Tspan8 is expressed in breast cancer and regulates E-cadherin/catenin signalling and metastasis accompanied by increased circulating extracellular vesicles

Tspan8 exhibits a functional role in many cancer types including pancreatic, colorectal, oesophagus carcinoma, and melanoma. We present a first study on the expression and function of Tspan8 in breast cancer. Tspan8 protein was present in the majority of human primary breast cancer lesions and metastases in the brain, bone, lung, and liver. In a syngeneic rat breast cancer model, Tspan8⁺ tumours formed multiple liver and spleen metastases, while Tspan8⁻ tumours exhibited a significantly diminished ability to metastasise, indicating a role of Tspan8 in metastases. Addressing the underlying molecular mechanisms, we discovered that Tspan8 can mediate up-regulation of E-cadherin and down-regulation of Twist, p120-catenin, and β-catenin target genes accompanied by the change of cell phenotype, resembling the mesenchymal–epithelial transition. Furthermore, Tspan8⁺ cells exhibited enhanced cell–cell adhesion, diminished motility, and decreased sensitivity to irradiation. As a regulator of the content and function of extracellular vesicles (EVs), Tspan8 mediated a several-fold increase in EV number in cell culture and the circulation of tumour-bearing animals. We observed increased protein levels of E-cadherin and p120-catenin in these EVs; furthermore, Tspan8 and p120-catenin were co-immunoprecipitated, indicating that they may interact with each other. Altogether, our findings show the presence of Tspan8 in breast cancer primary lesion and metastases and indicate its role as a regulator of cell behaviour and EV release in breast cancer. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

More expression,less function: cleaved dynamin in glomerular kidney disease

The role of dynamin in regulation of kidney filtration barrier is well documented. Dynamin binds to and produces filamentous actin, which is a key component of healthy podocyte foot processes (FPs). Destruction of dynamin, for example by cathepsin L, leads to loss of a functional actin network and uncoordinated membrane signaling, a situation that allows for effacement of FPs and proteinuria. Now, Khalil et al have examined the dynamin expression in kidneys of proteinuric animal models as well as in kidney patients and produced data that further clarifies the role of dynamin in glomerular and tubular proteinuria and may aid in pinpointing patients who are affected by loss of dynamin function and may benefit from appropriate therapeutic approaches. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Single and combined inhibition of tumor necrosis factor,interleukin‐1, and RANKL pathways in tumor necrosis factor–induced arthritis: Effects on synovial inflammation,bone erosion,and cartilage destruction

Objective

To investigate the efficacy of single and combined blockade of tumor necrosis factor (TNF), interleukin‐1 (IL‐1), and RANKL pathways on synovial inflammation, bone erosion, and cartilage destruction in a TNF‐driven arthritis model.

Methods

Human TNF–transgenic (hTNFtg) mice were treated with anti‐TNF (infliximab), IL‐1 receptor antagonist (IL‐1Ra; anakinra), or osteoprotegerin (OPG; an OPG‐Fc fusion protein), either alone or in combinations of 2 agents or all 3 agents. Synovial inflammation, bone erosion, and cartilage damage were evaluated histologically.

Results

Synovial inflammation was inhibited by anti‐TNF (−51%), but not by IL‐1Ra or OPG monotherapy. The combination of anti‐TNF with either IL‐1Ra (−91%) or OPG (−81%) was additive and almost completely blocked inflammation. Bone erosion was effectively blocked by anti‐TNF (−79%) and OPG (−60%), but not by IL‐1Ra monotherapy. The combination of anti‐TNF with IL‐1Ra, however, completely blocked bone erosion (−98%). Inhibition of bone erosion was accompanied by a reduction of osteoclast numbers in synovial tissue. Cartilage destruction was inhibited by anti‐TNF (−43%) and was weakly, but not significantly, inhibited by IL‐1Ra, but was not inhibited by OPG monotherapy. The combination of anti‐TNF with IL‐1Ra was the most effective double combination therapy in preventing cartilage destruction (−80%). In all analyses, the triple combination of anti‐TNF, IL‐1Ra, and OPG was not superior to the double combination of anti‐TNF and IL‐1Ra.

Conclusion

Articular changes caused by chronic overexpression of TNF are not completely blockable by monotherapies that target TNF, IL‐1, or RANKL. However, combined approaches, especially the combined blockade of TNF and IL‐1 and, to a lesser extent, TNF and RANKL, lead to almost complete remission of disease. Differences in abilities to block synovial inflammation, bone erosion, and cartilage destruction further strengthen the rationale for using combined blockade of more than one proinflammatory pathway.

     

4-Chloro-m-cresol is a Trigger of Malignant Hyperthermia in Susceptible Swine

Background: 4-Chloro-m-cresol (4-CmC) induces marked contractures in skeletal muscle specimens from individuals susceptible to malignant hyperthermia (MHS). In contrast, 4-CmC induces only small contractures in specimens from normal (MHN) patients. 4-CmC is a preservative within a large number of commercially available drug-preparations (e.g., insulin, heparin, succinylcholine), and it has been suggested that 4-CmC might trigger malignant hyperthermia. This study was designed to investigate the effects of 4-CmC in vivo and in vitro in the same animals.

