Targeting light-gated chloride channels to neuronal somatodendritic domain reduces their excitatory effect in the axon

Light-gated chloride channels are emerging as promising optogenetic tools for inhibition of neural activity. However, their effects depend on the transmembrane chloride electrochemical gradient and may be complex due to the heterogeneity of this gradient in different developmental stages, neuronal types, and subcellular compartments. Here we characterized a light-gated chloride channel, GtACR2, in mouse cortical neurons. We found that GtACR2 activation inhibited the soma, but unexpectedly depolarized the presynaptic terminals resulting in neurotransmitter release. Other light-gated chloride channels had similar effects. Reducing the chloride concentrations in the axon and presynaptic terminals diminished the GtACR2-induced neurotransmitter release, indicating an excitatory effect of chloride channels in these compartments. A novel hybrid somatodendritic targeting motif reduced the GtACR2-induced neurotransmitter release while enhancing the somatic photocurrents. Our results highlight the necessity of precisely determining the effects of light-gated chloride channels under specific experimental conditions and provide a much-improved light-gated chloride channel for optogenetic inhibition.

Genomic signatures reveal selection of characteristics within and between Meishan pig populations

The Chinese Meishan pig breed is well known for its high prolificacy. Moreover, this breed can be divided into three types based on their body size: big Meishan, middle Meishan (MMS) and small Meishan (SMS) pigs. Few studies have reported on the genetic signatures of Meishan pigs, particularly on a genome-wide scale. Exploring for genetic signatures could be quite valuable for revealing the genetic architecture of phenotypic variation. Thus, we performed research in two parts based on the genome reducing and sequencing data of 143 Meishan pigs (74 MMS pigs, 69 SMS pigs). First, we detected the selection signatures among all Meishan pigs studied using the relative extended haplotype homozygosity test. Second, we detected the selection signatures between MMS and SMS pigs using the cross-population extended haplotype homozygosity and F_ST methods. A total of 111 398 SNPs were identified from the sequenced genomes. In the population analysis, the most significant genes were associated with the mental development (RGMA), reproduction (HDAC4, FOXL2) and lipid metabolism (ACACB). From the cross-population analysis, we detected genes related to body weight (SPDEF, PACSIN1) in both methods. We suggest that rs341373351, located within the PACSIN1 gene, might be the causal variant. This study may have achieved consistency between selection signatures and characteristics within and between Meishan pig populations. These findings can provide insight into investigating the molecular background of high prolificacy and body size in pig.

Otud7a Knockout Mice Recapitulate Many Neurological Features of 15q13.3 Microdeletion Syndrome

15q13.3 microdeletion syndrome is characterized by a wide spectrum of neurodevelopmental disorders, including developmental delay, intellectual disability, epilepsy, language impairment, abnormal behaviors, neuropsychiatric disorders, and hypotonia. This syndrome is caused by a deletion on chromosome 15q, which typically encompasses six genes. Here, through studies on OTU deubiquitinase 7A (Otud7a) knockout mice, we identify OTUD7A as a critical gene responsible for many of the cardinal phenotypes associated with 15q13.3 microdeletion syndrome. Otud7a-null mice show reduced body weight, developmental delay, abnormal electroencephalography patterns and seizures, reduced ultrasonic vocalizations, decreased grip strength, impaired motor learning/motor coordination, and reduced acoustic startle. We show that OTUD7A localizes to dendritic spines and that Otud7a-null mice have decreased dendritic spine density compared to their wild-type littermates. Furthermore, frequency of miniature excitatory postsynaptic currents (mEPSCs) is reduced in the frontal cortex of Otud7a-null mice, suggesting a role of Otud7a in regulation of dendritic spine density and glutamatergic synaptic transmission. Taken together, our results suggest decreased OTUD7A dosage as a major contributor to the neurodevelopmental phenotypes associated with 15q13.3 microdeletion syndrome, through the misregulation of dendritic spine density and activity.

