Association between skin lymphangiogenesis parameters and arterial hypertension status in patients: An observational study

BACKGROUND

Recent studies have indicated that the skin lymphatic system and interstitium may play a role in the pathophysiology of arterial hypertension (AH).

OBJECTIVES

We aimed to determine whether the set of pathway parameters described previously in rodents would allow for the distinction between hypertensive and normotensive patients.

MATERIAL AND METHODS

Molecular and histopathological parameters from the skin and blood of patients with AH (AH group, n = 53), resistant AH (RAH group, n = 32) and control (C group, n = 45) were used, and a statistical multivariate bootstrap methodology combining partial least squares-discriminant analysis (PLS-DA) and selectivity ratio (SR) were applied.

RESULTS

The C vs RAH model presented the best prediction performance (AUC test = 0.90) and had a sensitivity and specificity of 73.68% and 83.33%, respectively. However, the parameters selected for the C vs AH group model were the most important for the pathway described in the rodent model, i.e., greater density of the skin lymphatic vessels (D2-40 expression) and greater number of macrophages (CD68 expression), higher expression of the messenger ribonucleic acid (mRNA) of nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGFC) and podoplanin (PDPN) in the skin, greater concentration of hyaluronic acid (HA) in the skin, and lower serum concentration of VEGF-C.

CONCLUSIONS

Our study suggests that the NFAT5/VEGF-C/lymphangiogenesis pathway, previously described in rodent studies, may also be present in human HA. Further experiments are needed to confirm our findings.

Sodium accumulation in the skin is associated with higher density of skin lymphatic vessels in patients with arterial hypertension

PURPOSE

Recent studies, conducted mainly on the rodent model, have demonstrated that regulatory pathway in the skin provided by glycosaminoglycans, nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGF-C) and process of lymphangiogenesis may play an important role in extrarenal regulation of sodium (Na+) balance, body water volume, and blood pressure. We aimed to investigate the concentrations and relations among the main factors of this pathway in human skin to confirm that this regulatory axis also exists in humans.

PATIENTS AND METHODS

Skin specimens from patients diagnosed with arterial hypertension and from control group were histologically and molecularly examined.

RESULTS

The primary hypertensive and control groups did not differ in Na+ ​concentrations in the skin. However, the patients with hypertension and higher skin Na+ concentration had significantly greater density of skin lymphatic vessels. Higher skin Na+concentration was associated with higher skin water content. In turn, skin water content correlated with factors associated with lymphangiogenesis, i.e. NFAT5, VEGF-C, and podoplanin (PDPN) mRNA expression in the skin. The strong mutual pairwise correlations of the expressions of NFAT5, VEGF-C, vascular endothelial growth factor D (VEGF-D) and PDPN mRNA were noted in the skin in all of the studied groups.

CONCLUSIONS

Our study confirms that skin interstitium and the lymphatic system may be important players in the pathophysiology of arterial hypertension in humans. Based on the results of our study and existing literature in this field, we propose the hypothetical model which might explain the phenomenon of salt-sensitivity.

Targeting SOX18 Transcription Factor Activity by Small-Molecule Inhibitor Sm4 in Non-Small Lung Cancer Cell Lines

The transcription factor SOX18 has been shown to play a crucial role in lung cancer progression and metastasis. In this study, we investigated the effect of Sm4, a SOX18 inhibitor, on cell cycle regulation in non-small cell lung cancer (NSCLC) cell lines LXF-289 and SK-MES-1, as well as normal human lung fibroblast cell line IMR-90. Our results demonstrated that Sm4 treatment induced cytotoxic effects on all three cell lines, with a greater effect observed in NSCLC adenocarcinoma cells. Sm4 treatment led to S-phase cell accumulation and upregulation of p21, a key regulator of the S-to-G2/M phase transition. While no significant changes in SOX7 or SOX17 protein expression were observed, Sm4 treatment resulted in a significant upregulation of SOX17 gene expression. Furthermore, our findings suggest a complex interplay between SOX18 and p21 in the context of lung cancer, with a positive correlation observed between SOX18 expression and p21 nuclear presence in clinical tissue samples obtained from lung cancer patients. These results suggest that Sm4 has the potential to disrupt the cell cycle and target cancer cell growth by modulating SOX18 activity and p21 expression. Further investigation is necessary to fully understand the relationship between SOX18 and p21 in lung cancer and to explore the therapeutic potential of SOX18 inhibition in lung cancer.

