Mutations in the gene encoding gap junction protein beta-3 associated with autosomal dominant hearing impairment

Hearing impairment is the most commonly occurring condition that affects the ability of humans to communicate. More than 50% of the cases of profound early-onset deafness are caused by genetic factors. Over 40 loci for non-syndromic deafness have been genetically mapped, and mutations in several genes have been shown to cause hearing loss. Mutations in the gene encoding connexin 26 (GJB2) cause both autosomal recessive and dominant forms of hearing impairment. To study the possible involvement of other members of the connexin family in hereditary hearing impairment, we cloned the gene (GJB3) encoding human gap junction protein beta-3 using homologous EST searching and nested PCR. GJB3 was mapped to human chromosome 1p33-p35. Mutation analysis revealed that a missense mutation and a nonsense mutation of GJB3 were associated with high-frequency hearing loss in two families. Moreover, expression of Gjb3 was identified in rat inner ear tissue by RT-PCR. These findings suggest that mutations in GJB3 may be responsible for bilateral high-frequency hearing impairment.

Interaction of the protein kinase Raf-1 with 14-3-3 proteins

Members of a family of highly conserved proteins, termed 14-3-3 proteins, were found by several experimental approaches to associate with Raf-1, a central component of a key signal transduction pathway. Optimal complex formation required the amino-terminal regulatory domain of Raf-1. The association of 14-3-3 proteins and Raf-1 was not substantially affected by the activation state of Raf.

ADME Evaluation in Drug Discovery. 4. Prediction of Aqueous Solubility Based on Atom Contribution Approach

A novel method for the estimation of aqueous solubility was solely based on simple atom contribution. Each atom in a molecule has its own contribution to aqueous solubility and was developed. Altogether 76 atom types were used to classify atoms with different chemical environments. Moreover, two correction factors, including hydrophobic carbon and square of molecular weight, were used to account for the inter-/intramolecular hydrophobic interactions and bulkiness effect. The contribution coefficients of different atom types and correction factors were generated based on a multiple linear regression using a learning set consisting of 1290 organic compounds. The obtained linear regression model possesses good statistical significance with an overall correlation coefficient (r) of 0.96, a standard deviation (s) of 0.61, and an unsigned mean error (UME) of 0.48. The actual prediction potential of the model was validated through an external test set with 21 pharmaceutically and environmentally interesting compounds. For the test set, a predictive r=0.94, s=0.84, and UME=0.52 were achieved. Comparisons among eight procedures of solubility calculation for those 21 molecules demonstrate that our model bears very good accuracy and is comparable to or even better than most reported techniques based on molecular descriptors. Moreover, we compared the performance of our model to a test set of 120 molecules with a popular group contribution method developed by Klopman et al. For this test set, our model gives a very effective prediction (r=0.96, s=0.79, UME=0.57), which is obviously superior to the predicted results (r=0.96, s=0.84, UME=0.70) given by the Klopman's group contribution approach. Because of the adoption of atoms as the basic units, our addition model does not contain a "missing fragment" problem and thus may be more simple and universal than the group contribution models and can give predictions for any organic molecules. A program, drug-LOGS, had been developed to identify the occurrence of atom types and estimate the aqueous solubility of a molecule.

ADME evaluation in drug discovery. 5. Correlation of Caco-2 permeation with simple molecular properties

The correlations between Caco-2 permeability (logPapp) and molecular properties have been investigated. A training set of 77 structurally diverse organic molecules was used to construct significant QSAR models for Caco-2 cell permeation. Cellular permeation was found to depend primarily upon experimental distribution coefficient (logD) at pH = 7.4, high charged polar surface area (HCPSA), and radius of gyration (rgyr). Among these three descriptors, logD may have the largest impact on diffusion through Caco-2 cell because logD shows obvious linear correlation with logPapp (r=0.703) when logD is smaller than 2.0. High polar surface area will be unfavorable to achieve good Caco-2 permeability because higher polar surface area will introduce stronger H-bonding interactions between Caco-2 cells and drugs. The comparison among HCPSA, PSA (polar surface area), and TPSA (topological polar surface area) implies that high-charged atoms may be more important to the interactions between Caco-2 cell and drugs. Besides logD and HCPSA, rgyr is also closely connected with Caco-2 permeabilities. The molecules with larger rgyr are more difficult to cross Caco-2 monolayers than those with smaller rgyr. The descriptors included in the prediction models permit the interpretation in structural terms of the passive permeability process, evidencing the main role of lipholiphicity, H-bonding, and bulk properties. Besides these three molecular descriptors, the influence of other molecular descriptors was also investigated. From the calculated results, it can be found that introducing descriptors concerned with molecular flexibility can improve the linear correlation. The resulting model with four descriptors bears good statistical significance, n = 77, r = 0.82, q = 0.79, s = 0.45, F = 35.7. The actual predictive abilities of the QSAR model were validated through an external validation test set of 23 diverse compounds. The predictions for the tested compounds are as the same accuracy as the compounds of the training set and significantly better than those predicted by using the model reported. The good predictive ability suggests that the proposed model may be a good tool for fast screening of logPapp for compound libraries or large sets of new chemical entities via combinatorial chemistry synthesis.