Dietary butylated hydroxytoluene improves lipid metabolism, antioxidant and anti-apoptotic response of largemouth bass (Micropterus salmoides)

A 10-week growth trail was conducted to investigate the efficacy and tolerance of dietary butylated hydroxytoluene (BHT) by evaluating inflammation, apoptosis and hepatic disease related to oxidative stress in largemouth bass (Micropterus salmoides). Four experimental diets were prepared with BHT supplement levels of 0 (B0), 150 (B150), 300 (B300) and 1500 (B1500) mg/kg, in which B150 was at the maximum recommended level established by European Union Regulation, and the B300 and B1500 levels were 2 and 10-fold of B150, respectively. Each diet was fed to 6 replicates with 30 largemouth bass (initial body weight, IBW = 6.20 ± 0.01 g) in each tank. The BHT inclusion level did not affect the specific growth rate, but fish in the B150 group showed the lowest feed conversion rate (P < 0.05). BHT inclusion significantly decreased the levels of plasma TC, TG, LDL, ALT and AKP, and increased the (HDL-C)/TC ratio (P < 0.05). Plasma MDA was significantly decreased in the B150 group and GSH-Px was extremely enhanced in each BHT inclusion group (P < 0.05). Hepatic T-AOC was significantly enhanced and O₂^- was significantly decreased in each BHT inclusion group compared to the B0 group (P < 0.05), as well as hepatic MDA was significantly decreased in B1500 group (P < 0.05). Dietary BHT inclusion down-regulated the hepatic mRNA levels of inflammation, apoptosis and fibrosis related genes, including TNFα, TGF-β1, α-SMA, IL8, IL11β and caspase-9. Moreover, BHT could improve hepatic lipid metabolism via up-regulating the mRNA levels of APOA1, CYP7A1, CYP8B1, and down-regulating the mRNA levels of PPAR-γ and APOB. Histological examination of the liver morphology with H&E and Sirius Red staining showed that BHT inclusion decreased necrotic degenerative changes and collagen deposition in largemouth bass. An immunofluorescence examination revealed significantly decreased cleaved caspase-3 signals in the BHT groups. In conclusion, the results demonstrated that ROS induces hepatic cell apoptosis and fibrosis via the intrinsic pathway of apoptosis by activating caspase-9 in the mitochondria and then initiates apoptosis by activating caspase-3. Consuming 2.32-23.80 mg/kg·bw/d (150-1500 mg/kg in diet) of BHT effectively improved the plasma and hepatic lipid metabolism, antioxidant response as well as reduced ROS production, protecting hepatic cells from injury. It is implied that even a 10-fold increase of the maximum level of BHT (150 mg/kg) is safe for the largemouth bass.

FAM196B acts as oncogene and promotes proliferation of gastric cancer cells through AKT signaling pathway

Gastric cancer (GC) is the second leading cause of cancer-related deaths worldwide, but the mechanisms remain unknown. Here we report that family with sequence similarity 196 member B (FAM196B) is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic characteristics of GC. In this experiment, knockdown of FAM196B suppressed GC cell proliferation and induced G1/G0 to S phase cell cycle arrest by regulating Cyclin D1, Cyclin A and CDK2 expressions. Furthermore, we investigated the molecular mechanism of FAM196B action in GC. The results showed that knockdown of FAM196B inhibited the activation of AKT signaling pathway. We further revealed that activating of AKT rescued the effect of FAM196B knockdown on cell proliferation and drove cell re-enter into the S phase of the cell cycle with SC79 (a AKT activator). Our findings demonstrated that FAM196B may promote GC cell proliferation by activating AKT signaling pathway. Taken together, this study provides a new evidence that FAM196B functions as a novel oncogene and could be a potential therapeutic target in therapy of GC.

Polymorphisms of TGFB1, TLE4 and MUC22 are associated with childhood asthma in Chinese population

OBJECTIVE

To investigate whether the genetic variants of TGFB1, TLE4, MUC22 and IKZF3 are associated with the development of asthma in Chinese children.

METHODS

572 adolescent asthma patients and 590 age-matched healthy controls were included in this study. A total of four SNPs were genotyped, including rs2241715 of TGFB1, rs2378383 of TLE4, rs2523924 of MUC22, and rs907092 of IKZF3. Allele frequencies of the patients and the control group were compared by the Chi-square test. The Student t test was used to analyse the relationship between genotypes and clinical feature of the patients.

RESULTS

Patients were found to have significantly different frequencies of allele A of rs2241715, allele G of rs2378383 and allele A of rs2523924 as compared with the controls (40.4% vs. 45.9%, p=0.01 for rs2241715; 17.2% vs. 13.4%, p=0.01 for rs2378383; 15.3% vs. 11.9%, p=0.02 for rs2523924). For patients with severe asthma, those with genotype AA/AG of rs2241715 had remarkably higher FEV1% as compared with those with genotype GG (59.1±4.3% vs. 55.4±3.7%, p<0.001). Moreover, those with genotype GG/GA of rs2378383 had remarkably lower FEV1% as compared with those with genotype AA (54.6±2.9% vs. 58.6±4.1%, p<0.001).

