Diagnosis of intellectual disability/global developmental delay via genetic analysis in a central region of China.

BACKGROUND: Advanced technology has become a valuable tool in etiological studies of intellectual disability/global developmental delay (ID/GDD). The present study investigated the role of genetic analysis to confirm the etiology in ID/GDD patients where the cause of the disease was uncertain in central China. METHODS: We evaluated 1051 ID/GDD children aged 6 months to 18 years from March 2009 to April 2017. Data concerning basic clinical manifestations were collected, and the method of etiology confirmation was recorded. Genome-wide copy number variations (CNVs) detection and high-throughput sequencing of exons in the targeted regions was performed to identify genetically-based etiologies. We compared the incidence of different methods used to confirm ID/GDD etiology among groups with differing degrees of ID/GDD using the Chi-square or Fisher exact probability test. RESULTS: We recruited 1051 children with mild (367, 34.9%), moderate (301, 28.6%), severe (310, 29.5%), and profoundly severe (73, 6.9%) ID/GDD. The main causes of ID/GDD in the children assessed were perinatal factors, such as acquired brain injury, as well as single gene imbalance and chromosomal gene mutation. We identified karyotype and/or CNVs variation in 46/96 (47.9%) of cases in severe ID/GDD patients, which was significantly higher than those with mild and moderate ID/GDD of 34/96 (35.4%) and 15/96 (15.6%), respectively. A total of 331/536 (61.8%) patients with clear etiology have undergone genetic analysis while 262/515 (50.9%) patients with unclear etiology have undergone genetic analysis (χ = 12.645, P < 0.001). Gene structure variation via karyotype analysis and CNV detection increased the proportion of children with confirmed etiology from 51.0% to 56.3%, and second-generation high-throughput sequencing dramatically increased this to 78.9%. Ten novel mutations were detected, recessive mutations in X-linked genes (ATPase copper transporting alpha and bromodomain and WD repeat domain containing 3) and dominant de novo heterozygous mutations in X-linked genes (cyclin-dependent kinase like 5, protocadherin 19, IQ motif and Sec7 domain 2, and methyl-CpG binding protein 2) were reported in the study. CONCLUSIONS: The present study indicates that genetic analysis is an effective method to increase the proportion of confirmed etiology in ID/GDD children and is highly recommended, especially in ID/GDD children with uncertain etiology.

Novel West syndrome candidate genes in a Chinese cohort.

AIMS: West syndrome (WS) is a classic form of early infantile epileptic encephalopathy (EIEE) characterized by tonic spasms with clustering, arrest of psychomotor development, and hypsarrhythmia on electroencephalography. Genetic defects play a critical role in the pathology of WS, and 54 EIEE genes have been identified till date. This study was designed to uncover new candidate genes for West syndrome. METHODS: In this study, we recruited 56 Chinese families with WS of unknown etiology. Whole exome sequencing (WES) was performed to identify Mendelian inheritance rare or novel variants. The association between candidate genes and WS was analyzed from many aspects, including recurrent genes in patients, predicted variant effect on genes, human tolerance to deficient genes, gene expression in the nervous system, coexpression with EIEE genes, mutual interaction with known EIEE proteins, genes related to ion channel or fragile X mental retardation protein function, and mouse models with manifestation of seizures. Genes with supporting evidence from those aspects were defined as highlight candidate genes. RESULTS: Whole exome sequencing identified 112 candidate variants in 89 genes. Among the candidate genes, 33 were autosomal dominant, 22 were autosomal recessive, and 34 were X-linked. Complex bioinformatic analysis revealed 17 highlight candidate genes: ATP2A2, CD99L2, CLCN6, CYFIP1, CYFIP2, GNB1, GPT2, HUWE1, KMT2D, MYO18A, NOS3, RYR1, RYR2, RYR3, TAF1, TECTA, and UBA1. The majority of highlight candidate genes are calcium-signaling pathway and mental retardation genes. CONCLUSIONS: This is the first WES study of Chinese WS patients with unknown etiology. This combination of phenotypic and genomic data will enable further testing to elucidate mechanisms underlying the pathogenesis of WS.

Bioconversion of lutein to form aroma compounds by Pantoea dispersa.

