal mortality rate in several districts of Sichuan province]

A survey of the suicidal mortality rates in two cities and six districts in Sichuan province was carried out from 1980 to 1988 by the authors. The average suicidal mortality rate (ASMR) in these districts from 1980 to 1988 was 15.5/10(5), and the population and suicidal mortality rate positively correlated, r = 0.53. The ASMR in the male was 14.9/10(5), in the female 17.1/10(5), in the urban area 9.4/10(5), in the rural area 21/10(5), and the ASMR in the urban area was higher than that in the rural area (P < 0.05). The peak age of suicidal mortality was around twenty years.