BCL11A Expression in Non-Small Cell Lung Cancers

B-cell leukemia/lymphoma 11A (BCL11A) may be one of the potential biomarkers of non-small cell lung cancer (NSCLC). However, its role in the development of this cancer has not yet been precisely established. The aim of this study was to investigate the expression of BCL11A at the mRNA and protein levels in NSCLC cases and non-malignant lung tissue (NMLT) and to determine the relationship between BCL11A expression and the clinicopathological factors and Ki-67, Slug, Snail and Twist. The localization and the level of BCL11A protein were examined using immunohistochemistry (IHC) on 259 cases of NSCLC, and 116 NMLT samples were prepared as tissue microarrays and using immunofluorescence (IF) in the following cell lines: NCI-H1703, A549 and IMR-90. The mRNA expression of BCL11A was determined using real-time PCR in 33 NSCLC cases, 10 NMLT samples and the cell lines. BCL11A protein expression was significantly higher in NSCLC cases compared to NMLT. Nuclear expression was found in lung squamous cell carcinoma (SCC) cells, while cytoplasmic expression was demonstrated in adenocarcinoma (AC) cells. Nuclear expression of BCL11A decreased with increasing malignancy grade and correlated positively with Ki-67 and Slug and Twist expression. The opposite relationships were found for the cytoplasmic expression of BCL11A. Nuclear expression of BCL11A in NSCLC cells may affect tumor cell proliferation and change their phenotype, thus promoting tumor progression.

BCL11A Expression in Breast Cancer

B-cell leukemia/lymphoma 11A (BCL11A) is a transcription factor that regulates the expression of genes involved in cell division or apoptosis. A link between high BCL11A expression and a worse prognosis has been demonstrated in patients with various cancers. The aim of this study was to investigate the expression pattern of BCL11A in breast cancer (BC) cases and mastopathy samples and to correlate the results with the clinicopathological data. The expression of the BCL11A protein was investigated using immunohistochemistry (IHC) on 200 cases of BC and 13 mastopathy samples. The level of BCL11A mRNA was determined using real-time PCR in 22 cases of BC and 6 mastopathy samples. The expression of BCL11A was also examined at the protein and mRNA levels in BC cell lines. A higher expression level of BCL11A in BC cases was shown compared to mastopathy samples. The expression level of BCL11A in BC cases and in the studied cell lines decreased with the increasing grade of histological malignancy (G). It was also negatively correlated with the primary tumor size. A significantly lower expression of BCL11A was found in BC that did not express estrogen or progesterone receptors and in triple-negative cases. The results of our research suggest that BCL11A may be relevant in the development of BC.

Cornelian Cherry (Cornus mas L.) Iridoid and Anthocyanin-Rich Extract Reduces Various Oxidation, Inflammation, and Adhesion Markers in a Cholesterol-Rich Diet Rabbit Model

Atherogenesis leads to the development of atherosclerosis, a progressive chronic disease characterized by subendothelial lipoprotein retention and endothelial impairment in the arterial wall. It develops mainly as a result of inflammation and also many other complex processes, which arise from, among others, oxidation and adhesion. Cornelian cherry (Cornus mas L.) fruits are abundant in iridoids and anthocyanins-compounds with potent antioxidant and anti-inflammatory activity. This study aimed to determine the effect of two different doses (10 mg and 50 mg per kg of body weight, respectively) of iridoid and anthocyanin-rich resin-purified Cornelian cherry extract on the markers that are important in the progress of inflammation, cell proliferation and adhesion, immune system cell infiltration, and atherosclerotic lesion development in a cholesterol-rich diet rabbit model. We used biobank blood and liver samples that were collected during the previous original experiment. We assessed the mRNA expression of MMP-1, MMP-9, IL-6, NOX, and VCAM-1 in the aorta, and the serum levels of VCAM-1, ICAM-1, CRP, PON-1, MCP-1, and PCT. The application of the Cornelian cherry extract at a dose of 50 mg/kg bw resulted in a significant reduction in MMP-1, IL-6, and NOX mRNA expression in the aorta and a decrease in VCAM-1, ICAM-1, PON-1, and PCT serum levels. The administration of a 10 mg/kg bw dose caused a significant decrease in serum ICAM-1, PON-1, and MCP-1. The results indicate the potential usefulness of the Cornelian cherry extract in the prevention or treatment of atherogenesis-related cardiovascular diseases, such as atherosclerosis or metabolic syndrome.

