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BackgroundMesenchymal stem cells (MSCs) can regenerate missing tissues and treat diseases. Hence, the current work aimed to compare the proliferation rate and the osteogenic differentiation potential of bone marrow MSCs (BMSCs), gingival MSCs (GMSCs) and submandibular MSCs (SMSCs).Material and MethodsMSCs derived from bone marrow, gingiva and submandibular salivary gland were isolated and cultured from rats. The proliferation capacity was judged by MTT proliferation Assay. Osteogenic differentiation was assessed by Alzarin red stain and quantitative RT-PCR was performed for Runx-2 and MMP-13.ResultsThe highest significant proliferation was estimated in the BMSCs compared to GMSCs and SMSCs (p-value was < 0.01). All studied cell types formed mineralized nodules as stained with Alizarin Red stain at the 3rd passage of differentiation. However, BMSCs seemed to generate the highest level of mineralization compared to GMSCs and SMSCs. RT-PCR revealed that the expression of Runx-2 and MMP-13 mRNAs was significantly increased in the BMSCs compared to GMSCs and SMSCs (p-value was < 0.01).ConclusionsBMSCs displayed maximum osteogenesis results followed by the GMSCs and lastly by the SGSCs. Thus, it could be recommended that GMSCs can be used as a second choice after BMSCs when bone tissue reconstruction is needed. Key words:Mesenchymal stem cells, osteogenic differentiation, Runx-2, MMP-13.

The current review aims to systematically assess the osteogenic capacity of gingiva-derived mesenchymal stem cells (GMSCs) in preclinical studies. A comprehensive electronic search of PubMed, Embase, Web of Science, and Scopus databases, as well as a manual search of relevant references, was performed in June 2020 without date or language restrictions. Eligibility criteria were the following: studies that compared mesenchymal stem cells (MSCs) derived from the gingiva with other MSC sources (in vitro or in vivo) or cell-free scaffold (in vivo) and studies that reported at least one of the following outcomes: osteogenic potential and new bone formation for in vitro and in vivo, respectively. Moreover, the assessment of included studies was conducted using appropriate guidelines. From 646 initial retrieved studies, 35 full-text articles were subjected to further screening and 26 studies were selected (20 in vitro studies and 6 in vivo studies). GMSCs showed great proliferation capacity and expressed recognized mesenchymal stem cell markers, particularly CD90. In vitro, MSC sources including GMSCs were capable of undergoing osteogenic differentiation with less ability in GMSCs, while most in vivo studies confirmed the capacity of GMSCs to regenerate bony defects. Concerning the assessment of methodological quality, in vitro studies met the relevant guideline except in five areas: the sample size calculation, randomization, allocation concealment, implementation, and blinding, and in vivo publications had probably low risk of bias in most domains except in three areas: allocation concealment, attrition, and blinding items.

Background: Extra hepatic adverse effects associated with the therapy of chronic HCV infection with sofosbuvir treatment regimens have recently arisen. Objective: This study aimed to assess the inflammatory effect of sofosbuvir and its influence on cellular proliferation, functionality and differentiation of both submandibular (SMGs) and Von Ebner's salivary glands (EGs). Methodology: 21 adult male albino rats were divided into three equal groups: GroupI (control) received orally distilled water; GroupII received orally sofosbuvir (40 mg/kg/day) dissolved in distilled water for one month and GroupIII received sofosbuvir for 2 months. SMGs and EGs sections were processed for H&E, immunohistochemical (using anti-COX-2 and anti-PCNA antibodies) and immunofluorescence (using anti α-amylase antibody) examination. Results: Compared to control group, groupII displayed atrophic changes in SMGs and EGs which were accentuated in groupIII; shrunken acini, glandular cell vacuolization, nuclear degenerative signs, wide degenerative stromal areas and flattening of excretory ductal lining with stagnant secretion as well as the transformation of few serous glandular cells into mucous-like cells particularly in SMGs of groupIII. Likewise, both glands of groupIІ showed significantly increased immunoreactivity to COX-2 in acini and some ductal cells but with a significant decrease in those of groupIII. Regarding PCNA immunoreactivity and α-amylase immunofluorescence, significantly diminished positivity in the glandular cells of both glands in groupII was detected compared to control group whilst insignificant improvement was elucidated in those of groupIII comparing to groupII except for the significant reactivity to α-amylase in EGs of groupIII. Conclusions: It was concluded that the oxidative stress associated degenerative changes caused by sofosbuvir in salivary glands after one month of administration seemed to be diminished after two months of administration due to the body acquired drug tolerance to restore the disturbed physiological processes. Hence, the use of anti-oxidants as an adjuvant treatment could be beneficial.

Background: Regulation of the plasminogen activation system (PAS) is a vital component in governing proteolytic events within the extracellular matrix (ECM). PAS is believed to play a substantial role in the destruction and healing of periodontal tissues. Thus, the current work aimed to study the histopathological effect of open flap debridement (OFD) on periodontitis, as well as its effect on tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) gene levels in gingival tissues. Methods: A total of 30 subjects were enrolled in the present study. They were divided into two groups: Group I (control group) included 10 periodontally healthy volunteers and group II (periodontitis group) comprised 20 patients suffering from stage III grade B periodontitis. Gingival tissue samples were collected from all periodontitis patients, before and after OFD, and from healthy controls. Hematoxylin and eosin (H&E) stained slides were subsequently examined and gene expression levels of t-PA and PAI-1 were assessed in the gingiva through quantitative reverse transcription polymerase chain reaction (RT-PCR). Results: Gingival tissue samples from periodontitis patients showed widely dilated blood vessels, diffuse hemorrhage, areas of edema, and disorganized collagen fibers together with large amounts of inflammatory cells in between. Following OFD, smaller sized blood vessels, a restored collagen fiber distribution, and an obvious decrease in the inflammatory infiltrate were noted. Gene expression levels of t-PA and PAI-1 were significantly higher in the periodontitis patients compared to the healthy controls. Although their levels showed a significant decrease following OFD in the periodontitis group, they were still significantly higher than the control group. Conclusion: OFD procedures resulted in down regulation of t-PA and PAI-1 expression levels in the gingiva of periodontitis patients, which could signify an important role of these proteins on periodontal disease progression.