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Introduction: Patients with isoniazid-resistance and rifampicin-sensitivity pulmonary tuberculosis (Hr-TB) can have resistance to other anti-TB drugs. Incorrect treatment may increase the resistance of mycobacteria TB (MBT) and develop multidrug and extensively drug-resistant TB. In the Russian Federation (RF), levofloxacin (Lfx) and capreomycin (Cm) are key drugs for treatment of Hr-TB, with addition of three 1st-line anti-TB drugs. Objective: To determine the effect of additional drug resistance (DR) of MBT in patients with Hr-TB on the efficacy of chemotherapy. Methods: We studied MTB drug resistance (DR) in 1379 Hr-TB patients started treatment in 2015 from 18 regions of the Russian Federation. All patients were distributed into 4 groups: group 1- DR to Lfx and Cm - 23/1379, group 2 – DR to Lfx and drug sensitivity (DS) to Cm - 56/1379, group 3 - DS to Lfx and DR to Cm - 41/1379, group 4 - DS to Lfx and Cm -1259/1379. Unfavorable outcome was registed in patients with culture positive at the 5th month of chemotherapy. Results: Significance of additional DR of MBT in Hr-TB patients was defined. Statistically significant differences were revealed between 1 and 4 groups. In the case of MBT sensitivity to fluoroquinolone and polypeptide, an unfavorable outcome was determined in 12.8% (162/1259), while in the case of resistance to fluoroquinolones and polypeptide in 34.7% (8/23) (OR=3.44;p Conclusion: DR simultaneously to both TB-drugs (Lfx, Cm) is a predictor of unfavorable outcome in Hr-TB cases, compared to the preserved sensitivity to both TB-drugs.

Introduction: Study of Regional mycobacterium tuberculosis (MBT) Drug Resistance (DR) allows to adopt treatment strategy in regions with high burden of XDR-TB. Aims and Objectives: To assess the frequency and spectrum of DR to first and second line drugs in the Ural regions. Methods: Multicenter trial in the six regions (Kurgan, Sverdlovsk, Tyumen, Chelyabinsk, Khanty-Mansiysk and Yamalo-Nenets) of the Ural was conducted in 2018. Totally 3.953 new TB cases patients and 1650 retreatment TB cases were registered. 1931 new TB cases and 1650 retreatment (relapse and chronic TB patients) have culture confirmation of TB. DST results for H; R; E; Z, Ofx, Lfx, Mfx, Km, Am, Cm were available for 1,852 new TB cases and 943 retreatment TB cases. Results: Among new TB cases: DR-TB was detected in 56.6% [95%CI 53.6-59.5], including Z and E resistance respectively in 9.1% [95%CI 7.5-9.8] and 25.0% [95%CI 22.5-27.6]. MDR-TB in 30.6% [95%CI 27.9-33.4] cases. Pre-XDR-TB with resistance to SLD injectable was found in 6.5% [95%CI 4.1-9.5] and pre-XDR-TB with resistance to Fq in 9.0% [95%CI 6.2-12.3] out of new MDR-TB cases. XDR TB was found in 12.2% [95%CI 8.9-15.9] out of MDR-TB cases. Among retreatment cases: DR-TB was detected in 83.5% [95%CI 80.2-86.5], MDR-TB in 45.6%, [95% CI 41.4-49.8]. Pre-XDR-TB with resistance to SLD injectable was found in 9.1% [95%CI 5.8-12.9] and with resistance to Fq in 7.4% [95%CI 4.5-11.0] out of new MDR-TB cases. XDR TB was found in 19.0% [95% CI 909-18.5] out of MDR-TB cases. Conclusions: In the Ural regions there is distribution of MDR strains with high level DR to first and second line drugs including XDR TB among new TB cases and retreatment cases in 12.2% and 19.0% respectively.