CONCLUSIONS

Genes TGFB1, TLE4 and MUC22 are associated with the risk of childhood asthma in Chinese population. Our results associating TGFB1 and TLE4 with clinical features of asthma suggest potential application of these parameters in the management of asthma children.

MeCP2, a target of miR-638, facilitates gastric cancer cell proliferation through activation of the MEK1/2-ERK1/2 signaling pathway by upregulating GIT1

Methyl-CpG binding protein 2 (MeCP2) is involved in the carcinogenesis and progression of multiple types of cancer. However, its precise role in gastric cancer (GC) and the relevant molecular mechanism remain unknown. In the present study, we found that miR-638 levels were lower in GC tissues and GC cell lines than in adjacent normal tissues and normal gastric epithelial cell lines, respectively. Low miR-638 levels were associated with poor tumor differentiation, tumor size and lymph node metastasis. MeCP2 expression levels were higher in GC tissues than in adjacent normal tissues. It was found that miR-638 inhibited GC cell proliferation, colony formation, G1–S transition and tumor growth, and induced cell apoptosis by directly targeting MeCP2. MeCP2 promoted GC cell proliferation, colony formation and G1–S cell-cycle transition, and suppressed apoptosis. Molecular mechanistic investigations were performed using an integrated approach with a combination of microarray analysis, chromatin immunoprecipitation sequencing and a reporter gene assay. The results showed that MeCP2 bound to the methylated CpG islands of G-protein-coupled receptor kinase-interacting protein 1 (GIT1) promoter and upregulated its expression, thereby activating the MEK1/2–ERK1/2 signaling pathway and promoting GC cell proliferation. Taken together, our study demonstrates that MeCP2, a target of miR-638, facilitates GC cell proliferation and induces cell-cycle progression through activation of the MEK1/2–ERK1/2 signaling pathway by upregulating GIT1. The findings suggest that MeCP2 plays a significant role in GC progression, and may serve as a potential target for GC therapy.

Quantitative real-time imaging of glutathione

Glutathione plays many important roles in biological processes; however, the dynamic changes of glutathione concentrations in living cells remain largely unknown. Here, we report a reversible reaction-based fluorescent probe—designated as RealThiol (RT)—that can quantitatively monitor the real-time glutathione dynamics in living cells. Using RT, we observe enhanced antioxidant capability of activated neurons and dynamic glutathione changes during ferroptosis. RT is thus a versatile tool that can be used for both confocal microscopy and flow cytometry based high-throughput quantification of glutathione levels in single cells. We envision that this new glutathione probe will enable opportunities to study glutathione dynamics and transportation and expand our understanding of the physiological and pathological roles of glutathione in living cells.

Fluorescent sensors for small biomolecules are needed to shed insight into real-time cellular processes. Here the authors develop RealThiol, a sensor that can quantitatively monitor glutathione dynamics in living cells, and measure increased antioxidant capability of activated neurons and glutathione changes during ferroptosis.

Genetic variation and genetic structure of five Chinese indigenous pig populations in Jiangsu Province revealed by sequencing data

In this study, we investigated the genetic variants, including SNPs and indels (short insertions or deletions, less than 50 bp in length), in the genomes and genetic structures of five pig populations (in the northern Taihu Lake region, Jiangsu Province) using the genotyping by genome reducing and sequencing (GGRS) approach. A total of 581 million good reads with an average depth of 11× and an average coverage of 2.16% were used to call variants. In general, 202 106 SNPs and 34 415 indels were obtained, of which 2690 SNPs and 224 indels were capable of inducing protein‐coding changes. The genes containing these variants were extracted for functional annotation. The results of gene enrichment analysis revealed that the SNPs under investigation may be associated with reproduction, disease resistance, meat quality and adipose tissue traits, whereas the indels were associated mainly with adipose tissue and disease. Analysis of the genetic structure showed that each population displayed comparable, large differentiations from the others, indicating their uniqueness. In conclusion, the results of our study provide the first genomic overview of the genetic variants and population structures of five Chinese indigenous pig populations.

Respiratory Network Stability and Modulatory Response to Substance P Require Nalcn

Respiration is a rhythmic activity as well as one that requires responsiveness to internal and external circumstances; both the rhythm and neuromodulatory responses of breathing are controlled by brainstem neurons in the preBötzinger complex (preBötC) and the retrotrapezoid nucleus (RTN), but the specific ion channels essential to these activities remain to be identified. Because deficiency of sodium leak channel, non-selective (Nalcn) causes lethal apnea in humans and mice, we investigated Nalcn function in these neuronal groups. We found that one-third of mice lacking Nalcn in excitatory preBötC neurons died soon after birth; surviving mice developed apneas in adulthood. Interestingly, in both preBötC and RTN neurons, the Nalcn current influences the resting membrane potential, contributes to maintenance of stable network activity, and mediates modulatory responses to the neuropeptide substance P. These findings reveal Nalcn's specific role in both rhythmic stability and responsiveness to neuropeptides within the respiratory network.

