Syntaxin 4 Enrichment in β-Cells Prevents Conversion to Autoimmune Diabetes in Non-Obese Diabetic (NOD) Mice

Syntaxin 4 (STX4), a plasma membrane-localized SNARE protein, regulates human islet β-cell insulin secretion and preservation of β-cell mass. We found that human type 1 diabetes (T1D) and NOD mouse islets show reduced β-cell STX4 expression, consistent with decreased STX4 expression, as a potential driver of T1D phenotypes. To test this hypothesis, we generated inducible β-cell-specific STX4-expressing NOD mice (NOD-iβSTX4). Of NOD-iβSTX4 mice, 73% had sustained normoglycemia vs. <20% of control NOD (NOD-Ctrl) mice by 25 weeks of age. At 12 weeks of age, before diabetes conversion, NOD-iβSTX4 mice demonstrated superior whole-body glucose tolerance and β-cell glucose responsiveness than NOD-Ctrl mice. Higher β-cell mass and reduced β-cell apoptosis were also detected in NOD-iβSTX4 pancreata compared with pancreata of NOD-Ctrl mice. Single-cell RNA sequencing revealed that islets from NOD-iβSTX4 had markedly reduced interferon-γ signaling and tumor necrosis factor-α signaling via nuclear factor-κB in islet β-cells, including reduced expression of the chemokine CCL5; CD4⁺ regulatory T cells were also enriched in NOD-iβSTX4 islets. These results provide a deeper mechanistic understanding of STX4 function in β-cell protection and warrant further investigation of STX4 enrichment as a strategy to reverse or prevent T1D in humans or protect β-cell grafts.

[Posterior sternocleidomastoid border approach of gasless transaxillary endoscopic thyroidectomy in patients with papillary thyroid carcinoma: comparison with sternocleidomastoid fascia approach]

Objective: To examine the posterior sternocleidomastoid border approach which elevated whole sternocleidomastoid in gasless transaxillary endoscopic thyroidectomy. Methods: The clinical data of 46 patients with papillary thyroid carcinoma treated with gasless transaxillary endoscopic thyroidectomy from May 2019 to June 2020 at Department of Head and Neck Surgery, Sichuan Cancer Hospital was analyzed retrospectively. There were 9 males and 37 females, aged (38.6±12.0) years (range: 19 to 74 years). Fourteen and 32 cases performed posterior sternocleidomastoid border and sternocleidomastoid fascia approach, respectively. Comparative analysis were performed on clinical characters, surgical outcomes, postoperative complications, postoperative pain score, and quality-of-life of postoperative 1 month by t test, Wilcoxon rank sum test, Fisher exact test and χ2 test,respectively. Resuts Complete exposure of central compartment was higher (11/14 vs. 34.4%(11/32),χ²=7.624, P=0.006), more lymph nodes was retrieved (4.2±2.9 vs. 2.0±2.5, t=2.663, P=0.011) in posterior sternocleidomastoid border approach. There were no significant differences between groups in postoperative complications such as recurrent laryngeal nerve palsy (1/14 vs. 3.1%(1/32), P=0.521) and transient hypoparathyroidism (0 vs. 6.2%(2/32), P=1) and pains and quality-of-life. Conclusion: Posterior sternocleidomastoid border approach of gasless transaxillary endoscopic thyroidectomy is safe and reliable and has the advantage of central compartment dissection without increasing trauma.

[Progression of diagnosis and treatment of medullary thyroid carcinoma]

Objective: To review and summarize recent update on preoperative diagnostic criteria, treatment and postoperative follow-up for medullary thyroid carcinoma. Methods: The relevant literatures and guidelines about medullary thyroid carcinoma were analyzed and summarized. Results: In the early stages of the disease radical surgery still dominated. Ultrasound results suggested that prophylactic lateral neck dissection was required for patients with high risk factors or high levels of carcinoembryonic antigen and calcitonin need prophylactic. Early hereditary medullary carcinoma could receive prophylactic thyroidectomy based on RET gene test results. Advanced progressive medullary thyroid carcinoma could be treated with palliative surgery,molecular targeted drugs and chemotherapy. Conclusions: The prognosis of medullary thyroid carcinoma is poor and lymph node metastasis is easy to occur early. The extent of initial operation should be enough. Locally advanced or distant metastatic medullary thyroid carcinoma can be treated with palliative surgery,molecular targeted drugs and chemotherapy.

Autoantibody against integrin αv β3 contributes to thrombocytopenia by blocking the migration and adhesion of megakaryocytes

Essentials The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. We analyzed the role of anti-αvβ3 autoantibody in the pathogenesis of ITP in patients. Anti-αvβ3 autoantibody impeded megakaryocyte migration and adhesion to the vascular niche. Anti-αv β3 autoantibody potentially contributes to the pathogenesis of refractory ITP.

SUMMARY

Background The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. Anti-αvβ3 integrin autoantibody is detected in chronic ITP patients, but its contribution to ITP is still unclear. Objectives To clarify the potential role of anti-αvβ3 integrin autoantibody in chronic ITP and the related mechanism. Methods Relationship between levels of anti-αvβ3 autoantibody and platelets in chronic ITP patients was evaluated. The influence of anti-αvβ3 antibody on megakaryocyte (MK) survival, differentiation, migration and adhesion was assessed, and the associated signal pathways were investigated. Platelet recovery and MKs' distribution were observed in an ITP mouse model pretreated with different antibodies. Result In this study, we showed that the anti-αvβ3 autoantibody usually coexists with anti-αIIbβ3 autoantibody in chronic ITP patients, and patients with both autoantibodies have lower platelets. In in vitro studies, we showed that the anti-αvβ3 antibody had no significant effect on the survival and proliferation of MKs, whereas it decreased formations of proplatelet significantly. Anti-αvβ3 antibody impeded stromal cell derived facor-1 alpha (SDF-1α)- mediated migration and inhibited the phosphorylation of protein kinase B. Anti-αvβ3 antibody significantly inhibited MKs' adhesion to endothelial cells and Fibrogen. The phosphorylation of focal adhesion kinase and proto-oncogene tyrosine-protein kinase Src induced by adhesion was inhibited when MKs were pretreated with anti-αvβ3 antibody. In in vivo studies, we showed that injection with anti-αv antibody delayed platelet recovery in a mouse model of ITP. Conclusions These findings demonstrate that the autoantibody against integrin αv β3 may aggravate thrombocytopenia in ITP patients by impeding MK migration and adhesion to the vascular niche, which provides new insights into the pathogenesis of ITP.

[Application of virtual reality in surgical treatment of complex head and neck carcinoma]

Objective: To investigate the application of virtual reality technology in the preoperative evaluation of complex head and neck carcinoma and he value of virtual reality technology in surgical treatment of head and neck carcinoma. Methods: The image data of eight patients with complex head and neck carcinoma treated from December 2016 to May 2017 was acquired. The data were put into virtual reality system to built the three-dimensional anatomical model of carcinoma and to created the surgical scene. The process of surgery was stimulated by recognizing the relationship between tumor and surrounding important structures. Finally all patients were treated with surgery. And two typical cases were reported. Results: With the help of virtual reality, surgeons could adequately assess the condition of carcinoma and the security of operation and ensured the safety of operations. Conclusions: Virtual reality can provide the surgeons with the sensory experience in virtual surgery scenes and achieve the man-computer cooperation and stereoscopic assessment, which will ensure the safety of surgery. Virtual reality has a huge impact on guiding the traditional surgical procedure of head and neck carcinoma.