Effect of lentiviral silencing of Piezo1 on osteogenic differentiation and TAZ expression in human bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Piezo1,a mechanosensitive protein,is tightly connected to osteogenic differentiation,and it has been demonstrated that TAZ has a role in regulating osteogenic differentiation.It is unclear whether TAZ participates in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells by Piezo1,so it is crucial to investigate its unique mechanism to prevent osteonecrosis of the femoral head. OBJECTIVE:To elucidate what function Piezo1 plays in osteogenic differentiation and TAZ expression in human bone marrow mesenchymal stem cells. METHODS:The siRNA targeting Piezo1 was constructed and transfected into 293T cells.The silencing efficiency was detected by RT-qPCR.The selected Piezo1-Home-2337 was packaged according to the silencing efficiency,and its optimal multiplicity of infection value was assayed by immunofluorescence staining.The packaged Piezo1 silencing recombinant lentivirus was transfected into human bone marrow mesenchymal stem cells,and its silencing effect was detected by RT-qPCR and western blot assay.Alizarin red staining,alkaline phosphatase activity analysis,immunofluorescence staining,RT-qPCR and western blot assay were utilized to analyze the effect of silencing Piezo1 on the osteogenic differentiation of human bone marrow mesenchymal stem cells. RESULTS AND CONCLUSION:(1)The mRNA and protein levels of Piezo1 in human bone marrow mesenchymal stem cells transfected by si-Piezo1 were decreased significantly,with a statistically significant difference compared with normal and negative control groups.(2)The alkaline phosphatase activity in the si-Piezo1 group was much lower and the calcium deposition in the si-Piezo1 group was significantly reduced compared with the negative control group.(3)The mRNA levels of osteogenesis-related genes including Runt-related transcription factor 2(Runx2),osteopontin(OPN),distal-less homeobox 5(DLX5),osteocalcin,β-catenin and Tafazzin(TAZ)in the si-Piezo1 group were significantly decreased compared with the negative control group.Afterward,the expression levels of TAZ and β-catenin protein in the si-Piezo1 group were down-regulated significantly compared with the negative control group,whereas the expression levels of p-TAZ and p-β-catenin protein in the si-Piezo1 group had the opposite condition.(4)The results of immunofluorescence staining showed that the expression of TAZ and β-catenin in human bone marrow mesenchymal stem cells in the si-Piezo1 group was less compared with the negative control group.(5)These findings indicate that Piezo1 can promote the osteogenic differentiation of human bone marrow mesenchymal stem cells.The osteogenic ability of human bone marrow mesenchymal stem cells is significantly reduced after silencing Piezo1,and the expression of TAZ is also reduced.

Research Progress on the Novel Mechanosensitive Ion Channel Piezo1 in Cardiac Fibrosis / 医用生物力学

During the occurrence and development of various heart diseases,continuous deterioration of myocardial fibrosis leads to remodeling and dysfunction of the cardiac structure.As a newly discovered mechanically sensitive ion channel,Piezo1 has opened up a new field of research on cellular mechanical transduction.Piezo1 combines a fine force transducer with Ca2+ influx and participates in the regulation of cellular mechanical transduction,thereby regulating cellular biological functions.Recent studies have shown that the biomechanical changes induced by myocardial injury regulate the expression of Piezo1 in cardiomyocytes and cause an imbalance in calcium homeostasis,which plays an important role in the positive feedback loop of myocardial fibrosis.This review summarizes the theoretical basis and related studies of Piezo1 in regulating cardiac fibrosis and suggests that the Piezo1 channel may become a new target for the treatment of cardiac fibrosis,thereby providing a new research horizon for the prevention and treatment of cardiac fibrosis.

Mechanism of Piezo1 channel activation promoting increase in intracellu-lar calcium concentration of rat coronary smooth muscle cells / 中国病理生理杂志

