The role of Bruton’s tyrosine kinase in autoimmunity and implications for therapy

Bruton’s tyrosine kinase (BTK) mediates B cell signaling and is also present in innate immune cells but not T cells. BTK propagates B cell receptor (BCR) responses to antigen-engagement as well as to stimulation via CD40, toll-like receptors (TLRs), Fc receptors (FCRs) and chemokine receptors. Importantly, BTK can modulate signaling, acting as a “rheostat” rather than an “on-off” switch; thus, overexpression leads to autoimmunity while decreased levels improve autoimmune disease outcomes. Autoreactive B cells depend upon BTK for survival to a greater degree than normal B cells, reflected as loss of autoantibodies with maintenance of total antibody levels when BTK is absent. This review describes contributions of BTK to immune tolerance, including studies testing BTK-inhibitors for treatment of autoimmune diseases.     

DNA–histone complexes as ligands amplify cell penetration and nuclear targeting of anti‐DNA antibodies via energy‐independent mechanisms

We have generated three monoclonal cell‐penetrating antibodies (CPAbs) from a non‐immunized lupus‐prone (NZB × NZW)F₁ mouse that exhibited high anti‐DNA serum titres. These CPAbs are polyreactive because they bind to DNA and other cellular components, and localize mainly in the nucleus of HeLa cells, albeit with a distinct nuclear labelling profile. Herein, we have examined whether DNA–histone complexes (DHC) binding to CPAbs, before cell entry, could modify the cell penetration of CPAbs or their nuclear staining properties. By applying confocal microscopy and image analysis, we found that extracellular binding of purified CPAbs to DHC significantly enhanced their subsequent cell‐entry, both in terms of percentages of positively labelled cells and fluorescence intensity (internalized CPAb amount), whereas there was a variable effect on their nuclear staining profile. Internalization of CPAbs, either alone or bound to DHC, remained unaltered after the addition of endocytosis‐specific inhibitors at 37° or assay performance at 4°, suggesting the involvement of energy‐independent mechanisms in the internalization process. These findings assign to CPAbs a more complex pathogenetic role in systemic lupus erythematosus where both CPAbs and nuclear components are abundant.     

Serotonergic raphe magnus cell discharge reflects ongoing autonomic and respiratory activities

Serotonergic cells are located in a restricted number of brain stem nuclei, send projections to virtually all parts of the CNS, and are critical to normal brain function. They discharge tonically at a rate modulated by the sleep-wake cycle and, in the case of medullary serotonergic cells in raphe magnus and the adjacent reticular formation (RM), are excited by cold challenge. Yet, beyond behavioral state and cold, endogenous factors that influence serotonergic cell discharge remain largely mysterious. The present study in the anesthetized rat investigated predictors of serotonergic RM cell discharge by testing whether cell discharge correlated to three rhythms observed in blood pressure recordings that averaged >30 min in length. A very slow frequency rhythm with a period of minutes, a respiratory rhythm, and a cardiac rhythm were derived from the blood pressure recording. Cross-correlations between each of the derived rhythms and cell activity revealed that the discharge of 38 of the 40 serotonergic cells studied was significantly correlated to the very slow and/or respiratory rhythms. Very few serotonergic cells discharged in relation to the cardiac cycle and those that did, did so weakly. The correlations between serotonergic cell discharge and the slow and respiratory rhythms cannot arise from baroreceptive input. Instead we hypothesize that they are by-products of ongoing adjustments to homeostatic functions that happen to alter blood pressure. Thus serotonergic RM cells integrate information about multiple homeostatic activities and challenges and can consequently modulate spinal processes according to the most pressing need of the organism.     

Initial combination therapy with vildagliptin plus metformin in drug-naïve patients with T2DM: a 24-week real-life study from Asia

Aims: To assess the effectiveness and safety of vildagliptin/metformin initial combination therapy in drug-naïve patients with type 2 diabetes mellitus (T2DM).

Methods: INITIAL was a 24-week prospective, observational study in T2DM patients with glycated hemoglobin (HbA1c)?≥?7.5%, and prescribed vildagliptin/metformin as initial combination therapy. The primary endpoint was change in HbA1c from baseline to week 24. Key secondary endpoints were HbA1c change from baseline to week 12, proportion of patients achieving HbA1c ≤7.0%, change in body weight at 12 and 24 weeks, change in HbA1c by sub-groups (baseline HbA1c, age, body mass index [BMI], dosage strength, co-morbidities) from baseline to week 24, and safety.

