Tas2R143 regulates the expression of the Blood-Testis Barrier tight junction protein in TM4 cells through the NF-κB signaling pathway.

Although bitter receptors, known as Tas2Rs, have been identified in the testes and mature sperm, their expression in testicular Sertoli cells (SCs) and their role in recognizing harmful substances to maintain the immune microenvironment remain unknown. To explore their potential function in spermatogenesis, this study utilized TM4 cells and discovered the high expression of the bitter receptor Tas2R143 in the cells. Interestingly, when the Tas2R143 gene was knocked down for 24 and 48 h, there was a significant downregulation (P < 0.05) in the expression of tight junction proteins (occludin and ZO-1) and NF-κB. Additionally, Western blot results demonstrated that the siRNA-133+NF-κB co-treatment group displayed a significant downregulation (P < 0.05) in the expression of occludin and ZO-1 compared to both the siRNA-133 transfection group and the NF-κB inhibitors treatment group. These findings suggest that Tas2R143 likely regulates the expression of occludin and ZO-1 through the NF-κB signaling pathway and provides a theoretical basis for studying the regulatory mechanism of bitter receptors in the reproductive system, aiming to attract attention to the chemical perception mechanism of spermatogenesis.

[Mitochondrial tRNAThr G15927A mutation may influence the phenotypic manifestation of deafness-associated 12S rRNA A1555G mutation.].

We report here the clinical and genetic evaluations as well as mutational analysis of mitochondrial DNA (mtDNA) in a four-generation Chinese Han family with aminoglycoside-induced and nonsyndromic hearing loss. Strikingly, this family exhibited a high penetrance and expressivity of hearing loss. The penetrances of hearing loss in this family were 75% and 41.7% respectively, when aminoglycoside-induced deafness was included or was excluded. The severity of hearing loss in matrilineal relatives varied from profound hearing loss to normal hearing. Mutational analysis of mtDNA identified the homoplasmic A1555G mutation and a distinct set of mtDNA variants belonging to the Asian haplogroup B5b. Of these, the G15927A mutation absent in 156 Chinese controls is localized at the anticodon-stem of tRNAThr at conventional position 42. The guanine at this position (G42) of tRNAThr is highly conserved from bacteria to human mitochondria. Thus, it is antici-pated that the G15927A disrupted the highly conserved C-G base-pairing at the anticodon-stem of tRNAThr. The alteration of structure of this tRNA likely leads to a failure in tRNA metabolism, thereby worsens the mitochondrial dysfunction asso-ciated with the A1555G mutation. Thus, the G15927A mutation has a potential modifying role in increasing the penetrance and expressivity of hearing loss associated with the deafness-associated 12S rRNA A1555G mutation in this Chinese pedigree.

[Hearing loss and epilepsy may be associated with the novel mitochondrial tRNASer(UCN) 7472delC mutation in a Chinese family].

Mutations in mitochondrial DNA have been associated with a wide spectrum of clinical abnormalities. We reported here the clinical and genetic evaluations as well as mutational analysis of mitochondrial DNA(mtDNA) in a three-generation Chinese Han family with maternally transmitted hearing loss and epilepsy. Of 14 matrilineal relatives, three suffered from hearing loss, three had epilepsy, and other did not have significant clinical abnormalities. Sequence analysis of mitochondrial genome in this family identified the novel 7472delC in tRNASer(UCN) and 33 variants belonging to Asian haplogroup B4b1a2. The 7472delC locates at the highly conserved residue of T-arm of this tRNA. In fact, the 7472insC at the same position of this tRNA has been associated with hearing loss and epilepsy in several genetically unrelated families. The 7472insC has been shown to lead to a failure in tRNA metabolism and mitochondrial dysfunction. Thus, 7472delC mutation, similar to 7472insC mutation, may result in the mitochondrial dysfunctions responsible for the hearing loss and epilepsy. Furthermore, none of mutation in deafness-associated GJB2 gene was detected in this Chinese family. Therefore, the 7472delC is likely a new mitochondrial mutation with hearing loss and epilepsy.

[Expression and its promoter methylation of chemokine CXC ligand 14 in peripheral blood mononuclear cells from patients with lupus].

OBJECTIVE: To analyze the expression and its promoter methylation of chemokine CXC ligand 14 (CXCL14) in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: The RNAs of PBMCs from 28 SLE patients and 20 healthy controls were isolated and reversely transcribed into cDNAs. Using GAPDH as the internal reference, the levels of CXCL14 ex-pression were detected by real-time polymerase chain reaction (PCR). The correlation between CXCL14 expression and the clinic pathological fe atures of SLE were further analyzed. DNA methylation was analyzed by bisulfite sequencing PCR (BSP). RESULTS: Our data indicated that the level of CXCL14 in the PBMC of SLE patients was statistically lower than that in healthy controls (P < 0.05). Further analysis showed that CXCL14 expression was negatively correlated with anti-Sj gren syndrome B antibody(anti-SSB antibody, P < 0.01) and albuminuria(P < 0.05). However, CXCL14 expression was not significantly correlated with the indexes of SLE activity, renal damage, the level of anti-ds-DNA antibodies, complement C3 and C-reactive protein. In addition, we further demonstrated that the CXCL14 promoter hypermethylation expres-sion was significant higher than healthy controls. CONCLUSIONS: Down-regulated of CXCL14 expression in PBMC maybe involved in the occur-rence or development of SLE disease. The loss of CXCL14 expression was regulated by promoter hypermethylation.

Suberoylanilide Hydroxamic Acid, an Inhibitor of Histone Deacetylase, Induces Apoptosis in Rheumatoid Arthritis Fibroblast-Like Synoviocytes.

Here, we explored the effects of suberoylanilide hydroxamic acid (SAHA) on the viability and apoptosis of rheumatoid arthritis of fibroblast-like synoviocytes (rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS)). FLS obtained from RA patients were treated with SAHA. SAHA significantly inhibited the viability of RA FLS in a concentration-dependent manner up to 5 µM. SAHA-treated FLS showed a significant increase in the percentage of apoptosis and the expression and activity of caspase-3 and higher intracellular ROS levels. N-acetyl-l-cysteine (NAC) pretreatment significantly attenuated SAHA-induced apoptosis, decreasing the percentage of apoptosis by about 60 %. A significant decline in phosphorylated IκBα and nuclear factor kappa B (NF-κB) p65 and concomitant increase in total IκBα were shown in SAHA-treated FLS. Additionally, the levels of anti-apoptotic Bcl-2 proteins (Bcl-xL and Mcl-1) were significantly reduced by SAHA. Collectively, SAHA induces apoptosis of RA FLS, at least partially, through generation of ROS and suppression of NF-κB activation and Bcl-xL and Mcl-1 expression.