Lipid kinases as therapeutic targets for chronic pain

Existing analgesics are not efficacious in treating all patients with chronic pain and have harmful side effects when used long-term. A deeper understanding of pain signaling and sensitization could lead to the development of more efficacious analgesics. Nociceptor sensitization occurs under conditions of inflammation and nerve injury where diverse chemicals are released and signal through receptors to reduce the activation threshold of ion channels, leading to an overall increase in neuronal excitability [98; 28]. Drugs that inhibit specific receptors have so far been unsuccessful in alleviating pain, possibly because they do not simultaneously target the diverse receptors that contribute to nociceptor sensitization. Hence, focus has shifted towards targeting downstream convergence points of nociceptive signaling [98]. Lipid mediators, including phosphatidylinositol 4,5-bisphosphate (PIP2), are attractive targets as these molecules are required for signaling downstream of G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs). Furthermore, PIP2 regulates the activity of various ion channels [80]. Thus, PIP2 sits at a critical convergence point for multiple receptors, ion channels and signaling pathways that promote and maintain chronic pain. Decreasing the amount of PIP2 in neurons was recently shown to attenuate pronociceptive signaling and could provide a novel approach for treating pain. Here, we review the lipid kinases that are known to regulate pain signaling and sensitization and speculate on which additional lipid kinases might regulate signaling in nociceptive neurons

Peculiarities of formation and growth of nanodispersed intermetallic strengthening inclusions in rapidly-solidified alloys of Al–Mg–Zr–X-system

The paper is devoted to the influence of the fourth element on the microstructure of the rapidly-solidified alloys of the Al–Mg–Zr-system. Alloys were additionally doped with high-melting-point metals Ti, Hf, W, and Nb. In the structure of all samples in the immediate area of the cooled surface, uniformly distributed intermetallic inclusions of several nanometers in size were detected. Such a structure can be represented as a dispersion-strengthened composite. A quantitative metallographic analysis was carried out to quantitatively describe the structure of the obtained particles of the cooled melt. The obtained rapidly-solidified alloys can be described as dispersion-strengthened composite materials with the aluminum-magnesium alloy matrix and the intermetallic particles strengthener. Depending on the alloying component, these particles differ in shape (spheres, plates, agglomerates) and in size (from 200 nm when alloying with Hf and W up to 1.2-1.5 μm with Ti and Nb alloying). The X-ray phase analysis (XPA) showed that in the studied alloys of the Al–5Mg–1.2Zr–(0.5÷2.0)X-system, high cooling rates of melts lead to the formation of new intermetallic compounds that are absent in equilibrium systems. The example of an alloy with hafnium additive shows that an increase in the content of the alloying component (from 0.5 to 2 % by mass) leads to an increase in the volume ratio of intermetallic inclusions (from 5 to 12.8 %). At the same time, their shape and average size remain unchanged. The additional alloying component will improve the mechanical characteristics of aluminum alloys by increasing the recrystallization threshold of a rapidly-solidified alloy

The C-type natriuretic peptide induces thermal hyperalgesia through a noncanonical Gβγ-dependent modulation of TRPV1 channel

Natriuretic peptides (NPs) control natriuresis and normalize changes in blood pressure. Recent studies suggest that NPs are also involved in the regulation of pain sensitivity, although the underlying mechanisms remain largely unknown. Many biological effects of NPs are mediated by guanylate cyclase (GC)-coupled NP receptors, NPR-A and NPR-B, whereas the third NP receptor, NPR-C, lacks the GC kinase domain and acts as the NP clearance receptor. In addition, NPR-C can couple to specific Gα(i)-βγ-mediated intracellular signaling cascades in numerous cell types. We found that NPR-C is co-expressed in TRPV1-expressing mouse DRG neurons. NPR-C can be co-immunoprecipitated with Gα(i), and CNP treatment induced translocation of PKCε to the plasma membrane of these neurons, which was inhibited by pertussis toxin pre-treatment. Application of CNP potentiated capsaicin- and proton-activated TRPV1 currents in cultured mouse DRG neurons, and increased neuronal firing frequency, an effect that was absent in DRG neurons from TRPV1(−/−) mice. CNP-induced sensitization of TRPV1 activity was attenuated by pre-treatment of DRG neurons with the specific inhibitors of Gβγ, PLCβ or PKC, but not of PKA, and was abolished by mutations at two PKC phosphorylation sites in TRPV1. Further, CNP injection into mouse hind paw led to the development of thermal hyperalgesia that was attenuated by administration of specific inhibitors of Gβγ or TRPV1, and was also absent in TRPV1(−/−) mice. Thus, our work identifies the Gβγ-PLCβ-PKC-dependent potentiation of TRPV1 as a novel signaling cascade recruited by CNP in mouse DRG neurons that can lead to enhanced nociceptor excitability and thermal hypersensitivity