Gene expression in major depressive disorder

The search for genetic variants underlying major depressive disorder (MDD) has not yet provided firm leads to its underlying molecular biology. A complementary approach is to study gene expression in relation to MDD. We measured gene expression in peripheral blood from 1848 subjects from The Netherlands Study of Depression and Anxiety. Subjects were divided into current MDD (N=882), remitted MDD (N=635) and control (N=331) groups. MDD status and gene expression were measured again 2 years later in 414 subjects. The strongest gene expression differences were between the current MDD and control groups (129 genes at false-discovery rate, FDR<0.1). Gene expression differences across MDD status were largely unrelated to antidepressant use, inflammatory status and blood cell counts. Genes associated with MDD were enriched for interleukin-6 (IL-6)-signaling and natural killer (NK) cell pathways. We identified 13 gene expression clusters with specific clusters enriched for genes involved in NK cell activation (downregulated in current MDD, FDR=5.8 × 10(-5)) and IL-6 pathways (upregulated in current MDD, FDR=3.2 × 10(-3)). Longitudinal analyses largely confirmed results observed in the cross-sectional data. Comparisons of gene expression results to the Psychiatric Genomics Consortium (PGC) MDD genome-wide association study results revealed overlap with DVL3. In conclusion, multiple gene expression associations with MDD were identified and suggest a measurable impact of current MDD state on gene expression. Identified genes and gene clusters are enriched with immune pathways previously associated with the etiology of MDD, in line with the immune suppression and immune activation hypothesis of MDD.

Optical detection of a single rare-earth ion in a crystal

Rare-earth-doped laser materials show strong prospects for quantum information storage and processing, as well as for biological imaging, due to their high-Q 4f↔4f optical transitions. However, the inability to optically detect single rare-earth dopants has prevented these materials from reaching their full potential. Here we detect a single photostable Pr(3+) ion in yttrium aluminium garnet nanocrystals with high contrast photon antibunching by using optical upconversion of the excited state population of the 4f↔4f optical transition into ultraviolet fluorescence. We also demonstrate on-demand creation of Pr(3+) ions in a bulk yttrium aluminium garnet crystal by patterned ion implantation. Finally, we show generation of local nanophotonic structures and cell death due to photochemical effects caused by upconverted ultraviolet fluorescence of praseodymium-doped yttrium aluminium garnet in the surrounding environment. Our study demonstrates versatile use of rare-earth atomic-size ultraviolet emitters for nanoengineering and biotechnological applications.

PLA2G6 gene mutation in autosomal recessive early-onset parkinsonism in a Chinese cohort

OBJECTIVE

Mutations in the PLA2G6 gene at the PARK14 locus have been reported in complicated parkinsonism. To assess the prevalence of and phenotypes associated with PLA2G6 gene mutations, we screened PLA2G6 mutations in a cohort of patients with autosomal recessive early-onset parkinsonism (AREP).

METHODS

We selected 12 families with AREP in which the Parkin, PINK1, DJ-1, ATP13A2, and FBXO7 gene mutations had been previously excluded. All patients came from the mainland of China. The entire PLA2G6 coding region and exon-intron boundaries were sequenced from genomic DNA templates. We then performed PET studies on individuals in the pedigree with a homozygous PLA2G6 mutation, and investigated the enzyme activity level of the mutation.

RESULTS

A homozygous missense mutation, c.G991T (p.D331Y), was identified in an autosomal recessive case. A younger sister of the p.D331Y-carrying patient was also homozygous for the mutation, but with no extrapyramidal symptoms. A PET study showed a substantial reduction in dopamine transporter (DAT) binding in the p.D331Y patient, and a slight reduction in DAT binding in his sister. In vitro, we experimentally demonstrate that the D331Y mutation caused an approximately 70%reduction in enzyme activity.

