Clinical significance of copeptin as an early predictor of renal graft dysfunction in renal transplant recipients / 고신대학교의과대학학술지

Background@#Copeptin is the carboxyl-terminal part of the vasopressin precursor protein, and its concentration is an independent predictor of the onset of chronic kidney disease and a rapid decline in the glomerular filtration rate. The glomerular filtration rate is regarded as the best indicator of kidney transplant function and is a predictor of graft and patient survival. We investigated the clinical significance of copeptin as an early predictor of renal graft dysfunction in renal transplant recipients. @*Methods@#We measured serum creatinine, cystatin C, and copeptin concentrations in renal transplant recipients on the day of their operation, as well as on postoperative days 3, 7, 30, and 365. Acute rejection was defined as a sudden decrease in renal function accompanied by histological changes. @*Results@#Eight renal transplant recipients were enrolled in the study from July 2018 to December 2019. Four patients experienced histologically confirmed transplant rejection. All four cases involved acute T-cell rejection. No significant correlation was found between the copeptin level and the presence or absence of rejection at any time point. In subgroup analyses, changes in creatinine, the estimated glomerular filtration rate, cystatin, and copeptin did not show statistical significance. @*Conclusions@#We anticipated that copeptin would be useful to identify individuals at high risk of transplant rejection; however, our study failed to show an association. Further research will be needed to overcome the limitations of this study.

Autophagy inhibition by cudraxanthone D regulates epithelial–mesenchymal transition in SCC25 cells

Cudraxanthone D (CD) is a natural xanthone compound derived from the root barks of Cudrania tricuspidata . However, the biological functions of CD in human metabolism have been rarely reported until now. Autophagy is the self-degradation process related to cancer cell metastasis. Here, we elucidated the effects of CD on human oral squamous cell carcinoma (OSCC) cells’ metastatic ability. We confirmed that CD effectively decreased the proliferation and viability of SCC25 human OSCC cells in time- and dose-dependent manners. Also, the metastasis phenotype of the SCC25 cell (migration, invasion, and epithelial–mesenchymal transition [EMT]) was inhibited by CD. To further investigate the mechanism by which CD inhibited the metastatic capacity, we detected the relationship between EMT and autophagy in the SCC25 cells. The results revealed that CD inhibited the metastasis of the SCC25 cells by attenuating autophagy. Thus, our findings produced a potential novel agent for the treatment of human OSCC metastasis.

Autophagy inhibition by cudraxanthone D regulates epithelial–mesenchymal transition in SCC25 cells

Cudraxanthone D (CD) is a natural xanthone compound derived from the root barks of Cudrania tricuspidata . However, the biological functions of CD in human metabolism have been rarely reported until now. Autophagy is the self-degradation process related to cancer cell metastasis. Here, we elucidated the effects of CD on human oral squamous cell carcinoma (OSCC) cells’ metastatic ability. We confirmed that CD effectively decreased the proliferation and viability of SCC25 human OSCC cells in time- and dose-dependent manners. Also, the metastasis phenotype of the SCC25 cell (migration, invasion, and epithelial–mesenchymal transition [EMT]) was inhibited by CD. To further investigate the mechanism by which CD inhibited the metastatic capacity, we detected the relationship between EMT and autophagy in the SCC25 cells. The results revealed that CD inhibited the metastasis of the SCC25 cells by attenuating autophagy. Thus, our findings produced a potential novel agent for the treatment of human OSCC metastasis.

Alterations in Structural and Functional Connectivities in Patients with End-Stage Renal Disease