The Lipid Kinase PIP5K1C Regulates Pain Signaling and Sensitization

SummaryNumerous pain-producing (pronociceptive) receptors signal via phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis. However, it is currently unknown which lipid kinases generate PIP2 in nociceptive dorsal root ganglia (DRG) neurons and if these kinases regulate pronociceptive receptor signaling. Here, we found that phosphatidylinositol 4-phosphate 5 kinase type 1C (PIP5K1C) is expressed at higher levels than any other PIP5K and, based on experiments with Pip5k1c+/− mice, generates at least half of all PIP2 in DRG neurons. Additionally, Pip5k1c haploinsufficiency reduces pronociceptive receptor signaling and TRPV1 sensitization in DRG neurons as well as thermal and mechanical hypersensitivity in mouse models of chronic pain. We identified a small molecule inhibitor of PIP5K1C (UNC3230) in a high-throughput screen. UNC3230 lowered PIP2 levels in DRG neurons and attenuated hypersensitivity when administered intrathecally or into the hindpaw. Our studies reveal that PIP5K1C regulates PIP2-dependent nociceptive signaling and suggest that PIP5K1C is a therapeutic target for chronic pain

Synthesis of 2-((3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo [b] thiophen-2-yl)amino)-4-(4-methoxyphenyl)-4-oxobut-2-enoate

2-((3-(Ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)amino)-4-(4-methoxyphenyl)-4-oxobut-2-enoate has been synthesized by the reaction of ethyl (E)-2-((5-(4-methoxyphenyl)-2-oxofuran-3(2H)-ylidene)amino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate or 2-((3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)amino)-4-(4-methoxyphenyl)-4-oxobut-2-enoate with potassium tert-butoxide. © 2022 Author(s).The work was done with the financial support of the Russian Foundation for Basic Research (project no. 19-43-590023)

Synthesis of 2-((3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)amino)-4-(4-methoxyphenyl)-4-oxobut-2-enoate

Will be discussed synthesis of 2-((3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)amino)-4-(4-methoxyphenyl)-4-oxobut-2-enoate.The work was supported by an RFBR grant 19-43-590023

Comprehensive approach to improving the efficiency of treatment of purulent diseases of hand

63 patients with phlegmons of a hand of various localization were treated. Patients were divided into 2 groups of observations. The change in the indices of the T-cell link of immunity was revealed. Patients of the study group received immunotropic therapy in combination with the use of ultrasonic cavitation of wounds, and hydroactive wound coatings. The complex of measures used improves the results of treatment of patients with phlegmon.Проведено лечение 63 пациентов с флегмонами кисти различной локализации. Больные были разделены на 2 группы наблюдений. Выявлено изменение показателей Т-клеточного звена иммунитета. Пациенты группы исследования получали иммунотропную терапию в сочетании с использованием ультразвуковой кавитации ран и гидроактивных раневых покрытий. Используемый комплекс мероприятий улучшает результаты лечения больных с флегмонами кисти

Performance of the Genotype® MTBDRPlus assay in the diagnosis of tuberculosis and drug resistance in Samara, Russian Federation