Molecular profiling of the intestinal mucosa and immune cells of the colon by multi-parametric histological techniques

The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques. Inflammatory cells were identified by immunohistochemical staining. Molecular parameters were estimated using the Raman spectroscopy (RS) and Fourier Transform Infrared (FTIR) spectroscopic imaging. The 3D refractive index (3D-RI) distributions of samples were determined using the digital holographic tomography. The distribution of immune cells between post-mortem (PM) and normal controls did show significant differences for CD4 (P = 0.0016) or CD8 (P < 0.0001), whose expression level was decreased in PM cases. No association was found between individual PMI values and inflammatory cell distribution. However, there was a tendency for a negative correlation between CD4⁺ cells and PMI (r = - 0.542, P = 0.032). The alterations ongoing in post-mortem tissue may suggest that PMI has a suppressive effect on the effector properties of the cell-mediated immunity. Moreover, it was confirmed that spectroscopic and digital holotomographic histology are also a useful technique for characterization of the differences in inflammation of varying intensity and in GALT imaging in a solid tissue. Anatomical location of immune cells and methods of tissue fixation determine the molecular and optical parameters of the examined cases.

Effects of Long-Term High-Fat Diet and Its Reversal on Lipids and Lipoproteins Composition in Thoracic Duct Lymph in Pigs

Background

This study was carried out to evaluate the effects of a long-term high-fat diet on lipids and lipoproteins composition in thoracic duct lymph in pigs.

Material/Methods

We examined lymph taken from the thoracic duct from 24 female white sharp-ear pigs, divided into 3 experimental groups fed different diets for 12 months: (a) the control group, fed the standard balanced diet; (b) the HFD group, fed an unbalanced, high-fat diet, and (c) the reversal diet group (RD), fed an unbalanced, high-fat diet for 9 months and then a standard balanced diet for 3 months.

Results

Lymph analysis after 12 months of fixed diets revealed significantly higher concentration of proteins in the HFD group in comparison to the control and RD groups. Examination of lymph lipoproteins fractions showed that the high-fat diet in the HFD group in comparison to control group caused an increase in cholesterol, phospholipids, and proteins content within HDL and chylomicrons. There were also more proteins within HDL in the HFD group in comparison to the RD group and more triglycerides within chylomicrons in the HFD group in comparison to the control group.

Conclusion

A long-term high-fat diet resulted in changed structure of HDL and chylomicrons in the thoracic duct lymph. Alterations in HDL composition suggest that a high-fat diet enhances reverses cholesterol transport. Changes in chylomicrons structure show the adaptation to more intense transport of dietary fat from the intestine to the liver under the influence of a high-fat diet. Reversal to a standard balanced diet had the opposite effects.

Transcriptomic Alterations of the Aortic Intima and Media in Long-term High-fat Diet Fed Pigs and Its Reversal (P15-010-19)

Objectives

We have previously shown that 12 months (mo.) high-fat diet (HFD) in pigs led to pathophysiological alterations, incl. fattening and increased femoral artery intima-media-thickness, which were partly reversed after 3 mo. return to control diet (Zabek et al., PLoS One 2017). The aim of this study was to decipher underlying mechanism of action of these dietary interventions on the arteries by nutrigenomics analyses of intima and media of aorta.

Methods

32 female pigs were divided into 3 groups: Control diet (CD) for 12 mo; HFD for 12 mo; 3) Reversal diet group (RD): HFD for 9 mo followed by CD for 3 mo After 12 mo animals were killed and abdominal aorta collected. RNA was isolated from aorta intima and media for whole genome microarray analyses followed by bioinformatics analyses.

