PLK1-activating IFI16-STING-TBK1 pathway induces apoptosis of intestinal epithelial cells in patients with intestinal Behçet's syndrome

Inflammatory signals from immunological cells may cause damage to intestinal epithelial cells (IECs), resulting in intestinal inflammation and tissue impairment. Interferon-γ-inducible protein 16 (IFI16) was reported to be involved in the pathogenesis of Behçet's syndrome (BS). This study aimed to investigate how inflammatory cytokines released by immunological cells and IFI16 participate in the pathogenesis of intestinal BS. RNA sequencing and real-time quantitative PCR (qPCR) showed that the positive regulation of tumor necrosis factor-α (TNF-α) production in peripheral blood mononuclear cells (PBMCs) of intestinal BS patients may be related to the upregulation of polo like kinase 1 (PLK1) in PBMCs (P = 0.012). The plasma TNF-α protein level in intestinal BS was significantly higher than in healthy controls (HCs; P = 0.009). PBMCs of intestinal BS patients and HCs were co-cultured with human normal IECs (NCM460) to explore the interaction between immunological cells and IECs. Using IFI16 knockdown, PBMC-NCM460 co-culture, TNF-α neutralizing monoclonal antibody (mAb), stimulator of interferon genes (STING) agonist 2'3'-cGAMP, and the PLK1 inhibitor SBE 13 HCL, we found that PLK1 promotes the secretion of TNF-α from PBMCs of intestinal BS patients, which causes overexpression of IFI16 and induces apoptosis of IECs via the STING-TBK1 pathway. The expressions of IFI16, TNF-α, cleaved caspase 3, phosphorylated STING (pSTING) and phosphorylated tank binding kinase 1 (pTBK1) in the intestinal ulcer tissue of BS patients were significantly higher than that of HCs (all P < 0.05). PLK1 in PBMCs of intestinal BS patients increased TNF-α secretion, inducing IEC apoptosis via activation of the IFI16-STING-TBK1 pathway. PLK1 and the IFI16-STING-TBK1 pathway may be new therapeutic targets for intestinal BS.

Clinical heterogeneity and five phenotypes identified in pediatric Behçet's syndrome: a cohort study from Shanghai Behçet's syndrome database

OBJECTIVES

Behçet's syndrome (BS) is a rare disease of unknown etiology, with limited reports especially in pediatric BS. The clinical characteristics and phenotypes of pediatric BS as a highly heterogeneous variable vessel vasculitis were investigated in this study.

METHODS

A cross-sectional study was conducted to compare clinical variables and descriptive characteristics of BS by age of onset and gender. Cluster analysis was then performed to identify the phenotypes of pediatric BS.

RESULTS

A total of 2082 BS patients were included in this study, 1834 adults and 248 children. Compared with adult-onset BS, pediatric BS had a higher incidence of folliculitis [relative risks (RR) and 95% confidence interval (CI) 1.3 (1.0-1.5)], uveitis of the left eye [RR and 95% CI 2.3 (1.0-5.0)], intestinal ulcer complications [RR and 95% CI 2.1 (1.1-4.2)], pericarditis [RR and 95% CI 2.5 (1.0-6.2)], and psychiatric disorders [RR and 95% CI 2.8(1.0-7.9)], while the incidence of thrombocytopenia was lower [RR 0.2 (0.1-1.0)]. Among pediatric BS, females had more genital ulcers, while males were more likely to have skin lesions, panuveitis, vascular involvement, venous lesions, cardiac involvement, and aortic aneurysms. Cluster analysis classified pediatric BS into five clusters (C1-C5): C1 (n = 61, 24.6%) showed gastrointestinal (GI) involvement; C2 (n = 44, 17.7%) was the central nervous system (CNS) type where 23 cases overlapped joint involvement; in C3 (n = 35, 14.1%), all patients presented with arthritis or arthralgia; all patients in C4 (n = 29, 11.7%) manifested ocular involvement, with a few patients overlapping with GI involvement or joint damage; C5 (n = 79, 31.9%) was the mucocutaneous type, presenting both oral ulcers, genital ulcers, and skin lesions.

CONCLUSIONS

The clinical features of pediatric and adult BS differ significantly. Male and female pediatric BS also have a distinct demography. Five phenotypes including GI, CNS, joint, ocular, and mucocutaneous types were identified for pediatric BS.

