A Study of Familial Amyloid Polyneuropathy Induced by the TTR Val30Leu Mutation in China.

INTRODUCTION: Familial amyloid polyneuropathy is currently prevalent worldwide as the transthyretin (TTR) Val30Met mutation, and there are other types of mutations. The purpose of this study was to understand the clinical manifestations, electrophysiological characteristics, and outcomes of hormone-related therapy in patients with the TTR Val30Leu mutation in China. METHODS: Clinical data were collected from 9 members of a family with the TTR Val30Leu mutation in China, and blood samples of 7 members of the family were sequenced. The electrophysiological examinations of 4 of them were collected and analysed. RESULTS: A total of 7 people had the TTR gene c.148G>T missense mutation and the TTR protein Val30Leu mutation in this family, and the positive members all had similar symptoms, such as limb paraesthesia and gastrointestinal symptoms. In addition, electrophysiological examination showed abnormal nerve conduction velocity in all 4 patients. CONCLUSIONS: The clinical manifestations of this mutation involve mainly limb sensory or motor disorders or gastrointestinal symptoms or both, and the electrophysiological examination shows neurogenic damage.

Two high-fidelity variants: efSaCas9 and SaCas9-HF, which one is better?

CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated endonuclease Cas9) nucleases have been widely applied for genome engineering. Staphylococcus aureus Cas9 (SaCas9) is compact, which can be packaged in AAV (adeno-associated virus) vector for in vivo gene editing. While, wild-type SaCas9 can induce unwanted off-target mutations and substantially limits the applications. So far, there are two reported SaCas9 variants with high-fidelity, including efSaCas9 from our previous study and SaCas9-HF. However, it remains unknown which one possessing the better fidelity and higher activity. Here, we performed a parallel comparison of efSaCas9 and SaCas9-HF in human cells through fluorescent reporter system and target deep sequencing, respectively. The results demonstrated that efSaCas9 possesses higher cleavage activity and fidelity than SaCas9-HF at the most endogenous sites in human cells. Collectively, our study provides insights for the rational selection of suitable SaCas9 for human genome editing.

Aberrant expression of semaphorin 6B affects cell phenotypes in thyroid carcinoma by activating the Notch signalling pathway.

INTRODUCTION: Numerous semaphorins have been widely clarified to be involved in the development of multiple cancers. However, semaphorin 6B (SEMA6B) has not yet been extensively reported in cancers, especially in thyroid carcinoma. MATERIAL AND METHODS: Thyroid carcinoma RNA-Seq dataset from the TCGA database was used to assess the expression of SEMA6B in tissues, as well as its clinical significance. We adopted qRT-PCR and western blot analyses to measure the mRNA and protein expression of SEMA6B in thyroid carcinoma cells. The biological roles of SEMA6B in thyroid carcinoma cells were examined through cell counting kit 8, clone formation, and Transwell assays. Also, GSEA was used to identify the gene sets modulated by SEMA6B, which is further verified by western blot. RESULTS: According to the public dataset from the TCGA database, we found that the expression of SEMA6B was upregulated in thyroid carcinoma tissues compared to adjacent non-tumour tissues, and a high level of SEMA6B resulted in a poorer prognosis compared to the low-level SEMA6B group. Functional experiments showed that silencing SEMA6B suppressed the B-CPAP cells viability, invasiveness, and motility, whereas up-regulating SEMA6B in FTC-133 cells led to opposite outcomes. Furthermore, knockdown of SEMA6B in B-CPAP cells could significantly elevate the protein expression of NUMB and reduce the expression of NOTCH1, HES1, and Cyclin D1. Conversely, overexpression of SEMA6B in FTC-133 cells presented opposite results on the protein expression of these Notch signalling pathway-related markers. CONCLUSIONS: Our findings demonstrated that SEMA6B exerts a tumourigenic effect in thyroid carcinoma partly by activating Notch signalling pathway, which provides a possible biomarker for the therapeutic intervention in thyroid carcinoma.

Cytotoxicity and genotoxicity of bacterial magnetosomes against human retinal pigment epithelium cells.

A variety of nanomaterials have been developed for ocular diseases. The ability of these nanomaterials to pass through the blood-ocular barrier and their biocompatibility are essential characteristics that must be considered. Bacterial magnetosomes (BMs) are a type of biogenic magnetic nanomaterials synthesized by magnetotactic bacteria. Due to their unique biomolecular membrane shell and narrow size distribution of approximately 30 nm, BMs can pass through the blood-brain barrier. The similarity of the blood-ocular barrier to the blood-brain barrier suggests that BMs have great potential as treatments for ocular diseases. In this work, BMs were isolated from magnetotactic bacteria and evaluated in various cytotoxicity and genotoxicity studies in human retinal pigment epithelium (ARPE-19) cells. The BMs entered ARPE-19 cells by endocytosis after a 6-h incubation and displayed much lower cytotoxicity than chemically synthesized magnetic nanoparticles (MNPs). MNPs exhibited significantly higher genotoxicity than BMs and promoted the expression of Bax (the programmed cell death acceleration protein) and the induction of greater cell necrosis. In BM-treated cells, apoptosis tended to be suppressed via increased expression of the Bcl-2 protein. In conclusion, BMs display excellent biocompatibility and potential for use in the treatment of ocular diseases.

The Relationship between Serum Osteocalcin Concentration and Glucose and Lipid Metabolism in Patients with Type 2 Diabetes Mellitus ­ The Role of Osteocalcin in Energy Metabolism.

BACKGROUND: Recent animal studies have found that the osteocalcin secreted by osteoblasts could participate in glucose and lipid metabolism. Our study aimed to investigate the relationship between serum osteocalcin concentration and glucose and lipid metabolism in patients with type 2 diabetes mellitus. METHODS: 985 patients with type 2 diabetes were divided into the male group (n = 495) and the postmenopausal female group (n = 490). The average ages were 54.42 ± 10.535 and 64.93 ± 9.277, respectively. We collected the parameters of age, duration, fasting plasma glucose, HbA1c, fasting insulin, fasting C peptide, blood lipid, 25 (OH) VD3, parathyroid hormone (PTH), Alkaline phosphatase (ALP), procollagen type 1 N-terminal propeptide (P1NP), ß-C-terminal telopeptide of type I collagen (ß-CTx), osteocalcin, HOMA-IR, HOMA-ß, body mass index (BMI), and waist-to-hip ratio (WHR). The relationship of osteocalcin and these parameters were analyzed by Pearson/Spearman correlation analysis and stepwise multiple regression analysis. RESULTS: Osteocalcin was negatively correlated with HbA1c (p < 0.05) and it was also an independent relevant factor affecting HbA1c in both groups. Osteocalcin was positively correlated with HOMA-ß and it was an independent relevant factor affecting HOMA-ß in male group (p < 0.01). CONCLUSIONS: These findings indicate the association between serum osteocalcin and glucose metabolism and beta cell function. No relationship was found between osteocalcin and insulin resistance and lipid metabolism in type 2 diabetes.