Plasma Apolipoproteins A1/B and OxLDL Levels in Patients with Covid-19 As Possible Markers of the Disease.

The COVID-19 infection is associated with dyslipidemia and cardiovascular complications. The aim of the study was to determine the content of ApoA1, ApoB, and oxidized low-density lipoproteins (oxLDL) in the plasma of patients (n = 81) with COVID-19, diabetes, and cardiovascular disease (CVD). ApoA1, ApoB, and oxLDL were determined using enzyme-linked immunosorbent assay kits (Elabscience, United States). The measurements were performed at an optical wavelength of 450 nm. It was shown that the level of ApoA1 in the blood of patients with type 2 diabetes and especially with COVID-19 was significantly lower than in the blood of healthy people. Blood ApoA1 levels did not show a further decrease in patients with both COVID-19 and diabetes or CVD compared to patients with COVID-19 without concomitant diseases. It was found that the level of ApoB in the blood of patients with diabetes and, especially, with COVID-19 is significantly higher than in the blood of healthy people. Blood levels of ApoB and oxLDL are higher in patients with both COVID-19 and diabetes or CVD compared to patients with COVID-19 without comorbidities. Thus, levels of ApoA1, ApoB, and oxLDL may be promising markers of COVID-19.

INHIBITOR OF THE TRANSCRIPTION FACTOR NF-κB, DHMEQ, ENHANCES THE EFFECT OF PACLITAXEL ON CELLS OF ANAPLASTIC THYROID CARCINOMA IN VITRO AND IN VIVO.

Anticancer drug paclitaxel (Ptx) effect on biochemical mechanisms, regulating apoptosis in anaplas- tic thyroid carcinoma cells, was studied. It was shown that in addition to apoptotic cell death, Ptx induces signaling cascades that ensure cell survival. Paclitaxel-induced activation of nuclear factor kappa B (NF-κB) leads to an increase of some antiapoptotic proteins expression such as survivin, cIAP, XIAP. A novel NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), was found to enhance cytotoxic effect of Ptx in anaplastic thyroid carcinoma cells. An enhancement of caspase-3 and -9 activation and PARP cleavage as well as the decreased levels of proteins-inhibitors of apoptosis were observed when cells were treated with a combination of both drugs. Mitochondria transmembrane potential (Δψ (m)) loss was observed at higher concentrations of Ptx and DHMEQ. NF-κB inhibition also potentiates paclitaxel effect at tumors formed by xenotransplantation of FRO cells into mice. Tumor mass reduction, significantly different from the effects of each of the compounds alone, was observed in animals, treated with paclitaxel and NF-κB inhibitor. Thus, the combined use of paclitaxel and NF-κB inhibitor inhibits biochemical processes that contribute to the resistance of anaplastic thyroid carcinoma cells to paclitaxel action.

Biochemical effects of combined action of gamma-irradiation and paclitaxel on anaplastic thyroid cancer cells.

The aim of the paper was to describe the biochemical effects of Paclitaxel (Ptx), gamma-irradiation (IR) and their combination in undifferentiated thyroid cancer cells (ATC). IR activated common DNA damage-induced signaling and manifested certain mitogenic effect by inactivation of retinoblastoma protein (pRb). There was clear antagonism between Ptx and IR relative to cell cycle regulators--tumor suppressor p53, pRb, CHK2 and c-Abl as well as proapoptotic Bax expression, but combined action of both agents enhanced caspase-3 and, especially, caspase-8 activation. The Ptx at low (1-25 nM) concentrations caused noticeable radioprotective effect. Thus, in ATC cells the ionizing radiation and Ptx exhibited competitive effects upon phosphorylation of cell cycle controllers: p53, pRb, CHK2, cAbl and expression of Bax. At the same time, the combined effect of radiation and Ptx enhanced antiapoptotic Bcl-2 phosphorylation, caspases activation and survivin expression. The net effect of these events during the first 48-72 h of cells incubation can be considered as antiapoptotic--Ptx attenuated cytotoxic effect of IR.

[Effect of N-stearoylethanolamine on the DNA fragmentation intensity in tumour and extratumoral tissues of the human adrenal cortex].

The effect of different concentrations of N-stearoylethanolamine (NSE 18:0) on fragmentation of DNA in the tumoural and extratumour tissues of the adrenal glands in vitro was studied. In this work the following types of tissue were investigated: extratumoural tissue from patients with hormonally active tumours, benign tumour tissue (hormonally active and hormonally inactive), tissue of malignant tumours and hyperplasic tissue of the adrenal glands (Itsenko-Cushing disease). It has been established that the NSE increases the intensity of DNA fragmentation only in the tissue of hormonally inactive tumours. Benign hormonally active tumours, malignant tumours and hyperplastic tissue of the adrenal glands were resistant to the NSE. The possible mechanisms of resistance to the drug are discussed.