Background@#and Purpose: The aim of this study was to evaluate the structural and functional connectivities of brain network using graph theoretical analysis in neurologically asymptomatic patients with end-stage renal disease (ESRD). We further investigated the prevalence of cognitive impairment (CI) in ESRD patients and analyzed the association between network measures of brain connectivity and cognitive function. @*Methods@#We prospectively enrolled 40 neurologically asymptomatic ESRD patients, 40 healthy controls, and 20 disease controls. All of the subjects underwent diffusion-tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI). We calculated measures of structural and functional connectivities based on DTI and rs-fMRI, respectively, and investigated differences therein between the ESRD patients and the healthy controls. We assessed cognitive function in the ESRD patients using the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological battery. @*Results@#The ESRD patients exhibited decreased global structural and functional brain connectivities, as well as alterations of network hubs compared to the healthy controls and disease controls. About 70% of the ESRD patients had CI. Moreover, ESRD patients without CI exhibited decreased global connectivity and alterations of network hubs. Furthermore, there was a significant positive association between measures of brain connectivity and cognitive function. @*Conclusions@#We found that ESRD patients exhibited decreased structural and functional brain connectivities, and that there was a significant association between brain connectivity and cognitive function. These alterations in the brain network may contribute to the pathophysiological mechanism of CI in ESRD patients.

Anticancer effects of D-pinitol in human oral squamous carcinoma cells

D-pinitol is an analog of 3-methoxy-D-chiro-inositol found in beans and plants. D-pinitol has anti-inflammatory, antidiabetic, and anticancer effects. Additionally, D-pinitol induces apoptosis and inhibits metastasis in breast and prostate cancers. However, to date, no study has investigated the anticancer effects of D-pinitol in oral cancer. Therefore, in this study, whether the anticancer effects of D-pinitol induce apoptosis, inhibit the epithelialto-mesenchymal transition (EMT), and arrest cell cycle was investigated in squamous epithelial cells. D-pinitol decreased the survival and cell proliferation rates of CAL-27 and Ca9-22 oral squamous carcinoma cells in a concentration- and time-dependent manner. Evidence of apoptosis, including nuclear condensation, poly (ADP-ribose) polymerase, and caspase-3 fragmentation, was also observed. D-pinitol inhibited the migration and invasion of both cell lines. In terms of EMT-related proteins, E-cadherin was increased, whereas N-cadherin, Snail, and Slug weredecreased. D-pinitol also decreased the expression of cyclin D1, a protein involved in the cell cycle, but increased the expression of p21, a cyclin-dependent kinase inhibitor. Hence, D-pinitol induces apoptosis and cell cycle arrest in CAL-27 and Ca9-22 cells, demonstrating an anticancer effect by decreasing the EMT.

Anticancer effects of D-pinitol in human oral squamous carcinoma cells

D-pinitol is an analog of 3-methoxy-D-chiro-inositol found in beans and plants. D-pinitol has anti-inflammatory, antidiabetic, and anticancer effects. Additionally, D-pinitol induces apoptosis and inhibits metastasis in breast and prostate cancers. However, to date, no study has investigated the anticancer effects of D-pinitol in oral cancer. Therefore, in this study, whether the anticancer effects of D-pinitol induce apoptosis, inhibit the epithelialto-mesenchymal transition (EMT), and arrest cell cycle was investigated in squamous epithelial cells. D-pinitol decreased the survival and cell proliferation rates of CAL-27 and Ca9-22 oral squamous carcinoma cells in a concentration- and time-dependent manner. Evidence of apoptosis, including nuclear condensation, poly (ADP-ribose) polymerase, and caspase-3 fragmentation, was also observed. D-pinitol inhibited the migration and invasion of both cell lines. In terms of EMT-related proteins, E-cadherin was increased, whereas N-cadherin, Snail, and Slug weredecreased. D-pinitol also decreased the expression of cyclin D1, a protein involved in the cell cycle, but increased the expression of p21, a cyclin-dependent kinase inhibitor. Hence, D-pinitol induces apoptosis and cell cycle arrest in CAL-27 and Ca9-22 cells, demonstrating an anticancer effect by decreasing the EMT.

