Genomic Signature of Mismatch Repair Deficiency in Areca Nut-Related Oral Cancer

Areca nut (AN) chewing contributes to an increase of oral squamous cell carcinoma (OSCC) cases in South and Southeast Asia; however, genomic events underlying the carcinogenesis process of AN-related OSCC remain unclear. Here, we comprehensively describe the genomic and transcriptome alterations of 113 Chinese OSCC patients (89 AN related and 24 AN negative) by whole-exome sequencing and RNA sequencing, and we compared the genomic differences between AN-related and AN-negative samples by integrating sequencing data of 325 OSCC patients from The Cancer Genome Atlas database and 50 from a published Taiwanese study. We identified 11 significantly mutated genes for OSCC, including 4 novel ones (ATG2A, WEE1, DST, and TSC2), of which WEE1 and ATG2A mutated with significantly higher rates in AN-related samples (P = 0.04 and P = 0.003, respectively). Mutational signature analysis revealed that AN-related OSCCs were specially characterized by the genomic signature of mismatch repair deficiency (dMMR), which could also predict the prognosis status of AN-related OSCC. In addition, an elevated PD-L1 expression was also observed in both AN-related patients (P = 3.71 × 10^-11) and those with a high dMMR level (P = 1.99 × 10^-4). Further differential expression analysis and in vitro experiments confirmed the role of dMMR in the development of OSCC induced by AN exposure. Taken together, this study first revealed the molecular profiles and highlighted the role of dMMR in AN-related OSCC among the Chinese population and identified that AN-related OSCC may represent a potential cohort for effective anti-PD-1/L1 immunotherapy.

[Co-prevalence relationship analysis on different metabolic syndrome scores and behavioral risk factors in adults from Urumqi based]

Objective: To investigate the influence of the prevalence and co-prevalence of risk factors for metabolic syndrome on the scores of different levels of metabolic syndrome in people receiving physical examination in Urumqi. Methods: Using the 2017 Xinjiang Health Examination Database, a total of 175 927 people from 7 districts and 1 county in Urumqi were selected as subjects. Face-to-face survey and body measurements were used to collect cardiovascular risk factors and metabolic syndrome scores. Metabolic syndrome scores were used. For the 0-5 points at 6 levels, χ(2), χ(2) trend test, correlation analysis of ordered variable Kendall's tau-b, and logistic regression analysis of ordered results were used to analyze the influence of prevalence and co-prevalence of behavioral risk factors on the MS scores. Results: The percentages of 6 metabolic syndrome scores in the sample population were 23.82%, 27.87%, 22.41%, 16.03%, 8.02%, and 1.85%, respectively. The scores of metabolic syndrome were different in different age groups, ethnic groups, groups with different drinking rates, and groups with different dietary types, with the differences all significant (P<0.05).The MS score in men increased with the increase of oil/salt rate and excessive drinking rate (P<0.01). The score in women increased with the increase of the current smoking rate, oil/salt rate, and increased with the decrease of physical activity (P≤0.01). There was no significant difference in the distribution of regular drinking rates between different score groups (P>0.05). The scores of metabolic syndrome increased with the increase of risk factors (P<0.05). Ordered results logistic analysis found that in the men with ≥3 risk factors and the metabolic syndrome score was 1.15 (1.06-1.26) times higher than that in the men without risk factor, as well as in women with 2 risk factors and≥3 risk factors. The metabolic syndrome scores were 1.38 (1.22-1.55), 2.02 (1.53-2.66) times higher than those in the women without risk factors. Conclusions: The physical examination group in Urumqi, the more the metabolic syndrome disease behavior risk factors clustered, the higher the metabolic syndrome score was. Therefore, comprehensive intervention measures should be taken to control the different forms of metabolic syndrome to prevent the occurrence and progress of the disease.

[Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in chronic renal insufficiency rats]

Objective: To observe the effect of autophagy of tibial growth plate chondrocyte on apoptosis in chronic renal insufficiency (CRI) rats. Methods: Male 4-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=10); (2) CRI group: the left ureter was ligated to cause CRI (n=10). The urine from all the rats was collected 6 weeks after the operation and the total protein content was measured. Then all the rats were sacrificed and the concentrations of creatinine and urea nitrogen in intracardiac blood were detected. The proximal tibia were fixed and decalcified to prepare histological sections, and the number of chondrocytes of column cells in the proliferative area of tibia growth plate was observed by saffron O staining. The expression rate of protein Light Chain-3, an autophagy marker of chondrocytes, was detected by immunofluorescence. The apoptosis rate of chondrocytes was detected by the method of TUNEL assay. The level of glycogenin-1, a glycogen formation marker of chondrocyte was detected by immunohistochemistry in chondrocytes. Results: The 24 h urine total protein was higher in CRI group [(163.5±11.3) mg vs (38.6±9.8) mg, t=25.620, P<0.001]. The levels of blood creatinine [(67.3±16.2) μmol/L vs (28.4±11.5) μmol/L, t=5.974, P<0.001] and urea nitrogen [(16.4±6.4) mmol/L vs (4.8±2.0) mmol/L, t=5.198, P<0.001] were higher in CRI group. The number of chondrocytes of column cells in the proliferating area of tibia growth plate was lower in CRI group (4.2±2.1 vs 9.1±3.8, t=3.109, P=0.006). The expression rate of LC-3 protein in chondrocytes of CRI group was lower [(27.2±12.6)% vs (51.4±18.2)%, t=3.457, P=0.003]. The level of glycogenin-1 of chondrocytes in CRI group increased significantly (6.1±2.5 vs 3.5±1.8, t=2.669, P=0.016). The apoptosis rate of chondrocytes in CRI group also increased [(17.2±4.8)% vs (5.1±3.4)%, t=6.505, P<0.001]. Conclusion: Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in CRI rats, which might be caused by the failure of glycogen degradation in chondrocytes.

[Effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency young rats]

Objective: To observe the effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency (CRI) young rats. Methods: Male 2-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=6); (2) CRI group: the left ureter was ligated (n=6). Rats were sacrificed 2 weeks after the operation and the primary cilia expression rate of growth plate chondrocytes and key protein β-catenin in Wnt/β signaling pathway were observed in histological section of tibia specimen. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation. The primary cilia expression rate and the level of β-catenin were measured. The primary cilia expression rate was detected by agonists and antagonists Wnt/β signaling pathway in chondrocytes of CRI group. The level of β-catenin was detected by using serum-free culture and chloral hydrate to intervene chondrocytes in CRI group. Results: The primary cilia expression rate of growth plate chondrocytes in histological section of tibia specimen in CRI group was higher than that in Sham group [(17.5±7.7)% vs (8.7±3.6)%, t=3.237, P=0.005], and the level of β-catenin was higher in CRI group (5.1±0.7 vs 1.9±0.8, t=6.731, P<0.001). The primary cilia expression rate of growth plate chondrocytes cultured in vitro in CRI group was higher than that in Sham group [(20.9±8.1)% vs (11.8±4.7)%, t=3.073, P=0.007], and the level of β-catenin was higher in CRI group (0.49±0.12 vs 0.25±0.11, t=3.297, P=0.011). There was no significant change in primary cilia expression rate after intervention by using Wnt/β signaling agonists and antagonists to change the level of β-catenin [agonists group: (21.3±7.6)%, control: (20.6±6.8)%, antagonists group: (22.4±6.2)%, F=0.173, P=0.842]. The level of β-catenin was significantly changed after intervention by using serum-free culture, chloral hydrate to alter the primary cilia expression rate (serum-free culture group: 0.61±0.23, control: 0.39±0.24, chloral hydrate group: 0.15±0.11, F=6.476, P=0.012). There was a positive correlation between the level of β-catenin and primary cilia expression rate. Conclusion: The primary cilia expression rate and the level of Wnt/β signaling pathway were higher in tibial growth plate chondrocytes in CRI rats model, and primary cilia might have positive regulatory effects on the Wnt/β signaling pathway.

[Effect of primary cilia on growth plate chondrocyte proliferation of young rats with chronic renal insufficiency]