The effect of the combined action of roscovitine and Paclitaxel on the apoptotic and cell cycle regulatory mechanisms in colon and anaplastic thyroid cancer cells.

Aim. To study the significance of cyclin-dependent kinases (Cdks) in paclitaxel-dependent apoptosis in colon and undifferentiated thyroid cancer cells. Materials and Methods. Experiments were performed on undifferentiated thyroid carcinoma (KTC-2) and colon carcinoma (ARO) cell lines. Cells were treated with paclitaxel (Ptx) and inhibitor of Cdk, roscovitine. Cell survival test and Western blotting were used for characterization of the effects of paclitaxel and roscovitine on cancer cells. Results. It was shown that not c-Jun N-terminal kinase, but cyclin-dependent kinases are responsible for antiapoptotic Bcl-2 phosphorylation. Cdk inhibition enhanced the cytotoxic effects of Ptx at low drug concentrations. There was antagonism between Ptx and roscovitine at higher (25 nM) paclitaxel concentrations. Conclusion. Using of paclitaxel at low (2.5 to 5 nM) concentrations and roscovitine is a promising combination for further preclinical trials for the development of new therapeutic approaches to the treatment of colon and anaplastic thyroid cancer.

[The effect of potassium different concentrations on mRNA expression of protein StAR and cytochrome p-450(SCC) in human adrenocortical tissue].

The effect of different potassium concentrations on changes in steroidogenic acute regulatory protein (StAR) and cytochrome P-450(SCC) in human adrenal cortex tissue was studied. A rise in K+ concentration in incubation medium to 8.5 mM caused an increase in StAR and cytochrome P-450(SCC) mRNA level in adrenocorticocytes by 70 and 76%, respectively, compared with control. Thus, potassium ions caused an enhancement of minerocorticoid synthesis in the adrenal cortex, which is associated with mechanisms that regulate the intensity of expression of StAR and cytochrome P-450(SCC) on a transcriptional level.

[Effect of 17beta-estradiol on mRNA expression of Bax proapoptotic protein and DNA fragmentation level in the human adrenal cortex].

The effect of 17beta-estradiol on the change of proapoptotic protein Bax mRNA level and DNA laddering in human adrenal cortex tissue was studied. The adding of 17beta-estradiol to incubation medium caused a decrease of the proapoptotic protein Bax mRNA level in adrenocorticocytes by 22% in comparison with control. Hormone influence decreases the DNA fragmentation by 50%. The obtained data suggest that 17beta-estradiol caused a significant antiapoptotic effect in human adrenal cortex.

Effects of low and high concentrations of antitumour drug taxol in anaplastic thyroid cancer cells.

AIM: To study the changes of cell cycle, mitochondrial membrane potential and caspase activation in response to an antitumour drug Taxol in ARO and KTC-2 cell lines of anaplastic thyroid carcinoma. METHODS: Experiments were done on thyroid anaplastic cancer cell lines ARO and KTC-2 using Western blotting, flow cytometry, light and fluorescent microscopy. RESULTS: Taxol significantly activated caspases in ARO cells starting from drug concentration of 5 nM. Maximum activation was observed at 25 nM and further increase of Taxol concentration to 100 nM resulted in a reduction of caspase activation. Concomitant to caspase activation, a loss of mitochondrial membrane potential was observed. At Taxol concentration of 100 nM, most cells lost their mitochondrial membrane potential. Low Taxol concentrations (10 nM) caused changes in the cell cycle that are typical for apoptosis without cell cycle arrest. Higher drug doses starting from 50 nM arrested cell cycle in G2/M phase. In KTC-2 cell line Taxol concentration as low as 1 nM induced apoptosis. 6-15 nM of the drug caused massive (75-83%) cell death. Upon Taxol action, the increase in the number of cells displaying manifestations of accelerated senescence was insignificant. CONCLUSION: Taxol induces bona fide apoptosis in thyroid cancer cell cultures at low (1-25 nM) concentrations. Higher drug doses cause the loss of mitochondrial membrane potential and possibly lead to other types of cell death. No accelerated senescence at different Taxol concentrations was observed. The significance of subG1 and G2/M cell populations at low and high doses of Taxol is discussed.

[The influence of protein kinases ERK, JNK and nuclear transcriptional factor c-JUN on corticotropin signal transduction in adrenocortical cells].

The estradiol effect on the expression level of ERK1/2, JNK, p38 mitogen-activated protein kinases, c-Jun and c-Fos transcription factors in the adrenal cortex of male rats was studied. It was shown that a single corticotropin injection caused significant changes of the ERK1/2 protein kinases levels in the adrenal cortex. This index was 1.6 times higher 1 h after the injection and was decreased 6 h after the injection. The corticotropin influence on JNK level is very significant. The protein kinase JNK level was 2.4-fold increased I h after and was decreased 6 h after the injection. However, the level of p38 kinase was not changed in these conditions. The level of c-Jun transcriptional factor increased 1.7 times 1 h after corticotropin treatment and continued decreasing with the increase of time after the injection. The level of c-Fos factor increased 1.7 times only 6 h after the injection. These changes may be an important factor of activation of adrenocortical function provoked by corticotropin.

