Protein kinase D1 regulates the growth and metabolism of oral squamous carcinoma cells in tumor microenvironment / 华西口腔医学杂志

OBJECTIVE@#To observe the effect of protein kinase D1 (PKD1) on the growth and metabolism of oral squamous cell carcinoma HSC-4 cells and related molecular mechanisms in the tumor microenvironment.@*METHODS@#HSC-4 cell lines were transfected with shRNA plasmids. Three groups (Wild, control-shRNA, and PKD1-shRNA) were cultured under acidic or hypoxic environment for a certain time. Western blot was used to detect the expression of autophagy-related and glycolytic-related proteins. The proliferation changes were detected by CCK-8 kits.@*RESULTS@#The PKD1-knockdown HSC-4 cell line was established. PKD1 silencing increased autophagy activity. Under hypoxic and acidic conditions, the PKD1-knockdown HSC-4 cells showed lower proliferation than the parental cells. PKD1-knockdown also decreased the expression of hypoxia induciblefactor 1α (HIF-1α) and pyruvate kinase M2 (PKM2).@*CONCLUSIONS@#Under hypoxic and acidic conditions, PKD1 gene silencing can increase apoptotic autophagy activity. Downregulated PKD1 gene expression can reduce the glycolysis of oral squamous cell carcinoma cells and inhibit tumor cell proliferation. This study revealed the important role of PKD1 in the metabolism and growth of oral squamous cell carcinoma, making it a possible target for the treatment of oral squamous cell carcinoma.

Role of protein kinase D1 in regulating the growth, apoptosis and drug sensitivity of oral squamous carcinoma cells / 华西口腔医学杂志

OBJECTIVE@#This study aimed to investigate the role of protein kinase D (PKD)1 in regulating the growth, apop-tosis, and drug sensitivity of the squamous carcinoma cell line SCC-25.@*METHODS@#The SCC-25 cell line was transfected with either the control-shRNA or PKD1-shRNA plasmids. The stable transfected cells were selected, and the efficiency of PKD1 knockdown was detected by Western blot. The growth and apoptosis of SCC-25 were analyzed with a cell counting kit-8 (CCK8) and flow cytometry. The 50% inhibitory concentrations (IC50) of paclitaxel in the control and PKD1 knockdown cell lines were detected by CCK-8. The expression levels of Bax, Bcl-2, and P-gp were detected by Western blot.@*RESULTS@#PKD1 was constitutively expressed and phosphorylated in various cancer cell lines. Inhibiting the expression of PKD1 in SCC-25 cells by RNA interference could inhibit the growth and promote the apoptosis of SCC-25 cells via downregulating Bcl-2 expression. Additionally, inhibiting PKD1 expression could downregulate the expression of P-gp, thereby decreasing both the IC50 and resistance index of paclitaxel.@*CONCLUSIONS@#PKD1 plays an important role in regulating the biobehavior of SCC-25. It is a potential therapeutic target for oral squamous carcinoma.

Establishment of an ex vivo myocardial ischemia-reperfusion model in tree shrews / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an ex vivo model of myocardial ischemia reperfusion in tree shrews.</p><p><b>METHODS</b>The Langendorff ex vivo heart perfusion system was used to establish the myocardial ischemia reperfusion model in tree shrews with different irrigation and reperfusion time settings. Alanine aminotransferase (ALT), aspartate transaminase (AST) and lactic dehydrogenase (LDH) levels were measured by enzyme-labeled immunosorbent assay, creatine kinase MB (CK-MB) was detected using immunosuppression method, and malondialdehyde was measured with thiobarbital staining method; the infarct size was measured using 2, 3, 5-triphenyltrazoliumchloride (TTC) method.</p><p><b>RESULTS</b>Ischemia for 30 min and reperfusion for 30 and 60 min caused more significant increase in CK-MB and LDH levels in the perfusion fluid and also in the levels of ALT, CK-MB and AST in the myocardial tissue compared with other experimental settings (P<0.05), but these parameters were comparable between the former two settings (P>0.05). The mean heart rate in 30-min ischemia with 60-min reperfusion group was obviously lower than that in continuous reperfusion group, 15-min ischemia with 30-min reperfusion group and 30-min ischemia with 30-min reperfusion group (P<0.05), and the heart rate was similar between the latter 3 groups (P>0.05). ECG analysis showed that the mean heart rate in 30-min ischemia with 30-min reperfusion group was closer to the physiological heart rate of tree shrews.</p><p><b>CONCLUSION</b>We successfully established an ex vivo myocardial ischemia reperfusion model using tree shrews, and ischemia for 30 min followed by reperfusion for 30 min is the optimal experimental setting.</p>

