Mechanisms of hearing loss and cell death in the cochlea of connexin mutant mice.

Mutations in connexin 30 (Cx30) are known to cause severe congenital hearing impairment; however, the mechanism by which Cx30 mediates homeostasis of endocochlear gap junctions is unclear. We used a gene deletion mouse model to explore the mechanisms of Cx30 in preventing hearing loss. Our results suggest that despite severe loss of the auditory brain-stem response and endocochlear potential at postnatal day 18, Cx30-/- mice only show sporadic loss of the outer hair cells. This inconsistency in the time course and severity of hearing and hair cell losses in Cx30-/- mice might be explained, in part, by an increase in reactive oxygen species generation beginning at postnatal day 10. The expression of oxidative stress genes was increased in Cx30-/- mice in the stria vascularis, spiral ligament, and organ of Corti. Furthermore, Cx30 deficiency caused mitochondrial dysfunction at postnatal day 18, as assessed by decreased ATP levels and decreased expression of mitochondrial complex I proteins, especially in the stria vascularis. Proteomic analysis further identified 444 proteins that were dysregulated in Cx30-/- mice, including several that are involved in mitochondria electron transport, ATP synthesis, or ion transport. Additionally, proapoptotic proteins, including Bax, Bad, and caspase-3, were upregulated at postnatal day 18, providing a molecular basis to explain the loss of hearing that occurs before hair cell loss. Therefore, our results are consistent with an environment of oxidative stress and mitochondrial damage in the cochlea of Cx30-/- mice that is coincident with hearing loss but precedes hair cell loss.

[Analysis of risk factors for congenital auriclar deformity and its different types].

Objective:To Explore the clinical characteristics,risk factors,and differences in risk factors for different types of congenital auricular deformities,in order to provide theoretical basis for precise prevention and control of congenital auriclar deformity. Methods:Full-term newborns born in the Second Affiliated Hospital of Zhengzhou University from May 2022 to January 2023 were screened for auricle malformation, general information and data were collected,,and high-risk factors were investigated withself-made questionnaire.Using a case-control study method,newborns with auriclar deformities were selected as the case group and those without auriclar deformities during the same period were selected as the control group.A case-control study was conducted to analyze the incidence rate,high-risk factors,and differences in high-risk factors for different types of auricle deformities. Results:A total of 1 758 newborns （3 516 ears） were included in this study,including 562 newborns（927 ears） with auriclar deformities,the incidence of congenital malformations of the auricle is 26.37%.Among them,289 ears （8.22%） were helical rim deformity,244 ears （6.94%） were lidding/lop ear,166 ears （4.72%） were mixed deformities,131 ears （3.73%） were prominent/cup ear,79 ears （2.25%） were Stahl's ears,16 ears （0.46%） were abnormal conchal crus,and 2 ears （0.06%） were cryptotia.Maternal history of infection in early pregnancy（OR=1.513，95%CI 1.119-2.045）,previous miscarriage history（OR=1.300，95%CI 1.049-1.613）,and abnormal pregnancy（OR=1.278，95%CI 1.032-1.582） are risk factors for congenital auricular malformations.There was no statistically significant difference in the history of infection（χ²=1.877，P=0.391）,previous miscarriage（χ²=4.706，P=0.095）,and abnormal pregnancy（χ²=5.026，P=0.081） among mothers with helical rim deformity,lidding/lop ear,and mixed deformities. Conclusion:The incidence rate of congenital auricle deformity is high, with common malformations such as helical rim deformity, lidding/lop ear,and mixed deformities. Congenital auricular deformity is caused by various factors, the same risk factor has roughly the same impact on different types of morphological abnormalities.

Early truncation of the N-terminal variable region of EYA4 gene causes dominant hearing loss without cardiac phenotype.

BACKGROUND: Autosomal dominant hearing loss (ADHL) accounts for about 20% of all hereditary non-syndromic HL. Truncating mutations of the EYA4 gene can cause either non-syndromic ADHL or syndromic ADHL with cardiac abnormalities. It has been proposed that truncations of the C-terminal Eya domain lead to non-syndromic HL, whereas early truncations of the N-terminal variable region cause syndromic HL with cardiac phenotype. METHODS: The proband and all the other hearing impaired members of the family underwent a thorough clinical and audiological evaluation. The cardiac phenotype was examined by ECG and echocardiography. Their DNA was subjected to target exome sequencing of 129 known deafness genes. The sequencing data were analyzed and the candidate variants were interpreted following the ACMG guidelines for clinical sequence interpretation. The effect of candidate variant on EYA4 gene expression was assessed by quantitative PCR and western blot of gene production in blood. RESULTS: We report a Chinese family cosegregating post-lingual onset, progressive ADHL with a novel nonsense mutation NM_004100.4:c.543C>G (p.Tyr181Ter) of EYA4. Two affected members show no cardiac abnormalities at least until now revealed by electrocardiography and echocardiography. The overall expression level of the EYA4 gene in the proband was lower than that in his unaffected relative. CONCLUSION: This report expands the mutational spectrum of the EYA4 gene and highlights the fact that more data are needed to elucidate the complex genotype-phenotype correlation of EYA4 mutations.

