Background: Focal adhesions (FAs) is the most important process in the first step of osseointegration between preosteoblasts andtitanium (Ti). FAs improvement and pre-osteoblasts cell proliferation leads to successful Ti-based dental implants. This study aimed to confirm the applicability of rosmarinic acid (RA) as a functional substance for improving FAs and cell proliferation of MC3T3-E1 preosteoblasts on Ti surfaces during the first stage of osseointegration for successful Ti-based dental implants. Methods: We used MC3T3-E1 preosteoblasts on Ti discs incubated in a medium supplemented with or without 14 µg/ml to decipher the effects of RA on FAs and cell proliferation. FAs and proliferation of MC3T3-E1 cells on Ti discs were assessed via MTT assay.Actin-labeled cells and paxillin contacts were observed and imaged by fluorescent microscopy, and the associated signaling pathways were revealed through western blot analysis. Results: In RA-treated MC3T3-E1 cells on Ti discs, FAs between MC3T3-E1 preosteoblasts and Ti surfaces and the expression offocal adhesion kinase (FAK), phosphorylated FAK and paxillin proteins and filamentous-actin formation increased. RA increased the proliferation of MC3T3-E1 preosteoblasts on the Ti surface as well as the expression of Grab2, Ras, pERK1/2, and ERK1/2. In addition, the expression of secretory leukocyte protease inhibitor and thymosin b4, known as nanomolecules that enhance the interaction between implanted Ti materials and preosteoblasts in the RA-treated MC3T3-E1 preosteoblasts, increased. RA not only increased the FAs of MC3T3-E1 preosteoblasts on the Ti surface through the FAK/Paxillin signaling pathway, but also increased cell proliferation and mitosis through the FAK/Grab2/Ras/ERK1/2 signaling pathway. Conclusion RA can be applied as an effective functional substrate to improve the FAs and proliferation of MC3T3-E1 preosteoblatson Ti surfaces, which are essential in the first step of osseointegration between implanted Ti and bone tissue for the clinical success of Ti based dental implants.

Despite the widespread impact of the severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019, COVID-19) and vaccination in South Korea, our understanding of kidney diseases following these events remains limited. We aimed to address this gap by investigating the characteristics of glomerular diseases following the COVID-19 infection and vaccination in South Korea. Methods: Data from multiple centers were used to identify de novo glomerulonephritis (GN) cases with suspected onset following COVID-19 infection or vaccination. Retrospective surveys were used to determine the COVID-19–related histories of patients who were initially not implicated. Bayesian structural time series and autoregressive integrated moving average models were used to determine causality. Results: Glomerular diseases occurred shortly after the infection or vaccination. The most prevalent postinfection GN was podocytopathy (42.9%), comprising primary focal segmental glomerulosclerosis and minimal change disease, whereas postvaccination GN mainly included immunoglobulin A nephropathy (IgAN; 57.9%) and Henoch-Schönlein purpura nephritis (HSP; 15.8%). No patient progressed to end-stage kidney disease. Among the patients who were initially not implicated, nine patients with IgAN/HSP were recently vaccinated against COVID-19. The proportion of glomerular diseases changed during the pandemic in South Korea, with an increase in acute interstitial nephritis and a decrease in pauci-immune crescentic GN. Conclusion: This study showed the characteristics of GNs following COVID-19 infection or vaccination in South Korea. Understanding these associations is crucial for developing effective patient management and vaccination strategies. Further investigation is required to fully comprehend COVID-19’s impact on GN.

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been acknowledged as an effective mean of preventing infection and hospitalization.However, the emergence of highly transmissible SARS-CoV-2 variants of concern (VOCs) has led to substantial increase in infections among children and adolescents. Vaccineinduced immunity and longevity have not been well defined in this population. Therefore, we aimed to analyze humoral and cellular immune responses against ancestral and SARSCoV-2 variants after two shots of the BNT162b2 vaccine in healthy adolescents. Although vaccination induced a robust increase of spike-specific binding Abs and neutralizing Abs against the ancestral and SARS-CoV-2 variants, the neutralizing activity against the Omicron variant was significantly low. On the contrary, vaccine-induced memory CD4+ T cells exhibited substantial responses against both ancestral and Omicron spike proteins.Notably, CD4+ T cell responses against both ancestral and Omicron strains were preserved at 3 months after two shots of the BNT162b2 vaccine without waning. Polyfunctionality of vaccine-induced memory T cells was also preserved in response to Omicron spike protein.The present findings characterize the protective immunity of vaccination for adolescents in the era of continuous emergence of variants/subvariants.

Background: Secretory leukocyte protease inhibitor (SLPI) protects tissues from proteases and promotes cell proliferation andhealing. SLPI also reduces periodontal inflammation and alveolar bone resorption by inhibiting proinflammatory cytokine expression in rat periodontal tissues and osteoblasts. However, little is known of the role of SLPI in the expression of osteoclast regulatory factors from osteoblasts, which are crucial for the interaction between osteoblasts and osteoclasts. Therefore, we aimed to determine the effects of SLPI on the regulation of osteoclasts and osteoblasts in LPS-treated alveolar bone and osteoblasts. Methods: Periodontitis was induced in rats using LPS. After each LPS injection, SLPI was injected into the same area. Immu-nohistochemical analysis was performed with antibodies against SLPI, RANKL, OPG, and Runx2 in the periodontal tissue. RT-PCR and western blotting were performed to determine the expression levels of SLPI, RANKL, OPG, and Runx2 in LPS- and SLPI/LPS-treated MC3T3-E1 cells. SLPI/LPS-treated MC3T3-E1 cells were also stained with Alizarin Red S. Results: Immunohistochemical analysis showed that the expression levels of SLPI, OPG, and Runx2 were higher while that of RANKLwas lower in the LPS/SLPI group relative to those in the LPS group. The mRNA and protein expression of SLPI, OPG, and Runx2 was higher in SLPI/LPS/MC3T3-E1 cells than in LPS/MC3T3-E1 cells, and RANKL expression was lower. During differentiation, OPG and Runx2 protein levels were higher whereas RANKL levels were lower in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 cells on days 0, 4, 7, and 10. In addition, mineralization and matrix deposition were higher in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 on days 7 and 10. SLPI decreased RANKL expression in LPS-treated alveolar bone and osteoblasts but increased the expression of OPG and Runx2. Conclusion SLPI can be considered as a regulatory molecule that indirectly regulates osteoclast activation via osteoblasts andpromotes osteoblast differentiation.