OBJECTIVES: To investigate the conversion of lutein, a carotenoid, to aroma compounds by Pantoea dispersa Y08, a lutein-degrading bacterium isolated from marigold flower residue. Bioconversion conditions, including substrate concentration, applied co-solvent and reaction time, were optimized. RESULTS: A maximum biodegradation yield of 80 % for lutein at 10 g/l was achieved. The intermediate, 3-hydroxy-ß-ionone, and final ß-ionone products were revealed by GC-MS. A bioconversion pathway of lutein is proposed to involve cleavage at the 9-10 double bond position, followed by de-hydroxylation at the 3-hydroxy position. CONCLUSIONS: This is the first report of the ability of a bacterium, P. dispersa, to sequentially convert lutein to 3-hydroxy-ß-ionone and then ß-ionone.

[Predicting the impact of climate change in the next 40 years on the yield of maize in China].

Climate change will significantly affect agricultural production in China. The combination of the integral regression model and the latest climate projection may well assess the impact of future climate change on crop yield. In this paper, the correlation model of maize yield and meteorological factors was firstly established for different provinces in China by using the integral regression method, then the impact of climate change in the next 40 years on China's maize production was evaluated combined the latest climate prediction with the reason be ing analyzed. The results showed that if the current speeds of maize variety improvement and science and technology development were constant, maize yield in China would be mainly in an increasing trend of reduction with time in the next 40 years in a range generally within 5%. Under A2 climate change scenario, the region with the most reduction of maize yield would be the Northeast except during 2021-2030, and the reduction would be generally in the range of 2.3%-4.2%. Maize yield reduction would be also high in the Northwest, Southwest and middle and lower reaches of Yangtze River after 2031. Under B2 scenario, the reduction of 5.3% in the Northeast in 2031-2040 would be the greatest across all regions. Other regions with considerable maize yield reduction would be mainly in the Northwest and the Southwest. Reduction in maize yield in North China would be small, generally within 2%, under any scenarios, and that in South China would be almost unchanged. The reduction of maize yield in most regions would be greater under A2 scenario than under B2 scenario except for the period of 2021-2030. The effect of the ten day precipitation on maize yield in northern China would be almost positive. However, the effect of ten day average temperature on yield of maize in all regions would be generally negative. The main reason of maize yield reduction was temperature increase in most provinces but precipitation decrease in a few provinces. Assessments of the future change of maize yield in China based on the different methods were not consistent. Further evaluation needs to consider the change of maize variety and scientific and technological progress, and to enhance the reliability of evaluation models.

[Clinical features and genome-wide copy number variation analysis in 60 children with early-onset epileptic encephalopathies of unknown cause].

OBJECTIVE: To study the clinical features of early-onset epileptic encephalopathies (EEEs) of unknown cause, and to identify pathogenic microdeletion/microduplication of EEEs by genome-wide analysis of copy number variations (CNVs). METHODS: The clinical data of 60 children diagnosed with unexplained EEEs between July 2012 and April 2013 were obtained and analyzed. Specimens were collected from the selected children and their parents. Single nucleotide polymorphism array was used to detect genome-wide CNVs, and fluorescence in situ hybridization was performed to verify the results and analyze the source of the parents, further to identify suspected pathogenic CNVs of EEEs. RESULTS: Among the 60 children with unexplained EEEs, 34 were diagnosed with West syndrome, 3 with Ohtahara syndrome, 3 with Dravet syndrome, and 20 with unclassified EEEs. In total, 77% of the patients were associated with moderate to severe mental retardation. Head imaging test implied that 35% of the patients had brain dysplasia or astrophy. Among 54 patients, 17% showed microcephalus. After treatment, 28 patients had clinical seizures under control, 16 out of control, 5 dead, and 1 lost to follow-up. Genome-wide analysis of CNVs showed that 7 pathogenic or suspected pathogenic CNVs were present in 5 patients. CONCLUSIONS: EEEs of unknown cause are associated with high phenotypic heterogeneity and poor prognosis. Genome-wide CNVs analysis can demonstrate pathogenic or suspected pathogenic CNVs. This research expands the gene bank of EEEs and improves the understanding about possible etiology of unexplained EEEs. The results provide a reference for genetic counseling regarding reproduction in the patient's family.