Objective: To observe the effect of primary cilia on growth plate chondrocyte proliferation of young rats with chronic renal insufficiency (CRI). Methods: Male 2-week-old Sprague-Dawley rats were randomly divided into two groups (with 10 in each group): Sham group (only left ureter was exposed) and CRI group (left ureter was ligated). Rats were sacrificed 2 weeks after operation and the total length of tibia was measured. Histological sections of tibia were taken to observe the chondrocytes of growth plate proliferative region and the expression rate of primary cilia. Chondrocytes from growth plate in two groups were isolated and cultured in vitro to P3 generation and the chondrocyte proliferation rate at 24 h were detected. The primary cilia expression rate and cilia length of chondrocytes were measured. Western blot was used to detect the expression of intraflagellar transport 88 (IFT88) protein and the gray scale was analyzed. Results: The total length of tibia was shorter in CRI group [(35.84±4.56) mm vs (42.33±3.44) mm, P=0.002]. The results of tibial histological section showed that chondrocytes of growth plate proliferative region were unorganized and the number of chondrocyte with columnar structure was less in CRI group (2.71±1.10 vs 7.68±1.32, P<0.001). The primary cilia expression rate of chondrocytes was higher in CRI group [(35.53±7.41)% vs (18.31±5.12)%, P<0.001]. The chondrocyte proliferation rate at 24 h was lower in CRI group [(11.38±6.10)% vs (24.35±8.46)%, P=0.001]. The primary cilia expression rate of chondrocytes was higher in CRI group [(60.12±7.86)% vs (32.17±8.97)%, P<0.001], and the primary cilia length of chondrocytes was longer in CRI group [(3.54±1.61) μm vs (1.96±0.82) μm, P=0.012]. The protein IFT88 was more highly expressed in CRI group (0.47±0.23 vs 0.17±0.10, P=0.001). Conclusion: The primary cilia expression rate of growth plate chondrocytes was higher in the rats with CRI, resulting in decreased chondrocyte proliferation rate and growth retardation of tibial growth plate.

Reduction of Intracellular Chloride Concentration Promotes Foam Cell Formation

BACKGROUND

Previous work has demonstrated that the volume-regulated chloride channel is activated during foam cell formation, and inhibition of chloride movement prevents intracellular lipid accumulation. However, the mechanism explaining how chloride movement promotes foam cell formation is not clear.

METHODS AND RESULTS

Foam cell formation was determined by Oil Red O staining. Western blotting and co-immunoprecipitation were used to examine protein expression and protein-protein interaction. [Cl(-)]iwas measured using 6-methoxy-N-ethylquinolinium iodide dye. The results showed that [Cl(-)]iwas decreased in monocytes/macrophages from patients with hypercholesterolemia and from apoE(-/-)mice fed with a high-fat diet. Lowering [Cl(-)]iupregulated scavenger receptor A (SR-A) expression, increased the binding and uptake of oxLDL, enhanced pro-inflammatory cytokine production and subsequently accelerated foam cell formation in macrophages from humans and mice. In addition, low Cl(-)solution stimulated the activation of JNK and p38 mitogen-activated protein kinases. Inhibition of JNK and p38 blocked Cl(-)reduced medium-induced SR-A expression and lipid accumulation. In contrast, reduction of [Cl(-)]ipromoted the interaction of SR-A with caveolin-1, thus facilitating caveolin-1-dependent SR-A endocytosis. Moreover, disruption of caveolae attenuated SR-A internalization, JNK and p38 activation, and ultimately prevented SR-A expression and foam cell formation stimulated by low Cl(-)medium.

CONCLUSIONS

This data provide strong evidence that reduction of [Cl(-)]iis a critical contributor to intracellular lipid accumulation, suggesting that modulation of [Cl(-)]iis a novel avenue to prevent foam cell formation and atherosclerosis.

ClC-3 chloride channel/antiporter defect contributes to inflammatory bowel disease in humans and mice

BACKGROUND

ClC-3 channel/antiporter plays a critical role in a variety of cellular activities. ClC-3 has been detected in the ileum and colon.

OBJECTIVE

To determine the functions of ClC-3 in the gastrointestinal tract.

DESIGN

After administration of dextran sulfate sodium (DSS) or 2,4,6-trinitrobenzenesulfonic acid (TNBS), intestines from ClC-3-/- and wild-type mice were examined by histological, cellular, molecular and biochemical approaches. ClC-3 expression was determined by western blot and immunostaining.

RESULTS

ClC-3 expression was reduced in intestinal tissues from patients with UC or Crohn's disease and from mice treated with DSS. Genetic deletion of ClC-3 increased the susceptibility of mice to DSS- or TNBS-induced experimental colitis and prevented intestinal recovery. ClC-3 deficiency promoted DSS-induced apoptosis of intestinal epithelial cells through the mitochondria pathway. ClC-3 interacts with voltage-dependent anion channel 1, a key player in regulation of mitochondria cytochrome c release, but DSS treatment decreased this interaction. In addition, lack of ClC-3 reduced the numbers of Paneth cells and impaired the expression of antimicrobial peptides. These alterations led to dysfunction of the epithelial barrier and invasion of commensal bacteria into the mucosa.

