[Expression profile of microRNA secreted by rat condylar chondrocytes under tensile stress].

Objective: To preliminarily explore the mechanism of tensile stress regulating endochondral osteogenesis of condyle by analyzing the expression profiles of significantly different microRNAs (miRNAs) in exosomes of rat mandibular condylar chondrocytes (MCC) under quiescent and cyclic tensile strain (CTS) conditions. Methods: Rat condylar chondrocytes were cultured under static and CTS conditions respectively (10 SD rats, male, 2 weeks old), and exosomes were extracted. The two groups of exosomes were named as control group and CTS group respectively. The differential expression miRNAs were screened by high-throughput sequencing. Bioinformatics analysis and prediction of target genes related to osteogenesis were performed by TargetScan and miRanda website. Results: The exosomes of rat condylar chondrocytes cultured under tensile stress showed a "double concave disc" monolayer membrane structure, the expression of CD9 and CD81 were positive, and the particle size distribution accorded with the characteristics of exosomes, which was consistent with that of static cultured rat condylar chondrocytes. A total of 85 miRNAs with significantly different expression were detected by high-throughput sequencing (P<0.05). The main biological processes and molecular functions of differential miRNAs were biological processes and protein binding, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathway enrichment analysis showed that there was significant enrichment in mammalian target of rapamycin (mTOR) signal pathway. The candidate target genes of miR-199a-5p include bone morphogenetic protein 3 (BMP3), endothelin converting enzyme 1, and miR-186-5p may target Smad8 and BMP3 to exert osteogenesis-related functions. Conclusions: Compared with static state, tensile stress stimulation can change the expression of miRNAs such as miR-199a-5p, miR-186-5p in the exocrine body of rat condylar chondrocytes, which can be considered as a mean to regulate the application potential of the exosomes.

[Correlation between serum bilirubin and cardiovascular autonomic neuropathy in patients with type 2 diabetes].

Objective: To investigate the correlation between serum bilirubin and cardiovascular autonomic neuropathy (CAN) in type 2 diabetes mellitus patients. Methods: A total of 369 patients with type 2 diabetes mellitus who were hospitalized at the Department of Endocrinology, Nanjing Jinling Hospital from April 2017 to October 2018 were enrolled, including 226 males and 143 females, with an average age of (54.6±12.1) years. According to cardiovascular reflex tests (CARTs), all the patients were divided into Non CAN group(149 patients without CAN) and CAN group (220 patients complicated with CAN). The difference of serum bilirubin levels between the two groups was compared. The differences of CARTs and the incidence of CAN were compared by tertiles of serum bilirubin levels. The binary logistic regression was used to analyze the risk factors for diabetic cardiovascular autonomic neuropathy. Results: The serum total bilirubin [(9.28±2.74) µmol/L vs (11.08±2.98) µmol/L, P<0.001], direct bilirubin [(3.17±1.20) µmol/L vs (3.71±1.24) µmol/L, P<0.001] and indirect bilirubin levels [(6.11±1.89) µmol/L vs (7.37±2.10) µmol/L, P<0.001] in CAN group were significantly lower than that in Non CAN group. With the increase of serum bilirubin, the incidence of CAN decreased (P<0.01). Multivariate Logistic regression analysis showed that serum total bilirubin (OR=0.819, 95%CI: 0.744-0.901, P<0.001), direct bilirubin (OR=0.739, 95%CI: 0.601-0.908, P=0.004) and indirect bilirubin (OR=0.749, 95%CI: 0.653-0.860, P<0.001) were inversely correlated with the incidence of CAN. Conclusions: Within the physiological range, lower level of serum bilirubin is inversely correlated with the incidence of CAN. It is noteworthy to screen diabetic cardiovascular autonomic neuropathy in patients with type 2 diabetes mellitus who had a lower serum bilirubin level.

[High serum cholesterol: a novel risk factor for thyroid associated ophthalmopathy?]