[Effects of climate change on flax development and yield in Guyuan of Ningxia, Northwest China].

Based on variations of the annual mean temperature and precipitation analyzed using ob- servation data in Guyuan of Ningxia, the effects of climate change on the local flax developmental process and yield were investigated. The results showed that the annual mean temperature had an increasing trend (0.3 °C · (10 a)-1) and the annual precipitation had a decreasing trend (-20 mm · (10 a) -1) from 1957 to 2012. While the increasing trend of mean temperature during growing season of flax was more obviously than that of the annual temperature, the decreasing trend of precipitation during growing season was similar to that of annual precipitation. With temperature increasing and precipitation decreasing, the flax development rate was accelerated, resulting in the reduced growing period. Seedling stage was advanced 0.7 d with 1 °C increase in temperature during the period from sowing to seedling emergence. The duration from seedling emergence to two pairs of needles was shortened by 0.8 d with 1 °C increase in temperature and 0.1 d with 1 mm decrease in precipitation. Maturity stage was advanced 1.8 d with 1 °C increase in temperature and 0.1 d with 1 mm decrease in precipitation during the period from technical maturity to maturity. The flax development was accelerated because of temperature increasing and precipitation decreasing in the vegetative growth phase, which was one of the main causes of flax yield reduction year by year. Meanwhile, flower bud differentiation and pollination of flax were influenced by temperature increasing in the reproductive growth phase, which would affect the number of capsules and the seed setting rate per plant and lead to the decrease of flax yield. Therefore, adjusting plant structure and enlarging the planting area of late or middle-late variety were the important measures to reduce the effects of climate change on local flax production.

Cytoplasmic and nuclear localization of TCTP in normal and cancer cells.

Objective. Intracellular localization of translationally controlled tumour protein (TCTP) was investigated in cancer cells. Methods. The expression and localization of TCTP were detected at 12 h, 24 h, 48 h, 60 h time points in culture of human hepatocarcinoma cell line HepG2, human cervical carcinoma cell line HeLa, and human normal liver cell line HL-7702 by immunofluorescence. Results. TCTP was expressed in both normal and tumor cells, and its localization changes at different time points. TCTP was mainly expressed in cytoplasm from 24 h to 48 h then expressed in both nucleus and cytoplasm at 60 h in HL-7702 cells. While in HepG2 cells, TCTP first localized at cell membrane within 24 h then at both nucleus and cytoplasm from 48 h to 60 h; TCTP localized at both nucleus and cytoplasm from 12 h to 60 h in Hela cells. Conclusion. The translocation of intracellular expression of TCTP in normal and tumor cells at different time points may pave a path to the studying of TCTP role in tumor growth.

[Change trends of China agricultural thermal resources under climate change and related adaptation countermeasures].

Based on the 2011-2050 A2 climate scenario derived from the regional climate model PRECIS and the daily data of 1961-1990 baseline climate condition, this paper analyzed the possible changes of the agricultural thermal resources in China from 2011 to 2050. Comparing with the baseline climate condition in 1961-1990, the average frost-free periods in most parts of China in 2011-2050 under A2 climate scenario would have an obvious extension, mainly manifested in the advance of last frost date and the postpone of first frost date. The days with the daily average temperature stably passing 0 degrees C would also prolong significantly, and extend from 1 day to 14 days in most parts of the country. Especially from 2041 to 2050, the days with the daily average temperature stably passing 0 degrees C in most regions of Qinghai-Tibet Plateau, middle and lower reaches of Yangtze River, and western and southwestern regions of Gansu and Xinjiang could be extended by 49 days. The > or = 0 degrees C accumulated temperatures in most parts of the country would have increasing trends. In order to meet the future change trend of our agricultural thermal resources and to realize the sustainable development of agriculture in China, some countermeasures should be formulated, e.g., further adjusting agricultural cropping system, optimizing agricultural production distribution, developing biotechnology, and so on.

Intranasally delivered bFGF enhances neurogenesis in adult rats following cerebral ischemia.