CONCLUSIONS

We have confirmed that the PLA2G6 gene allocated PARK14 locus and is associated with AREP.

The cytokine-activated tyrosine kinase JAK2 activates Raf-1 in a p21ras-dependent manner

JAK2, a member of the Janus kinase superfamily was found to interact functionally with Raf-1, a central component of the ras/mitogen-activated protein kinase signal transduction pathway. Interferon-gamma and several other cytokines that are known to activate JAK2 kinase were also found to stimulate Raf-1 kinase activity toward MEK-1 in mammalian cells. In the baculovirus coexpression system, Raf-1 was activated by JAK2 in the presence of p21ras. Under these conditions, a ternary complex of p21ras, JAK2, and Raf-1 was observed. In contrast, in the absence of p21ras, coexpression of JAK2 and Raf-1 resulted in an overall decrease in the Raf-1 kinase activity. In addition, JAK2 phosphorylated Raf-1 at sites different from those phosphorylated by pp60v-src. In mammalian cells treated with either erythropoietin or interferon-gamma, a small fraction of Raf-1 coimmunoprecipitated with JAK2 in lysates of cells in which JAK2 was activated as judged by its state of tyrosine phosphorylation. Taken together, these data suggest that JAK2 and p21ras cooperate to activate Raf-1.

Increased Interleukin-6 Levels in the Astrocyte-Derived Exosomes of Sporadic Amyotrophic Lateral Sclerosis Patients

Neuroinflammation plays an important role in amyotrophic lateral sclerosis (ALS) pathogenesis. However, it is difficult to evaluate inflammation of the central nervous system (CNS) or the relationship between neuroinflammation and disease progression in ALS patients. Recent advances in the field of exosomes and CNS-derived exosomes extraction technology provide the possibility of measuring the inflammatory status in the CNS without brain biopsy. In this pilot study, we extracted astrocyte-derived exosomes from the plasma of sporadic ALS patients and age-, sex-matched healthy controls and determined Interleukin-6 (IL-6) levels by an enzyme-linked immunosorbent assay (ELISA). The IL-6 levels in astrocyte-derived exosomes were increased in sALS patients and positively associated with the rate of disease progression. However, the association between IL-6 levels and disease progression rate was limited to patients whose disease duration were less than 12 months. These data suggest an increased inflammatory cascade in the CNS of sALS patients. Our pilot study demonstrates that CNS-derived exosomes could be useful to reveal neuroinflammation of the CNS in ALS patients.

X-Ray Absorption and Electron Paramagnetic Resonance Studies of Cu(II) Sorbed to Silica: Surface-Induced Precipitation at Low Surface Coverages

Both EPR and XAFS spectroscopy were used to characterize the sorption of Cu(II) on silica surfaces at extremely low surface coverage (0.8 and 9.9% monolayer). The binding structure of Cu(II) on silica surfaces revealed by XAFS experiment was compared to that predicted by EPR spectra. Our XAFS results show that Cu(II) hydroxide clusters form on silica surfaces even at surface coverage as low as 0.8% of a monolayer. However, we observed low EPR intensity and line-broadening which has been assigned to dipole-dipole interactions between isolated Cu(II) ions. The results of our XAFS studies indicate that the loss of EPR intensity and line-broadening can be traced to Cu(OH)2 clusters on silica surfaces.

Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1

Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.

Role of protein kinase A and the serine-rich region of herpes simplex virus type 1 ICP4 in viral replication

Efficient expression of herpes simplex virus genes requires the synthesis of functional ICP4, a nuclear phosphoprotein that contains a prominent serine-rich region between amino acids 142 and 210. Residues in this region not only are potential sites for phosphorylation but also are involved in the functions of ICP4. By comparing the growth of a virus in which this region is deleted (d8-10) with wild-type virus (KOS) in PC12 cells or PC12 cells that are deficient in cyclic AMP-dependent protein kinase (PKA), two observations were made: (i) the growth of wild-type virus was impaired by 1 to 2 orders of magnitude in the PKA-deficient cells, indicating the involvement of PKA in the growth cycle of herpes simplex virus type 1, and (ii) while the growth of d8-10 was impaired by almost 2 orders of magnitude in wild-type cells, it was not further impaired (as was that of wild-type virus) in PKA-deficient cells, implicating the region deleted in d8-10 as a possible target for cellular PKA. In trigeminal'ganglia of mice, the d8-10 mutant virus grew poorly; however, it established latency in nearly 90% of ganglia tested. Studies of the phosphorylation of wild-type and d8-10 ICP4 proteins revealed that the serine-rich region is a major determinant for phosphorylation of ICP4 in vivo and that the phosphorylation state could change as a function of the PKA activity. Consistent with this observation, the serine-rich region of ICP4 was shown to be a target for PKA in vitro. While intact ICP4 was readily phosphorylated by ICP4 in vitro, the d8-10 mutant ICP4 was not. Moreover, a synthethic peptide representing a sequence in the serine tract that is predicted to be a substrate for PKA was phosphorylated by PKA in vitro, having a Km within the physiological range. These data suggest that PKA plays a role in viral growth through phosphorylation of one or more sites on the ICP4 molecule.