Comprehensive analysis of T-cell receptor repertoires reveals antigen-driven T-cell clusters in patients with Behçet's syndrome

T lymphocytes are the major components of adaptive immunity in Behçet's syndrome (BS) pathology. However, the precise mechanism of T-cell-induced inflammatory condition remains to be determined. We applied bulk sequencing of the T-cell receptor (TCR) β chain in peripheral blood samples from 45 patients with BS and 10 healthy donors as controls. TCR repertoires in BS patients displayed more clonality and less diversity than in healthy donors. Male patients exhibited lower diversity metrics of TCR and had a larger proportion in the top 10 clones than females (p = 0.016). There were no TCR clonality differences in other clinical features, such as age, disease duration, organ involvement, disease severity, and activity. By "Grouping of Lymphocyte Interactions by Paratope Hotspots" (GLIPH2) for antigen prediction, we found distinct 2477 clusters of TCR-β sequences that potentially recognize similar antigens shared between BS patients. We observed clonal T-cell expansion in BS patients. Sexual differences in TCR clonal expansion and public TCR groups deserve further study to reveal the underline T-cell-mediated immunity in BS.

Predictors of infliximab refractory intestinal Behçet's syndrome: A retrospective cohort study from the Shanghai Behçet's syndrome database

OBJECTIVES

This retrospective cohort study aimed to find out predictors and early biomarkers of Infliximab (IFX) refractory intestinal Behçet's syndrome (intestinal BS).

METHODS

We collected the baseline clinical characteristics, laboratory parameters, and concomitant therapies of intestinal BS patients treated by IFX from the Shanghai Behçet's syndrome database. After 1 year IFX therapy, intestinal BS patients with non-mucosal healing (NMH, intestinal ulcers detected by colonoscopy) and/or no clinical remission [NCR, scores of the disease activity index for intestinal Behçet's disease (DAIBD) ≥20] were defined as IFX refractory intestinal BS. Multivariate logistic regression analysis was performed to evaluate the predictors for NMH and NCR in IFX refractory intestinal BS.

RESULTS

In 85 intestinal BS patients, NMH was identified in 29 (34.12%) patients, and NCR was confirmed in 20 (23.53%) patients. Erythrocyte sedimentation rate (ESR; ≥24 mm/h) and free triiodothyronine (fT3; ≤3.3pmol/L) were the independent risk factors of NMH in IFX refractory intestinal BS. Drinking alcohol and the fT3/free thyroxine ratio (fT3/fT4; ≤0.24) were independent risk factors, and thalidomide was an independent protective factor, for NCR in intestinal BS patients treated by IFX.

CONCLUSION

This study may be applicable for adjusting the therapeutic strategy and sidestepping unnecessary exposure to IFX in intestinal BS patients. Routine assessments of ESR, fT3, and fT3/fT4 ratio are helpful to identify high-risk individuals of IFX refractory intestinal BS. Thalidomide is suggested to be a concomitant therapy with IFX for intestinal BS patients.

Clinical heterogeneity of ocular Behçet's syndrome versus intestinal Behçet's syndrome: a cross-sectional study from Shanghai Behçet's syndrome database

Background

Behçet’s syndrome (BS) is a rare variant vasculitis which can involve the eyes and gastrointestinal systems. However, ocular involvement rarely overlaps with intestinal lesions. This study aimed to compare the clinical characteristics and laboratory parameters of ocular BS and intestinal BS patients in China and analyze the differences between two key phenotypes to verify the heterogeneous conditions in BS patients.

Methods

A retrospective analysis was used to collect the demographic data, clinical characteristics, endoscopic findings, and laboratory parameters from 135 ocular BS and 174 intestinal BS patients. The Mann-Whitney U test and Pearson chi-square or continuity correction was used to analyze the differences between two groups.

Results

Among 916 BS patients enrolled in this study, ocular BS and intestinal BS accounted for 14.74% (135 cases) and 19.00% (174 cases), respectively. Ocular and intestinal involvements overlapped in only 7 cases (0.76%). Male gender (74.8% vs. 51.1%, P=0.00), erythema nodosum (45.9% vs. 32.2%, P=0.01), and vascular involvement (6.7% vs. 1.7%, P=0.03) were more frequent in the ocular BS group compared with the intestinal BS group. On the contrary, hematologic involvement (7.5% vs. 0.0%, P=0.00) and fever (17.8% vs. 4.4%, P=0.00) were more frequent in the intestinal BS group compared with the ocular BS group. Additionally, the inflammation markers including ESR [26.5 (16.0–41.5) vs. 9.0 (5.0–15.0) mm/H, P=0.00], CRP [14.8 (4.8–33.0) vs. 4.1 (1.6–8.3) mg/L, P=0.00], serum amyloid A [27.4 (10.8–92.3) vs. 11.3 (6.0–24.0) mg/L, P=0.00], and interleukin 6 [8.4 (1.7–18.7) vs. 1.7 (1.5–3.2) pg/mL, P=0.00] were higher in the intestinal BS group than those in the ocular BS group, respectively.