Methods: After approval of the animal care committee, six Pietrain MHS and six control (MHN) swine were anesthetized with azaperone 4 mg/kg intramuscularly and metomidate 10 mg/kg intraperitoneally. After endotracheal intubation, lungs were mechanically ventilated (inspired oxygen fraction 0.3) and anesthesia was maintained with etomidate 2.5 mg [middle dot] kg-1 [middle dot] h-1 and fentanyl 50 [micro sign]g [middle dot] kg-1 [middle dot] h-1. Animals were surgically prepared with arterial and central venous catheters for measurement of hemodynamic parameters and to obtain blood samples. Before exposure to 4-CmC in vivo, muscle specimens were excised for in vitro contracture tests with 4-CmC in concentrations of 75 and 200 [micro sign]M. Subsequently, pigs were exposed to cumulative administration of 3, 6, 12, 24, and 48 mg/kg 4-CmC intravenously. If an unequivocal episode of malignant hyperthermia occurred, as indicated by venous carbon dioxide concentration >or= to 70 mmHg, pH or= to 2 [degree sign]C, the animals were treated with dantrolene, 3.5 mg/kg.

Results: All MHS swine developed malignant hyperthermia after administration of 4-CmC in doses of 12 or 24 mg/kg. Venous carbon dioxide concentration significantly increased and pH significantly decreased. Temperature increased in all MHS animals more than 2 [degree sign]C. Blood lactate concentrations and creatine kinase levels were significantly elevated. All MHS swine were treated successfully with dantrolene. In contrast, no MHN swine developed signs of malignant hyperthermia. After receiving 4-CmC in a concentration of 48 mg/kg, however, all MHN animals died by ventricular fibrillation. The in vitro experiments showed that both concentrations of 4-CmC produced significantly greater contractures in MHS than in MHN specimens.     

Klinische Erfahrungen mit dem implantierbaren atrialen Defibrillator (Atrioverter) bei Patienten mit Vorhofflimmern

Due to the limited efficacy of drug therapy in atrial fibrillation and the high rate of recurrence, strong efforts were made to find non-pharmacological strategies. For three years now, the implantable atrial defibrillator Metrix from InControl has been available as an alternative therapy. From October 1995 to the present the atrial defibrillator was implanted in 179 patients worldwide. The sensitivity of the system and its algorithms to detect atrial fibrillation is 90%; the specificity to detect sinus rhythm is 100%. In 121 of 179 patients, 748 episodes of spontaneous atrial fibrillation were treated with 2.4 shocks per episode. No proarrhythmic event or stroke was seen. A cardioversion to sinus rhythm could be achieved in 95% of patients; the overall clinical success rate was 88%. In 7% of all patients, early recurrence of atrial fibrillation (ERAF) occurred that could not be converted into stable sinus rhythm after further cardioversions and antiarrhythmic therapy. In 4.1% there were lead-related complications, in 4 patients the device had to be explanted because of ineffective therapy, and in 3 patients the device had to be changed because of loss of telemetry or early depletion of battery. In 8 patients, postoperative complications were seen (infections, pneumothorax and thrombosis of the subclavian vein). Overall, the implantable atrial defibrillator Metrix is an effective and safe alternative in treating atrial fibrillation.     

Spectrum of reperfusion strategies and factors influencing the use of primary angioplasty in patients with acute myocardial infarction admitted to hospitals with the facilities to perform primary angioplasty

OBJECTIVE—To determine the frequency of the use of primary angioplasty in patients with acute myocardial infarction and the factors influencing its indications in hospitals with the facilities to perform this treatment.
DESIGN—Data from the maximal individual therapy in acute myocardial infarction (MITRA) trial were analysed, concerning the effects of the decisions of individual hospitals, the time of admission of patients, and the effects of patient characteristics on the selection of reperfusion treatment.
PATIENTS—Between June 1994 and January 1997 eight hospitals treated 1532 patients with acute myocardial infarction. 418 (27.3%) were treated conservatively, 641 (41.8%) were treated using intravenous thrombolysis, 387 (25.3%) were treated using primary angioplasty, and 86 (5.6%) received a combination of thrombolysis and angioplasty.
RESULTS—The proportion of patients treated with primary angioplasty varied from 1.8% to 57.7% among the eight hospitals. The use of primary angioplasty during non-office hours also showed wide variation, ranging from 20% to 54% between centres. The use of thrombolysis was comparatively evenly distributed during the non-office hours, ranging from 50-69%. Four hospitals with a primary angioplasty use rate > 30% showed no difference in the proportion of patients with contraindications for thrombolysis, high risk patients, or a combination of both, when compared with four hospitals with a lower rate of primary angioplasty use (98/322 (30.4%) v 19/65 (29.2%), respectively, p = 0.847).
CONCLUSIONS—In hospitals with the facilities for performing primary angioplasty the most important factors influencing its use were the discretion of the individual hospital and the time of patient admission. Characteristics of patients did not influence the choice of reperfusion treatment


Keywords: acute myocardial infarction; primary angioplasty; reperfusion treatment     

Immediate and long-term results of ATG induction therapy for delayed graft function compared to conventional therapy for immediate graft function

The use of polyclonal antibodies for delayed graft function (DGF) was tested in 83 renal allograft recipients. Conventional immunosuppression (CI) was given to 52 patients with immediate graft function (IGF) while 31 patients with DGF received the polyclonal antibody ATG. Administration of OKT3 was restricted to steroid-resistant acute rejections in both groups. The incidence and severity of acute rejections, graft survival rate, CMV infections, and lymphocyte subsets were examined. ATG patients experienced a total of 0.6 acute rejections per patient, whereas CI patients had 0.9 on the average (P < 0.05). Second and third acute rejections occurred less frequently and later in the ATG group than in the CI group (P < 0.01). Steroid-resistant acute rejections occurred in 20 of the CI patients (38 %) but in only 7 of ATG patients (23 %). One-year graft survival in the CI and ATG groups was 98.1 % and 93.2 %, respectively. A decreased CD4 + to CD8 + T-lymphocyte ratio of about 0.5 was still detectable 5 years after the initial ATG administration. Hence, patients with DGF appear to benefit from induction therapy with ATG. Received: 3 March 1998 Received after revision: 20 July 1998 Accepted: 23 September 1998