The pathogenic mechanism of syndactyly type V identified in aHoxd13Q50R knock-in mice

Syndactyly type V (SDTY5) is an autosomal dominant extremity malformation characterized by fusion of the fourth and fifthmetacarpals. In the previous publication, we first identified a heterozygous missense mutation Q50R in homeobox domain (HD) ofHOXD13 in a large Chinese family with SDTY5. In order to substantiate the pathogenicity of the variant and elucidate the underlyingpathogenic mechanism causing limb malformation, transcription-activator-like effector nucleases (TALEN) was employed togenerate a Hoxd13Q50R mutant mouse. The mutant mice exhibited obvious limb malformations including slight brachydactyly andpartial syndactyly between digits 2-4 in the heterozygotes, and severe syndactyly, brachydactyly and polydactyly in homozygotes.Focusing on BMP2 and SHH/GREM1/AER-FGF epithelial mesenchymal (e-m) feedback, a crucial signal pathway for limbdevelopment, we found the ectopically expressed Shh, Grem1 and Fgf8 and down-regulated Bmp2 in the embryonic limb bud atE10.5 to E12.5. A transcriptome sequencing analysis was conducted on limb buds (LBs) at E11.5, revealing 31 genes that exhibitednotable disparities in mRNA level between the Hoxd13Q50R homozygotes and the wild-type. These genes are known to be involvedin various processes such as limb development, cell proliferation, migration, and apoptosis. Our findings indicate that the ectopicexpression of Shh and Fgf8, in conjunction with the down-regulation of Bmp2, results in a failure of patterning along both theanterior-posterior and proximal-distal axes, as well as a decrease in interdigital programmed cell death (PCD). This cascadeultimately leads to the development of syndactyly and brachydactyly in heterozygous mice, and severe limb malformations inhomozygous mice. These findings suggest that abnormal expression of SHH, FGF8, and BMP2 induced by HOXD13Q50R may beresponsible for the manifestation of human SDTY5.

A novel phenotype with splicing mutation identified in a Chinese family with desminopathy

Background and Objective Desminopathy is a largely heterogeneous group of conditions involving inherited or sporadic myofibrillar myopathy.In terms of its mode of inheritance,the autosomal dominant form is predominant.Desmin gene(DES)mutations play a critical role among the pathogenic inherited factors associated with desminopathy.Desminopathy involves various phenotypes,mainly including different cardiomyopathies,skeletal myopathy and arrhythmia.The purposes of this study are characterization of a novel phenotype and identification of a DES splicing mutation in a Chinese family with desminnopathy.

A state‑domain robust autonomous integrity monitoring with an extrapolation method for single receiver positioning in the presence of slowly growing fault

Single receiver positioning has been widely used as a standard and standalone positioning technique for about 25 years.To detect the slowly growing faults caused by satellite and receiver clocks in single receiver positioning,the Autonomous Integrity Monitoring with an Extrapolation method(AIME)was proposed based on the Kalman filter measurement domain.However,AIME was designed with the assumption of there is the same number of visible satellites at each epoch,which limits its application.To address this issue,this paper proposes a state-domain Robust Autonomous Integrity Monitoring with the Extrapolation Method(SRAIME).The slowly growing fault detection statistics is established based on the difference between the estimates of the state propagator and the posterior state estimation in Kalman filtering.Meanwhile,singular value decomposition is adopted to factor the covariance matrix of the difference to increase computational robustness.Besides,the relevant formulas of the proposed method are theoretically derived,and it is proven that the proposed method is suitable for any positioning model based on the Kalman filter.Additionally,the results of two experiments indicate that SRAIME can detect slowly growing faults in single receiver positioning earlier than AIME.