Conclusions

Ocular BS was more prevalent in male patients and more likely to manifest with erythema nodosum and vascular involvement, while intestinal BS tends to have fever and hematologic disorders with higher inflammation markers. Ocular BS and intestinal BS are two distinct clinical phenotypes and very rarely overlapped.

New insight into the features of Behçet's disease with gastrointestinal ulcer: a cross-sectional observational study

BACKGROUND

Behçet's disease (BD) can involve any site of the alimentary canal. There has been research concerning intestinal BD. Nevertheless, the entire digestive tract not yet been studied extensively. Therefore, the purpose of study was to describe the prevalence, location, clinical features and possible risk factors of BD with gastrointestinal tract ulcer.

METHODS

This was a cross-sectional observational study that included 1232 consecutive BD patients who routinely underwent endoscopy upon their wishes. The clinical symptoms, endoscopic findings, and histologic features of BD with gastrointestinal ulcer and negative Helicobacter pylori (Hp) were identified.

RESULT

We found that 22.16% (273/1232) BD patients had ulcers of the alimentary tract. At presentation, 61.54% (168/273) patients were asymptomatic. Isolated gastroduodenal involvement is an extremely usual event. The second was the pairwise combination between bowel segments, and 24 cases involved three segments at the same time. One patient suffered from total gastrointestinal tract involvement. Inflammation was the most common histopathologic feature 77.60% (142/183). The 273 BD patients with gastrointestinal ulcer were at greater risk of having archenteric symptoms (OR 0.070, P < 0.001), fever (OR 0.115, P = 0.047), high CRP (OR 0.994, P = 0.027) and BDCAF level (OR 0.590, P = 0.010). Uveitis correlates negatively with gastrointestinal involvement in BD patients (OR 3.738, P = 0.011).

CONCLUSIONS

BD could affect the upper gastrointestinal tract independently. Endoscopy should be conducted in all patients in whom a diagnosis of BD is entertained, especially in patients with higher CRP, disease activity and fever. While, BD patients with uveitis correlates negatively with gastrointestinal involvement.

S-adenosyl-L-homocysteine hydrolase is necessary for aldosterone-induced activity of epithelial Na(+) channels

The A6 cell line was used to study the role of S-adenosyl-L-homocysteine hydrolase (SAHHase) in the aldosterone-induced activation of the epithelial Na(+) channel (ENaC). Because aldosterone increases methylation of several different molecules, and because this methylation is associated with increased Na(+) reabsorption, we tested the hypothesis that aldosterone increases the expression and activity of SAHHase protein. The rationale for this work is that general methylation may be promoted by activation of SAHHase, the only enzyme known to metabolize SAH, a potent end-product inhibitor of methylation. Although aldosterone increased SAHHase activity, steroid did not affect SAHHase expression. Antisense SAHHase oligonucleotide decreased SAHHase expression and activity. Moreover, this oligonucleotide, as well as a pharmacological inhibitor of SAHHase, decreased aldosterone-induced activity of ENaC via a decrease in ENaC open probability. The kinetics of ENaC in cells treated with antisense plus aldosterone were similar to those reported previously for the channel in the absence of steroid. This is the first report showing that active SAHHase, in part, increases ENaC open probability by reducing the transition rate from open states in response to aldosterone. Thus aldosterone-induced SAHHase activity plays a critical role in shifting ENaC from a gating mode with short open and closed times to one with longer open and closed times.

