Effect of Different Parameters of In Vitro Static Tensile Strain on Human Periodontal Ligament Cells Simulating the Tension Side of Orthodontic Tooth Movement.

This study aimed to investigate the effects of different magnitudes and durations of static tensile strain on human periodontal ligament cells (hPDLCs), focusing on osteogenesis, mechanosensing and inflammation. Static tensile strain magnitudes of 0%, 3%, 6%, 10%, 15% and 20% were applied to hPDLCs for 1, 2 and 3 days. Cell viability was confirmed via live/dead cell staining. Reference genes were tested by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and assessed. The expressions of TNFRSF11B, ALPL, RUNX2, BGLAP, SP7, FOS, IL6, PTGS2, TNF, IL1B, IL8, IL10 and PGE2 were analyzed by RT-qPCR and/or enzyme-linked immunosorbent assay (ELISA). ALPL and RUNX2 both peaked after 1 day, reaching their maximum at 3%, whereas BGLAP peaked after 3 days with its maximum at 10%. SP7 peaked after 1 day at 6%, 10% and 15%. FOS peaked after 3 days with its maximum at 3%, 6% and 15%. The expressions of IL6 and PTGS2 both peaked after 1 day, with their minimum at 10%. PGE2 peaked after 1 day (maximum at 20%). The ELISA of IL6 peaked after 3 days, with the minimum at 10%. In summary, the lower magnitudes promoted osteogenesis and caused less inflammation, while the higher magnitudes inhibited osteogenesis and enhanced inflammation. Among all magnitudes, 10% generally caused a lower level of inflammation with a higher level of osteogenesis.

Effect of Tension on Human Periodontal Ligament Cells: Systematic Review and Network Analysis.

Orthodontic tooth movement is based on the remodeling of tooth-surrounding tissues in response to mechanical stimuli. During this process, human periodontal ligament cells (hPDLCs) play a central role in mechanosensing and mechanotransduction. Various in vitro models have been introduced to investigate the effect of tension on hPDLCs. They provide a valuable body of knowledge on how tension influences relevant genes, proteins, and metabolites. However, no systematic review summarizing these findings has been conducted so far. Aim of this systematic review was to identify all related in vitro studies reporting tension application on hPDLCs and summarize their findings regarding force parameters, including magnitude, frequency and duration. Expression data of genes, proteins, and metabolites was extracted and summarized. Studies' risk of bias was assessed using tailored risk of bias tools. Signaling pathways were identified by protein-protein interaction (PPI) networks using STRING and GeneAnalytics. According to our results, Flexcell Strain Unit® and other silicone-plate or elastic membrane-based apparatuses were mainly adopted. Frequencies of 0.1 and 0.5 Hz were predominantly applied for dynamic equibiaxial and uniaxial tension, respectively. Magnitudes of 10 and 12% were mostly employed for dynamic tension and 2.5% for static tension. The 10 most commonly investigated genes, proteins and metabolites identified, were mainly involved in osteogenesis, osteoclastogenesis or inflammation. Gene-set enrichment analysis and PPI networks gave deeper insight into the involved signaling pathways. This review represents a brief summary of the massive body of knowledge in this field, and will also provide suggestions for future researches on this topic.

A Novel Arthropod Host of Brucellosis in the Arid Steppe Ecosystem.

Brucellosis is a severe public health problem in the Inner Mongolia regions of China. The recent prevalence of brucellosis outbreaks may be attributed to an increase in the activity of ticks and other air-borne vectors. Dermacentor nuttalli (D. nuttalli) is a native tick species of Inner Mongolia; similar to other tick species, D. nuttalli carries a variety of pathogens that can be transmitted to a wide range of animals. In this study, we have investigated the potential of D. nuttalli in transmitting brucellosis. From 2015 to 2019, 2,256 ticks were collected from 23 different pastoral areas of Hulun Buir. Brucellosis pathogen was detected using DNA extracted from different developmental stages of ticks. Salivary gland and midgut tissue samples were used as templates to amplify Brucella Bscp31 gene (Brucella genus-specific gene) by using TaqMan Real-Time polymerase chain reaction (PCR). To detect the presence of Bscp31 protein, which is specific to Brucella spp., in the midgut and salivary gland tissues of D. nuttalli, Western blotting and immunofluorescence were performed. Additionally, Brucella spp. were isolated using a culture medium. Tick samples were identified as D. nuttalli. Different percentages of Brucella genus-specific genes could be found in the tick samples. From 2015 to 2019, the positivity rate for the detection of Bscp31 gene in D. nuttalli ranged from 0.00 to 87.80%, with the highest rate of 89.00%. In addition, Brucella genus-specific genes were successfully detected in the samples isolated from all the developmental stages and anatomical regions of ticks. Bscp31 protein was present in the midgut and salivary gland of D. nuttalli. Further, B. melitensis biotype 3 was isolated from eggs and engorged adults of D. nuttalli. These findings demonstrate that D. nuttalli is a potent, long-term carrier of Brucella spp. that can exhibit transovarial transmission potential, presenting D. nuttalli as a novel arthropod host for Brucella spp. This study, therefore, indicates the potential risk of transmission of brucellosis via tick bites among animals as well as human beings.