Saliva of periodontitis patients promotes macrophage differentiation and activation / 华西口腔医学杂志

OBJECTIVE@#The aim of this study was to investigate the effect of saliva of patients with chronic periodontitis (CPD) on the differentiation, activation, and secretion of osteoclast-maturing mediators of macrophages.@*METHODS@#A total of 40 saliva samples were collected from healthy donors (n=20) and severe periodontitis patients (n=20). Peripheral blood mononuclear cells (PBMCs) and THP-1 monocyte line cells were challenged with 15% saliva for 5 days. The phenotype, surface marker, and phagocytosis of macrophages were analyzed by flow cytometry and microscopy. Osteoclast-maturing mediators were assayed by using enzyme-linked immunosorbent assay (ELISA) kits.@*RESULTS@#When PBMCs were treated with CPD saliva for 5 days, 61.25%±11.33% of cells were transformed into large granular cells; 86.78%±13.69% of large granular cells were identified as CD14⁺⁺CD16⁺ macrophages. When THP-1 cells were treated with CPD saliva, most cells attached to the bottom of cell culture plates, thereby exhibiting macrophage morphology and releasing additional osteoclast-maturing mediators. Furthermore, the phagocytosis of THP-1 cells considerably increased in the presence of CPD saliva (66.35%±9.67%) compared with medium control (33.33%±7.52%), or healthy saliva (40.71%±3.52%).@*CONCLUSIONS@#Saliva from patients with CPD can induce macrophage differentiation, activate phagocytose microorganisms, and secrete osteoclast-maturing mediators.

Analysis of causes and whole microbial structure in a case of rampant caries / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the whole microbial structure in a case of rampant caries to provide evidence for its prevention and treatment.</p><p><b>METHODS</b>Clinical samples including blood, supragingival plaque, plaque in the caries cavity, saliva, and mucosal swabs were collected with the patient's consent. The blood sample was sent for routine immune test, and the others samples were stained using Gram method and cultured for identifying colonies and 16S rRNA sequencing. DNA was extracted from the samples and tested for the main cariogenic bacterium (Streptococcus mutans) with qPCR, and the whole microbial structure was analyzed using DGGE.</p><p><b>RESULTS</b>The patient had a high levels of IgE and segmented neutrophils in his blood. Streptococci with extremely long chains were found in the saliva samples under microscope. Culture of the samples revealed the highest bacterial concentration in the saliva. The relative content of hemolytic bacterium was detected in the samples, the highest in the caries cavity; C. albicans was the highest in the dental plaque. In addition, 33 bacterial colonies were identified by VITEK system and 16S rDNA sequence phylogenetic analysis, and among them streptococci and Leptotrichia wade were enriched in the dental plaque sample, Streptococcus mutans, Fusobacterium nucleatum, and Streptococcus tigurinus in the caries cavity, and Lactobacillus in the saliva. S. mutans was significantly abundant in the mucosal swabs, saliva and plaque samples of the caries cavity as shown by qPCR. Compared to samples collected from a healthy individual and another two patients with rampant caries, the samples from this case showed a decreased bacterial diversity and increased bacterial abundance shown by PCR-DGGE profiling, and multiple Leptotrichia sp. were detected by gel sequencing.</p><p><b>CONCLUSION</b>The outgrowth of such pathogenic microorganisms as S. mutans and Leptotrichia sp., and dysbiosis of oral microbial community might contribute to the pathogenesis of rampant caries in this case.</p>

Experimental study on effect of Salvia miltiorrhiza on alveolar bone metabolism and variation in bone mass in diabetic rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of Salvia miltiorrhiza on alveolar bone metabolism and variation in bone mass in diabetic rats, in order to detect whether it has an inhibitory effect on alveolar bone osteoporosis caused by diabetics.</p><p><b>METHOD</b>Intraperitoneal injection of alloxan induced diabetes in rats. After one week of observation and maintenance of stable blood sugar level, they were treated with S. miltiorrhiza. The rats were sacrificed at the eighth week after fasting for 12 h and blood samples were collected for analysis of blood glucose and rate of bone metabolism. Meanwhile, their alveolar bones were collected for determining bone mineral density (BMD) and histological sections were made for histomorphology observation.</p><p><b>RESULT</b>Diabetic rats showed varying degrees of abnormality in bone metabolism indicators and significant reduction in bone mineral density. After treatment with S. miltiorrhiza, their symptoms reduced to some extend and all indicators were improved especially bone density.</p><p><b>CONCLUSION</b>S. miltiorrhiza has a certain inhibitory effect on alveolar bone osteoporosis in diabetic rats in early stage.</p>