<p>Abstract</p> <p>Background</p> <p>Russia is a high tuberculosis (TB) burden country with a high prevalence of multidrug resistant tuberculosis (MDRTB). Molecular assays for detection of MDRTB on clinical specimens are not widely available in Russia.</p> <p>Results</p> <p>We performed an evaluation of the GenoType^®MTBDRplus assay (HAIN Lifescience GmbH, Germany) on a total of 168 sputum specimens from individual patients at a public health laboratory in Central Russia, as a model of a middle income site in a region with high levels of drug resistance. Phenotypic drug resistance tests (DST) were performed on cultures derived from the same sputum specimens using the BACTEC 960 liquid media system.</p> <p>Interpretable GenoType^®MTBDRplus results were obtained for 154(91.7%) specimens with readability rates significantly higher in sputum specimens graded 2+ and 3+ compared to 1+ (RR = 1.17 95%CI 1.04–1.32). The sensitivity and specificity of the assay for the detection of rifampicin (RIF) and isoniazid (INH) resistance and MDR was 96.2%, 97.4%, 97.1% and 90.7%, 83.3%, 88.9% respectively. Mutations in codon 531 of the <it>rpoB </it>gene and codon 315 of the <it>katG </it>gene dominated in RIF and INH resistant strains respectively. Disagreements between phenotypical and molecular tests results (12 samples) could be explained by the presence of rare mutations in strains circulating in Russia and simultaneous presence of resistant and sensitive bacilli in sputum specimens (heteroresistance).</p> <p>Conclusion</p> <p>High sensitivity, short turnaround times and the potential for screening large numbers of specimens rapidly, make the GenoType^®MTBDRplus assay suitable as a first-line screening assay for drug resistant TB.</p

Analysis of gene mutations associated with isoniazid, rifampicin and ethambutol resistance among Mycobacterium tuberculosis isolates from Ethiopia

<p>Abstract</p> <p>Background</p> <p>The emergence of drug resistance is one of the most important threats to tuberculosis control programs. This study was aimed to analyze the frequency of gene mutations associated with resistance to isoniazid (INH), rifampicin (RMP) and ethambutol (EMB) among <it>Mycobacterium tuberculosis </it>isolates from Northwest Ethiopia, and to assess the performance of the GenoType^®MTBDRplus and GenoType^®MTBDRsl assays as compared to the BacT/ALERT 3D system.</p> <p>Methods</p> <p>Two hundred sixty <it>Mycobacterium tuberculosis </it>isolates from smear positive tuberculosis patients diagnosed between March 2009 and July 2009 were included in this study. Drug susceptibility tests were performed in the Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital of Leipzig, Germany.</p> <p>Results</p> <p>Of 260 isolates, mutations conferring resistance to INH, RMP, or EMB were detected in 35, 15, and 8 isolates, respectively, while multidrug resistance (MDR) was present in 13 of the isolates. Of 35 INH resistant strains, 33 had mutations in the <it>katG </it>gene at Ser315Thr 1 and two strains had mutation in the <it>inhA </it>gene at C15T. Among 15 RMP resistant isolates, 11 had <it>rpoB </it>gene mutation at Ser531Leu, one at His526Asp, and three strains had mutations only at the wild type probes. Of 8 EMB resistant strains, two had mutations in the <it>embB </it>gene at Met306Ile, one at Met306Val, and five strains had mutations only at the wild type probes. The GenoType^®MTBDRplus assay had a sensitivity of 92% and specificity of 99% for INH resistance, and 100% sensitivity and specificity to detect RMP resistance and MDR. The GenoType^®MTBDRsl assay had a sensitivity of 42% and specificity of 100% for EMB resistance.</p> <p>Conclusion</p> <p>The dominance of single gene mutations associated with the resistance to INH and RMP was observed in the codon 315 of the <it>katG </it>gene and codon 531 of the <it>rpoB </it>gene, respectively. The GenoType^®MTBDRplus assay is a sensitive and specific tool for diagnosis of resistance to INH, RMP and MDR. However, the GenoType^®MTBDRsl assay shows limitations in detecting resistance to EMB.</p