Acute rejection is still a common complication of kidney transplantation. IL‐17 is known to be associated with allograft rejection but the cellular source and the role of this cytokine remains ...unclear. We investigated IL‐17 graft expression in renal transplant recipients with acute antibody‐mediated rejection (ABMR), acute T‐cell‐mediated rejection (TCMR), interstitial fibrosis and tubular atrophy (IFTA) and acute tubular damage due to calcineurin‐inhibitor toxicity (CNI). In acute ABMR, tubular IL‐17 protein expression was significantly increased compared to TCMR, where most of the IL‐17+cells were CD4+graft infiltrating lymphocytes, IFTA and CNI control groups. The tubular expression of IL‐17 in acute ABMR colocalized with JAK2 phosphorylation and peritubular capillaries C4d deposition. In addition, IL‐17 tubular expression was directly and significantly correlated with the extension of C4d deposits. In cultured proximal tubular cells, C3a induced IL‐17 gene and protein expression along with an increased in JAK2 phosphorylation. The inhibition of JAK2 abolished C3a‐induced IL‐17 expression. The use of steroids and monoclonal antibodies reduced IL‐17 expression, JAK2 phosphorylation and C4d deposition in acute ABMR patients. Our data suggest that tubular cells represent a significant source of IL‐17 in ABMR and this event might be mediated by the complement system activation featuring this condition.
The authors demonstrate that tubular epithelial cells represent a significant source for IL‐17 in acute antibody‐mediated rejection through the activation of the complement cascade and JAK2 phosphorylation that, in the clinical area, may represent a suitable therapeutic target.
Rapamycin, an immunosuppressive drug used to prevent rejection after kidney transplantation, influences phosphate homeostasis, induces insulin resistance and has been shown to prolong lifespan in ...animal models. Because Klotho is an aging‐suppressor gene controlling phosphate metabolism and insulin sensitivity, we investigated the influence of rapamycin on Klotho expression. A total of 100 kidney transplant recipients, 50 chronically treated with rapamycin and 50 with calcineurin inhibitors, were enrolled; 20 healthy subjects were employed as control. In the rapamycin group, serum phosphate was lower than in the CNI group with an increase in phosphate excretion and a reduction in its reabsorption. In addition, rapamycin increased insulin resistance as shown by HOMA index. Rapamycin treatment of an immortalized proximal tubular cell line induced the expression of Klotho, the phosphorylation of AKT in Ser473, downstream target of mTORC2 and the expression of RICTOR, mTORC2 main component. AKT inhibition reduced the rapamycin‐induced expression of Klotho. In vivo rapamycin treatment induced higher degree of RICTOR and AKT Ser473 expression directly correlating with long‐term rapamycin exposure, FEPO4 and HOMA index. In conclusion, our data would suggest that rapamycin may influence phosphate homeostasis and insulin resistance modulating Klotho expression through mTORC2 activation.
Rapamycin influences phosphate homeostasis and insulin resistance modulating klotho expression in epithelial tubular cells and this event is mediated by mTORC2 through AKT phosphorylation.
IntroductionPancreatic adenocarcinoma is a tumour with poor prognosis. Usually diagnosed at a late stage, the high mortality is linked to resistance to conventional chemotherapy. Combination therapy ...and targeted therapies proved to be not very effective. Thus, a better understanding of the molecular mechanisms underlying drug resistance in pancreatic cancer could lead to the development of more effective therapeutic strategies.Material and methodsBX-PC3 pancreatic tumour cells were treated with increasing doses of NAA (2,4,8 and 16 mM) for 72 hour and cell viability was assessed by xCELLigence system technology. The gene expression profile induced by NAA treatment in BX-PC3 cells was examined using Real-Time qPCR. Anti-proliferative and differentiating effects of NAA in BX-PC3 treated cells were evaluated by flow cytometric analysis. Acetyl CoA levels after 72 hour NAA treatment was mesured by HPLC/HRMS. The expression of proteins involved in acetylation mechanism were measured by Western Blotting. The metabolic analysis were performed by the Seahorse Bioanalyzer. The effects of NAA in 3D cultures were studied morphologically by inverted microscope.Results and discussionsNAA treatment in BX-PC3 pancreatic tumour cells elicited anti-proliferative and differentiating effects evident with the arrest of proliferation and decreased expression of specific stemness markers such as cMyc, Klf4, Lin28 and Oct4. Exposure of cells to NAA induced down-regulation of CD133 and CD184 surface markers, arrest of cell cyle at G0/G1 phase, associated to increased levels of p53, p21 and p27 genes. Moreover, NAA-treated BX-PC3 cells showed decreased levels of the central metabolite Coenzyme A, which correlates with alterations in protein acetylation. In addition, an overall impairment of mitochondrial function was observed following NAA treatment, resulting in a revised feeding of metabolic substrates. Finally, NAA showed a strong effect on tumour spheroid growth, with reduction in colony size.ConclusionTo our knowledge, this is the first study that demonstrates the differentiating effects of NAA treatment in pancreatic tumour cells and its ability to reduce the size of 3D pancreatic carcinoma spheroids.