This study was aimed to investigate the association between dyslipidemia and thyroid associated ophthalmopathy (TAO). We evaluated the relationship between dyslipidemia and TAO in 218 patients with Graves' disease (GD) and found that the serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in the GD subjects with TAO (n=110) were significantly increased [(5.32±1.39) mmol/L vs. (3.18±2.12) mmol/L, (2.98±0.75) mmol/L vs. (1.25±0.98) mmol/L] than those in the GD subjects without TAO (n=108). TC and LDL-C were positively correlated with the Clinical disease activity score (CAS) [TC (r=0.7, P=0.03),LDL-C (r=0.82, P=0.03)], and the levels of TC (OR=2.56, P=0.02) and LDL-C(OR=2.01, P=0.015) were positively associated with TAO. These suggested that high serum cholesterol level is a novel risk factor for TAO, and management of blood lipids should be included in the treatment of TAO.

Neisseria gonorrhoeae elicits membrane ruffling and cytoskeletal rearrangements upon infection of primary human endocervical and ectocervical cells.

Neisseria gonorrhoeae is a strict human pathogen that is, primarily, transmitted by close sexual contact with an infected individual. Gonococcal infection of the male urogenital tract has been well studied in experimental human models and in urethral cell culture systems. Recent studies, using tissue culture cell systems, have suggested a role for the cervical epithelium in gonococcal infection of females; however, the nature of gonococcal infection of the normal uterine cervix remains controversial. To address this enigma, we have developed two primary human cervical epithelial cell systems from surgical biopsies. Gonococcal infection studies and electron microscopy show that N. gonorrhoeae is capable of infecting and invading both the endo- and the ectocervix. Invasion was found to occur primarily in an actin-dependent manner, but it does not appear to require de novo protein synthesis by either the bacterium or the host cervical cell. Membrane ruffles appear to be induced in response to gonococci. Consistent with membrane ruffling, gonococci were found residing within macropinosomes, and a concentrated accumulation of actin-associated proteins was observed to occur in response to gonococcal infection. Electron microscopy of clinically derived cervical biopsies show that lamellipodia formation and cytoskeletal changes, suggestive of membrane ruffles, also occur in the cervical epithelium of women with naturally acquired gonococcal cervicitis. These studies demonstrate the ability of N. gonorrhoeae to infect and invade both the endo- and the ectocervix of the normal uterine cervix. Gonococcal induced ruffling is a novel finding and may be unique to the cervical epithelium.

Infection of primary human bronchial epithelial cells by Haemophilus influenzae: macropinocytosis as a mechanism of airway epithelial cell entry.

Nontypeable Haemophilus influenzae is an exclusive human pathogen which infects the respiratory epithelium. We have initiated studies to explore the interaction of the nontypeable H. influenzae strain 2019 with primary human airway epithelial cells by electron and confocal microscopy. Primary human airway cell cultures were established as monolayers on glass collagen-coated coverslips or on semipermeable membranes at an air-fluid interface. Scanning electron microscopy indicated that bacteria adhered to nonciliated cells in the population. The surface of infected cells showed evidence of cytoskeletal rearrangements manifested by microvilli and lamellipodia extending toward and engaging bacteria. Confocal microscopic analysis demonstrated that infection induced actin polymerization with an increase in cortical actin as well as evidence of actin strands around the bacteria. Transmission electron microscopic analysis showed lamellipodia and microvilli surrounding organisms, as well as organisms adherent to the cell surface. These studies also demonstrated the presence of bacteria within vacuoles inside of airway cells. Confocal microscopic studies with Texas red-labeled dextran (molecular weight, 70,000) indicated that H. influenzae cells were entering cells by the process of macropinocytosis. These studies indicate that nontypeable H. influenzae can initiate cytoskeletal rearrangement within human airway epithelium, resulting in internalization of the bacteria within nonciliated human airway epithelial cells by the process of macropinocytosis.