[Clinical study of high intensity focused ultrasound ablation combined with GnRH-a and LNG-IUS for the treatment of adenomyosis]

Objective: To investigate the clinical effect of dysmenorrhea in patients with adenomyosis treated by high intensity focused ultrasound(HIFU)ablation combined with gonadotropin-releasing hormone agonist(GnRH-a)and levonorgestrel-releasing intrauterine system(LNG-IUS). Methods: From April 2012 to December 2015, 477 cases of adenomyosis patients with dysmenorrhea were treated by HIFU in the Third Xiangya Hospital. Among them, some patients were treated with HIFU alone, some of them were treated with HIFU combined with GnRH-a and(or)LNG-IUS, thus were classified as H group, H+G group, H+M group and H+G+M group. The improvements of clinical results were compared among the four groups and the influencing factors of HIFU treatment for adenomyosis were also analyzed. Results: During the follow-up period, the overall effective rates of the treatment decreased with time, 3 months 89.4%(345/386), 12 months 84.0%(221/263), 24 months 74.2%(98/132), and the overall recurrence rate was 12.9%(39/303). The significant difference in the curative at 3 months[H group 83.7%(170/203), H+M group 95.0%(95/100), H+G group 100.0%(43/43), H+G+M group 96.8%(30/31)], 12 months[H group 79.4%(123/155), H+M group 93.2%(69/74), H+G group 11/12, H+G+M group 15/17], and 24 months[H group 68.0%(51/75), H+M group 96.4%(27/28), H+G group 6/12, H+G+M group 15/15]after HIFU treatment and recurrence rate[H group 19.0%(29/153), H+M group 3.3%(3/90), H+G group 19.4%(6/31), H+G+M group 4.5%(1/22)]were observed among the four groups(P<0.05). Pairwise comparison further showed that, in 3 months after the treatment, the effect of H group was significantly lower than those of H+M group and H+G group(P= 0.003, P=0.005); in 12 months after the treatment, the effect of H group was significantly lower than that of H+M group(P=0.006); while in 24 months after treatment, the effect of H group was significantly lower than that of H+G+M group(P=0.005), and the effect of H+G group was lower than that of H+G+M group(P= 0.001); and the recurrence rate of H group was significantly higher than that of H+M group(P<0.008). In patients of group H, the effect of HIFU was related to uterine size, the effect of patients with large uterine volume was significantly higher than that of small volume of uterine of patients(P=0.017, OR=2.739, 95%CI: 1.200- 6.251); with increasing of age, the improvement of dysmenorrhea had a increasing trend(P<0.05). Conclusions: HIFU combined with GnRH-a and(or)LNG-IUS could improve the treatment effect in relief of dysmenorrhea. Based on our results, individual treatment protocol should be selected for different patients.

Genome-wide genetic variation discovery in Chinese Taihu pig breeds using next generation sequencing

The Chinese Taihu pig breeds are an invaluable component of the world's pig genetic resources, and they are the most prolific breeds of swine in the world. In this study, the genomes of 252 pigs of the six indigenous breeds in the Taihu Lake region were sequenced using the genotyping by genome reducing and sequencing approach. A total of 950 million good reads were obtained using an Illumina Hiseq2000 at an average depth of 13× (for SNP calling) and an average coverage of 2.3%. In total, 122 632 indels, 31 444 insertions, 44 056 deletions and 455 CNVs (copy number variants) were identified in the genomes of the pigs. Approximately 2.3% of these genetic markers were mapped to gene exon regions, and 25% were in QTL regions related to economically important traits. The KEGG pathway or GO enrichment analyses revealed that genetic variants assumed to be large‐effect mutations were significantly overrepresented in 22 SNP, 56 indel, 26 insertion, 28 deletion and three CNV gene sets. A total of 343 breed‐specific SNPs were also identified in the six Chinese indigenous pigs. The findings from this study can contribute to future investigations of the genetic diversity, population structure, positive selection signals and molecular evolutionary history of these pigs at the genome level and can serve as a valuable reference for improving the breeding and cultivation of these pigs.