Bafilomycin A1 inhibits V-type H+ ATPases on the molecular level, which acidifies endolysosomes. The main objective of the study was to assess the effect of bafilomycin A1 on Ca2+content, NAADP-induced Ca2+ release, and ATPase activity in rat hepatocytes and human colon
cancer samples. Chlortetracycline (CTC) was used for a quantitative measure of stored calcium in permeabilized rat hepatocytes. ATPase activity was determined by orthophosphate content released after ATP hydrolysis in subcellular post-mitochondrial fraction obtained from rat liver as well as from patients’ samples of colon mucosa and colorectal cancer samples. In rat hepatocytes, bafilomycin A1 decreased stored Ca2+ and prevented the effect of NAADP on stored Ca2+. This effect was dependent on EGTA–Ca2+ buffers in the medium. Bafilomycin A1 significantly increased the activity of Ca2+ATPases of endoplasmic reticulum (EPR), but not plasma membrane (PM) Ca2+ ATPases in rat liver.
Bafilomycin A1 also prevented the effect of NAADP on these pumps. In addition, bafilomycin A1 reduced Na+/K+ ATPase activity and increased basal Mg2+ ATPase activity in the subcellular fraction of rat liver. Concomitant administration of bafilomycin A1 and NAADP enhanced these effects. Bafilomycin A1 increased the activity of the Ca2+ ATPase of EPR in the subcellular fraction of normal human colon mucosa and also in colon cancer tissue samples. In contrast, it decreased Ca2+ ATPase PM activity in samples of normal human colon mucosa and caused no changes in colon cancer. Bafilomycin A1 decreased Na+/K+ ATPase activity and increased basal Mg2+ ATPase activity
in normal colon mucosa samples and in human colon cancer samples. It can be concluded that bafilomycin A1 targets NAADP-sensitive acidic Ca2+ stores, effectively modulates ATPase activity, and assumes the link between acidic stores and EPR. Bafilomycin A1 may be useful for cancer therapy.
Keywords: molecular mechanisms; colon cancer; ATPase; autophagy; hepatocytes; liver; NAADP; biomarkers; bafilomycin A1; Ca2+ store
UDC 577.352:616-006.44:542.978
Endo-lysosomal system through the process of autophagy
is involved in the pathogenesis of many diseases. Acidification of these organelles is carried out by V-type H+-ATPases, which is inhibited by bafilomycin A1. Endosomes and lysosomes are also important Ca2+-storage in a cell. Nіcotіnіc acіd adenіne dіnucleotіde phosphate (NAADP) releases Cа2+ from endo-lysosomes. The main purpose of the study was to found out the effect of bafilomycin A1 and NAADP on stored Ca2+ and on the ATPase activity of rat hepatocytes. The stored Ca2+ was estimated using chlorotetracycline in permeabilized hepatocytes of rats. ATPase activity was determined by level of orthophosphate spectrophotometrically. It was found that bafilomycin A1 reduces stored Ca2+ in permeabilized hepatocytes of rats in the micromolar range of concentration (20 and 0.04 mkM) and averted the effect of NAADP on calcium content. Lower concentrations of bafilomycin A1 (0.001 mkM) did not alter the content of stored calcium, but prevented the influence of NAADP in permeabilized hepatocytes of rats. In the subcellular fraction of rat liver bafilomycin A1 (0.001 mkM) increased Ca2+-ATPase and basal Mg2+-ATPase activities and reduced Na+/K+-ATPase activity. Preincubation of the subcellular fraction with bafilomycin A1 completely averts any changes in the activity of estimated ATPases by means of NAADP. It was concluded that the bafilomycin-sensitive store in hepatocytes of rats is NAADP-sensitive endo-lysosomal Ca2+-store. Using of bafilomycin A1 may be useful in treating autophagy-depended diseases.
UDC: 616.24-002.5:615.015.8]-022.16-085.281-039.71-053.2/.
Summary.
120 exposed children/adolescents (75 children and 45 adolescents) from the multi-drug resistant tuberculosis sites underwent the complex clinical radiological and immunological examination. Insignificant functional disorders of cellular response (immunoregulatory processes) caused by the prevalence of suppressor and cytotoxic reactions by 1.3 times and by the prevalence of pro-inflammatory cytokines in the regulatory
system (2.0 times above the norm, TNF-α/IL 10.0. р<0.01) were revealed in the infected children/adolescents from the multi-drug resistant tuberculosis sites, while their СD3+. СD3+СD4+. СD3+СD8+ were within norm. The evident disorders of the regulatory system and cell immune system were eliminated after the completion of the autumn-spring BI-V course. The non-specific immune regulator BI-V is efficient for the prevention of multi-drug resistant tuberculosis for the exposed children/adolescents from the multi-drug tuberculosis sites. Consequently, the latent TB infection grew into the active form by 2.8 times less often in the children that took BI-V as compared to the infected children who did not take the drug.
Key words: BIVEL immunomodulator, pulmonary tuberculosis in children, cellular immunity, tuberculosis.
In the article, the authors analyze the problem of using modern innovative nanotechnologies in dentistry. Currently, nanotechnology is used in treatment, prosthetics, preventive care of the oral cavity and teeth. Based on this, the use of nanotechnology in dentistry has a number of
advantages compared to the traditional materials used, as they are more effective, affordable, structured, meet all modern parameters, and have high quality. Despite the widespread use of nanotechnology, in some cases, they may carry certain risks. Nanomaterials have higher activity, high permeability through the skin, lungs, and digestive tract. But the impact of nanoparticles on the body remains unexplored. In addition to safety problems of nanomaterials, their production is associated with a number of other problems: engineering, biological, and social. Specialists think about new ways to solve currentprofessional problems. Time will tell how successful the process of integrating narrowprofile research into practical activity will be. The development of new and implementation of existing nanotechnology medical technologies is a promising direction of the development of modern dentistry.
Keywords: nanotechnology, nanomaterials, nanoparticles, dentistry, medicine.