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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Effect of low-level laser therapy on bisphosphonate-treated osteoblasts / 대한악안면성형재건외과학회지

BACKGROUND: This study investigates the effect of alendronate-treated osteoblasts, as well as the effect of low-level laser therapy (LLLT) on the alendronate-treated osteoblasts. Bisphosphonate decreases the osteoblastic activity. Various treatment modalities are used to enhance the bisphosphonate-treated osteoblasts; however, there were no cell culture studies conducted using a low-level laser. METHODS: Human fetal osteoblastic (hFOB 1.19) cells were treated with 50 μM alendronate. Then, they were irradiated with a 1.2 J/cm² low-level Ga-Al-As laser (λ = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1 cm²; NDLux, Seoul, Korea). The cell survivability was measured with the MTT assay. The three cytokines of osteoblasts, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF) were analyzed. RESULTS: In the cells treated with alendronate at concentrations of 50 μM and higher, cell survivability significantly decreased after 48 h (p < 0.05). After the applications of low-level laser on alendronate-treated cells, cell survivability significantly increased at 72 h (p < 0.05). The expressions of OPG, RANKL, and M-CSF have decreased via the alendronate. The RANKL and M-CSF expressions have increased, but the OPG was not significantly affected by the LLLT. CONCLUSIONS: The LLLT does not affect the OPG expression in the hFOB cell line, but it may increase the RANKL and M-CSF expressions, thereby resulting in positive effects on osteoclastogenesis and bone remodeling.

Synergistic Effects of Chios Gum Mastic Extract and Low Level Laser Therapy on Osteoblast Differentiation

In the present study, we evaluated the effect of CGM on osteogenic differentiation of cultured osteoblasts, and determined whether combination treatment with LLLT had synergistic effects on osteogenic differentiation. The results indicated that CGM promoted proliferation, differentiation, and mineralization of osteoblasts at the threshold concentration of 10 µg/ml; whereas, CGM showed cytotoxic properties at concentrations above 100 µg/ml. ALP activity and mineralization were increased at concentrations above 10 µg/ml. CGM in concentrations up to 10 µg/ml also increased the expression of osteoblast-activated factors including type I collagen, BMP-2, RUNX2, and Osterix. The CGM (50 µg/ml) and LLLT (80 mW for 15 sec) combination treatment group showed the highest proliferation levels, ALP activity, and mineralization ratios. The combination treatment also increased the levels of phosphorylated forms of p38, ATF2, PKD, ERK, and JNK. In addition, the osteoblast differentiation factors including type I collagen, BMP-2, RUNX2, and Osterix protein levels were clearly increased in the combination treatment group. These results suggested that the combination treatment of CGM and LLLT has synergistic effects on the differentiation and mineralization of osteoblastic cells.

Effects of propofol-induced autophagy against oxidative stress in human osteoblasts

BACKGROUND: Oxidative stress occurs during the aging process and other conditions such as bone fracture, bone diseases, and osteoporosis, but the role of oxidative stress in bone remodeling is unknown. Propofol exerts antioxidant effects, but the mechanisms of propofol preconditioning on oxidative stress have not been fully explained. Therefore, the aim of this study was to evaluate the protective effects of propofol against H2O2-induced oxidative stress on a human fetal osteoblast (hFOB) cell line via activation of autophagy. METHODS: Cells were randomly divided into the following groups: control cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol. Hydrogen peroxide (H2O2) group cells were exposed to H2O2 (200 µM) for 2 h, propofol preconditioning (PPC)/H2O2 group cells were pretreated with propofol then exposed to H2O2, 3-methyladenine (3-MA)/PPC/H2O2 cells were pretreated with 3-MA (1 mM) and propofol, then were exposed to H2O2. 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 and bone nodular mineralization were decreased significantly by H2O2, and this effect was rescued by propofol preconditioning. Propofol preconditioning effectively decreased H2O2-induced hFOB cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol. In western blot analysis, propofol preconditioning increased protein levels of collagen type I, BMP-2, osterix, and TGF-β1. CONCLUSIONS: This study suggests that propofol preconditioning has a protective effect on H2O2-induced hFOB cell death, which is mediated by autophagy activation.

Symptomatic Hypermagnesemia in Normal Kidney Function with a Colonic Cleansing Agent / 대한내과학회지

Most reported cases of hypermagnesemia are related to laxative abuse and impaired renal function, while hypermagnesemia is uncommon without iatrogenic magnesium administration and decreased renal function. Magnesium-containing bowel-cleansing agents are widely used before colonoscopy, usually without complications. However, we experienced a case of symptomatic hypermagnesemia with normal renal function after using a bowel-cleansing agent. A 74-year-old man with normal renal function complained of lethargy and motor weakness after taking a bowel-cleansing agent containing 14 grams of magnesium before a colonoscopy for hematochezia. His magnesium level was 12 mg/dL. Fluid stasis in the gut due to colonic obstruction might have caused the hypermagnesemia. He was treated successfully with a bowel enema and intravenous calcium. We should be cautious when prescribing drugs for colonoscopy if colonic obstruction is suspected.