A recurrent homozygous missense mutation in CCDC103 causes asthenoteratozoospermia due to disorganized dynein arms / 亚洲男科学杂志(英文版)

Asthenoteratozoospermia is one of the most severe types of qualitative sperm defects. Most cases are due to mutations in genes encoding the components of sperm flagella, which have an ultrastructure similar to that of motile cilia. Coiled-coil domain containing 103 (CCDC103) is an outer dynein arm assembly factor, and pathogenic variants of CCDC103 cause primary ciliary dyskinesia (PCD). However, whether CCDC103 pathogenic variants cause severe asthenoteratozoospermia has yet to be determined. Whole-exome sequencing (WES) was performed for two individuals with nonsyndromic asthenoteratozoospermia in a consanguineous family. A homozygous CCDC103 variant segregating recessively with an infertility phenotype was identified (ENST00000035776.2, c.461A>C, p.His154Pro). CCDC103 p.His154Pro was previously reported as a high prevalence mutation causing PCD, though the reproductive phenotype of these PCD individuals is unknown. Transmission electron microscopy (TEM) of affected individuals' spermatozoa showed that the mid-piece was severely damaged with disorganized dynein arms, similar to the abnormal ultrastructure of respiratory ciliary of PCD individuals with the same mutation. Thus, our findings expand the phenotype spectrum of CCDC103 p.His154Pro as a novel pathogenic gene for nonsyndromic asthenospermia.

Lower expression of dynein axonemal intermediate china 1 in lung adenocarcinoma and inhibits the invasion of lung adenocarcinoma cells / 解剖学报

Objective To investigate the expression of dynein axonemal intermediate chain l(DNAI1) in lung adenocarcinoma (LUAD) and its influence on invasive ability of lung adenocarcinoma. Methods Microarray gene chip analysis was used to screen different expression genes in lung adenocarcinoma (3 samples) and adjacent normal tissues(3 samples); Heatmap and volcano plot were performed demonstrate the mRNA expression and distribution after screening; DAVID database used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes of Genomes (KEGG) analysis; STRING database and Cytoscape 3.6.1 software for protein-protein interaction (PPI) analysis and screening of Hub genes; Objective genes were selected based on the differential expression of each Hub gene in lung adenocarcinoma in DEGs and Ualcan database; Real-time PCR and Western blotting were used to detect the expression of DNAI1 in BEAS-2B, H1299 and A549; observe the morphological changes after DNAI1 overexpression; Transwell invasion assay was used to detect the change of invasion ability of A549 cells after DNAI1 overexpression. Results The microarray result showed that there were 86 up-regulated genes and 396 down-regulated genes; different genes were involved in the RNA polymerase II promoter positive regulation of transcription, apoptosis process of negative regulation, protein binding, and other functions, widely distributed within the cell, and associated with the metabolic pathway, cancer and other signal pathways were closely related ; DEGs database and Ualcan database showed that DNAI1 was the most downregulated among Hub genes in LUAD; the result of Real-time PCR and Western blotting showed that DNAI1 had lower expression in H1299 and A549 compared with BEAS-2B; after DNAI1 overexpression, A549 cells became round and a few shed off; invasion assay showed that the invasion ability of A549 cells was significantly reduced. Conclusion DNAI1 has a lower expression and inhibits the ability of invasion in LUAD, and this study can provide a potential molecular target and provide a theoretical basis for targeted therapy of LUAD.

Axonemal Dynein DNAH5 is Required for Sound Sensation in Drosophila Larvae / 神经科学通报·英文版

Chordotonal neurons are responsible for sound sensation in Drosophila. However, little is known about how they respond to sound with high sensitivity. Using genetic labeling, we found one of the Drosophila axonemal dynein heavy chains, CG9492 (DNAH5), was specifically expressed in larval chordotonal neurons and showed a distribution restricted to proximal cilia. While DNAH5 mutation did not affect the cilium morphology or the trafficking of Inactive, a candidate auditory transduction channel, larvae with DNAH5 mutation had reduced startle responses to sound at low and medium intensities. Calcium imaging confirmed that DNAH5 functioned autonomously in chordotonal neurons for larval sound sensation. Furthermore, disrupting DNAH5 resulted in a decrease of spike firing responses to low-level sound in chordotonal neurons. Intriguingly, DNAH5 mutant larvae displayed an altered frequency tuning curve of the auditory organs. All together, our findings support a critical role of DNAH5 in tuning the frequency selectivity and the sound sensitivity of larval auditory neurons.