Results: A total of 532 patients were enrolled. The mean age, HbA1c, and BMI were 49.6?±?11.27 years, 9.3?±?1.57%, and 26.7?±?4.50?kg/m², respectively. Cardiovascular risk factors present at baseline were dyslipidemia (30.1%), hypertension (29.7%), and obesity (20.9%). The mean reductions in HbA1c from baseline to week 12 (?1.6?±?1.59%) and 24 (?1.9?±?1.70%) were statistically significant (p?Conclusions: Overall, in a relatively young drug-naïve T2DM Asian study population with high baseline HbA1c and often associated with cardiovascular risk factors, vildagliptin/metformin combination therapy was associated with significant and clinically relevant HbA1c reduction from baseline. This effect was seen at week 12, was maintained over 24 weeks, and was accompanied by good tolerability.     

Heme oxygenase-1 and carbon monoxide suppress autoimmune neuroinflammation

Heme oxygenase-1 (HO-1, encoded by HMOX1) dampens inflammatory reactions via the catabolism of heme into CO, Fe, and biliverdin. We report that expression of HO-1 dictates the pathologic outcome of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS). Induction of EAE in Hmox1(-/- )C57BL/6 mice led to enhanced CNS demyelination, paralysis, and mortality, as compared with Hmox1(+/+) mice. Induction of HO-1 by cobalt protoporphyrin IX (CoPPIX) administration after EAE onset reversed paralysis in C57BL/6 and SJL/J mice and disease relapse in SJL/J mice. These effects were not observed using zinc protoporphyrin IX, which does not induce HO-1. CoPPIX protection was abrogated in Hmox1(-/-) C57BL/6 mice, indicating that CoPPIX acts via HO-1 to suppress EAE progression. The protective effect of HO-1 was associated with inhibition of MHC class II expression by APCs and inhibition of Th and CD8 T cell accumulation, proliferation, and effector function within the CNS. Exogenous CO mimicked these effects, suggesting that CO contributes to the protective action of HO-1. In conclusion, HO-1 or exposure to its end product CO counters autoimmune neuroinflammation and thus might be used therapeutically to treat MS.     

Risk and protective factors for sexual risk taking among adolescents involved in Prime Time

This article describes a preliminary qualitative evaluation of risk and protective factors associated with consistent contraceptive use and healthy sexual decision-making among ten of the first participants in the Prime Time intervention study. Prime Time is an 18-month intervention including one-on-one case management and peer educator training targeting sexually active 13-17-year-old girls who are recruited from health care clinics. Using an approach grounded in findings from previous research, social cognitive theory, and the social development model, Prime Time aims to improve participants' contraceptive use consistency, reduce number of sexual partners, and reduce unwanted sexual activity. Findings from this preliminary evaluation alert health care providers to the complex and dynamic nature of adolescent girls' sexual behaviors and to a broad range of risk and protective factors within individuals and their environments that may influence adolescent girls' sexual behaviors and contraceptive use. Findings suggest that an ongoing, supportive relationship with a case manager who is able to pace and tailor an intervention to the individual young person can have positive effects on adolescent girls' sexual behaviors and contraceptive use.     

Surgical training for anatomical endoscopic enucleation of the prostate

Anatomical endoscopic enucleation of the prostate has been proposed as a potentially superior benign prostatic hyperplasia surgery than conventional transurethral resection of prostate. However, the learning curve of the procedure is steep, hence limiting its generalisability worldwide. In order to overcome the learning curve, a proper surgical training is extremely important. This review article discussed about various aspects of surgical training in anatomical endoscopic enucleation of the prostate. In summary, no matter what surgical technique or energy modality you use, the principle of anatomical enucleation should be followed. When one starts to perform prostate enucleation, a 50 to 80 g prostate appears to be the ‘best case’ to begin with. Mentorship is extremely important to shorten the learning curve and to prevent drastic complications from the procedure. A proficiency-based progression training programme with the use of simulation and training models should be the best way to teach and learn about prostate enucleation. Enucleation ratio efficacy is the preferred measure for assessing skill level and learning curve of prostate enucleation. Morcellation efficiency is commonly used to assess morcellation performance, but the importance of safety rather than efficiency must be emphasised.