AIM:To investigate the mechanism of Piezo1 channel activation promoting the increase in intra-cellular Ca2+ concentration([Ca2+]i)of rat coronary artery smooth muscle cells(CASMCs).METHODS:The primary CASMCs of SD rats were cultured,and the expression and subcellular localization of Piezo1 in the cells were observed by immunofluorescence staining.The Piezo1 and stromal interaction molecule 1(STIM1)in CASMCs were knocked down by siRNA transfection,and the expression levels of the proteins were detected by Western blot.Utilizing laser confocal mi-croscopy,the change of[Ca2+]i in CASMCs was detected by Fluo-4 AM fluorescent probes.RESULTS:It was confirmed by immunofluorescence staining that the expression of Piezo1 existed in primary rat CASMCs.Immunofluorescence staining also showed that Piezo1 was co-located with sarco-/endoplasmic reticulum Ca2+-ATPase 2(SERCA2),mitochondrial outer membrane protein TOM20 and nuclear membrane protein lamin B1.Western blot results showed that the protein expres-sion levels of STIM1 and Piezo1 were significantly down-regulated by siRNA transfection(P<0.05).Compared with con-trol group,Yoda1,the agonist of Piezo1,could increase the extracellular Ca2+ influx of CASMCs(P<0.01).However,the Ca2+ influx mediated by Yoda1 was not affected by the inhibition of L-type calcium channels.Treatment with Yoda1 in-creased the intracellular Ca2+ release of CASMCs(P<0.01).However,inhibition of calcium channels on endoplasmic re-ticulum,ryanodine receptor and inositol 1,4,5-triphosphate receptor,did not affect intracellular Ca2+ release mediated by Yoda1.After the Ca2+ in endoplasmic reticulum was emptied using thapsigargin(TG),Yoda1 also mediated the Ca2+ re-lease of other organelles in CASMCs(P<0.01).After inhibition of L-type calcium channels,treatment with store-operated calcium channel(SOCC)inhibitor BTP2 or knockdown of STIM1 led to the decrease in extracellular Ca2+ influx of CASMCs mediated by Yoda1(P<0.01).Treatment with TG increased the release of Ca2+ from the endoplasmic reticulum of CASMCs after knockdown of Piezo1(P<0.05),but the extracellular Ca2+ influx mediated by TG was not affected.After inhibition of L-type calcium channels and SOCC,knockdown of Piezo1 led to the decreases in intracellular Ca2+ release and extracellular Ca2+ influx induced by Yoda1(P<0.01).CONCLUSION:The Piezo1 agonist orchestrates the influx of extracellular Ca2+ by activating Piezo1 channels on the cell membrane and inducing the indirect activation of SOCC.More-over,it facilitates the release of Ca2+ from organelles.Consequently,these pathways synergistically elevate the[Ca2+]i of rat CASMCs.

PIEZO1 Channel is Involved in Electric Field Guided Cell Migration / 生物化学与生物物理进展

ObjectiveDisruption of epithelial layer may instantaneously induce the generation of endogenous electric fields, which was proved to play an important role in guiding the cell migration and promoting wound healing. PIEZO1 is a kind of mechanic sensitive channel, may be regulated by voltage, is proved to involve in chemotactic migration of cells and play an important role in the process of wound healing. In this paper, the role of PIEZO1 and its downstream proteins FAK and integrin β1 in the electric field guided cell migration were investigated by HaCaT cells (human immortalized keratinocyte). MethodsCell migration was tracked by Living Cell Imaging System in directed current (DC) electric field (EF). Inhibitors and RNAi techniques were applied to study the function of PIEZO1 and other related proteins in electric fields. Western blot was used to detect the expression and phosphorylation levels of integrin β1 and FAK in electric field guided migration under EF stimulation. ResultsPiezo1 RNAi as well as Ruthenium red and GsMTx4 treatment all significantly inhibited the electrotaxis of HaCaT cells. Electric field stimulation with GsMTx4 treatment alone increased FAK phosphorylation level and the expression of integrin β1. Electric field promoted the expression level of integrin β1 and the phosphorylation level of FAK. Inhibiting the expression of PIEZO1 by RNAi significantly attenuated the phosphorylation level of FAK under EF stimulation. Inhibition of integrin β1 and FAK by inhibitor significantly decrease the electric field guided cell migration. ConclusionPIEZO1 as well as integrin β1 and FAK are involved in the electric field guided cell migration of HaCaT cells. Electric field signals regulate the expression of integrin β1 and the activation of FAK through PIEZO1-mediated signal pathway to orchestrate cell migration.

Differential Analysis of Erythrocyte Flexibility of PbK173 Artemisinin-sensitive Strains / 中国实验方剂学杂志