γ-Secretase is an intramembrane cleaving protease involved in the generation of the Alzheimer's disease (AD)-associated amyloid β peptide (Aβ). γ-Secretase is ubiquitously expressed in different organs, and also in different cell types of the human brain. Besides the involvement in the proteolytic generation of Aβ from the amyloid precursor protein, γ-secretase cleaves many additional protein substrates, suggesting pleiotropic functions under physiological and pathophysiological conditions. Microglia exert important functions during brain development and homeostasis in adulthood, and accumulating evidence indicates that microglia and neuroinflammatory processes contribute to the pathogenesis of neurodegenerative diseases. Recent studies demonstrate functional implications of γ-secretase in microglia, suggesting that alterations in γ-secretase activity could contribute to AD pathogenesis by modulation of microglia and related neuroinflammatory processes during neurodegeneration. In this review, we discuss the involvement of γ-secretase in the regulation of microglial functions, and the potential relevance of these processes under physiological and pathophysiological conditions. This article is part of the series "Beyond Amyloid".

Microglia are resident immune cells in the brain and exert important functions in the regulation of inflammatory processes during infection or cellular damage. Upon activation, microglia undergo complex morphological and functional transitions, including increased motility, phagocytosis and cytokine secretion. Recent findings indicate that exosomes, small vesicles that derive from fusion of multivesicular bodies with the plasma membrane, are involved in secretion of certain cytokines. The presence of specific receptors on the surface of microglia suggests communication with neurons by neurotransmitters. Here, we demonstrate expression of serotonin receptors, including 5-HT2a,b and 5-HT4 in microglial cells and their functional involvement in the modulation of exosome release by serotonin. Our data demonstrate the involvement of cAMP and Ca(2+) dependent signaling pathways in the regulation of exosome secretion. Co-culture of microglia with embryonic stem cell-derived serotonergic neurons further demonstrated functional signaling between neurons and microglia. Together, these data provide evidence for neurotransmitter-dependent signaling pathways in microglial cells that regulate exosome release.

A combination of biochemical, genetic, and imaging approaches is used to show that phosphorylation and lipidation exhibit a complex interplay in sorting of GAP43. Palmitoylation tags GAP43 for global sorting by inducing piggybacking on exocytic vesicles, whereas phosphorylation locally regulates plasma membrane targeting of palmitoylated GAP43., Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43.

Triggering receptor expressed on myeloid cells-2 (TREM2) and its signaling adaptor protein TYROBP/DAP12 play important roles in signal transduction in dendritic cells, osteoclasts, tissue macrophages, and microglia. Recently, TREM2 variants have been shown to be linked to late onset Alzheimer disease. Here, we demonstrate that TREM2 undergoes sequential proteolytic processing by ectodomain shedding and intramembrane proteolysis. The C-terminal fragment (CTF) of TREM2 generated by ectodomain shedding is cleaved by γ-secretase. Importantly, pharmacologic and genetic γ-secretase inhibition resulted in accumulation of TREM2 CTF at the plasma membrane that also interacts with the signaling adaptor protein DAP12. Thus, the accumulated TREM2 CTF thereby might limit the interaction of DAP12 with the functional full-length receptor, resulting in decreased DAP12 phosphorylation and impaired metabolism of phosphatidylinositol 4,5-bisphosphate. Together, these data demonstrate γ-secretase-mediated intramembranous proteolysis of TREM2 and functionally link two Alzheimer disease-associated proteins in one signaling pathway.