Contrasting effects of cPLA2 on epithelial Na+ transport

Activity of the epithelial Na+ channel (ENaC) is the limiting step for discretionary Na+ reabsorption in the cortical collecting duct. Xenopus laevis kidney A6 cells were used to investigate the effects of cytosolic phospholipase A2 (cPLA2) activity on Na+ transport. Application of aristolochic acid, a cPLA2 inhibitor, to the apical membrane of monolayers produced a decrease in apical [3H]arachidonic acid (AA) release and led to an approximate twofold increase in transepithelial Na+ current. Increased current was abolished by the nonmetabolized AA analog 5,8,11,14-eicosatetraynoic acid (ETYA), suggesting that AA, rather than one of its metabolic products, affected current. In single channel studies, ETYA produced a decrease in ENaC open probability. This suggests that cPLA2 is tonically active in A6 cells and that the end effect of liberated AA at the apical membrane is to reduce Na+ transport via actions on ENaC. In contrast, aristolochic acid applied basolaterally inhibited current, and the effect was not reversed by ETYA. Basolateral application of the cyclooxygenase inhibitor ibuprofen also inhibited current. Both effects were reversed by prostaglandin E2 (PGE2). This suggests that cPLA2 activity and free AA, which is metabolized to PGE2, are necessary to support transport. This study supports the fine-tuning of Na+ transport and reabsorption through the regulation of free AA and AA metabolism.

Enac degradation in A6 cells by the ubiquitin-proteosome proteolytic pathway

Amiloride-sensitive epithelial Na(+) channels (ENaC) are responsible for trans-epithelial Na(+) transport in the kidney, lung, and colon. The channel consists of three subunits (alpha, beta, gamma) each containing a proline rich region (PPXY) in their carboxyl-terminal end. Mutations in this PPXY domain cause Liddle's syndrome, an autosomal dominant, salt-sensitive hypertension, by preventing the channel's interactions with the ubiquitin ligase Neural precursor cell-expressed developmentally down-regulated protein (Nedd4). It is postulated that this results in defective endocytosis and lysosomal degradation of ENaC leading to an increase in ENaC activity. To show the pathway that degrades ENaC in epithelial cells that express functioning ENaC channels, we used inhibitors of the proteosome and measured sodium channel activity. We found that the inhibitor, MG-132, increases amiloride-sensitive trans-epithelial current in Xenopus distal nephron A6 cells. There also is an increase of total cellular as well as membrane-associated ENaC subunit molecules by Western blotting. MG-132-treated cells also have increased channel density in patch clamp experiments. Inhibitors of lysosomal function did not reproduce these findings. Our results suggest that in native renal cells the proteosomal pathway is an important regulator of ENaC function.

Differential effects of protein kinase C on the levels of epithelial Na+ channel subunit proteins

Regulation of epithelial Na(+) channel (ENaC) subunit levels by protein kinase C (PKC) was investigated in A6 cells. PKC activation altered ENaC subunit levels, differentially decreasing the levels of both beta and gamma, but not alphaENaC. Temporal regulation of beta and gammaENaC by PKC differed; gammaENaC decreased with a time constant of 3.7 +/- 1.0 h, whereas betaENaC decreased in 13.9 +/- 3. 0 h. Activation of PKC also resulted in a decrease in trans-epithelial Na(+) reabsorption for up to 48 h. PMA activation of PKC resulted in negative feedback inhibition of PKC protein levels beginning within 4 h. Both beta and gammaENaC levels, as well as transport tended toward pretreatment values after 48 h of PMA treatment. PKC inhibitors attenuated the effects of PMA on ENaC subunit levels and Na(+) transport. These results directly show for the first time that PKC differentially regulates ENaC subunit levels by decreasing the levels of beta and gamma but not alphaENaC protein. These results imply a PKC-dependent, long term decrease in Na(+) reabsorption.

The effect of rapamycin on single ENaC channel activity and phosphorylation in A6 cells

Rapamycin and FK-506 are immunosuppressive drugs that bind a ubiquitous immunophilin, FKBP12, but immunosuppressive mechanisms and side effects appear to be different. Rapamycin binds renal FKBP12 to change renal transport. We used cell-attached patch clamp to examine rapamycin's effect on Na(+) channels in A6 cells. Channel NP(o) was 0.5 +/- 0.08 (n = 6) during the first 5 min but fell close to zero after 20 min. Application of 1 microM rapamycin reactivated Na(+) channels (NP(o) = 0.47 +/- 0.1; n=6), but 1 microM FK-506 did not. Also, GF-109203X, a protein kinase C (PKC) inhibitor, mimicked the rapamycin-induced reactivation in a nonadditive manner. However, rapamycin did not reactivate Na(+) channels if cells were exposed to 1 microM FK-506 before rapamycin. In PKC assays, rapamycin was as effective as the PKC inhibitor; however, epithelial Na(+) channel (ENaC) phosphorylation was low under baseline conditions and was not altered by PKC inhibitors or activators. These results suggest that rapamycin activates Na(+) channels by binding FKBP12 and inhibiting PKC, and, in renal cells, despite binding the same immunophilin, rapamycin and FK-506 activate different intracellular signaling pathways.