CONCLUSIONS

A defect in ClC-3 may contribute to the pathogenesis of IBD by promoting intestinal epithelial cell apoptosis and Paneth cell loss, suggesting that modulation of ClC-3 expression might be a new strategy for the treatment of IBD.

Lipoapoptosis pathways in pancreatic β-cells and the anti-apoptosis mechanisms of adiponectin

Lipoapoptosis is the main form of pancreatic β-cell death in diabetes. Adiponectin is an adipocyte-derived hormone, which has anti-apoptosis effect in numerous cells. The present study was designed to explore the role of the 'extrinsic' (death receptor-induced) and the 'intrinsic' (mitochondrial) pathways in pancreatic β-cell lipoapoptosis and the anti-apoptosis effect of adiponectin on pancreatic β-cells. Palmitate (0.4 mmol/l) or oleate (0.4 mmol/l) was used to induce the apoptosis of Min 6 cells for 24 h. Z-LETD-FMK or Z-IEHD-FMK (40 μM) was used to inhibit the activity of caspase-8 or -9. When adiponectin was used, Min 6 cultures were pretreated in the absence or presence of fAd (5 μg/ml) for 2 h and then subjected to palmitate for 24 h. Apoptosis was evaluated using Annexin V-Cy3 kit. The expression levels of cleaved caspase-3, -8, -9, B-cell lymphoma 2 (BCL-2), and Bax were examined by Western blotting. Palmitate-induced pancreatic β-cell apoptosis was accompanied by the activation of caspase-8, -9, and -3. Blockade of caspase-9 rather than caspase-8, showed an inhibitory effect on caspase-3 activation. Moreover, adiponectin treatment prevented palmitate-induced apoptosis by inhibition of caspase-9 activation, but not of caspase-8, and induced an upregulation of BCL-2 and a downregulation of Bax in protein level. Both extrinsic and intrinsic pathways are activated in pancreatic β-cell lipoapoptosis, and the intrinsic apoptosis pathway is the major one. Adiponectin prevents pancreatic β-cells from apoptosis by inhibition of intrinsic apoptosis pathway via regulation of the BCL2 family. Therefore, protection of intrinsic apoptosis pathway is a potential therapeutic strategy for diabetes.

Adiponectin-induced inhibition of intrinsic and extrinsic apoptotic pathways protects pancreatic β-cells against apoptosis

Apoptosis is the main form of β-cell death in type 2 diabetes mellitus. There are 2 major pathways leading to apoptosis, 'intrinsic and extrinsic pathways'. Adiponectin is an adipocyte-derived hormone, which plays an important role in glucose and lipid metabolism. The main aims of this study were to investigate related apoptotic pathways in diabetes and the anti-apoptosis effects of adiponectin on pancreatic β-cell and the underlying mechanisms. Diabetic mice were generated by intraperitoneal injection of streptozotocin (STZ, 50 mg/kg/d for 5 days) and high-fat diet. Adiponectin overexpressing mice were developed by injecting lentivirus expressing mouse full length adiponectin (plenti-acdc-EGFP) through tail vein. Fourteen days after plenti-acdc-EGFP lentivirus injection, plasma adiponectin protein levels were increased 2-fold. Plasma triglyceride and glucose levels, but not total cholesterol, were significantly reduced in plenti-acdc-EGFP-treated mice. Pancreatic β-cell apoptotic numbers and the expression of caspase-8, -9, -3 in islet increased in diabetic mice, which was reversed by elevated adiponectin in plenti-acdc-EGFP-treated mice. These results suggest that both intrinsic and extrinsic apoptotic pathways have an important role in diabetic β-cell apoptosis. Adiponectin has antidiabetic and anti-apoptotic effects by regulating glucose and lipid metabolisms and inhibiting intrinsic and extrinsic apoptotic pathway in pancreatic β-cells.