Results

HFD compared to CD group significantly affected gene expression profile in intima with genes belonging to the chemotaxis, inflammation or endothelial permeability. RD induced gene expression profile was distinct from the CD group. This suggests that 3 mo of reversal to CD is not sufficient to correct gene expression changes induced by HFD. Comparison of RD profile with that of HFD group revealed a group of genes with opposite expression, e.g., genes regulating inflammation, toll-like cell signaling pathway or cytoskeleton organization involved in the regulation of cell permeability. This suggests that return to the RD only partly restored gene expression alterations due to the HFD. Significant changes in expression of genes in media following HFD were also observed, such as genes involved in cytoskeleton organization and migration MAPK signaling. As for intima, the expression profile of media of pigs on RD was different on that of these on CD diet. Compared to HFD, a group of genes involved in PI3K or MAPK pathways presented opposite expression suggesting that RD can partly correct the changes in genomic effect induced by HFD.

Conclusions

This study revealed genomic modifications induced by long-term HFD consumption on arterial intima and media. The return to normal diet for 3 mo was not sufficient to counteract the genomic effect of long-term HFD consumption.

Funding Sources

WROVASC Integrated Cardiovascular Centre, co-financed by the European Regional Development Fund.

The iridoid loganic acid and anthocyanins from the cornelian cherry (Cornus mas L.) fruit increase the plasma l-arginine/ADMA ratio and decrease levels of ADMA in rabbits fed a high-cholesterol diet

BACKGROUND

Although fruit and vegetable-rich diets have beneficial effects on cardiovascular diseases, we have little knowledge of the impact of fruits and their constituents, iridoids and anthocyanins, on the l-arginine-ADMA-DDAH pathway. Our previous study demonstrated the modulation of those factors by the oral administration of the cornelian cherry fruit.

HYPOTHESIS/PURPOSE

We have assessed the effects of the oral administration of two main constituents isolated from the cornelian cherry fruit, iridoid loganic acid and anthocyanins, on l-arginine, its derivatives (ADMA, SDMA), metabolites (DMA, l-citrulline), and the hepatic DDAH activity and its isoform expression in rabbits fed a high-cholesterol diet. We have also analyzed eNOS expression in the thoracic aorta as well as the redox status in blood.

STUDY DESIGN

In the present study, we used an animal model of diet induced atherosclerosis. For 60 days, white New Zealand rabbits were fed a standard diet, a 1% cholesterol enriched diet, or concomitantly with the investigated substances. l-arginine, ADMA, SDMA, DMA, and l-citrulline were assessed using the LC-MS/MS method. DDAH activity and redox parameters were analyzed spectrophotometrically. DDAH1 and DDAH2 isoform expressions were assessed by western blotting, mRNA expression of eNOS was quantified by real-time PCR.

RESULTS

We demonstrated that the administration of loganic acid (20 mg/kg b.w.), and to a lesser extent of anthocyanins (10 mg/kg b.w.), caused an increase in the l-arginine level and the l-arginine/ADMA ratio. Also, both substances decreased ADMA, DMA, and l-citrulline, but not SDMA levels. Anthocyanins, but not loganic acid, enhanced the activity of DDAH in the liver. Anthocyanins also significantly enhanced both DDAH1 and DDAH2 expression, while loganic acid to a lesser extent enhanced DDAH1 but not DDAH2 expression. Both loganic acid and anthocyanins pronouncedly increased mRNA expression of eNOS in thoracic aortas. Both loganic acid and anthocyanins reversed the blood glutathione level depleted by dietary cholesterol. Cholesterol feeding decreased the blood GPx level, and the change was not reversed by anthocyanins or loganic acid. We did not observe any significant differences in the blood levels of MDA or SOD among the groups.

CONCLUSION

Iridoids and anthocyanins may modulate the l-arginine-ADMA pathway in subjects fed a high-cholesterol diet.

The impact of sitagliptin, inhibitor of dipeptidyl peptidase-4 (DPP-4), on the ADMA-DDAH-NO pathway in ischemic and reperfused rat livers

BACKGROUND

A correlation between the level of asymmetric dimethylarginine (ADMA) - the inhibitor of the nitric oxide (NO) synthesis - and the liver function and survival after a liver transplantation has been reported.

OBJECTIVES

The aim of this study was to evaluate the effect of sitagliptin -the inhibitor of dipeptidyl peptidase-4 (DPP-4) - on the NO-ADMA-dimethylarginine dimethylaminohydrolase (DDAH) pathway in rat livers subjected to ischemia/reperfusion (IR).