Analysis of phosphorylation sites of herpes simplex virus type 1 ICP4

The herpes simplex virus ICP4 protein is required for induction of early and late viral gene transcription as well as for repression of expression of its own gene and several other viral genes. Several electrophoretic forms of ICP4 have been observed, and phosphorylation is thought to contribute to this heterogeneity and possibly to the multiple functions of ICP4. To define the complexity of the site(s) of phosphorylation of ICP4 and to initiate mapping of this site(s), we have performed two-dimensional phosphopeptide mapping of wild-type and mutant forms of ICP4 labeled in infected cells or in vitro. Wild-type ICP4 labeled in infected cells shows a complex pattern of phosphopeptides, and smaller mutant forms of ICP4 show progressively fewer phosphopeptides, arguing that multiple sites on ICP4 are phosphorylated. The serine-rich region of ICP4, residues 175 to 198, was shown to be a site for phosphorylation. Furthermore, the serine-rich region itself or the phosphorylation of this region increases phosphorylation of all phosphopeptides. A mutant ICP4 molecule lacking the serine-rich region showed low levels of phosphorylation by protein kinase A or protein kinase C in vitro. These results suggest that there may be a sequential phosphorylation of ICP4, with phosphorylation of the serine-rich region stimulating phosphorylation of the rest of the molecule. In addition, purified ICP4 showed an associated kinase activity or an autophosphorylation activity with properties different from those of protein kinase A or protein kinase C.

Tyrosine phosphorylation of the proto-oncoprotein Raf-1 is regulated by Raf-1 itself and the phosphatase Cdc25A

There is a growing body of evidence demonstrating that Raf-1 is phosphorylated on tyrosines upon stimulation of a variety of receptors. Although detection of Raf-1 tyrosine phosphorylation has remained elusive, genetic analyses have demonstrated it to be important for Raf-1 activation. Here we report new findings which indicate that Raf-1 tyrosine phosphorylation is regulated in vivo. In both a mammalian and baculovirus expression system, a kinase-inactive allele of Raf-1 was found to be tyrosine phosphorylated at levels much greater than that of wild-type Raf-1. The level of tyrosine phosphate on Raf-1 was markedly increased upon treatment with phosphatase inhibitors either before or after cell lysis. Cdc25A was found to dephosphorylate Raf-1 on tyrosines that resulted in a significant decrease in Raf-1 kinase activity. In NIH 3T3 cells, coexpression of wild-type Raf-1 and phosphatase-inactive Cdc25A led to a marked increase in Raf-1 tyrosine phosphorylation in response to platelet-derived growth factor. These data suggest that the tyrosine phosphorylation of Raf-1 is regulated not only by itself but also by Cdc25A.

A novel locus (DSAP2) for disseminated superficial actinic porokeratosis maps to chromosome 15q25.1-26.1

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. It develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. The first locus for DSAP was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.

OBJECTIVES

To determine whether DSAP is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation Chinese family with DSAP.

METHODS

Genetic linkage analysis was carried out in this family using 15 microsatellite markers between D12S1671 and D12S369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.

RESULTS

Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. A genome-wide scan and fine mapping finally localized the locus for DSAP in this family to a 6.4-cM region between markers D15S1023 and D15S1030 at chromosome 15q25.1-26.1. This DSAP locus was named DSAP2.

CONCLUSIONS

The previous results and this study have shown that DSAP is a genetically heterogeneous disorder; a novel locus for DSAP, termed DSAP2, was mapped to a 6.4-cM region between markers D15S1023 and D15S1030.