Comparative Characterization of Four Calcium-Binding EF Hand Proteins from Opisthorchis viverrini

Four isoforms of calcium binding proteins containing 2 EF hand motifs and a dynein light chain-like domain in the human liver fluke Opisthorchis viverrini, namely OvCaBP1, 2, 3, and 4, were characterized. They had molecular weights of 22.7, 21.6, 23.7, and 22.5 kDa, respectively and showed 37.2–42.1% sequence identity to CaBP22.8 of O. viverrini. All were detected in 2- and 4-week-old immature and mature parasites. Additionally, OvCaBP4 was found in newly excysted juveniles. Polyclonal antibodies against each isoform were generated to detect the native proteins in parasite extracts by Western blot analysis. All OvCaBPs were detected in soluble and insoluble crude worm extracts and in the excretory-secretory product, at approximate sizes of 21–23 kDa. The ion-binding properties of the proteins were analyzed by mobility shift assays with the divalent cations Ca²⁺, Mg²⁺, Zn²⁺, and Cu²+. All OvCaBPs showed mobility shifts with Ca²⁺ and Zn²⁺. OvCaBP1 showed also positive results with Mg²⁺ and Cu²⁺. As tegumental proteins, OvCaBP1, 2, and 3 are interesting drug targets for the treatment of opisthorchiasis.

Cellular model of neuronal atrophy induced by DYNC1I1 deficiency reveals protective roles of RAS-RAF-MEK signaling

Neuronal atrophy is a common pathological feature occurred in aging and neurodegenerative diseases. A variety of abnormalities including motor protein malfunction and mitochondrial dysfunction contribute to the loss of neuronal architecture; however, less is known about the intracellular signaling pathways that can protect against or delay this pathogenic process. Here, we show that the DYNC1I1 deficiency, a neuron-specific dynein intermediate chain, causes neuronal atrophy in primary hippocampal neurons. With this cellular model, we are able to find that activation of RAS-RAF-MEK signaling protects against neuronal atrophy induced by DYNC1I1 deficiency, which relies on MEK-dependent autophagy in neuron. Moreover, we further reveal that BRAF also protects against neuronal atrophy induced by mitochondrial impairment. These findings demonstrate protective roles of the RAS-RAF-MEK axis against neuronal atrophy, and imply a new therapeutic target for clinical intervention.

Some adaptation ways of creature in liquid environment / 国际生物医学工程杂志

Creatures living in liquid environment can form special exterior structure, internal framework, movement and substance distribution according to their respective living condition. This paper focused on the analysis via examples of macroscopic and microscopic organism. Quantitative analysis is used to make the description more exact and internal features of the organism easier to be examed.

Biochemical Characterization of ATPase Activity of Dynamitin / 中国生物化学与分子生物学报

Dynactin is a multi-subunit complex that has been implicated in the function of cytoplasmic dynein which is a minus end - directed microtubule motor protein with numerous functions including nuclear migration, mitotic spindle orientation, and cytoskeletal reorientation during interphase and mitosis. Dynamitin,the 50 kD subunit of dynactin, is important for stabilizing the dynactin complex. To gain more insight into the mechanism of stabilizing, we analyzed the sequence of dynamitin and revealed that domains of dynamitin is homology to the Walker A and Walker B ATPase motifs. The purified GST-dynamitin and GST-free dynamitin both showed ATPase activity specifically. An inactivating mutation in the Walker A, but not the Walker B ATPase motif abolished the ATPase activity of dynamitin. The mutational analysis studies further supported that dynamitin is an ATPase. Kinetic studies of the ATPase activity of dynamitin revealed a Km for ATP of 125.78μmol/L and a kcat of 7.4 min-1.

A Case of Immotile Cilia Syndrome Diagnosed by Lack of Dynein Inner Arms on Electron Microscopy / 소아알레르기및호흡기학회지

Immotile cilia syndrome is an inherited disorder characterized by specific ultrastructural defects of cilia and associated impairment of ciliary motion and mucociliary clearance. Disorders of ciliary structure or function result in chronic sinopulmonary diseases manifested as chronic sinusitis, bronchitis, otitis media, nasal polyposis, and ultimately bronchiectasis. In addition, situs inversus, dextrocardia, and infertility can be associated with dysfunctional ciliary activity. We experienced a case of immotile cilia syndrome presenting with recurrent bronchitis, pneumonia, chronic sinusitis, otitis media, and bronchiectasis. She was diagnosed by lack of dynein inner arm on electron microscopy. Treatment included chest percussion, bronchodilators, antibiotics, and surgical intervention. She has been followed up at regular intervals. We report this case with related literatures.

ULTRASTRUCTURE OF RESPIRATORY CILIA IN HUMAN / 解剖学报

The respiratory cilia of normal and abnormal regions in 20 patients with lung cancer or tuberculosis were observed under electron microscope.The results show that the 9?2+2 microtubules arrangement was seen in cross section of the cilium. Ultrastructure of the cilia is about the same as that of other mammalian ceils. However,a very interesting finding was that the ciliary rootlets became greatly hypertrophied.Thus,the structure was easily identified.It appeared as striated muscles. Therefore we propose a new idea that is quite different from Satir's hypothesis about the mechanism of ciliary movement.We think that ciliary rootlets may generate movement rather than fix cilia.Dynein arms and radial spoke may be involved in supporting and fixing for ciliary movement.