Basic fibroblast growth factor (bFGF) is a very important mitogenic factor with proved neurogenesis effects in the central nervous system. Intranasal administration can bypass blood-brain barrier and deliver drugs into the brain directly. We investigated whether intranasal administration of bFGF at later time points after ischemia could promote adult neurogenesis and improve neurologic functions. Rats received bFGF or saline intranasally once daily for 6 consecutive days, starting at 1 day after transient middle cerebral artery occlusion (MCAO). Bromodeoxyuridine (BrdU) was injected at 5 and 6 days after MCAO. Rats were killed at 7 or 28 days after MCAO. Neurogenesis was assessed by immunostaining for BrdU and cell type-specific markers. Neurological functions were evaluated by the modified Neurological Severity Scores. Compared with the control animals, intranasal administration of bFGF improved behavioral recovery without affecting infarct size, and enhanced proliferation of progenitor cells in the subventricular zone and the subgranular zone of the dentate gyrus (DG). Furthermore, the new proliferated cells could differentiate into neurons (BrdU+NeuN+ cells) in the striatum and DG at 28 days after MCAO. Intranasal administration of bFGF offers a non-invasive alternative for the treatment of stroke.

Intranasal bFGF-induced progenitor cell proliferation and neuroprotection after transient focal cerebral ischemia.

Basic fibroblast growth factor (bFGF) is a neurotrophic and vasoactive factor, and has therapeutic potential for some central nervous system (CNS) disorders. In this study, we used the intranasal pathway to administer bFGF in adult rats, and evaluated its neuroprotective benefits and effects on endogenous neural stem cells. The bFGF levels after intranasal administration in normal rats were determined by western blot. Transient focal ischemia was achieved by occlusion of the right middle cerebral artery for 2 h. bFGF was given intranasally 2 h after reperfusion and daily thereafter on 3 successive days. Dividing progenitor cells were labeled with bromodeoxyuridine (BrdU) on day 3 of reperfusion. Rats were killed the next day after BrdU labeling. bFGF levels were significantly raised in the olfactory bulb (OB) and striatum following intranasal administration. Intranasal bFGF treatment improved neurological function and reduced infarct volume after cerebral ischemia/reperfusion, while no influence was observed on the blood pressure. And the BrdU incorporation was enhanced in the ipsilateral subventricular zone (SVZ) and striatum following intranasal administration of bFGF. These results demonstrated that bFGF can be directly delivered into brain following intranasal administration, and protects against cerebral ischemia/reperfusion. The protective effects may be attributed to the reduction of infarct volume and enhancement of endogenous progenitors in brain. Therefore, intranasal administration of bFGF may provide an alternative treatment for brain ischemia and some other CNS disorders.

Extracellular signal-regulated kinase involved in NGF/VEGF-induced neuroprotective effect.

Compelling evidence has shown that extracellular signal-regulated kinase (ERK) is widely expressed in many tissues, including the brain. In the present work, we investigated the temporospatial alterations of ERK1 immunoreactivity in hippocampus and perifocal cortex, and the expression involved in NGF/VEGF-induced neuroprotective effect. We demonstrated that ERK1 expression was first increased in hippocampal CA3/DG 1 h after reperfusion, then it was also increased 6 h after reperfusion in other brain regions, with a peak at day 1-3, and then gradually decreased to basal level at day 14. The expression of caspase-3 was strongly increased 1 h after reperfusion, with peak demonstrated at 3d. NGF/VEGF significantly inhibited the expression of ERK1 and caspase-3. These results suggest that ERK1 signaling pathway may be involved in neuronal cell death and NGF/VEGF-induced neuroprotective effect and there appeared an association between ERK and caspase-3. Inhibition of the ERK signaling pathway might therefore provide an efficient way to prevent neuronal cell death after ischemic cerebral injuries.

Intranasally delivered TGF-beta1 enters brain and regulates gene expressions of its receptors in rats.