MATERIAL AND METHODS

The rats received sitagliptin (5 mg/kg, per os - p.o.) (groups: S - livers not subjected to IR procedure, and SIR - livers subjected to IR procedure) or a saline solution (groups: C - livers not subjected to IR procedure, and CIR - livers subjected to IR procedure) for 14 days; following this, livers in the SIR and CIR groups were subjected to ischemia (60 min) and reperfusion (24 h). Aminotransferases were measured before the surgery; additionally, the arginine (ARG), ADMA and symmetric dimethylarginine (SDMA) levels were estimated just before ischemia and during reperfusion (at 0.5, 4 and 24 h). After IR, citrulline, the DDAH activity, mRNA for type 1 DDAH (DDAH1), and arginine methyltransferase type 1 (PRMT1) were determined.

RESULTS

The increase in the initial level of ARG/ADMA0 (A/A) ratio in group S compared to group C verged on statistical significance. At 0.5 and 4 h of reperfusion, the highest concentration of ADMA was found in group CIR. At those time points, the ARG level and the A/A ratio were decreased in groups CIR and SIR as compared to groups C and S, respectively. The alanine transaminase (ALT) activity was lower in the sitagliptin-treated group than in the non-treated one. The DDAH and citrulline levels were reduced in group CIR as compared to group C, but were greater in group SIR as compared to group S. The PRMT1 mRNA expression was higher in groups CIR and SIR, compared to groups C and S, respectively.

CONCLUSIONS

The increased A/A ratio suggests a protective effect of sitagliptin on livers not subjected to IR. Changes in the DDAH activity and the PRMT1 mRNA expression also imply the protective activity of sitagliptin during IR.

Pretransplant Immune Interplay Between Donor and Recipient Influences Posttransplant Kidney Allograft Function

BACKGROUND

Renal transplant candidates present immune dysregulation caused by chronic uremia, and deceased kidney donors present immune activation induced by brain death. Pretransplant donor and recipient immune-related gene expression were examined in the search for novel predictive biomarkers crosslinking recipient and donor pretransplant immune status with transplant outcome.

MATERIALS AND METHODS

This study included 33 low-risk consecutive renal transplant recipients and matched deceased donors. The expression of 29 genes linked to tissue injury, T-cell activation, cell migration, and apoptosis were assessed in postreperfusion kidney biopsies, as well as 14 genes in pretransplant peripheral blood of the kidney recipients. Gene expression was analyzed with real-time polymerase chain reaction on custom-designed low-density arrays.

RESULTS

Donor MMP9 expression was related to delayed graft function occurrence (P = .036) and short term kidney allograft function (14th day r_s = -0.44, P = .012; 1st month r_s = -0.46, P = .013). Donor TGFB1 expression was associated with short- and long-term graft function (14th day r_s = -0.47, P = .007; 3rd month r_s = -0.63, P = .001; 6th month r_s = -0.52, P = .010; 12th month r_s = -0.45, P = .028; 24th month r_s = -0.64, P = .003). Donor TGFB1 expression was not related to donor age (r_s = 0.32, P = .081), which was also an independent factor influencing the outcome. Recipient gene expression was not related to graft function but determined the acute rejection risk. Recipient IFNG and, to a lesser extent, IL18 expression were protective against acute rejection (area under the curve [AUC] 0.84, P < .001, and AUC 0.79, P < .001, respectively).

CONCLUSION

Kidney transplant outcome depends on the interplay between donor-related immune factors, which mostly affect allograft function and recipient immune milieu, influencing an alloreactive response.

Association Between Interleukin-10 Receptors and the CD45-Immunophenotype of Central Nervous System Tumors: A Preliminary Study

BACKGROUND/AIM

One of the current hypotheses assumes that brain tumors exert an immunosuppressive influence on the surrounding cellular environment. Interleukin-10 (IL-10) is one of the immunosuppressive cytokines modifying the biological activity of cancer. The aim of this study was to assess the expression of IL10R in CD45⁺ cells within primary brain tumors and metastases and establish its association with tumor basic immunophenotype.