Ontogeny of StAR and ACTH-R genes in ovine placenta

It has been demonstrated that the ovine placenta secretes estrogen, progesterone and cortisol, and that plasma concentrations of estrogen and cortisol increase before birth. Among the elements important for steroid production is steroidogenic acute regulatory protein (StAR) which acutely delivers cholesterol from the outer to the inner mitochondrial membrane for rapid steroidogenesis. This study was designed to determine if StAR is present in ovine placenta, and if its expression changes during fetal development. In addition, because cortisol is secreted by the placenta, we also examined the expression of adrenocorticotropic hormone receptor (ACTH-R) to determine if it was present and if the pattern of expression changed as gestation proceeded. The mRNA levels for StAR and ACTH-R were assessed by RNase protection assay (RPA) and protein levels were measured by Western blot in placentas from pregnant ewes (100-105 days of gestation, n = 8; 120 days of gestation, n = 5; 135-142 days of gestation, n = 8). The data show that the ovine placenta expresses StAR and ACTH-R. There was a significant increase in the StAR mRNA and protein between 100 and 142 days of gestation, but there were no significant age-related changes in ACTH-R mRNA and protein levels. The data suggest that the increased steroid production by the placenta in late gestation may be related to the increased expression of StAR.

[Immunofluorescence study of intermediate filament protein vimentin of CP-activated macrophages]

Vimentin is an important cytoskeleton protein for the biological function of macrophages. Alterations of vimentin filaments of CP-activated macrophages stained with FITC-labeled anti-vimentin antibody were observed under immunofluorescence microscope. Activated macrophages showed changes with the following characteristics: the intensity of immunofluorescence of vimentin was increased; the filaments of vimentin became thicker than those of normal macrophages when they were treated with colchicine; and the arrangement of vimentin filaments was parallel in direction to the polarization of the activated macrophages.

[Isolation, purification and antibody preparation of vimentin]

Vimentin was isolated and purified from pig lens with DEAE 52 and CM32 chromatography, which was identified by the following procedures: SDS-PAGE, analysis of amino acid composition, negative staining for electron microscopy and Western Blot. Antiserum of vimentin was prepared and its specificity was detected in normal and tumor tissues by immunohistochemical technique. Distribution of vimentin in 3T3 and L-929 cells was studied with immunofluorescence technique. The result showed that vimentin appeared as networks in the cytoplasm, and the antibody thus prepared might be used for basic research work and pathologic diagnosis.

Lateral diffusion of human histocompatibility antigens in isolated plasma membranes

We have prepared large (5-10 microns) plasma membrane fragments by lysis of VA-2, human, cells adherent to Sephadex beads. The membrane fragments may be removed from beads by sonication and stained with fluorescent antibodies to human histocompatibility antigens, HLA antigens. Lateral diffusion of labelled antigens is followed by the method of fluorescence photobleaching recovery (FPR). HLA antigens of isolated membranes diffuse at the same rate, approx. (2-4) X 10(-10) cm2 X s-1 as they do in intact cells. This rate may be modified by incubating membranes in a variety of media. Buffers of slightly acid pH (6.5 or less) enhance lateral diffusion, while the presence of divalent ions slightly reduces diffusion rates. Our major finding is that incubation of 37 degrees in 0.10 M phosphate buffer increases lateral diffusion 3-5-fold.

Time-lapse microcinematographic and phase contrast studies on the cell reformation of Chirocephalus yolk granules in vitro

In this article we report on a time-lapse microcinematographic and phase contrast study of the cell reformation of yolk granules which were isolated from mature oocytes in the genital sac of the middle female intersex of Chirocephalus nankinensis. The observations on yolk granules were made in fixed positions and the morphological changes of cell reformation were continuously recorded in vitro. The transformation of yolk granules into cellular structures may be tentatively described as follows: At the early stages in culture, it can be seen that the granular or bubbly structures gradually appear within the hyaloid and homogeneous yolk granules; the appearance of yolk granules gradually changes from elliptical into round shape. With further transformation, their appearances in general take the shape of oblate spheroids, their size is smaller than before and inside the yolk granules their granular and bubbly structures become more and more obvious. Finally, the nuclear and cellular structures can be seen in these transforming yolks. By means of time-lapse microcinematographic and phase contrast examinations in fixed positions, single yolk granules obtained from the mature oocyte with little amounts of adhering cytoplasm are continuously recorded and have been shown to occur, steadily and gradually build up cellular structures by self-organization and self-assembly. Up to the present, we have cultured these kinds of cellular organizations repeatedly. Therefore, it can be concluded that the existence of cell reformation on the basis of yolk granules according to the dynamic morphological changes is an objective reality.