This study is aimed to evaluate the brain distribution of transforming growth factor-beta1 (TGF-beta1) following intranasal administration and the subsequent biological effects of TGF-beta1. Adult rats were given recombinant human TGF-beta1 (rhTGF-beta1) or vehicle solution intranasally. TGF-beta1 concentrations were significantly raised in several brain regions and the trigeminal nerve following intranasal delivery. The elevation appeared within 30 min and was sustained for at least 6 h, reaching its greatest level at 60 min. A concentration gradient in the central nervous system (CNS) regions was produced during the first 2 h after intranasal administration, with the OB presenting a significantly higher concentration than any other CNS regions. The nasally administered TGF-beta1 subsequently regulated gene expressions of its two receptors (TGF-beta receptor types I and II) in vivo, but did not affect mRNA level of TGF-beta1 itself. Our results suggest that TGF-beta1 can be transported into the CNS via the olfactory and trigeminal pathways, and may consequently exert its biological effects by regulating gene expressions of its receptors. Intranasal administration of neurotrophic factors may offer a potential strategy for treating some CNS disorders.

[Expression and activity change of angiotensin converting enzyme in the placenta of preeclampsia].

OBJECTIVE: To investigate the effect of angiotensin converting enzyme (ACE) in the pathogenesis of preeclampsia. METHODS: A cross-sectional study was conducted with 42 pregnant women in the following categories: 30 cases of preeclampsia (mild preeclampsia, n=15; severe preeclampsia, n=15), and normal pregnancy (control group,n=12). The expression and localization of ACE mRNA in the placenta of the 3 groups were respectively examined by in situ hybridization. Ultraviolet radiation colorimetry was used to detect the activity of ACE in the placenta tissue homogenate and the mothers' serum in the 3 groups. RESULTS: The expression of ACE mRNA was found in the endothelial cells of villus and trophoblasts in the placenta. The positive index of ACE mRNA in the placenta of preeclampsia(3.12+/-0.94) was higher than that in the normal pregnancies(1.65+/-0.67) (P<0.05), and there was significant difference between severe preeclampsia and mild preeclampsia (P<0.05). The levels of ACE activity in the placenta tissue homogenate and the maternal serum of preeclampsia were higher than those in the normal pregnancies (P<0.05), and there was significant difference between severe preeclampsia and mild preeclampsia (P<0.05). The placenta tissue homogenate ACE activity was correlated with ACE activity of the maternal serum (r=0.781,P<0.05). CONCLUSION: The expression and activity of local ACE in the placenta tissue may play an important role in preeclampsia and contribute to the development of preeclampsia.

Ectopic expression of a microbial-type rhodopsin restores visual responses in mice with photoreceptor degeneration.

The death of photoreceptor cells caused by retinal degenerative diseases often results in a complete loss of retinal responses to light. We explore the feasibility of converting inner retinal neurons to photosensitive cells as a possible strategy for imparting light sensitivity to retinas lacking rods and cones. Using delivery by an adeno-associated viral vector, here, we show that long-term expression of a microbial-type rhodopsin, channelrhodopsin-2 (ChR2), can be achieved in rodent inner retinal neurons in vivo. Furthermore, we demonstrate that expression of ChR2 in surviving inner retinal neurons of a mouse with photoreceptor degeneration can restore the ability of the retina to encode light signals and transmit the light signals to the visual cortex. Thus, expression of microbial-type channelrhodopsins, such as ChR2, in surviving inner retinal neurons is a potential strategy for the restoration of vision after rod and cone degeneration.

Heterogeneous expression of voltage-dependent Na+ and K+ channels in mammalian retinal bipolar cells.

Retinal bipolar cells show heterogeneous expression of voltage-dependent Na+ and K+ currents. We used whole-cell patch-clamp recordings to investigate the possible roles of these currents in the response properties of bipolar cells in rats. Isolated bipolar cells showed robust spontaneous regenerative activity, but the regenerative potential of rod bipolar cells reached a more depolarized level than that of cone bipolar cells. In both isolated cells and cells in retinal slices, the membrane depolarization evoked by current injection was apparently capped. The evoked membrane potential was again more depolarized in rod bipolar cells than in cone bipolar cells. Application of tetraethylammonium and 4-aminopyridine shifted the spontaneous regenerative potential as well as the evoked potential to a more depolarized level. In addition, a subclass of cone bipolar cells showed a prominent spike in the initial phase of the voltage response when the cells were depolarized from a relatively negative membrane potential. The spike was mediated mainly by tetrodotoxin-sensitive Na+ current. The presence of the spike sped up the response kinetics and enhanced the peak membrane potential. Results of this study raise the possibility that voltage-dependent K+ currents may play a role in defining different membrane operating ranges of rod and cone bipolar cells and that voltage-dependent Na+ currents may enhance the response kinetics and amplitude of certain cone bipolar cells.