Piperlongumine suppressed osteoclastogenesis in RAW264.7 macrophages

Piperlongumine (PL) is a natural product found in long pepper (Piper longum). The pharmacological effects of PL are well known, and it has been used for pain, hepatoprotection, and asthma in Oriental medicine. No studies have examined the effects of PL on bone tissue or bone-related diseases, including osteoporosis. The current study investigated for the first time the inhibitory effects of PL on osteoclast differentiation, bone resorption, and osteoclastogenesis-related factors in RAW264.7 macrophages stimulated by the receptor activator for nuclear factor-κB ligand (RANKL). Cytotoxicity was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and osteoclast differentiation and bone resorption were confirmed by tartrate-resistant acid phosphatase (TRAP) staining and pit formation analysis. Osteoclast differentiation factors were confirmed by western blotting. PL exhibited toxicity in RAW264.7 macrophages, inhibiting osteoclast formation and bone resorption, in addition to inhibiting the expression of osteoclastogenesis-related factors, such as tumor necrosis factor receptor-associated factor 6 (TRAF6), c-Fos, and NFATc1, in RANKL-stimulated RAW264.7 macrophages. These findings suggest that PL is suitable for the treatment of osteoporosis, and it serves as a potential therapeutic agent for various bone diseases.

Combined effect of recombinant human bone morphogenetic protein-2 and low level laser irradiation on bisphosphonate-treated osteoblasts

OBJECTIVES: The purpose of this study was to evaluate the synergic effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-level laser therapy (LLLT) on bisphosphonate-treated osteoblasts. MATERIALS AND METHODS: Human fetal osteoblast cells (hFOB 1.19) were cultured with 100 µM alendronate. Low-level Ga-Al-As laser alone or with 100 ng/mL rhBMP-2 was then applied. Cell viability was measured with MTT assay. The expression levels of receptor activator of nuclear factor kappa-B ligand (RANKL), macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG) were analyzed for osteoblastic activity inducing osteoclastic activity. Collagen type and transforming growth factor beta-1 were also evaluated for bone matrix formation. RESULTS: The results showed that rhBMP-2 and LLLT had a synergic effect on alendronate-treated osteoblasts for enhancing osteoblastic activity and bone matrix formation. Between rhBMP-2 and LLLT, rhBMP-2 exhibited a greater effect, but did not show a significant difference. CONCLUSION: rhBMP-2 and LLLT have synergic effects on bisphosphonate-treated osteoblasts through enhancement of osteoblastic activity and bone formation activity.

Combined Treatment with Low-Level Laser and rhBMP-2 Promotes Differentiation and Mineralization of Osteoblastic Cells under Hypoxic Stress

BACKGROUND: The aim of this study was to evaluate the combined effect of low-level laser treatment (LLLT) and recombinant human bone morphological protein-2 (rhBMP-2) applied to hypoxic-cultured MC3T3-E1 osteoblastic cells and to determine possible signaling pathways underlying differentiation and mineralization of osteoblasts under hypoxia. METHODS: MC3T3-E1 cells were cultured under 1% oxygen tension for 72 h. Cell cultures were divided into four groups: normoxia control, low-level laser (LLL) alone, rhBMP-2 combined with LLLT, and rhBMP-2 under hypoxia. Laser irradiation was applied at 0, 24, and 48 h. Cells were treated with rhBMP-2 at 50 ng/mL. Alkaline phosphatase activity was measured at 3, 7, and 14 days to evaluate osteoblastic differentiation. Cell mineralization was determined with Alizarin red S staining at 7 and 14 days. Western blot assays were performed to evaluate whether p38/protein kinase D (PKD) signaling was involved. RESULTS: The results indicate that LLLT and rhBMP-2 synergistically increased alkaline phosphatase (ALP) activity and mineralization. Western blot analyses showed that expression of type I collagen, runt-related transcription factor 2 (RUNX2), and Osterix (Osx), increased and expression of hypoxia-inducible factor 1-alpha (HIF-1α), decreased more in the LLLT and rhBMP-2 combined group than in the rhBMP-2 or LLL alone groups. Moreover, LLLT and rhBMP-2 stimulated p38 phosphorylation and rhBMP-2 and LLLT increased Prkd1 phosphorylation. CONCLUSION: Combined treatment with rhBMP-2 and LLL induced differentiation and mineralization of hypoxiccultured MC3T3-E1 osteoblasts by activating p38/PKD signaling in vitro.