The quality of colonoscopy has been related to a higher risk of interval cancer, and this issue has been addressed extensively in developed countries. The aim of our study was to explore the main quality indicators of colonoscopy in a large emerging country.Consecutive patients referred for colonoscopy in 14 centres were prospectively included between July and October 2014. Before colonoscopy, several clinical and demographic variables were collected. Main quality indicators (i.e. caecal intubation rate, (advanced) adenoma detection rate, rate of adequate cleansing and sedation) were collected. Data were analysed atA total of 8829 (males: 35%; mean age: 57 + 14 years) patients were included, with 11 centres enrolling at least 100 patients. Screening (including non-alarm symptoms) accounted for 59% (5188/8829) of the indications. Sedation and split preparation were used in 26% (2294/8829) and 25% (2187/8829) of the patients. Caecal intubation was achieved in 7616 patients (86%), and it was ≥85% in 8/11 (73%) centres. Adenoma detection rate was 18% (1550/8829), and it was higher than 20% in five (45%) centres, whilst it was lower than 10% in four (33%) centres. At multivariate analysis, age (OR: 1.020, 95% CI: 1.015-1.024), male sex (OR: 1.2, 95% CI: 1.1-1.3), alarm symptoms (OR: 1.8, 95% CI: 1.7-2), split preparation (OR: 1.4, 95% CI: 1.2-1.6), caecal intubation rate (OR: 1.6, 95% CI: 1.3-1.9) and withdrawal time measurement (OR: 1.2, 95% CI: 1.6-2.1) were predictors of a higher adenoma detection rate, while adequate preparation (OR: 3.4: 95% CI: 2.9-3.9) and sedation (OR: 1.3; 95% CI: 1.1-1.6) were the strongest predictors of caecal intubation rate.According to our study, there is a substantial intercentre variability in the main quality indicators. Overall, the caecal intubation rate appears to be acceptable in most centres, whilst the overall level of adenoma detection appears low, with less than half of the centres being higher than 20%. Educational and quality assurance programs, including higher rates of sedation and split regimen of preparation, may be necessary to increase the key quality indicators.

Understanding the developmental steps shaping the formation of the neuromuscular junction (NMJ) connecting motoneurons to skeletal muscle fibers, is critical. Wnt morphogens are key players in the formation of this specialized peripheral synapse. Yet, the individual and collaborative functions of Wnts as well as their downstream pathways remain poorly understood at the NMJ. Here, we demonstrate through Wnt4 and Wnt11 gain of function studies in culture or in mice that Wnts enhance acetylcholine receptor (AChR) clustering and motor axon outgrowth. In contrast, loss of Wnt11 or Wnt-dependent signaling in vivo decreases AChR clustering and motor nerve terminal branching. Both Wnt4 and Wnt11 stimulate AChR clustering and mRNA downstream activation of the β-catenin pathway. Strikingly, Wnt4 and Wnt11 co-immunoprecipitate with Vangl2, a core component of the Planar Cell Polarity (PCP) pathway, which accumulates at embryonic NMJ. Moreover, mice bearing a Vangl2 loss of function mutation (looptail) exhibit a decreased number of AChR clusters and overgrowth of motor axons bypassing AChR clusters. Taken together, our results provide genetic and biochemical evidences that Wnt4 and Wnt11 cooperatively contribute to mammalian NMJ formation through activation of both the canonical and Vangl2-dependent core PCP pathways.

Proteolytic processing of the amyloid precursor protein (APP) leads to amyloid-β (Aβ) peptides. So far, the mechanism of APP processing is insufficiently characterized at the molecular level. Whereas the knowledge of Aβ generation by several proteases has been expanded, the contribution of the Kunitz-type protease inhibitor domain (KPI) present in two major APP isoforms to the complex proteolytic processing of APP is poorly understood. In this study, we have identified KPI-containing APP as a very potent, slow-binding inhibitor for the membrane-bound proteolytic regulator of iron homeostasis matriptase-2 by forming stable complexes with its target protease in HEK cells. Inhibition and complex formation depend on the intact KPI domain. By inhibiting matriptase-2, KPI-containing APP is protected from matriptase-2-mediated proteolysis within the Aβ region, thus preventing the generation of N-terminally truncated Aβ.

Alexander disease is a fatal neurodegenerative disease caused by mutations in the astrocyte intermediate filament glial fibrillary acidic protein (GFAP). The disease is characterized by elevated levels of GFAP and the formation of protein aggregates, known as Rosenthal fibers, within astrocytes. Lithium has previously been shown to decrease protein aggregates by increasing the autophagy pathway for protein degradation. In addition, lithium has also been reported to decrease activation of the transcription factor STAT3, which is a regulator of GFAP transcription and astrogliogenesis. Here we tested whether lithium treatment would decrease levels of GFAP in a mouse model of Alexander disease. Mice with the Gfap-R236H point mutation were fed lithium food pellets for 4 to 8 weeks. Four weeks of treatment with LiCl at 0.5% in food pellets decreased GFAP protein and transcripts in several brain regions, although with mild side effects and some mortality. Extending the duration of treatment to 8 weeks resulted in higher mortality, and again with a decrease in GFAP in the surviving animals. Indicators of autophagy, such as LC3, were not increased, suggesting that lithium may decrease levels of GFAP through other pathways. Lithium reduced the levels of phosphorylated STAT3, suggesting this as one pathway mediating the effects on GFAP. In conclusion, lithium has the potential to decrease GFAP levels in Alexander disease, but with a narrow therapeutic window separating efficacy and toxicity.