Retraction Note: RNAi targeting CXCR4 inhibits proliferation and invasion of esophageal carcinoma cells.

The Editor-in-Chief has retracted this article [1] because Fig. 3 shows overlap with Fig. 6 in [2], Fig. 2b in [3] and Fig. 6a in [4]. An investigation by Zhengzhou University has confirmed that these figures overlap. The data reported in this article are therefore unreliable.

PRMT1-RBM15 axis regulates megakaryocytic differentiation of human umbilical cord blood CD34+ cells.

Protein arginine methyltransferase 1 (PRMT1) serves pivotal roles in various cellular processes. However, its role in megakaryocytic differentiation has not been clearly reported. The aim of the present study was to explore the role of the PRMT-RNA binding motif protein 15 (RBM15) axis in human MK differentiation and the feasibility of targeting PRMT1 for leukemia treatment. In the present study, PRMT1 was overexpressed and the RBM15 protein was knocked down in human umbilical cord blood cluster of differentiation (CD)34+ cells and the cells were then cultured in megakaryocytic differentiation medium. Flow cytometry was used to analyze CD41 and CD42 double-positive cells, as well as the protein expression levels of PRMT1 and RBM15. The results demonstrated that human cord blood CD34+ cells differentiate into mature MKs in high thrombopoitin medium, as demonstrated by CD41 and CD42 expression. Overexpression of PRMT1 in human umbilical cord blood CD34+ cells blocked the maturation of megakaryocytic cells. Knockdown of RBM15 by short hairpin RNA produced less mature MKs. PRMT1 inhibitor rescued PRMT1-blocked megakaryocytic differentiation. These results provide evidence for a novel role of PRMT1 in the negative regulation of megakaryocytic differentiation. PRMT1 may be a therapeutic target for leukemia treatment.

Chromosomal abnormalities and molecular landscape of metastasizing mucinous salivary adenocarcinoma.

BACKGROUND: Mucinous adenocarcinoma of the salivary gland (MAC) is a lethal cancer with unknown molecular etiology and a high propensity to lymph node metastasis. Mostly due to its orphan status, MAC remains one of the least explored cancers that lacks cell lines and mouse models that could help translational and pre-clinical studies. Surgery with or without radiation remains the only treatment modality but poor overall survival (10-year, 44%) underscores the urgent need for mechanism-based therapies. METHODS: We developed the first patient-derived xenograft (PDX) model for pre-clinical MAC studies and a cell line that produces aggressively growing tumors after subcutaneous injection into nude mice. We performed cytogenetic, exome, and proteomic profiling of MAC to identify driving mutations, therapeutic targets, and pathways involved in aggressive cancers based on TCGA database mining and GEO analysis. RESULTS: We identified in MAC KRAS (G13D) and TP53 (R213X) mutations that have been previously reported as drivers in a variety of highly aggressive cancers. Somatic mutations were also found in KDM6A, KMT2D, and other genes frequently mutated in colorectal and other cancers: FAT1, NBEA, RELN, RLP1B, and ZFHX3. Proteomic analysis of MAC implied epigenetic up-regulation of a genetic program involved in proliferation and cancer stem cell maintenance. CONCLUSION: Genomic and proteomic analyses provided the first insight into potential molecular drivers of MAC metastases pointing at common mechanisms of CSC propagation in aggressive cancers. The in vitro/in vivo models that we created should aid in the development and validation of new treatment strategies against MAC.

RNAi targeting CXCR4 inhibits proliferation and invasion of esophageal carcinoma cells.

CXC chemokine receptor 4 was found to be expressed by many different types of human cancers and its expression has been correlated with tumor aggressiveness, poor prognosis and resistance to chemotherapy. However the effect of CXCR4 on the esophageal carcinoma cells remains unclear, the present study explored the effects of CXCR4 siRNA on proliferation and invasion of esophageal carcinoma KYSE-150 and TE-13 cells. Two siRNA sequence targeting CXCR4 gene were constructed and then were transfected into KYSE-150 and TE-13 cells by Lipofectamine™2000. Changes of CXCR4 mRNA and protein were analyzed by qRT-PCR and Western blot. Effect of CXCR4 siRNA on KYSE-150 and TE-13 cells proliferation was determined by MTT. Transwell invasion assay was used to evaluate the invasion and metastasis of KYSE-150 and TE-13 cells. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. qRT-PCR and Western blot demonstrate that the expression level of CXCR4 gene were obviously decreased in KYSE-150 and TE-13 cells transfected with CXCR4 targeting siRNA expression vectors. The average amount of cells transfected with CXCR4 siRNA penetrating Matrigel was significantly decreased (p<0.05). Injection of CXCR4 siRNA transfected cells inhibited tumor growth in a xenograft model compared with blank and negative control groups (p <0.05). CXCR4 silenced by siRNA could suppress the proliferation, invasion and metastasis of esophageal carcinoma cell lines KYSE-150 and TE-13 in vitro and in vivo. The results provide a theoretical and experimental basis for the gene therapy of ESCC using RNAi technology based on CXCR4 target site. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3502376691001138.