MicroRNAs (miRNAs) are small non-coding RNAs that contain 22 to 25 nucleotides and play important roles in post-transcriptional regulation of target genes. MiRNAs are involved in cell proliferation, differentiation, apoptosis, inflammation, and cancer development. Alveolar bone resorption is the main clinical manifestation of periodontitis. Osteoclasts are unique cells regulated by osteoblasts and inflammatory cytokines and are responsible for bone resorption in periodontitis. Recently, miRNAs have emerged as an important regulator of osteoclast differentiation and function. In this study, we review the recent research progress on the effects of miRNAs on osteoclast differentiation and function, particularly the mechanisms of miRNAs-mediated osteoclast formation and bone loss in periodontitis.
Bone Resorption ; Bone and Bones ; Cell Differentiation ; Cell Proliferation ; Humans ; MicroRNAs ; Osteoblasts ; Osteoclasts

Ferroptosis is an iron-dependent form of regulated cell death,which is distinct from apoptosis,ne-crosis,and pyroptosis.Recent studies have found that activators of ferroptosis,such as Erastin,can activate autophagy-re-lated proteins,induce the formation of autophagosomes,and ultimately release ferric ions to mediate ferroptosis.This pro-cess,called ferritinophagy,is initiated by the binding of an autophagic cargo receptor protein,nuclear receptor coactivator 4(NCOA4),to iron-laden ferritin.The transfer of NCOA4-ferritin to the lysosome by ferritinophagy results in the proteoly-sis of ferritin,and,in turn,the release of its iron content and lipid-reactive oxygen species(ROS)accumulation.Ferritin-ophagy has been closely associated with central nervous system disorders,circulatory system diseases,and cancer.Fur-thermore,the regulation mechanism of ferritinophagy is also a hot topic in the study of iron-dependent cell death process.With the in-depth study of ferritinophagy,great progress has been made in the study of key components of ferritinophagy as well as its molecular mechanisms and processes.However,a comprehensive summary of the methods for detecting ferritin-ophagy is still unclear.To further deepen the understanding of ferritinophagy and its detection methods,this review focus-es on the concept,characteristics,methods,and precautions during detection of ferritinophagy.This review provided ex-perimental reference for subsequent researchers and promoting the progress of research related to ferritinophagy.

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.