Mesenchymal stem cells (MSC), a distinct type of adult stem cell, are easy to isolate, culture, and manipulate in ex vivo culture. These cells have great plasticity and potential for therapeutic application, but their properties are poorly understood because of their low frequency and the lack of knowledge on cell surface markers and their location of origin. The present study was designed to address the undefined lineage relationship of hematopoietic and mesenchymal stem cells. Genetically marked, highly purified hematopoietic stem cells (HSCs) were transplanted into wild-type animals and, after bone marrow repopulation, the progeny were rigorously investigated for differentiation potential into mesenchymal tissues by analyzing in vitro differentiation into mesenchymal tissues. None/very little of the hematopoietic cells contributed to colony-forming units fibroblast activity and mesenchymal cell differentiation; however, unfractionated bone marrow cells resulted in extensive replacement of not only hematopoietic cells but also mesenchymal cells, including MSCs. As a result, we concluded that purified HSCs have no significant potency to differentiate into mesenchymal lineage. The data strongly suggest that hematopoietic cells and mesenchymal lineage cells are derived from individual lineage-specific stem cells. In addition, we succeeded in visualizing mesenchymal lineage cells using in vivo microimaging and immunohistochemistry. Flow cytometric analysis revealed CD140b (PDGFR␤) could be a specific marker for mesenchymal lineage cells. The results may reinforce the urgent need for a more comprehensive view of the mesenchymal stem cell identity and characteristics.

Neutrophil-related proteins were enriched in deciduous teeth GCF and immunoglobulins in permanent teeth GCF. This suggests that neutrophil accumulation plays a protective role in innate immunity against bacterial infection in gingival tissue of deciduous teeth.

The levels of apoB and oxLDL in gingival crevicular fluid change according to the periodontal tissue conditions.

IntroductionPeriodontal disease is a chronic oral infectious disease affecting adults worldwide as well as a lifestyle-related disease related to diabetes. Bisphosphonate is a drug often taken by patients with osteoporosis; however, it reportedly can cause jawbone necrosis. Due to its mechanism of action on bone tissue, bisphosphonate has been used topically on periodontal tissue to treat periodontal disease. However, the long-term systemic effects of bisphosphonates on periodontal tissues are unclear. This paper describes a protocol evaluating the effects of systemic bisphosphonate administration to prevent periodontal tissue destruction in patients with periodontal disease. No systematic review has attempted to summarise the evidence for systemic bisphosphonates in periodontal therapy. The results of the proposed systematic review will inform the practice and design of future clinical trials.Methods and analysisThis paper describes a protocol for a systematic review of the relevant published analytic research using an aggregative thematic approach according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. Two authors will perform a comprehensive search for studies on Medline/PubMed, Scopus, Embase, LILACS and the Cochrane Central Register of Controlled Trials databases. Abstract screening, full-text screening and data extraction will be performed independently by two authors. A meta-analysis will be conducted as appropriate.Ethics and disseminationThe protocol of this systematic review will be provided in a peer-reviewed journal. Formal ethics approval is not necessary because researchers will not identify individuals in the report.PROSPERO registration numberCRD42020212698 (http://www.crd.york.ac.uk/PROSPERO/).