Luteolin Induces Apoptosis via Mitochondrial Pathway and Inhibits Invasion and Migration of Oral Squamous Cell Carcinoma by Suppressing Epithelial-Mesenchymal Transition Induced Transcription Factors

Oral squamous cell carcinoma (OSCC) is the most common type of oral malignancy. Numerous therapies have been proposed for its cure. Research is continually being conducted to develop new forms of treatment as current therapies are associated with numerous side-effects. Luteolin, a common dietary flavonoid, has been demonstrated to possess strong anti-cancer activity against various human cancer cell lines. Nevertheless, research into luteolin-based anticancer activity against oral cancer remains scarce. Thus, the objective of this study was to assess the effect of luteolin as an anti-cancer agent. After treatment with luteolin, Ca9-22 and CAL-27 oral cancer cells showed condensed nuclei and enhanced apoptotic rate with evidence of mitochondria-mediated apoptosis. Epithelialmesenchymal transition (EMT) is closely related to tumor migration and invasion. Luteolin suppressed cancer cell invasion and migration in the current study. Elevated expression of E-cadherin, an adherens junction protein, was evident in both cell lines after luteolin treatment. Luteolin also significantly inhibited transcription factors (i.e., N-cadherin, Slug, Snail, Twist, and ZEB-1) that regulated expression of tumor suppressors such as E-cadherin based on Western blot analysis and quantitative PCR. Thus, luteolin could induce mitochondrial apoptosis and inhibit cancer cell invasion and migration by suppressing EMT-induced transcription factors.

Basiliximab-Induced Non-Cardiogenic Pulmonary Edema in a Kidney Transplant Patient / 대한이식학회지

Induction therapy with basiliximab is widely administered after kidney transplantation to prevent acute rejection. Herein, we report a case of non-cardiogenic pulmonary edema induced by basiliximab. To the best of our knowledge, such case has not been reported to date in Korea. A 54-year-old man with polycystic kidney disease received kidney transplantation. As induction therapy, he was prescribed basiliximab. On day 4, the second dose of basiliximab was administered. The patient complained of acute hypoxia 23 hours later, which led to circulatory collapse. He was discharged 3 weeks later with stable renal function. Pulmonary edema was presumed to have been caused by increased pulmonary capillary permeability. A possible hypothesis for this event occurring after the second basiliximab injection is steroid-related effects. Non-cardiogenic pulmonary edema is a complication that might occur after basiliximab induction therapy. Physicians should be aware of this potentially life-threatening complication.

Effects of Remifentanil Preconditioning Attenuating Oxidative Stress in Human Dermal Fibroblast

Human dermal fibroblast is essential in wound healing of the skin through the synthesis of extracellular matrix proteins. With respect to oxidative stress, the effects of remifentanil on human dermal fibroblast have received little attention. Therefore, we investigated the effects of remifentanil on the apoptosis and autophagic reaction of human dermal fibroblasts under oxidative stress. The subjects were divided into the following groups: Control group: cells were incubated at 37℃ in a humidified atmosphere with 5% CO₂. Hydrogen peroxide (H₂O₂) group: cells were exposed to H₂O₂ for 2 h. RPC/H₂O₂ group: cells were pretreated with remifentanil for 2 h and exposed H₂O₂ for 2 h. 3-MA/RPC/H₂O₂ group: cells were pretreated with 3-methyladenine (3-MA) and remifentanil for 1 h and 2 h, respectively. We measured cell viability using MTT assay. Western blot analysis was used to determine the expression levels of proteins associated with apoptosis and autophagy. Quantification of apoptotic cells was performed using flow cytometer analysis, and autophagic vacuoles were observed under a fluorescence microscope. Remifentanil treatment increased the proliferation of human dermal fibroblast and decreased apoptotic cell death, enhancing autophagic activity under oxidative stress. However, 3-MA, the autophagy pathway inhibitor, inhibited the protective effect of remifentanil in oxidative stress. This study demonstrates that remifentanil activated autophagy and decreased apoptotic death of human dermal fibroblasts under oxidative stress. Our results suggest that remifentanil may help in the treatment of oxidative stress.

