TTC5 syndrome: Clinical and molecular spectrum of a severe and recognizable condition.

Biallelic mutations in the TTC5 gene have been associated with autosomal recessive intellectual disability (ARID) and subsequently with an ID syndrome including severe speech impairment, cerebral atrophy, and hypotonia as clinical cornerstones. A TTC5 role in IDs has been proposed based on the physical interaction of TTC5 with p300, and possibly reducing p300 co-activator complex activity, similarly to what was observed in Menke-Hennekam 1 and 2 patients (MKHK1 and 2) carrying, respectively, mutations in exon 30 and 31 of CREBBP and EP300, which code for the TTC5-binding region. Recently, TTC5-related brain malformation has been linked to tubulinopathies due to the function of TTC5 in tubulins' dynamics. We reported seven new patients with novel or recurrent TTC5 variants. The deep characterization of the molecular and phenotypic spectrum confirmed TTC5-related disorder as a recognizable, very severe neurodevelopmental syndrome. In addition, other relevant clinical aspects, including a severe pre- and postnatal growth retardation, cryptorchidism, and epilepsy, have emerged from the reversal phenotype approach and the review of already published TTC5 cases. Microcephaly and facial dysmorphism resulted in being less variable than that documented before. The TTC5 clinical features have been compared with MKHK1 published cases in the hypothesis that clinical overlap in some characteristics of the two conditions was related to the common p300 molecular pathway.

Ultrasound-targeted microbubble destruction (UTMD)-mediated miR-150-5p attenuates oxygen and glucose deprivation-induced cardiomyocyte injury by inhibiting TTC5 expression.

BACKGROUND: Cardiomyocyte injury is a typical feature in cardiovascular diseases. Changes in cardiomyocytes strongly affect the progression of cardiovascular diseases. This work aimed to investigate the biological function and potential mechanism of action of miR-150-5p in cardiomyocytes. METHODS AND RESULTS: A myocardial ischemia (MI) injury rat model was constructed to detect miR-150-5p and tetratricopeptide repeat domain 5 (TTC5) expression during heart ischemia injury. Primary cardiomyocytes were isolated for in vitro study. CCK-8 assays were used to detect cardiomyocyte viability. Western blots were used to detect TTC5 and P53 expression. qPCR was utilized to measure RNA expression of miR-150-5p and TTC5. The TUNEL assay was used to determine cell apoptosis. ELISA was used to determine cytokine (TNF-α, IL-1ß, IL-6, and IL-8) levels in heart tissues and cell culture supernatants. A dual-luciferase reporter assay was carried out to verify the binding ability between miR-150-5p and TTC5. Oxygen-glucose deprivation (OGD) treatment significantly inhibited cell viability. Ultrasound-targeted microbubble destruction (UTMD)-mediated uptake of miR-150-5p inverted these results. Additionally, UTMD-mediated uptake of miR-150-5p retarded the effects of OGD treatment on cell apoptosis. Besides, UTMD-mediated uptake of miR-150-5p counteracted the effects of OGD treatment on the inflammatory response by regulating cytokine (TNF-α, IL-1ß, IL-6, and IL-8) levels. For the mechanism of the protective effect on the heart, we predicted and confirmed that miR-150-5p bound to TTC5 and inhibited TTC5 expression. CONCLUSIONS: UTMD-mediated uptake of miR-150-5p attenuated OGD-induced primary cardiomyocyte injury by inhibiting TTC5 expression. This discovery contributes toward further understanding the progression of primary cardiomyocyte injury.

Evaluation of the Role of p53 Tumour Suppressor Posttranslational Modifications and TTC5 Cofactor in Lung Cancer.

Mutations in the p53 tumor suppressor are found in over 50% of cancers. p53 function is controlled through posttranslational modifications and cofactor interactions. In this study, we investigated the posttranslationally modified p53, including p53 acetylated at lysine 382 (K382), p53 phosphorylated at serine 46 (S46), and the p53 cofactor TTC5/STRAP (Tetratricopeptide repeat domain 5/ Stress-responsive activator of p300-TTC5) proteins in lung cancer. Immunohistochemical (IHC) analysis of lung cancer tissues from 250 patients was carried out and the results were correlated with clinicopathological features. Significant associations between total or modified p53 with a higher grade of the tumour and shorter overall survival (OS) probability were detected, suggesting that mutant and/or modified p53 acts as an oncoprotein in these patients. Acetylated at K382 p53 was predominantly nuclear in some samples and cytoplasmic in others. The localization of the K382 acetylated p53 was significantly associated with the gender and grade of the disease. The TTC5 protein levels were significantly associated with the grade, tumor size, and node involvement in a complex manner. SIRT1 expression was evaluated in 50 lung cancer patients and significant positive correlation was found with p53 S46 intensity, whereas negative TTC5 staining was associated with SIRT1 expression. Furthermore, p53 protein levels showed positive association with poor OS, whereas TTC5 protein levels showed positive association with better OS outcome. Overall, our results indicate that an analysis of p53 modified versions together with TTC5 expression, upon testing on a larger sample size of patients, could serve as useful prognostic factors or drug targets for lung cancer treatment.

TRIP13 interference inhibits the proliferation and metastasis of thyroid cancer cells through regulating TTC5/p53 pathway and epithelial-mesenchymal transition related genes expression.

This study aimed to investigate the effect of interfering thyroid hormone receptor interacting protein 13 (TRIP13) expression on the proliferation, apoptosis and metastasis of thyroid cancer (TC) cells and the involved mechanisms. RT-PCR, immunohistochemical analysis and western blot found that compared with normal tissues, the expressions of TRIP13 and N-cadherin in TC tissues were significantly increased, while the expressions of tetratricopeptide repeat protein 5 (TTC5), p-p53 and E-cadherin were significantly decreased (P < 0.05). RT-PCR and western blot revealed that compared with C643 cells, TRIP13 expression in TPC1 cells and BHT101 cells increased significantly (P < 0.05). Therefore, TPC1 cells and BHT101 cells were selected for subsequent experiments. Interference efficiency of TRIP13 interference sequences (sh-TRIP13) was verified by RT-PCR and western blot. After sh-TRIP13 transfection, cell viability and migration rates of cells at 24 h and 48 h decreased significantly (P < 0.05); the number of S phase cells increased remarkably, while the number of G1 and G2 phase cells decreased significantly (P < 0.05); cell apoptosis was enhanced sharply (P < 0.05); cell numbers in the lower chamber of Transwell assay were reduced significantly (P < 0.05). RT-PCR and western blot found that compared with the Control group, expressions of TTC5 and E-cadherin in sh-TRIP13 group were elevated sharply, while N-cadherin expression decreased significantly (P < 0.05). Compared with the Control group, sh-TRIP13 transfection elevated the ratio of p-p53 expression to p53 expression (p-p53/p53) remarkably (P < 0.05). In conclusion, TRIP13 interference inhibited the proliferation and metastasis of thyroid cancer cells through regulating TTC5/p53 pathway and epithelial-mesenchymal transition related genes expression.