Mammalian retinal bipolar cells express inwardly rectifying K+ currents (IKir) with a different distribution than that of Ih.

Retinal bipolar cells comprise multiple subtypes that are well known for the diversity of their physiological properties. We investigated the properties and functional roles of the hyperpolarization-activated currents in mammalian retinal bipolar cells using whole cell patch-clamp recording techniques. We report that bipolar cells express inwardly rectifying K+ currents (IKir) in addition to the hyperpolarization-activated cationic currents (Ih) previously reported. Furthermore, these two currents are differentially expressed among different subtypes of bipolar cells. One group of cone bipolar cells in particular displayed mainly IKir. A second group of cone bipolar cells displayed both currents but with a much larger Ih. Rod bipolar cells, on the other hand, showed primarily Ih. Moreover, we showed that IKir and Ih differentially influence the voltage responses of bipolar cells: Ih facilitates and/or accelerates the membrane potential rebound, whereas IKir counteracts or prevents such rebound. The findings of the expression of IKir and the differential expression of Ih and IKir in bipolar cells may provide new insights into an understanding of the physiological properties of bipolar cells.

Glycine receptors and glycinergic synaptic input at the axon terminals of mammalian retinal rod bipolar cells.

We investigated the properties of glycine receptors and glycinergic synaptic inputs at the axon terminals of rod bipolar cells (RBCs) in rats by patch-clamp recording. Glycine currents recorded from isolated axon terminals were larger than those from isolated somata/dendrites; this was confirmed by puffing glycine onto these two regions in retinal slices. The current density at terminal endings was more than one order of magnitude higher than the density at somatic/dendritic regions. Glycine currents from isolated terminals and isolated somata/dendrites showed similar sensitivity to picrotoxinin blockade. Single-channel opening recorded from isolated terminals and somata/dendrites displayed a similar main-state conductance of ~46 pS. Application of glycine effectively suppressed depolarization-evoked increases in intracellular Ca2+ at the terminals. In the presence of GABAA and GABAC antagonists, strychnine-sensitive chloride currents were evoked in RBCs in retinal slices by puffing kainate onto the inner plexiform layer. No such currents were observed if the recorded RBCs did not retain axon terminals or if Ca2+ was replaced by Co2+ in the extracellular solution. The currents displayed discrete miniature-like events, which were partially blocked by tetrodotoxin. Consistent with early studies in the rabbit and mouse, this study demonstrates that glycine receptors are highly concentrated at the axon terminals of rat RBCs. The pharmacological and physiological properties of glycine receptors located in the axon terminal and somatic/dendritic regions, however, appear to be the same. This study provides evidence for the existence of functional glycinergic synaptic input at the axon terminals of RBCs, suggesting that glycine receptors may play a role in modulating bipolar cell synaptic transmission.

Spontaneous regenerative activity in mammalian retinal bipolar cells: roles of multiple subtypes of voltage-dependent Ca2+ channels.

Patch-clamp recordings were used to investigate the properties of the regenerative activity in acutely isolated bipolar cells from the rat retina. Spontaneous, pacemaker-like membrane potential oscillations were observed in all rod bipolar cells and the majority of cone bipolar cells. The waveform of the regenerative potential was stereotypical but distinct among different bipolar cell groups, especially between rod and cone bipolar cells. The spontaneous activity was completely blocked by Co2+, suggesting that Ca2+ influx through voltage-dependent Ca2+ channels was required for initiating such activity. Ca2+-induced Ca2+ release, however, was not found to be involved. The spontaneous activity was also blocked by mibefradil, a T-type Ca2+ channel antagonist. In contrast, application of nimodipine, an L-type Ca2+ current antagonist, affected mainly the waveform of the regenerative potential. This study shows that mammalian retinal bipolar cells in isolation are also capable of generating Ca2+-dependent spontaneous regenerative potential. However, T-type Ca2+ channels appear to be essential for the initiation of the spontaneous activity in mammalian bipolar cells.