Recombinant human bone morphogenic protein-2 Induces the Differentiation and Mineralization of Osteoblastic Cells Under Hypoxic Conditions via Activation of Protein Kinase D and p38 Mitogen-Activated Protein Kinase Signaling Pathways

Hypoxia suppresses osteoblastic differentiation and the bone-forming capacity. As the leading osteoinductive growth factor used clinically in bone-related regenerative medicine, recombinant human bone morphogenic protein-2 (rhBMP- 2) has yielded promising results in unfavorable hypoxic clinical situations. Although many studies have examined the effects of rhBMP-2 on osteoblastic differentiation, mineralization and the related signaling pathways, those of rhBMP-2 on osteoblastic cells remain unknown, particularly under hypoxic conditions. Therefore, this study was conducted under a 1% oxygen tension to examine the differentiating effects of rhBMP-2 on osteoblastic cells under hypoxia. rhBMP-2 could also induce the differentiation and mineralization of Osteoblastic (MC3T3-E1) cells under1%hypoxic conditions. rhBMP-2 could also induce the differentiation and mineralization of MC3T3-E1 cells under 1% hypoxic conditions. rhBMP-2 increased the alkaline phosphatase {ALP} activity in a time dependent manner, and expression of ALP, collagen type-1 (Col-1) and osteocalcin (OC) mRNAwere up-regulated significantly in a time- and concentration-dependent manner. In addition, the area of the mineralized nodules increased gradually in a concentration-dependent manner. Western blot analysis, which was performed to identify the signaling pathways underlying rhBMP-2-induced osteoblastic differentiation under hypoxic conditions, showed that rhBMP-2 significantly promoted the phosphorylation of the p38 mitogen-activated protein kinase (MAPK) in a time-dependent manner. A pretreatment with SB203580, a p38 MAPK inhibitor, inhibited the rhBMP-2-mediated differentiation and mineralization. Moreover, the phosphorylation of p38 induced by rhBMP-2 was inhibited in response to a pretreatment of the cells with Go6976, a protein kinase D {PKD) inhibitor. These findings suggest that rhBMP-2 induces the differentiation and mineralization of MC3T3-E1 cells under hypoxic conditions via activation of the PKD and p38 MAPK signaling pathways.

Propofol protects human keratinocytes from oxidative stress via autophagy expression

BACKGROUND: The skin consists of tightly connected keratinocytes, and prevents extensive water loss while simultaneously protecting against the entry of microbial pathogens. Excessive cellular levels of reactive oxygen species can induce cell apoptosis and also damage skin integrity. Propofol (2,6-diisopropylphenol) has antioxidant properties. In this study, we investigated how propofol influences intracellular autophagy and apoptotic cell death induced by oxidative stress in human keratinocytes. METHOD: The following groups were used for experimentation: control, cells were incubated under normoxia (5% CO₂, 21% O₂, and 74% N₂) without propofol; hydrogen peroxide (H₂O₂), cells were exposed to H₂O₂ (300 µM) for 2 h; propofol preconditioning (PPC)/H₂O₂, cells pretreated with propofol (100 µM) for 2 h were exposed to H₂O₂; and 3-methyladenine (3-MA)/PPC/H₂O₂, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to H₂O₂. Cell viability, apoptosis, and migration capability were evaluated. Relation to autophagy was detected by western blot analysis. RESULTS: Cell viability decreased significantly in the H₂O₂ group compared to that in the control group and was improved by propofol preconditioning. Propofol preconditioning effectively decreased H₂O₂-induced cell apoptosis and increased cell migration. However, pretreatment with 3-MA inhibited the protective effect of propofol on cell apoptosis. Autophagy was activated in the PPC/H₂O₂ group compared to that in the H₂O₂ group as demonstrated by western blot analysis and autophagosome staining. CONCLUSION: The results suggest that propofol preconditioning induces an endogenous cellular protective effect in human keratinocytes against oxidative stress through the activation of signaling pathways related to autophagy.