Progressive accumulation of the amyloid β protein in extracellular plaques is a neuropathological hallmark of Alzheimer disease. Amyloid β is generated during sequential cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. In addition to the proteolytic processing by secretases, APP is also metabolized by lysosomal proteases. Here, we show that accumulation of intracellular sphingosine-1-phosphate (S1P) impairs the metabolism of APP. Cells lacking functional S1P-lyase, which degrades intracellular S1P, strongly accumulate full-length APP and its potentially amyloidogenic C-terminal fragments (CTFs) as compared with cells expressing the functional enzyme. By cell biological and biochemical methods, we demonstrate that intracellular inhibition of S1P-lyase impairs the degradation of APP and CTFs in lysosomal compartments and also decreases the activity of γ-secretase. Interestingly, the strong accumulation of APP and CTFs in S1P-lyase-deficient cells was reversed by selective mobilization of Ca(2+) from the endoplasmic reticulum or lysosomes. Intracellular accumulation of S1P also impairs maturation of cathepsin D and degradation of Lamp-2, indicating a general impairment of lysosomal activity. Together, these data demonstrate that S1P-lyase plays a critical role in the regulation of lysosomal activity and the metabolism of APP.

Rare coding variants in the triggering receptor expressed on myeloid cells‐2 (TREM2) gene have been associated with Alzheimer disease (AD) and homozygous TREM2 loss‐of‐function variants have been reported in families with monogenic frontotemporal‐like dementia with/without bone abnormalities. In a whole‐exome sequencing study of a family with probable AD‐type dementia without pathogenic variants in known autosomal dominant dementia disease genes and negative for the apolipoprotein E (APOE) ε4 allele, we identified an extremely rare TREM2 coding variant, that is, a glycine‐to‐tryptophan substitution at amino acid position 145 (NM_018965.3:c.433G>T/p.[Gly145Trp]). This alteration is found in only 1 of 251,150 control alleles in gnomAD. It was present in both severely affected as well as in another putatively affected and one 61 years old as yet unaffected family member suggesting incomplete penetrance and/or a variable age of onset. Gly145 maps to an intrinsically disordered region (IDR) of TREM2 between the immunoglobulin‐like and transmembrane domain. Subsequent cellular studies showed that the variant led to IDR shortening and structural changes of the mutant protein resulting in an impairment of cellular responses upon receptor activation. Our results, suggest that a p.(Gly145Trp)‐induced structural disturbance and functional impairment of TREM2 may contribute to the pathogenesis of an AD‐like form of dementia.

Background Triggering receptor expressed on myeloid cells-2 (TREM2) exerts important functions in the regulation of monocytes, like dendritic cells, osteoclasts, tissue macrophages, and microglia. Mutations in TREM2 are associated with several diseases, including Nasu-Hakola disease, frontotemporal dementia, and Alzheimer’s disease (AD). TREM2 undergoes sequential proteolytic processing by ectodomain shedding and intramembrane proteolysis. Findings We show that inhibition of γ-secretase-dependent cleavage of the TREM2 C-terminal fragment in cellular membranes interferes with TREM2-dependent signaling and cellular function. Inhibition of γ-secretase decreases membrane-proximal signaling and intracellular Ca2+ response. Decreased signaling alters morphological changes and phagocytic activity of cells upon selective stimulation of TREM2. Conclusions The data demonstrate the importance of γ-secretase-dependent intramembrane processing in TREM2-mediated signaling and, thus, a functional relation of two AD-associated proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0479-9) contains supplementary material, which is available to authorized users.