Cultivation of Chlorella sp. with livestock waste compost for lipid production

Cultivation of microalgae Chlorella sp. with livestock waste compost as an alternative nutrient source was investigated in this present study. Five culture media with different nutrient concentrations were prepared. The characteristics of algal growth and lipid production were examined. The results showed that the specific growth rate together with biomass and lipid productivities was different among all the cultures. As the initial nutrient concentration decreased, the lipid content of Chlorella sp. increased. The variations in lipid productivity of Chlorella sp. among all the cultures were mainly due to the deviations in biomass productivity. The livestock waste compost medium with 2000mgL^-1COD provided an optimal nutrient concentration for Chlorella sp. cultivation, where the highest productivities of biomass (288.84mgL^-1day^-1) and lipid (104.89mgL^-1day^-1) were presented.

Homozygous loss-of-function mutation of the LEPREL1 gene causes severe non-syndromic high myopia with early-onset cataract

High myopia is a severe visual impairment which can increase the risk of retinal degeneration, subretinal hemorrhage, choroidal neovascularization, cataract and retinal detachment. We recruited an autosomal-recessive high myopia family, with affected subjects who also present early-onset cataract, retinal degeneration and other complications. Using targeted capturing and whole exome sequencing, we identified a homozygous non-sense mutation in the LEPREL1 gene which causes premature termination of the translation at the fifth amino acid (c.13C>T; p.Q5X), co-segregating with the phenotypes. LEPREL1 encodes a proline hydroxylase called prolyl 3-hydroxylase 2 (P3H2), a 2-oxoglutarate-dependent dioxygenase that hydroxylates collagens. The results show that LEPREL1 plays an important role in eye development and homozygous loss-of-function mutation of this gene can cause severely high myopia and early-onset cataract. Our study also strongly suggests that the disruption of collagen modification is one of the pathogenic mechanisms of high myopia and cataract.

An improved mechanical technique for assisted hatching

BACKGROUND

Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it.

METHODS

A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro.

RESULTS

The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P = 0.01).

CONCLUSIONS

Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.

Non-viral ex vivo transduction of human hepatocyte cells to express factor VIII using a human ribosomal DNA-targeting vector

BACKGROUND

In gene therapy, one of the most important issues is the choice of the vectors. pHrneo is a human-derived vector previously constructed by our group, which can target a foreign gene into a human ribosomal DNA (hrDNA) locus.

METHODS AND RESULTS

In this study, we inserted an expression cassette of reconstructive hFVIII (hFVIII-BDDAK39) to pHrneo to construct a targeting vector: pHrneo-BDDAK39. Through electroporation of pHrneo-BDDAK39 into HL7702 cells (human hepatocyte), we identified the homologous recombinants using polymerase chain reaction, and tested the expression of hFVIII-BDDAK39 located at the hrDNA locus. The hFVIII-BDDAK39 was successfully targeted into the hrDNA locus of HL7702 by pHrneo-BDDAK39, and the efficiency of site-specific integration was 1.1 x 10(-5). The hFVIII-BDDAK39 at the hrDNA locus of HL7702 was found to be able to express efficiently (4.3 +/- 0.9 ng 10(-6) cells 24 h(-1)).

CONCLUSION

It has been indicated that the targeting vector pHrneo-BDDAK39 can be used in gene therapy for hemophilia A.

Experimental study on TGF-β1-mediated CD147 expression in oral submucous fibrosis

OBJECTIVE

Although previous evidence indicates that CD147 is closely involved in the progression of organ fibrosis and various signaling pathways have been proven to regulate its expression, the role of CD147 in oral submucous fibrosis (OSF) remains largely unknown.

METHODS

In this study, we investigated the expression of CD147 and transforming growth factor β1 (TGF-β1) in human samples of an OSF tissue array by immunohistopathology. Pearson's correlation analysis was conducted to explore the correlation between CD147 and TGF-β1. Immunofluorescence and Western blotting were used to investigate to levels of CD147 in Human Oral Keratinocytes (HOKs) followed by TGF-β1 or LY2157299, an inhibitor of TGF-β1 receptor and arecoline stimulation.

RESULTS

We found that CD147 was highly expressed in both HOKs and the fibrotic oral mucosa and that this expression was correlated with TGF-β1 expression. Additionally, CD147 levels were significantly associated with the fibrosis stage. The TGF-β1 signaling pathway was found to be mainly responsible for CD147 up-regulation after arecoline treatment whereas inhibition of TGF-β1 down-regulated CD147 expression.

CONCLUSION

Our findings suggest arecoline promotes CD147 expression via the TGF-β1 signaling pathway in HOKs, whereas overexpression of CD147 may promote OSF progression.