Propofol protects against oxidative-stress-induced COS-7 cell apoptosis by inducing autophagy

BACKGROUND: In oxidative stress, reactive oxygen species (ROS) production contributes to cellular dysfunction and initiates the apoptotic cascade. Autophagy is considered the mechanism that decreases ROS concentration and oxidative damage. Propofol shows antioxidant properties, but the mechanisms underlying the effect of propofol preconditioning (PPC) on oxidative injury remain unclear. Therefore, we investigated whether PPC protects against cell damage from hydrogen peroxide (H₂O₂)-induced oxidative stress and influences cellular autophagy. METHOD: COS-7 cells were randomly divided into the following groups: control, cells were incubated in normoxia (5% CO₂, 21% O₂, and 74% N₂) for 24 h without propofol; H₂O₂, cells were exposed to H₂O₂ (400 µM) for 2 h; PPC + H₂O₂, cells pretreated with propofol were exposed to H₂O₂; and 3-methyladenine (3-MA) + PPC + H₂O₂, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to H₂O₂. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide thiazolyl blue (MTT) reduction. Apoptosis was determined using Hoechst 33342 staining and fluorescence microscopy. The relationship between PPC and autophagy was detected using western blot analysis. RESULTS: Cell viability decreased more significantly in the H₂O₂ group than in the control group, but it was improved by PPC (100 µM). Pretreatment with propofol effectively decreased H₂O₂-induced COS-7 cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol during apoptosis. Western blot analysis showed that the level of autophagy-related proteins was higher in the PPC + H₂O₂ group than that in the H2O2 group. CONCLUSION: PPC has a protective effect on H₂O₂-induced COS-7 cell apoptosis, which is mediated by autophagy activation.

Headache attributed to acute pyelonephritis

Objective: This study identified the incidence and risk factors for headache attributed to acute pyelonephritis. Methods: The inclusion criteria were patients who were admitted with acute pyelonephritis at our hospital and ≥ 18 years of age. The following exclusion criteria were used: 1) patients who could not express their headache because of mental deterioration, 2) the presence of meningitis or meningoencephalitis, or 3) structural lesions on brain computed tomography or magnetic resonance images that could cause headache. The primary outcome was headache attributed to acute pyelonephritis as a dependent variable. The differences were analyzed using demographic and laboratory profiles as independent variables. Additionally, correlation analysis was performedbetweenseverity of headache using VAS score and demographic and laboratory profiles including age, WBC, and CRP. Results: A total of 479 patients met the inclusion criteria for this study, and 97 patients developed headache attributed to acute pyelonephritis. Patients with headache were younger and more likely to be female, and had a lower incidence of diabetes than those without headache. However, laboratory profiles that reflected the severity of acute pyelonephritis were not predictive factors for headache. Multiple logistic regression analysis demonstrated that young age and non-diabetes were independently significant variables for the prediction of headache attributed to acute pyelonephritis. In addition, the VAS score was found to be negative correlated with age, whereas it was not correlated with WBC and CRP. Conclusions: We determined that headache attributed to acute pyelonephritis was relatively common, and it was related to demographic characteristics but not acute pyelonephritis severity.

Protective effects of remifentanil against H₂O₂-induced oxidative stress in human osteoblasts

BACKGROUND: Bone injury is common in many clinical situations, such as surgery or trauma. During surgery, excessive reactive oxygen species (ROS) production decreases the quality and quantity of osteoblasts. Remifentanil decreases ROS production, reducing oxidative stress and the inflammatory response. We investigated remifentanil's protective effects against H₂O₂-induced oxidative stress in osteoblasts. METHODS: To investigate the effect of remifentanil on human fetal osteoblast (hFOB) cells, the cells were incubated with 1 ng/ml of remifentanil for 2 h before exposure to H2O2. For induction of oxidative stress, hFOB cells were then treated with 200 µM H₂O₂ for 2 h. To evaluate the effect on autophagy, a separate group of cells were incubated with 1 mM 3-methyladenine (3-MA) before treatment with remifentanil and H₂O₂. Cell viability and apoptotic cell death were determined via MTT assay and Hoechst staining, respectively. Mineralized matrix formation was visualized using alizarin red S staining. Western blot analysis was used to determine the expression levels of bone-related genes. RESULTS: Cell viability and mineralized matrix formation increased on remifentanil pretreatment before exposure to H₂O₂-induced oxidative stress. As determined via western blot analysis, remifentanil pretreatment increased the expression of bone-related genes (Col I, BMP-2, osterix, and TGF-β). However , pretreatment with 3-MA before exposure to remifentanil and H₂O₂ inhibited remifentanil's protective effects on hFOB cells during oxidative stress. CONCLUSIONS: We showed that remifentanil prevents oxidative damage in hFOB cells via a mechanism that may be highly related to autophagy. Further clinical studies are required to investigate its potential as a therapeutic agent.