Nano-hydroxyapatite for repair of rabbit jaw bone defect Bone mineral density analysis / 中国组织工程研究

BACKGROUND: Nano-hydroxyapatite (Nano-HA) has been shown to be a good choice of bone repair material owing to its salts composition consistent with natural bone and its scaffold structure homothetic to natural bone structure. OBJECTIVE: To investigate the feasibility of nano-HA in repair of jaw bone defect in rabbits. DESIGN, TIME AND SETTING: Materials-based animal experimental observation was performed at Laboratory Animal Center of Jiamusi University and Beijing Ji Shui Tan Hospital between January 2003 and June 2005. MATERIALS: Neutralization reaction of calcium biphosphate and calcium hydroxide was used to construct the system. The reactants were managed to be cotloidal by reaction control and using appropriate nucleating agents. Acerata HA crystal obtained under different conditions was sintered to obtain the nano-HA granule with a diameter of 1-56 nm. METHODS: Twenty-four healthy Chinese Harbin rabbits were randomly and evenly divided into an experimental group and a control group. After anesthesia, a penetrating 1.5 cm x1.5 cm defect was made with the GX micro-drill at the mandibular edge in each rabbit. Nano-HA was implanted in defects of the experimental group, and common HA was used in the control group. Antibiotics were used for 5 days afterwards. MAIN OUTCOME MEASURES: Change in bone mineral density after implantation of nano-HA. RESULTS: After repair of bone defect, the bone mineral density in the expedmental group increased gradually to a normal level and tended to be stable; whereas it was gradually decreased in the control group. There was significant difference between the experimental and control groups (P < 0.01). CONCLUSION: Nano-HA can promote new bone maturation, and this material produces favorable results in repair of bone defects.

Histological analysis of nano-hydroxyapatite for repairing defect in rabbit jaw / 中国组织工程研究

BACKGROUND: To repair bone defect, histocompatibility, growing characteristics, biodegradation and repairing mechanism of nanometer need to be further studied in clinic. OBJECTIVE: To observe the growing characteristics and histocompatibility of nano-hydroxyapatite (Nano-HA) for repairing jaw defect of rabbits.DESIGN: Randomized grouping animal study.SETTING: Beijing Jishuitan Hospital and Stomatology College of Jiamusi University.MATERIALS: A total of 24 New Zealand rabbits, either gender, weighing 2.5-3.5 kg, were provided by Animal Experimental Center of Jiamusi University. The animal experiment had got confirmed consent from local ethic committee. Nano-HA was provided by Material Engineering College of Jiamusi University and dealt with routine hyperthermia/hypertension sterilization. In addition, hydroxyapatite was provided by Wuhan Industry University, and the diameter was 1.0-2.0 μm.METHODS: The experiment was carried out in the Experimental Animal Center of Jiamusi University from November 2001 to May 2006. All rabbits were randomly divided into experimental group and control group with 12 in each group. Bone defect in the diameter of 1.0 cm was produced on body of mandible. Nano-HA was used to repair the bone defect of rabbits in the experimental group, while hydroxyapatite was used to repair the bone defect of rabbits in the control group. At 1, 4, 8 and 12 weeks after operation, all rabbits were sacrificed. In addition, medical imaging analysis system was used to analyze generative quantity of tissue in the two groups; meanwhile, histological quality and quantity were also analyzed so as to observe histocompatibility and newborn osteogenesis. MAIN OUTCOME MEASURES: Histocompatibility and newborn osteogenesis.RESULTS: With the time passing by, the amount of repairing materials was decreased because of the combination with newborn tissue into bone in bone defect-repaired region in the experimental group. When it was closed to normal bone, the amount was stable. However, bony callus was not able to grow in materials in the control group. Results of correlation analysis demonstrated that materials were negatively straight-line correlation with newborn bone (r = -0.912 0, P < 0.01). During the repairing procedure of bone defect, newborn bone was closely correlative with Nano-HA; while, with the increase of newborn bone, the amount of repairing materials was decreased because of the combination with newborn tissue into bone.CONCLUSION: Nano-HA can combine with newborn bone tissue so as to rapidly generate bone, while it has an excellent biocompatibility.