PATIENTS AND METHODS

Tissue samples were obtained intraoperatively during surgeries of 32 patients suffering from meningiomas (n=9), gliomas (n=12) and metastatic tumors (n=11). Expression was assessed with flow cytometry and immunohistochemical reactions.

RESULTS

Expression of IL10R subunits within the leukocyte population (CD45⁺ cells) was significantly higher in primary tumors than in metastases.

CONCLUSION

To the best of our knowledge, this is the first study describing a correlation between the IL10R expression on leukocytes and histological types of brain tumors.

Nogo-B expression, in arterial intima, is impeded in the early stages of atherosclerosis in humans

Nogo-B (Reticulon 4B) is considered to be a novel vascular marker, which may have a protective role in injury-induced neointima formation and atherosclerosis. Nogo A/B is found to be crucial for monocyte/macrophage recruitment in acute inflammation and it is expressed in CD68 + macrophages. We hypothesize that macrophage infiltration in atherosclerosis is not dependent on Nogo-B expression in arterial wall. We have assessed Nogo-B expression and macrophage accumulation in the iliac arteries of healthy organ donors and organ donors with cardiovascular risk factors. Paraffin sections of 66 iliac arteries, from 44 deceased organ donors (17 women and 27 men), were studied. The healthy and cardiovascular risk (CVR) subgroups were created. With regard to staging of the atherosclerotic process, the thickness of arterial intima was measured in digitalized images of H+E stained tissue sections. Immunohistochemical reactions (Nogo-B and CD68) were carried out in all arteries (66 samples). Western blotting (WB-19 samples) and real-time PCR (27 samples) were performed on selected arteries. Significantly higher Nogo-B expression was demonstrated in the intima of the healthy subjects' subgroup, using immunohistochemistry. WB and real-time PCR revealed a trend toward lower Nogo-B expression in the adventitia of the CVR subgroup. Furthermore, the thickness of the intima was found to negatively correlate with the expression of Nogo-B in the intima and media (r = -0.32; p < 0.05; r = -0.32; p < 0.05). Macrophage infiltrates were more prominent in intima of CVR subjects (0.65 vs 3.52 a.u.; p < 0.01). Macrophage density in intima increased with atherosclerosis progression (r = 0.37; p < 0.01). CD68 macrophages density in adventitia was lower in CVR arteries than in healthy arteries. The expression of Nogo-B, in arterial intima, is impeded in the early stages of atherosclerosis. Accumulation of arterial intimal CD68 macrophages has been shown to progress; however, the overall macrophage density in the adventitia is reduced in arteries shown to have intimal thickening. Macrophage infiltration is not accompanied by Nogo-B expression in atherosclerotic arteries.

Ceramide galactosyltransferase (UGT8) is a molecular marker of breast cancer malignancy and lung metastases

BACKGROUND

It was shown recently on the level of gene expression that UGT8, coding UDP-galactose:ceramide galactosyltransferase, is one of six genes whose elevated expression correlated with a significantly increased the risk of lung metastases in breast cancer patients. In this study primary tumours and their lung metastases as well as breast cancer cell lines were analysed for UGT8 expression at the protein level.

METHODS

Expression of UGT8 in breast cancer tissue specimens and breast cancer cell lines was analysed using IHC, real-time PCR and Western blotting.

RESULTS

Comparison of the average values of the reaction intensities (IRS scale) showed a significant difference in UGT8 expression between (1) primary and metastatic tumours (Mann-Whitney U, P<0.05), (2) tumours of malignancy grades G3 and G2 (Mann-Whitney U, P<0.01) as well as G3 and G1 (Mann-Whitney U, P<0.001) and (3) node-positive and node-negative tumours (Mann-Whitney U, P<0.001). The predictive ability of increased expression of UGT8 was validated at the mRNA level in three independent cohorts of breast cancer patients (721). Similarly, breast cancer cell lines with the 'luminal epithelial-like' phenotype did not express or weakly expressed UGT8, in contrast to malignant, 'mesenchymal-like,' cells forming metastases in nude mice.

CONCLUSION

Our data suggest that UGT8 is a significant index of tumour aggressiveness and a potential marker for the prognostic evaluation of lung metastases in breast cancer.