IntroductionRecently, several studies have highlighted the key role of cancer stem cells (CSC) in tumour initiation, metastasis, and relapses. The CSC pool generally exhibits higher resistance to ...conventional chemo-radiotherapy and a different cell metabolism. Aim of our study is to investigate the main metabolic differences in the human osteosarcoma stem-like cells (3ABOS) and differentiated osteosarcoma cells (MG63) to unveil new metabolic therapeutic targets.Material and methodsMetabolic analyses were performed with Seahorse Bioanalyzer. Live cell imaging for ROS content, mitochondrial membrane potential and morphology, were performed by confocal microscopy by using DCF-DA, Mito-Tracker Red and NAO as selective probes, respectively. Protein expression was revealed by qPCR and western blot.Results and discussionsOur results showed a significant reduction of the mitochondrial oxygen consumption rate in 3ABOS compared with MG63 cells. Next, we assessed the specific contributions of glucose, fatty acid and glutamine to the respiratory phenotype, unveiling larger reliance on oxidation of these three main fuels with a significant reduction in mitochondrial flexibility in 3ABOS. The lower OXPHOS is compensated by a shift in glucose metabolism demonstrated by increased extracellular acidification rate.These results were further supported by a significant reduction of 3ABOS proliferation in glucose shortage. According to this scenario, confocal microscopy highlighted reduced mitochondrial membrane potential, and increased ROS content in 3ABOS compared to MG63. Additionally, 3ABOS displayed a lower mitochondrial DNA amount associated with more elongated mitochondrial network confirmed by both live cell imaging and Mitofusin expression analysis. Moreover, members of the NADPH oxidases family resulted to be differently expressed in the two cell lines, thus suggesting a potential role of ROS mediated signalling in cancer cell phenotype.ConclusionOverall our results demonstrated that the oxidative metabolic phenotype hallmarks cancer biology. Further investigations are ongoing to define specific drugs acting on metabolic target and their effectiveness as a therapeutic approach.
IntroductionBreast cancer is one of the common cause of cancer-related deaths in women, and the vast majority of breast cancer-related deaths involve metastatic disease. Thus, an understanding of the ...molecular and cellular mechanism supporting tumour progression is essential for developing targeted treatments. Recently, several studies have recognised the critical role of the metabolic setting and of microenvironmental cues in tumour development and therapeutic responses. In the present study we investigated the tumor-stroma metabolic interplay in MDA-MB-231 (high metastatic) cultured with conditioned medium (CM) from mammary adipose tissue-derived mesenchymal stem cells (MSC) either under high (HG) and low glucose (LG) regimen.Material and methodsMetabolic fluxes analyses were performed with Seahorse Bioanalyzer providing both mitochondrial respiratory activity, as oxygen consumption rate (OCR), and glycolysis-related extracellular acidification rate (ECAR). Live cell imaging for mitochondrial membrane potential Δψm, was performed by confocal microscopy by using TMRE as selective probe. Cell migration was evaluated by scratch assay monitoring the wound’s closure after 24 hour.Results and discussionsMetabolic fluxes analysis showed that HG growth condition caused a significant reduction of OCR and ECAR in MDA cell line as well as in MSC. MDA grown in MSC-derived CM revealed a dampening of OCR and ECAR and this effect was attained irrespectively of the glucose concentration. Analysis of Δψm showed a significant decrease only in MDA cultured with CM from HG-MSC. Intriguingly, in a specular setup MSC cultured with CM from theMDA, a significant reduction of ECAR, both in HG and LG was observed whereas OCR resulted to be strongly reduced only in HG. Our results would indicate a reciprocal interplay between the one of the most aggressive breast cancer cell line and MSC in rewiring the mitochondrial oxidative metabolism and likely the tumour phenotype. Consistently, in vitro scratch assay showed an increasing migration of MDA cultured with CM from MSC HG, thus suggesting a key role of MSC in facilitating cancer progression/invasiveness.ConclusionOur results strongly support the involvement of stromal MSC in tumour metabolism of malignant phenotypes. Further experiments are needed to define the factors released from MDA acting on MSC metabolism. Understanding these interactions is fundamental to develop therapeutic interventions addressing the MSC-tumour interaction.
IntroductionHepatocellular carcinoma (HCC) represents the sixth leading cancer and the third most common cause of death from cancer. Many different aetiological factors are involved in the ...development of HCC, which may be modulated by both estrogens and androgens hormones during its initiation, progression and metastasis. The misuse of anabolic androgenic steroids (AAS) is associated with serious adverse effects to the liver, including cellular adenomas and adenocarcinomas, and is considered a factor risk of developing hepatic sex hormone related tumours. The purpose of this study was to investigate the role of Nandrolone, one of the most commonly used AAS, in regulating proliferation and differentiation of HCC.Material and methodsHuman HCC cell line HepG2 was treated with Nandrolone, a synthetic androgen ligand, for 48 hs and its viability and proliferation was assessed by MTS and cell cycle analysis, respectively. The expression of protein involved in cell cycle regulation and differentiation markers were analysed by western blot and real time PCR. Measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were performed using Seahorse XF96 extracellular flux analyzer. Respiratory chain complex activities were assayed spectrophotometrically. Stemness surface markers expression was detected by FACSCalibur flow cytometer.Results and discussionsNandrolone treatment caused cell growth inhibition associated to a downregulation of cyclin D1 and an upregulation of the cyclin-dependent kinase inhibitors p21Waf1/Cip1 leading to cell cycle arrest in the G2 phase. Moreover, a significant overall impairment of mitochondrial functions, resulting in a reduced OCR and impairment of OXPHOS complexes activities were also observed, thus suggesting a role in the control of the metabolic reprogramming. Finally, a significant increase of the stemness markers was detected following Nandrolone treatment, also confirmed in additional human stem cell types and in an in vivo mouse model.ConclusionNandrolone shows a strong anti-proliferative effect in differentiated tumour cells, promoting cancer cells stemness through cellular metabolic reprogramming. These results could have important public health implications in order to improve the primary prevention such as revising altered lifestyles, like AAS abuse.
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