ObjectiveTo detect the flexibility differences of Plasmodium berghei K173 （PbK173）-infected red blood cells with varying degrees of sensitivity to artemisinin-based drugs and to preliminarily explore the underlying mechanisms of the differences. MethodA total of 102 specific-pathogen-free （SPF） male C57BL/6 mice were randomly divided into three groups， with 30 mice each in the control group and PbK173-resistant （PbK173-R） group， and 42 mice in the PbK173-sensitive （PbK173-S） group. Except for the control group， the rest groups were vaccinated with 1×107 PbK173-S/PbK173-R infected red blood cells to establish a mouse malaria model. During the administration and recovery periods （control group， PbK173-R/PbK173-S）， dihydroartemisinin （DHA， 40 mg·kg-1） and malaridine （MD， 6 mg·kg-1） were administered continuously for four days. Peripheral blood was taken from the PbK173-S/PbK173-R groups with an infection rate equal to or greater than 20%. Peripheral blood and each organ were taken on the first day at the end of administration （dosing period） and on the fifth day at the end of administration （recovery period）， and blood parameters and organ indices of each group were examined. The osmotic fragility of peripheral blood red blood cells in each group was detected using the red blood cell osmotic fragility test. Western blot was applied to determine the levels of Piezo1 and Band3 proteins in the red blood cell membrane. ResultDuring the administration and recovery periods， there were no significant differences between the PbK173-S MD group and the DHA group. During the administration period， there were no significant differences in hematological parameters between PbK173-S and PbK173-R in the MD group. However， during the recovery period， the red blood cell count， hemoglobin concentration and hematocrit of the PbK173-R group were significantly higher than those of the PbK173-S group （P<0.05） in the MD group. Compared with that of the control group， the osmotic fragility of the PbK173-S/PbK173-R groups was significantly enhanced （P<0.01）， and the osmotic fragility of the PbK173-S group was significantly stronger than that of the PbK173-R group （P<0.01）. The osmotic fragility of red blood cells in the PbK173-S group during the administration period was significantly stronger than that in the control group and PbK173-R group during the administration period （P<0.01）. The osmotic fragility of red blood cells in the PbK173-R group during the recovery period was significantly higher than that in the control group during the administration period and the PbK173-S group during the recovery period （P<0.05）. Compared with those in the control group， the Piezo1 protein and Band3 protein in the red blood cell membrane of the PbK173-S group were significantly reduced （P<0.01）. Compared with those in the PbK173-R group， the Piezo1 protein and Band 3 protein in the red blood cell membrane of the PbK173-S group were significantly reduced. ConclusionThe flexibility of PbK173-infected red blood cells with different sensitivities to artemisinins differed. Plasmodium-infected red blood cells significantly reduced the levels of Piezo1 and Band3 proteins in the red blood cell membrane， and the erythrocyte flexibility exhibited a decreasing trend in the following order： normal group， PbK173-R group， and PbK173-S group.

Biomechanopharmacology of Chinese Medicine Based on Mechano-ion Channel Piezo1： A Review / 中国实验方剂学杂志

Ischemic stroke is one of the leading causes of death and disability worldwide. In Han dynasty， HUA Tuo proposed the original preventive medicine idea that "with good blood circulation， the disease cannot be born"， which opened a broad space for the cross-research of blood-related mechanical factors and pharmacology. In the pathogenesis of ischemic stroke， mechanical factors comprehensively affect the function and crosstalk of platelets and endothelial cells. In recent years， as the well-known effects on thrombosis and stroke， more attention has been paid to hemodynamic factors as the participants involved in pathological mechanisms and potential therapeutic targets of ischemic stroke. The mechanical force ion channel Piezo1 widely exists on the surface of many types of cells. Besides being regulated by chemical and endogenous substances， Piezo1 responds to different mechanical conditions， regulates the opening and closing of channels， and activates different downstream signaling pathways. Piezo1 is now regarded as an important connection between mechanical and biochemical signals. A variety of Chinese medicine can affect the activity of Piezo1 protein， which may prevent and treat thrombotic diseases such as ischemic stroke through Piezo1 protein. In this paper， the effects of Piezo1 protein on the physiological and pathological functions of endothelial cells and platelet under different mechanical conditions and the role of Piezo1 in the process of thrombosis were reviewed， as well as the effects of Chinese medicine， chemical medicine， and endogenous substances targeting Piezo1 channel. These could provide new ideas for further exploring the mechanisms of Chinese medicines in activating blood circulation， developing new drugs， and deepening biomechanical-pharmacology research.