Influence of commonly used clinical antidotes on antioxidant systems in human hepatocyte culture intoxicated with alpha-amanitin

α-Amanitin (α-AMA) is the main toxin of Amanita phalloides and its subspecies (A. virosa and A. verna). The primary mechanism of α-AMA toxicity is associated with protein synthesis blocking in hepatocytes. Additionally, α-AMA exhibits prooxidant properties that may contribute to its severe hepatotoxicity. The aim of the present study was to assess the effect of α-AMA on lipid peroxidation and the activities of superoxide dismutase (SOD) and catalase (CAT) in human hepatocyte culture. The effects of benzylpenicillin (BPCN), N-acetyl-L-cysteine (ACC), and silibinin (SIL) on SOD and CAT activities and on lipid peroxidation in human hepatocyte culture intoxicated with α-AMA were also examined. In human hepatocyte culture, 48-hour exposure to α-AMA at a 2-μM concentration caused an increase in SOD activity, a reduction of CAT activity, and a significant increase in lipid peroxidation. Changes in SOD and CAT activity caused by α-AMA could probably enhance lipid peroxidation by increased generation of hydrogen peroxide combined with reduced detoxification of that oxygen radical. The addition of antidotes (ACC or SIL) to the culture medium provided more effective protection against lipid peroxidation in human hepatocytes intoxicated with α-AMA than the addition of BPCN, possessing no antioxidant properties.

Benzylpenicillin, acetylcysteine and silibinin as antidotes in human hepatocytes intoxicated with alpha-amanitin

Fatalities due to mushroom poisonings are increasing worldwide, with high mortality rate resulting from ingestion of amanitin-producing species. Intoxications caused by amanitin-containing mushrooms represent an unresolved problem in clinical toxicology since no specific and fully efficient antidote is available. The objective of this study was a comparative evaluation of benzylpenicillin (BPCN), acetylcysteine (ACC) and silibinin (SIL) as an antidotes in human hepatocytes intoxicated with alpha-amanitin (alpha-AMA). All experiments were performed on cultured human hepatocytes. Cytotoxicity evaluation of cultured cells using MTT assay and measurement of lactate dehydrogenase (LDH) activity was performed at 12, 24 and 48h of exposure to alpha-AMA and/or antidotes. The significant decline of cell viability and significant increase of LDH activity were observed in all experimental hepatocyte cultures after 12, 24 and 36h exposure to alpha-AMA at concentration 2microM. Exposure of the cells to alpha-AMA resulted also in significant reduction of cell spreading and attachment. However, addition of tested antidotes to experimental cultures significantly stimulated cell proliferation and attachment. In cell cultures exposed simultaneously to alpha-AMA and tested antidotes cytotoxic parameters (MTT and LDH) were not significantly different from control incidences. The cytoprotective effect of all antidotes was not dose-related, which reflects a high efficacy of all these substances. Administration of studied antidotes was not associated with any adverse effects in hepatocytes. The administration of ACC, BPCN or SIL to human hepatocyte cultures showed a similar strong protective effect against cell damage in alpha-AMA toxicity.

The role of AT1 and AT2 angiotensin receptors in the mechanism of apoptosis in renal tubular cells after physical exercise

Intensive physical exercise disturbs the entire homeostasis in the body and leads to changes in haemodynamic and metabolic alterations not only in skeletal muscles but also in many distant organs. In response to acute physical exercise, a decrease of the glomerular filtration may occur, followed by stimulation of the renin-angiotensin system (RAS). Recent studies have shown that both AT1 and AT2 angiotensin receptors may play a role in mediating the apoptotic process in the kidney. Our previous studies have demonstrated an occurrence of apoptosis in rat renal tubular cells after an excessive exercise. The aim of the present study was to determine the possible mechanism of exercise-induced apoptosis in rat kidney. The analysis was performed on kidneys of rats, subjected to treadmill running until exhaustion. Apoptosis was detected in paraffin sections by the TUNEL technique. The expression of AT1 and AT2 receptors in renal tubular cells was examined by immunohistochemistry and Western blot. Our results confirmed that apoptosis after physical exercise is present in renal distal tubular cells. Moreover, there was an increased expression of AT1 and AT2 receptors in distal tubular cells. These studies suggest that physical exercise may induce apoptosis by a mechanism, involving the activation of angiotensin AT1 and AT2 receptors.