An image analysis on pathological changes in pulmonary arteries in chronic obstructive pulmonary disease

The changes in small pulmonary arteries of 15 patients with chronic obstructive pulmonary disease (COPD) were investigated by light and electron microscopy, image analysis etc. It was found that the structural changes in the pulmonary arteries of the patients with COPD were characterized by muscularization of non-muscular arterioles, media hypertrophy, longitudinal smooth muscle bundles in the intima and fibrosis in both the media and intima. In the course of time, these lesions resulted in thickening of the arterial wall and narrowing of the lumen. Clinically, the patients developed pulmonary hypertension causing cor pulmonale. Initial data on the structure of arterial wall at different segments were compared statistically. There was very significant difference between the COPD and control groups (P less than 0.001). By Fisher's auto-classification (automatic pattern recognition), the rate recognized was correct in more than 90% in the small arteries of less than 200 microns in diameter. It is suggested that these arteriolar changes are closely related to pulmonary hypertension. The image analysis showed that the ratios of MWA/MVA and MWT/MD were of great value in evaluating the degree of the changes in the arteries of the patients with COPD.

Reconstruction of the frequency distribution of A- and B-cell size in the pancreatic islets from several animal species--an important stereological operation in QMSOC

The stereological algorithms for the conversion of the profile-size frequency distribution (PSFD) observed in histological section to the sphere-size frequency distribution (SSFD) in three-dimensional space was developed to a computer program and its practical application was described in this paper. The reconstructions of SSFD were based on the data of PSFD of A- and B-cells measured in sections of the pancreatic islets from ophiocephalus argus, toad, chicken, cat, rabbit and rat. The sizes of both profile and sphere were expressed by their caliper diameters. The experimental results showed that the patterns of SSFD of A- and B-cells from six animal species were somewhat different, and that all the peaks of them, however, occurred in the range from 6 to 12 microns in caliper diameter.

Information medicine and its primary functions of exploitation of medical resources

The aim of this paper is to continue the discussion on the defects of the structures of medical resources and their applicability at the present time, and then to design the qualitative networklike subsystem of the new research Quantitatively Medicine Simulating and Operating by Computer (QMSOC) and a five-library model of the new knowledge-base of QMSOC. Finally, a set of results from the primary functions of exploitation of pancreas-glucagon-insulin information by QMSOC are presented.

Structure characteristics of QMSOC and the relevant operators

This article presents a further description on the background, significance, and structure characteristics of Quantitative Medicine Simulation and Operation by Computer (QMSOC). Also some basic operators were recommended for calculations of biomedical events such as estimation of substance concentrations, exploration of etiology, evaluation of biomedical effects, etc. At last some differences of QMSOC from other artificial intelligent systems in the medical field were discussed.

Application of the method of multiple thresholding to white blood cell classification

A new method of image segmentation based on the principle of multiple grey level thresholding has been applied to a data set consisting of 1149 white blood cells of 13 different, clinically important types, randomly chosen on 20 blood smears from leukemia patients. Classification of these cells on the basis of quantitative measurements in the segmented images yields an accuracy of 82.6%. Some of the erroneous classifications must be attributed to intrinsic problems in the assignment of a priori labels. Correcting for such cases, the performance of the method, as measured on the present data set, increases to 89.8%. This illustrates the practical applicability of the segmentation method in automated white blood cell and possibly other cytological and histological analysis systems.

Automated white blood cell classification revisited

A novel approach to the problem of automated white blood cell classification is described. Whereas in most earlier attempts the segmentation of the cells has been recognized as the most difficult and most critical step in the sequence of operations resulting in the classification, the method described here eliminates the necessity of the detection of the contour of the nucleus and of the cytoplasm, and is therefore less sensitive to such disturbing factors as the presence of granules, of other cells touching the cell of interest, etc. The multiple sequential threshold method to be described here in two slightly different variants yields a correct classification rate of 94.7% for a 4 class problem (90 cells in the test set), and 91.8% for an 8 class problem (279 cells in the test set). Both experiments include immature cell types.