Dexmedetomidine attenuates H₂O₂-induced cell death in human osteoblasts

BACKGROUND: Reactive oxygen species play critical roles in homeostasis and cell signaling. Dexmedetomidine, a specific agonist of the α₂-adrenoceptor, has been commonly used for sedation, and it has been reported to have a protective effect against oxidative stress. In this study, we investigated whether dexmedetomidine has a protective effect against H₂O₂-induced oxidative stress and the mechanism of H₂O₂-induced cell death in normal human fetal osteoblast (hFOB) cells. METHODS: Cells were divided into three groups: control group—cells were incubated in normoxia without dexmedetomidine, hydrogen peroxide (H2O2) group—cells were exposed to H₂O₂ (200 µM) for 2 h, and Dex/H₂O₂ group—cells were pretreated with dexmedetomidine (5 µM) for 2 h then exposed to H₂O₂ (200 µM) for 2 h. Cell viability and apoptosis were evaluated. Osteoblast maturation was determined by assaying bone nodular mineralization. Expression levels of bone-related proteins were determined by western blot. RESULTS: Cell viability was significantly decreased in the H₂O₂ group compared with the control group, and this effect was improved by dexmedetomidine. The Hoechst 33342 and Annexin-V FITC/PI staining revealed that dexmedetomidine effectively decreased H₂O₂-induced hFOB cell apoptosis. Dexmedetomidine enhanced the mineralization of hFOB cells when compared to the H₂O₂ group. In western blot analysis, bone-related protein was increased in the Dex/H₂O₂ group. CONCLUSIONS: We demonstrated the potential therapeutic value of dexmedetomidine in H₂O₂-induced oxidative stress by inhibiting apoptosis and enhancing osteoblast activity. Additionally, the current investigation could be evidence to support the antioxidant potential of dexmedetomidine in vitro.

Low-level laser therapy affects osseointegration in titanium implants: resonance frequency, removal torque, and histomorphometric analysis in rabbits

OBJECTIVES: The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. MATERIALS AND METHODS: Thirteen New Zealand white male rabbits weighing 3.0+/-0.5 kg were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. RESULTS: The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. CONCLUSION: Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects.

Anticancer Properties of Icariside II in Human Oral Squamous Cell Carcinoma Cells

OSCC is currently the most common malignancy of the head and neck, affecting tens of thousands of patients per year worldwide. Natural flavonoids from plants are potential sources for novel anti-cancer drugs. Icariin is the active ingredient of flavonol glycoside, which is derived from the medical plant Herba Epimedii. A metabolite of icariin, icariside II exhibits a variety of pharmacological actions, including anti-rheumatic, anti-depressant, cardiovascular protective, and immunomodulatory functions. However, the exact mechanism causing the apoptosis-inducing effect of icariside II in OSCC is still not fully understood. In the present study, we assessed the anti-cancer effect of icariside II in OSCC cell lines by measuring its effect on cell viability, cell proliferation, and mitochondria membrane potential (MMP). Icariside II treatment of OSCC cells resulted in a dose- and time-dependent decrease in cell viability. Hoechst staining indicated apoptosis in icariside II-treated HSC cells. Icariside II inhibited cell proliferation and induced apoptosis in HSC cells, with significant increases in all present parameters in HSC-4 cells. The results clearly suggested that icariside II induced apoptosis via activation of intrinsic pathways and caspase cascades in HSC-4 cell lines. The collective findings of the study suggested that Icariside II is a potential treatment for OSCC; in addition, the data could provide a basis for the development of a novel anti-cancer strategy.