The expression and significance of Piezo1 in chronic rhinosinusitis with nasal polyps / 临床耳鼻咽喉头颈外科杂志

Objective:To explore the expression and importance of Piezo1, E-cadherin, and Vimentin in nasal polyps patients. Methods:Thirty-five patients undergoing endoscopic sinus surgery under general anesthesia were streamed into 20 cases of nasal polyps（NP group） and 15 cases of simple septoplasty without any sinus disease（Control group）. Immunofluorescence staining and Western Blot were applied to detect the protein level of Piezo1, E-cadherin, and Vimentin in NP tissues and nasal polyp-derived primary human nasal epithelial cells（pHNECs）. Also, BEAS-2B cell lines were treated with human TGF-β1 protein to establish epithelial mesenchymal transition（EMT） model in vitro and quantitative real-time polymerase chain reaction were used to calculate Piezo1 and above biomarkers in the model. Results:Compared with control group, Piezo1 and Vimentin showed higher level while E-cadherin was lower in NP tissues and pHNECs.In EMT model in vitro, Piezo1 and Vimentin were demonstrated higher expression with decreased level of E-cadherin. Conclusion:The tendency of Piezo1 is consistent with the mesenchymal-related biomarker Vimentin, going against with epithelial-related biomarker E-cadherin, implying its involvement with EMT process in nasal polyps.

Potentiation of PIEZO2 mechanically-activated currents in sensory neurons mediates vincristine-induced mechanical hypersensitivity

Vincristine, a widely used chemotherapeutic agent for treating different cancer, often induces severe peripheral neuropathic pain. A common symptom of vincristine-induced peripheral neuropathic pain is mechanical allodynia and hyperalgesia. However, mechanisms underlying vincristine-induced mechanical allodynia and hyperalgesia are not well understood. In the present study, we show with behavioral assessment in rats that vincristine induces mechanical allodynia and hyperalgesia in a PIEZO2 channel-dependent manner since gene knockdown or pharmacological inhibition of PIEZO2 channels alleviates vincristine-induced mechanical hypersensitivity. Electrophysiological results show that vincristine potentiates PIEZO2 rapidly adapting (RA) mechanically-activated (MA) currents in rat dorsal root ganglion (DRG) neurons. We have found that vincristine-induced potentiation of PIEZO2 MA currents is due to the enhancement of static plasma membrane tension (SPMT) of these cells following vincristine treatment. Reducing SPMT of DRG neurons by cytochalasin D (CD), a disruptor of the actin filament, abolishes vincristine-induced potentiation of PIEZO2 MA currents, and suppresses vincristine-induced mechanical hypersensitivity in rats. Collectively, enhancing SPMT and subsequently potentiating PIEZO2 MA currents in primary afferent neurons may be an underlying mechanism responsible for vincristine-induced mechanical allodynia and hyperalgesia in rats. Targeting to inhibit PIEZO2 channels may be an effective analgesic method to attenuate vincristine-induced mechanical hypersensitivity.

Mechanosensitive ion channel Piezo1 induces senescence of atrial fibroblasts by activating β-catenin / 中国药理学通报

Aim To observe whether the mechanosensitive ion channel Piezo1 was involved in the senescence of atrial fibroblasts by activating β-catenin based on our previous study which found marked increase of Piezo1 mRNA in senescent atrial fibroblasts. Methods Primary mouse atrial fibroblasts (MAFs) were isolated from male C57BL/6 mice (3-4 weeks) by enzyme digestion, and tert-butyl hydroperoxide (TBHP) was used to induce the senescence of cells. The ratio of senescent cells was detected by senescence-associated β-galactosidase (SA-β-Gal) staining. The protein levels of Piezo1, β-catenin/p-β-catenin, senescence-associated proteins p53 and p21 in the cells treated with TBHP (100 μmol · L

Apport de la piézochirurgie et l'ostéotomie dans la surélévation sinusienne par voie crestale / Contribution of piezosurgery and osteotomy in crestal sinus lift

Dans la région postérieure maxillaire, après extractions dentaires, les crêtes subissent une résorption osseuse continue. Dans cette région s'ajoute un obstacle anatomique formé par le sinus maxillaire qui nécessite des conduites particulières avant et au moment de la pose d'implants. Parmi les techniques d'augmentation de volume osseux, la voie d'abord crestale

In the maxillary posterior region, after dental extractions, the ridges undergo continuous bone resorption. In this region, there is also an anatomical obstacle formed by the maxillary sinus, which requires special management before and at the time of implant placement. Techniques for bone augmentation include the crestal approach with osteotomes and piezo surgery

Prestin-Mediated Frequency Selectivity Does not Cover Ultrahigh Frequencies in Mice / 神经科学通报·英文版