Differential effects of low and high doses of Taxol in anaplastic thyroid cancer cells: possible implication of the Pin1 prolyl isomerase.

AIM: To study the molecular mechanisms of dose-dependent effects of an anticancer drug, Taxol, on the cell cycle machinery and apoptosis-related proteins in thyroid anaplastic cancer cell lines ARO and KTC-2. MATERIALS AND METHODS: Western blot analysis was used for the detection of various proteins and of their phosphorylated forms. RESULTS: Low dose of Taxol that cause apoptosis (25 nM) enhanced Rb protein phosphorylation, decreased the expression of cyclin-dependent kinase inhibitors p27(KIP1) and p21(WAF1) , and potentiated the accumulation of phosphorylated p53 and of the prolyl isomerase Pin1. High Taxol doses (100 and 1000 nM) that cause necrosis-like cell death drastically decreased Pin1 level in both cell lines. CONCLUSION: Low doses of Taxol promoted G(1)/S transition, thus exhibiting mitogen-like effect. Drug-induced Pin1 accumulation could probably facilitate this transition and in parallel contribute to apoptosis via the p53/p73-dependent mechanism. At higher doses of Taxol, there was a dramatic decrease of Pin1 levels which may be a reason for G(2)/M cell cycle arrest.

Antineoplastic and apoptotic effects of cannabinoids. N-acylethanolamines: protectors or killers?

The proapoptotic and antineoplastic properties of cannabinoids with emphasis on effects of N-acylethanolamines were analyzed. Cannabinoids enhanced apoptotic and necrotic processes in many types of tumour cells and tissues. Involvement of different types of receptors and signaling pathways in mediating the proapoptotic effects of cannabinoids are discussed. The evidences in favour of both proapoptotic, pronecrotic and protective, antiapoptotic effects of cannabinoids and, especially N-acylethanolamines, are evaluated. The hypothesis is suggested that N-acylethanolamines, formed in some tissues under strong stress conditions, can be not a consequence of tissue damage but cause such damage. The conclusion is made on promising of cannabinoids as potential anticancer agents.

[Effect of adrenocorticotropic hormone on the caspase-3 level and DNA fragmentation in hyperplasia tissue of human adrenals].

The effect of corticotropin and inhibitor of protein kinase C, chelerythrine chloride, on the change of caspase-3 level and on the rate of DNA laddering in hyperplasia adrenal cortex tissue of patient with Cushing's syndrome was studied. It was established that ACTH caused significant antiapoptotic effect in the human adrenal cortex. The adding of ACTH to incubation medium caused a sharp decrease of the caspase-3 level in adrenocorticocytes. Chelerythrine chloride, on the contrary, increases the caspase-3 level by 22%. ACTH influence decreases DNA laddering. Either the adding of chelerythrine chloride to incubation medium, or the adding of chelerythrine chloride simultaneously with ACTH, led to the enhancing of DNA fragmentation. The obtained data suggest that antiapoptotic effect of ACTH in adrenal cortex tissue estimated according by the caspase-3 level and by the rate of DNA fragmentation depends on activation of protein kinase C. However, the intensification of DNA laddering can be also explained by cytotoxic effect, high level of interaction with DNA and strong intercalation ability of this alkaloid.

[Participation of cyclic nucleotides, protein kinase A and C in realization of n-acylethanolamine action in human adrenocortical cells].

The messenger mechanisms mediating N-acylethanolamines (NAE) regulatory signals in the adrenal cortex were studied. An analysis of the mechanisms of realization of NAE effects in the post-operation human adrenal cortex was carried out in vitro. Influence of NAE mix on cAMP and cGMP level, protein kinase A and C activity in sub-cellular fraction of adrenocorticocytes and homogenates of conditionally normal adrenal cortex tissues was investigated. It was shown, that N-acylethanolamines treatment resulted in a decrease of cAMP level in adrenocortical cells. cGMP level is not changed in these conditions. The rise of protein kinase C activity was obtained in the membrane fraction after N-acylethanolamines in vitro treatment (3.3 microg/ml). Activity of cAMP-dependent protein kinase A significantly decreased in cytosol fraction of adrenocorticocytes. It was concluded, that steroid genesis activation is determined by protein kinase C activation, inhibition is determined by cAMP-dependent messenger system.

[Effect of mitogen-activated protein kinases and transcriptional factor c-Fos on estradiol signal transduction in the rat adrenocorticocytes].