Formation of regulated and unregulated disinfection byproducts during chlorination and chloramination: Roles of dissolved organic matter type, bromide, and iodide

Algal blooms and wastewater effluents can introduce algal organic matter(AOM) and effluent organic matter(Ef OM) into surface waters, respectively. In this study, the impact of bromide and iodide on the formation of halogenated disinfection byproducts(DBPs) during chlorination and chloramination from various types of dissolved organic matter(DOM, e.g., natural organic matter(NOM), AOM, and Ef OM) were investigated based on the data collected from literature. In general, higher formation of trihalomethanes(THMs) and haloacetic acids(HAAs) was observed in NOM than AOM and Ef OM, indicating high reactivities of phenolic moieties with both chlorine and monochloramine. The formation of haloacetaldehydes(HALs), haloacetonitriles(HANs) and haloacetamides(HAMs) was much lower than THMs and HAAs. Increasing initial bromide concentrations increased the formation of THMs, HAAs, HANs, and HAMs, but not HALs. Bromine substitution factor(BSF) values of DBPs formed in chlorination decreased as specific ultraviolet absorbance(SUVA) increased. AOM favored the formation of iodinated THMs(I-THMs) during chloramination using preformed chloramines and chlorination-chloramination processes. Increasing prechlorination time can reduce the I-THM concentrations because of the conversion of iodide to iodate, but this increased the formation of chlorinated and brominated DBPs. In an analogous way, iodine substitution factor(ISF) values of I-THMs formed in chloramination decreased as SUVA values of DOM increased. Compared to chlorination, the formation of noniodinated DBPs is low in chloramination.

Keratin 5-Cre-driven deletion of Ncstn in an acne inversa-like mouse model leads to a markedly increased IL-36a and Sprr2 expression

Familial acne inversa (AI) is an autoinflammatory disorder that affects hair follicles and is caused by loss-of-function mutations in y-secretase component genes.We and other researchers showed that nicastrin (NCSTN) is the most frequently mutated gene in familial AI.In this study,we generated a keratin 5-Cre-driven epidermis-specific Ncstn conditional knockout mutant in mice.We determined that this mutant recapitulated the major phenotypes of AI,including hyperkeratosis of hair follicles and inflammation.In Ncstnflox/flox;K5-Cre mice,the IL-36a expression level markedly increased starting from postnatal day 0 (P0),and this increase occurred much earlier than those of TNF-α,IL-23A,IL-1 3,and TLR4.RNA-Seq analysis indicated that Sprr2d,a member of the small proline-rich protein 2 family,in the skin tissues of the Ncstnflox/flox,;K5-Cre mice was also upregulated on P0.Quantitative reverse-transcription polymerase chain reaction showed that other Sprr2 genes had a similar expression pattern.Our findings suggested that IL-36a might be a key inflammatory cytokine in the pathophysiology of AI and implicate malfunction of the skin barrier in the pathogenesis of AI.

A pig model carrying heterozygous point mutation of NCSTN simulates familial acne inversa and reveals dysregulated cholesterol biosynthesis via the Notch-p AMPK-HMGCR pathway

Acne inversa(Al,OMIM#142690)is an autosomal dominant chronic inflammatory disease of the hair follicles[1].Despite medications and procedures aimed at treating Al,patient responses vary widely to different therapies,and no curative regimen or treatment is available[2].In 2010,our group first idenrified nicas-trin(NCSTN),an y-secretase component gene,as a pathogenic gene for familial Al patients[3].

Novel mutation c.1210-3C>G in cis with a poly-T tract of 5T affects CFTR mRNA splicing in a Chinese patient with cystic fibrosis

Cystic fibrosis(CF)is a rare autosomal recessive disease with only one pathogenic gene cystic fibrosis transmembrane conductance regulator(CFTR).To identify the potential pathogenic mutations in a Chinese patient with CF,we conducted Sanger sequencing on the genomic DNA of the patient and his parents and detected all 27 coding exons of CFTR and their flanking intronic regions.The patient is a compound heterozygote of c.2909G>A,p.Gly970Asp in exon 18 and c.1210-3C>G in cis with a poly-T of 5T(T5)sequence,3 bp upstream in intron 9.The splicing effect of c.1210-3C>G was verified via minigene assay in vitro,indicating that wild-type plasmid containing c.1210-3C together with T7 sequence produced a normal transcript and partial exon 10-skipping-transcript,whereas mutant plasmid containing c.1210-3G in cis with T5 sequence caused almost all mRNA to skip exon 10.Overall,c.1210-3C>G,the newly identified pathogenic mutation in our patient,in combination with T5 sequence in cis,affects the CFTR gene splicing and produces nearly no normal transcript in vitro.Moreover,this patient carries a p.Gly970Asp mutation,thus confirming the high-frequency of this mutation in Chinese patients with CF.