In mammals, the piezoelectric protein, Prestin, endows the outer hair cells (OHCs) with electromotility (eM), which confers the capacity to change cellular length in response to alterations in membrane potential. Together with basilar membrane resonance and possible stereociliary motility, Prestin-based OHC eM lays the foundation for enhancing cochlear sensitivity and frequency selectivity. However, it remains debatable whether Prestin contributes to ultrahigh-frequency hearing due to the intrinsic nature of the cell's low-pass features. The low-pass property of mouse OHC eM is based on the finding that eM magnitude dissipates within the frequency bandwidth of human speech. In this study, we examined the role of Prestin in sensing broad-range frequencies (4-80 kHz) in mice that use ultrasonic hearing and vocalization (to >100 kHz) for social communication. The audiometric measurements in mice showed that ablation of Prestin did not abolish hearing at frequencies >40 kHz. Acoustic associative behavior tests confirmed that Prestin-knockout mice can learn ultrahigh-frequency sound-coupled tasks, similar to control mice. Ex vivo cochlear Ca2+ imaging experiments demonstrated that without Prestin, the OHCs still exhibit ultrahigh-frequency transduction, which in contrast, can be abolished by a universal cation channel blocker, Gadolinium. In vivo salicylate treatment disrupts hearing at frequencies <40 kHz but not ultrahigh-frequency hearing. By pharmacogenetic manipulation, we showed that specific ablation of the OHCs largely abolished hearing at frequencies >40 kHz. These findings demonstrate that cochlear OHCs are the target cells that support ultrahigh-frequency transduction, which does not require Prestin.

Progress of diagnosis and treatment of PIEZO2-related diseases / 国际儿科学杂志

As a basic mechanism of cell function, mechanical transduction plays a key role in human growth and development, physiological and pathological processes.And its molecular mechanism has always been a research hotspot.In recent years, Piezo2 has been identified as a mechanically sensitive cationic channel, which serves as an important component of mechanical transduction participating in regulating and maintaining of respiratory rhythm, bowel movement, cartilage stress, tactile sense and multiple other physiological processes.PIEZO2-related diseases have been reported in recent years before which are characterized by distal joint contracture, scoliosis, low muscular tension, and delayed motor development.In this review, we summarizes the clinical phenotype and progress in diagnosis and possible treatment of PIEZO2-related diseases, hoping to improve the recognition of this disease which is essential for long-term management of patients, and provide ideas for the gene research and development of drug targets.

Clinical study on the expression of Piezo1 in small intestinal mucosa of 57 patients with Crohn′s disease / 中华消化杂志

Objective:To investigate the expression of Piezo1 in small intestinal mucosal epithelial cells of patients with Crohn′s disease (CD) and its clinical correlation with CD.Methods:From January 1st 2010 to November 30th 2020, the clinical data including age, gender, disease location and biological behavior, etc of 57 patients with CD (CD group) who underwent surgery at The First Affiliated Hospital of Anhui Medical University were retrospectively. And at same time the normal samll intestinal epithelial tissues of 10 healthy individuals who underwent colonoscopy were collected as the healthy control group. The expression of Piezo1 in small intestinal epithelial cells of CD patients with different disease sites, biological behavior and disease activity were detected by immunofluorescence staining and hematoxylin-eosin staining. The histological score system and intestinal fibrosis score were used to analyze the inflammation and fibrosis of the intestinal tissues of patients with CD. Semi-quantitative analysis of Piezo1 in small intestinal epithelial cells was analyzed by ImageJ software. And the correlation between Piezo1 expression and clinical characteristics and pathological features of small intestine was also analyzed. Independent sample t test and analysis of variance were used for statistical analysis. Results:In CD group, there were 37 males (64.9%) and 20 females (35.1%). The age was (39.1±14.2) years old, ranged from 18 to 71 years old, and the average duration of the disease was (26.5±24.1) months. There were 29 cases (50.9%)of ileal type, 26 cases (45.6%) of ileocolonin type and 2 cases (3.5%) of colonic type. There were 12 cases (21.1%) of non-penetrating non-stenotic type, 31 cases (54.4%) of stenotic type and 14 cases (24.6%) of penetrating type. There were 47 cases (82.5%) with moderate activity and 10 cases (17.5%) with severe activity. There were 17 cases (29.8%) of moderate intestinal inflammation, 40 cases (70.2%) of severe intestinal inflammation. The score of intestinal fibrosis in six cases (10.5%) was 1, 28 cases (49.1%) was 2, 18 cases (31.6%) was 3, five cases was 4. The relative expression level of Piezo1 in intestinal mucosal epithelial cells of CD group was higher than that of healthy control group (12.9±4.6 vs. 8.5±1.1), the relative expression of Piezo1 in intestinal mucosal epithelia cells of stenotic type and penetrating type CD patients were both higher than that of non-penetrating and non-stenotic CD patients (12.6±3.8 and 9.8±2.4 vs. 6.0±1.3), and the differences were all statistically significant ( t=3.00, -3.66 and -3.32, all P<0.01). The relative expression of Piezo1 in small intestinal epithelial cells of CD patients with severe intestinal inflammation was higher than that of CD patients with moderate intestinal inflammation (13.1±4.0 vs. 9.7±3.1), and the difference was statistically significant ( t=-2.65, P<0.05). The relative expression levels of Piezo1 in small intestinal epithelial cells of patients with intestinal fibrosis score of 4, 3, 2 and 1 were 17.6±5.2, 12.6±1.7, 9.1±2.1 and 5.8±1.1, respectively; the relative expression levels of Piezo1 in intestinal epithelial cells of patients scored 4 were higher than that of patients scored 3, 2 and 1, and that of patients scored 3 was higher than patients scored 2 and 1, and that of patients scored 2 was higher than that of patients scored 1, and the differences were all statistically significant ( t=-2.98, -5.10, -3.84, 4.60, 6.55 and 2.56, all P<0.05). The relative expression of Piezo1 in intestinal mucosal epithelial cells was related to the severity of intestinal inflammation and fibrosis. The more severe the intestinal inflammation and fibrosis, the higher the relative expression of Piezo1 in intestinal mucosal epithelial cells. Conclusions:The relative expression of Piezo1 in small intestinal epithelial cells is related to the biological behavior and the severity of intestinal inflammation and fibrosis of CD. It is speculated that the expression of Piezo1 in small intestinal epithelial cells may be clinically related to the process of intestinal wall fibrosis in CD to some extent, however whether it plays an important role in the process of intestinal wall fibrosis in CD and its specific mechanism need to be further studied.