Signal transduction mechanisms mediating estradiol regulatory signals in the adrenal cortex were studied in rats. The effect of estradiol benzoate treatment on corticosteroids secretion, levels of ERK1/2, JNK, p38 mitogen-activated protein kinases, transcription factors c-Jun and c-Fos in adrenal cortex were investigated. The level of ERK1/2 was increased 1.7-fold in adrenocortical tissue after injections (3 days, 100 mkg per rat) of estradiol. However, the level of p38 kinase and protein kinase JNK was not changed in these conditions. The transcription factor AP-1, which includes c-Fos and c-Jun factors, is involved in realization of estradiol signal transduction. The level of c-Fos protein raised 1.8-fold after estradiol treatment, c-Jun protein was not increased. We conclude that ERK1/2 kinase and transcriptional factor c-Fos mediate fast estrogen signal transduction in adrenocorticocytes.

[Effects of estradiol on synthesis of corticosteroids, protein kinase A and C activity in the adrenal cortex of intact and orchiectomized rats].

Estradiol treatment produced significant increase of total 11-hydroxycorticosteroids level in the blood of intact and castrated rats. Activity of protein kinase A increased in the cytosol and membrane fraction of adrenocorticocytes of intact and orchiectomized rats after estradiol influence. Activity of protein kinase C significantly raised in the cytosol and membrane fraction of adrenocortical cells in all investigated groups. Our results suggest that cAMP-dependent protein kinase A and protein kinase C mediate estradiol effects in adrenal cortex.

[The role of protein kinase C in intracellular regulation mechanisms of adrenocortical cell function in norm and in pathology].

The data on the role of protein kinase C enzymes family in regulation of biochemical processes in adrenocortical cells and other types of steroid-producing cells were analyzed. The involvement of these protein kinase reactions in signal transduction of main regulators of adrenocortical function--ACTH, angiotensin II and potassium ions was considered. Data about interactions and transregulation influences between different secondary messenger systems, which mediate intracellular signal transduction of agonists and provide functional activity of adrenocortical cells are discussed. The participation of protein kinase C is shown in changing of the steroidogenic genes expression. The role of protein kinase C isoforms in tumorogenesis is described.

[The role of phosphoinositides, protein kinase C and protein kinase A in the K+ regulatory signal transduction in human adrenocortical cells].

The messenger mechanisms mediating K+ regulatory signals in human adrenocorticocytes were studied. It was shown that potassium ions initiated decay of polyphosphoinositides to inositolphosphates and obviously diacylglycerol. The latter compounds activate protein kinase C as affected by different agonists. Using western blotting method we showed translocation of PKCalpha from cytosol to membranes after adrenal tissue preincubation in the medium with increased K+ content (8.5 mM). Translocation means activation of the enzyme. Activity of PKC increased in the microsomal fraction and did not change in cytosol. Increased concentration of K+ in the incubation medium also activates protein kinase A, although to a lesser extent compared to PKC. Unlike PKC activity of PKA was changed in cytosol as well. The possibility of involvement of several messenger systems in K+ signal transduction in human adrenocortical cells as well as the hypothesis on cross-talk between messenger mechanisms for main physiological agonists controlling aldosterone biosynthesis in the adrenals are discussed.

[ACTH activates in vitro protein kinases A and C in human adrenal cortex].

The activation of protein kinases A and C by corticotropin in the human adrenal cortex was analyzed. ACTH influence in vitro significantly increase protein kinase A activity, total protein kinase C activity in the membrane fraction of adrenocorticocytes and 11-hydroxycorticosteroids production of adrenal cortex tissue. Either cAMP-dependent protein kinase A or protein kinase C are included to postreceptoral messenger mechanism, that mediates ACTH action in adrenocortical cells.

[The effect of ovariectomy and estradiol on DNA, RNA and protein metabolism in the adrenal cortex of rats]. / Vyvchennia vplyvu ovariektomiï ta estradiolu na metabolizm DNK, RNK i bilka v kori nadnyrkovykh zaloz shchuriv.

The effects of ovariectomy and oestradiol on incorporation of specific labelled precursors into DNA, RNA and protein were studied. Ovariectomy caused a decrease in the adrenal weight as well as an increase in the DNA content. That effect has been demonstrated most clearly 8 weeks after ovariectomy. Oestradiol treatment of ovariectomized rats during 3 days resulted in an increase of incorporation of [3H]-thymidine, [3H]-uridine and [3H]-leucine into DNA, RNA and protein, respectively. Higher rates of the label incorporation into the tissue from animals taken into experiment 8 weeks after ovariectomy were observed. Significant changes in incorporation of the specific precursors into DNA, RNA and protein were absent in the case of oestradiol treatment of intact rats. These data demonstrate that oestradiol have an anabolic effect on metabolism of DNA, RNA and protein in the adrenal cortex of ovariectomized rats.