Mechanisms of the mechanically activated ion channel Piezo1 protein in mediating osteogenic differentiation of periodontal ligament stem cells via the Notch signaling pathway / 华西口腔医学杂志

OBJECTIVE@#To explore the mechanism of Piezo1 protein in mediating the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) via the Notch signaling pathway.@*METHODS@#In this study, young permanent teeth extracted from impacted teeth of 8-14-year-
old children from January 1, 2016 to January 1, 2018 in the Department of Orthodontic, Beijing Children's Hospital were selected as cell sources. hPDLSCs were extracted by enzymatic digestion. Immunohistochemical staining was used to detect the expression of keratin and vimentin, and flow cytometry was used to identify the markers (CD146 and STRO-1) of hPDLSCs. The construction and screening of Piezo1 siRNA gene interference vector and Piezo1 gene overexpression plasmid were completed. Flexcell 4000T mechanical distraction stress instrument was used to construct hPDLSC cell model in vitro. According to the preliminary results, the experiment was divided into five groups: siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group. Real time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of Piezo1, Notch1, alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and bone sialoprotein (BSP). Western blot was used to detect the expression of ALP and Runx2. Fluo-3 AM probe was used to detect intracellular calcium content.@*RESULTS@#Vimentin staining of hPDLSCs was positive, and keratin staining was negative. Flow cytometry was used to detect the expression of STRO-1 and CD146, markers of hPDLSC. Empty viral vectors, siRNA-Piezo1 interference sequence, and Piezo1 overexpression vector sequence could be transfected into hPDLSC by lentivirus, and the transfection efficiency was high (approximately 90%). The reverse transcription-polymerase chain reaction (RT-PCR) results showed that there were significant differences in Piezo1 gene levels among the siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group (F=9.573, P<0.05). The level of Piezo1 in the overexpression group was significantly higher than that in the siRNA interference group (q=3.893, P<0.05). The level of Piezo1 in the stretch stress group was significantly higher than that in the blank control group (q=2.006, P<0.05). The expression of Notch1 and osteogenic genes ALP, Runx2, OCN, and BSP had the same trend. Western blot results showed that there were significant differences in the expression of ALP in the siRNA interference group, overexpression group, blank control group, stretch stress group, and negative control group (F=11.207, P<0.001). The expression level of ALP in the overexpression group was significantly higher than that in the siRNA interference group (q=2.991, P<0.05). The expression of ALP in the stretch stress group was significantly higher than that in the blank control group (q=3.007, P<0.05). The expression of Runx2 protein showed the same trend. The intracellular calcium fluorescence intensity of the overexpression group was significantly higher than that of the siRNA interference group, and the intracellular calcium fluorescence intensity of the stretch stress group was significantly higher than that of the siRNA interference group.@*CONCLUSIONS@#Mechanical stretch stress can promote the expression of Piezo1 protein. Ca2+ is the second messenger, activates the Notch1 signaling pathway and the expression of ALP, Runx2, OCN, and BSP; and promotes the osteogenic differentiation of hPDLSC. The siRNA-Piezo1 interfering plasmid can block this process. On the contrary, the overexpression plasmid of Piezo1 can promote the osteogenic differentiation of PDLSCs.

Research advances of mechanically sensitive ion channel Piezo1 in cardiovascular diseases / 中国临床药理学与治疗学

Mechanically sensitive ion channels play an important role in the cells' perception of external pressure and the growth of tissues and organs, and participate in the regulation of various cell functions. Among them, Piezo1 is a non-selective mechanically sensitive ion channel, which mainly exists in endothelial cells and vascular smooth muscle cells. The regulation of vascular function affects the progression of cardiovascular diseases such as atherosclerosis and hypertension. This article mainly reviews the role of Piezo1 in cardiovascular diseases, and provides new directions for the clinical intervention research of cardiovascular diseases.

Progress in Research on Mechanosensitive Ion Channel Piezo1/2 in Digestive System Diseases / 胃肠病学

Piezo proteins, including Piezo1, Piezo2, are non-selective mechanosensitive ion channels. They have similar biophysical characteristics, which can transform mechanical signals into biological electric signals. Studies have shown that Piezo proteins play important roles in mechanical-relevant physiological functions and pathophysiological changes of a variety of organs, including gastrointestinal tract. This article reviewed the relationship between Piezo1/2 proteins and digestive system diseases, and discussed the roles of Piezo1/2 under mechanical stress in the development of digestive system diseases, so as to provide a novel target in the study of pathogenesis and treatment of relevant digestive system diseases.

Xerocitosis hereditaria. Presentación de dos casos clínicos pediátricos / Hereditary xerocytosis. Presentation of two pediatric cases

La xerocitosis hereditaria es un desorden poco frecuente causado por defectos en la permeabilidad eritrocitaria, que se caracteriza por anemia hemolítica de gravedad variable y sobrecarga de hierro. El diagnóstico suele ser tardío y confundirse con otras anemias hemolíticas, lo que puede llevar a indicaciones de procedimientos, como la esplenectomía, contraindicados en estos pacientes. Se reportan las características clínicas, hematológicas y moleculares de dos pacientes pediátricos no relacionados con diagnóstico de xerocitosis hereditaria. Ambos presentaban eritrocitos deshidratados con alta concentración de hemoglobina corpuscular media, frotis no patognomónico, marcadores de hemólisis y una curva de fragilidad osmótica resistente. El diagnóstico se confirmó por la secuenciación del gen PIEZO.Se resalta la importancia de reconocer la causa de la anemia hemolítica para dar un enfoque terapéutico preciso y dar adecuado consejo genético

Hereditary xerocytosis is a rare disorder caused by defects of red blood cell permeability that are characterized by hemolytic anemia of variable degree and iron overload. Diagnosis is usually late and confused with other hemolytic anemias, which can lead to procedural indications, such as splenectomy, contraindicated in these patients. We report the clinical, haematological, and molecular characteristics of two patients from two unrelated families affected by hereditary xerocytosis. Both patients had dehydrated erythrocytes with a high concentration of mean corpuscular hemoglobin, non-pathognomonic smears, markers of hemolysis and a resistant osmotic fragility curve. The diagnosis was confirmed by the sequencing of the PIEZO gene. We emphasize the importance of recognizing the cause of hemolytic anemia to give an accurate therapeutic approach and give adequate genetic counseling.

Evaluation of surface integrity of root end cavities prepared using conventional and piezoelectric devices: A scanning electron microscopy study

Introduction: An array of factors control the success of endodontic surgery. One of them is the technique used to prepare the root end cavities which is conventionally being done with burs. In past decades, ultrasonic instruments have been introduced for the same. Studies comparing these instruments on root surface integrity are scarce. Thus, an in-vitro Scanning Electron Microscopy study was designed to evaluate the surface integrity of root end cavities prepared using conventional and piezoelectric devices. Methodology: Twelve single-rooted human intact mandibular premolar teeth were endodontically treated and included in the study. They were divided into two groups. In the first group, 3 mm root-end cavities were prepared using conventional retro preparation burs and in the second group, 3 mm root-end cavities were prepared using piezoelectric retro-tips. The specimens were coded for blind evaluation and analysed under scanning electron microscope at 100x, 500x and 1000x magnification for smear layer and debris. Gutmann's scoring criteria was followed to score the specimens. Statistical analysis was carried out using Shapiro Wilk test and the independent sample t-test was used to check mean differences between variables. Results: It was noted that significant statistical differences existed in mean debris and smear layer scores (p<0.001) between the two groups. In the piezoelectric group, significantly lower debris layer and smear layer was found, compared to the conventional bur group. Conclusion: Root-end cavities prepared using piezo retrotips produced cleaner, well-centered and more conservative surface with minimal debris & smear layer, compared to root-end cavities prepared using conventional burs.

Técnica de disyunción horizontal del reborde alveolar con bisturí piezoeléctrico y colocación de implantes en el maxilar inferior: informe de casos clínicos / Horizontal split crest technique using a piezoelectric scalpel and immediate implant placement in the jaw: report of clinical cases

Objetivo: Presentar una técnica quirúrgica de disyunción con bisturí piezoeléctrico y expansión de rebordes delgados en maxilar inferior que permita la colocación de implantes en la posición tridimensional correcta en el mismo acto quirúrgico. Casos clínicos: Se presenta la resolución de dos casos clínicos de pacientes que acudieron a la Cátedra de Odontología Integral Adultos de la Facultad de Odontología de la Universidad de Buenos Aires. Ambos requerían la colocación de implantes en sectores posteroinferiores. Las imágenes tomográficas mostraban adecuada altura del reborde alveolar pero deficiente espesor para la colocación de implantes en la posición tridimensional correcta. Se decidió realizar una técnica de disyunción horizontal del reborde alveolar con bisturí piezoeléctrico, expansión del reborde y colocación de implantes e injerto óseo particulado de forma simultánea. Luego de 3 meses, se efectuó la segunda cirugía para iniciar la rehabilitación protésica. Conclusión: La técnica de disyunción horizontal del reborde alveolar mediante el uso del bisturí piezoeléctrico permitió ubicar al implante en la posición tridimensional correcta dentro del tejido óseo nativo sin la necesidad de realizar regeneraciones complejas en rebordes alveolares delgados (AU)

Aim: Present the horizontal split crest technique with a piezoelectric scalpel and the immediate implant placement in the correct tridimensional position, in thin mandibular alveolar ridges. Cases report: The surgical resolutions of 2 clinical cases of patients who attended the Adult Integral Dentistry Chair of the Faculty of Dentistry of the UBA, are presented. Both patients required implant placement in posterior madibular residual ridge. The tomographic images showed adequate height of the alveolar ridge but poor thickness for implants placement in a correct three-dimensional position. It was decided to perform a horizontal split crest technique of the alveolar ridge with piezoelectric scalpel, ridge expansion, and immediate implant placement with xenograft. After 3 months, the second surgery was performed to start with the prosthetic rehabilitation. Conclusion: The horizontal split crest technique using a piezoelectric scalpel, allowed immediate implant placement in the correct tridimensional position within native bone tissue, avoiding a guided bone regeneration technique, in these cases with thin alveolar ridges (AU)

Effect of knocking down Piezo1 mechanically sensitive protein on migration of MC3T3-E1 osteoblast cells / 中国修复重建外科杂志

Objective: To discuss the effect of Piezo1 mechanically sensitive protein in migration process of mouse MC3T3-E1 osteoblast cells. Methods: The 5th-10th generation mouse MC3T3-E1 osteoblasts were divided into Piezo1-small interfering RNA (siRNA) transfection group (group A), negative control group (group B), and blank control group (group C). Piezo1-siRNA or negative control siRNA was transfected into mouse MC3T3-E1 osteoblasts by siRNA transfection reagent, respectively; group C was only added with siRNA transfection reagent; and the cell morphology was observed under inverted phase contrast microscope and fluorescence microscope, and the transfection efficiency was calculated. The expression of Piezo1 protein was detected by immunofluorescence staining and Western blot. Transwell cell migration assay and cell scratch assay were used to detect the migration of MC3T3-E1 osteoblasts after Piezo1-siRNA transfection. Results: After 48 hours of transfection, group A showed a slight increase in cell volume and mutant growth, but cell colonies decreased, suspension cells increased and cell fragments increased when compared with untransfected cells. Under fluorescence microscope, green fluorescence was observed in MC3T3-E1 osteoblasts of group B, and the transfection efficiency was 68.56%±4.12%. Immunofluorescence staining and Western blot results showed that the expression level of Piezo1 protein in group A was significantly lower than that in groups B and C ( P0.05). Transwell cell migration assay and cell scratch assay showed that the number of cells per hole and the scratch healing rate of cells cultured for 1-4 days in group A were significantly lower than those in groups B and C ( P0.05). Conclusion: Piezo1 knocked down by siRNA can inhibit the migration ability of MC3T3-E1 osteoblast cells.