Kinetics of Different Blood Biomarkers during Polymyxin-B Extracorporeal Hemoperfusion in Abdominal Sepsis.

INTRODUCTION: Comparison of the marker kinetics procalcitonin, presepsin, and endotoxin during extracorporeal hemoperfusion with polymyxin-B adsorbing cartridge (PMX-HA) has never been described in abdominal sepsis. We aimed to compare the trend of three biomarkers in septic post-surgical abdominal patients in intensive care unit (ICU) treated with PMX-HA and their prognostic value. METHODS: Ninety abdominal post-surgical patients were enrolled into different groups according to the evidence of postoperative sepsis or not. Non-septic patients admitted in the surgical ward were included in C group (control group). ICU septic shock patients with endotoxin levels <0.6 EAA receiving conventional therapy were addressed in S group and those with endotoxin levels ≥0.6 EAA receiving treatment with PMX-HA, besides conventional therapy, were included in SPB group. Presepsin, procalcitonin, endotoxin and other clinical data were recorded at 24 h (T0), 72 h (T1) and 7 days (T2) after surgery. Clinical follow-up was performed on day 30. RESULTS: SPB group showed reduced levels of the three biomarkers on T2 versus T0 (p < 0.001); presepsin, procalcitonin and endotoxin levels decreased, respectively, by 25%, 11%, and 2% on T1 versus T0, and 40%, 41%, and 26% on T2 versus T0. All patients in C group, 73% of patients in SPB group versus 37% of patients in S group survived at follow-up. Moreover, procalcitonin had the highest predictive value for mortality at 30 days, followed by presepsin. CONCLUSION: The present study showed the reliability of presepsin in monitoring PMX-HA treatment in septic shock patients. Procalcitonin showed better predicting power for the mortality riSsk.

mTOR and SGLT-2 Inhibitors: Their Synergistic Effect on Age-Related Processes.

The aging process contributes significantly to the onset of chronic diseases, which are the primary causes of global mortality, morbidity, and healthcare costs. Numerous studies have shown that the removal of senescent cells from tissues extends lifespan and reduces the occurrence of age-related diseases. Consequently, there is growing momentum in the development of drugs targeting these cells. Among them, mTOR and SGLT-2 inhibitors have garnered attention due to their diverse effects: mTOR inhibitors regulate cellular growth, metabolism, and immune responses, while SGLT-2 inhibitors regulate glucose reabsorption in the kidneys, resulting in various beneficial metabolic effects. Importantly, these drugs may act synergistically by influencing senescence processes and pathways. Although direct studies on the combined effects of mTOR inhibition and SGLT-2 inhibition on age-related processes are limited, this review aims to highlight the potential synergistic benefits of these drugs in targeting senescence.

MUC1 Expression Affects the Immunoflogosis in Renal Cell Carcinoma Microenvironment through Complement System Activation and Immune Infiltrate Modulation.

Mucin1 (MUC1), a glycoprotein associated with an aggressive cancer phenotype and chemoresistance, is aberrantly overexpressed in a subset of clear cell renal cell carcinoma (ccRCC). Recent studies suggest that MUC1 plays a role in modulating cancer cell metabolism, but its role in regulating immunoflogosis in the tumor microenvironment remains poorly understood. In a previous study, we showed that pentraxin-3 (PTX3) can affect the immunoflogosis in the ccRCC microenvironment by activating the classical pathway of the complement system (C1q) and releasing proangiogenic factors (C3a, C5a). In this scenario, we evaluated the PTX3 expression and analyzed the potential role of complement system activation on tumor site and immune microenvironment modulation, stratifying samples in tumors with high (MUC1H) versus tumors with low MUC1 expression (MUC1L). We found that PTX3 tissue expression was significantly higher in MUC1H ccRCC. In addition, C1q deposition and the expressions of CD59, C3aR, and C5aR were extensively present in MUC1H ccRCC tissue samples and colocalized with PTX3. Finally, MUC1 expression was associated with an increased number of infiltrating mast cells, M2-macrophage, and IDO1+ cells, and a reduced number of CD8+ T cells. Taken together, our results suggest that expression of MUC1 can modulate the immunoflogosis in the ccRCC microenvironment by activating the classical pathway of the complement system and regulating the immune infiltrate, promoting an immune-silent microenvironment.

mTOR inhibitors improve both humoral and cellular response to SARS-CoV-2 messenger RNA BNT16b2 vaccine in kidney transplant recipients.

Kidney transplant recipients (KTRs) have been considered as patients at higher risk of SARS-CoV-2-related disease severity, thus COVID-19 vaccination was highly recommended. However, possible interferences of different immunosuppression with development of both humoral and T cell-mediated immune response to COVID-19 vaccination have not been determined. Here we evaluated the association between mTOR-inhibitors (mTOR-I) and immune response to mRNA BNT162b2 (Pfizer-BioNTech) vaccine in KTR. To this aim 132 consecutive KTR vaccinated against COVID-19 in the early 2021 were enrolled, and humoral and T cell-mediated immune response were assessed after 4-5 weeks. Patients treated with mTOR-I showed significantly higher anti-SARS-CoV-2 IgG titer (p = .003) and higher percentages of anti-SARS-CoV-2 S1/RBD Ig (p = .024), than those without. Moreover, SARS-CoV-2-specific T cell-derived IFNγ release was significantly increased in patients treated with mTOR-I (p < .001), than in those without. Multivariate analysis confirmed that therapy with mTOR-I gained better humoral (p = .005) and T cell-mediated immune response (p = .005) in KTR. The presence of mTOR-I is associated with a better immune response to COVID-19 vaccine in KTR compared to therapy without mTOR-I, not only by increasing vaccine-induced antibodies but also by stimulating anti-SARS-CoV-2 T cell response. These finding are consistent with a potential beneficial role of mTOR-I as modulators of immune response to COVID-19 vaccine in KTR.

Therapeutic Approach for Recurrent Focal Segmental Glomerulosclerosis in Pediatric Renal Transplant Recipients: A Single-Center Experience.

INTRODUCTION: Recurrence of focal segmental glomerulosclerosis (FSGS) after kidney transplantation (KTx) develops in 40% of patients, leading to graft loss in half of cases. Extracorporeal apheretic treatments, combined with immunosuppressive drugs, seem to be the most promising therapies, but at now limited reports are available, mainly in pediatric patients. OBJECTIVE: We aimed to assess the efficacy of immunoadsorption (IA) to treat recurrent FSGS in pediatric patients. METHODS: We report a case series of 4 pediatric patients (aged 4-12 years) followed at our institution for early recurrent FSGS after KTx. FSGS recurrence was treated with early and intensive apheretic treatments IA. RESULTS: After IA initiation, a partial remission (PR) of proteinuria at 24-month follow-up was achieved only in 1 patient. The others showed a mild reduction of nephrotic proteinuria, without PR, but gained a significant improvement in clinical signs of nephrotic syndrome (reduction of edema, increased serum albumin, and total protein levels). After a median follow-up of 38 (22-48) months, renal function was almost stable over time in all patients, except one who returned to hemodialysis after 22 months. No severe IA-related complications occurred. CONCLUSIONS: According to our clinical experience, IA revealed as a safe and effective therapy to treat patients with recurrent FSGS after KTx and it could maintain stable renal function in 75% of patients.

Unraveling the Link between Interferon-α and Systemic Lupus Erythematosus: From the Molecular Mechanisms to Target Therapies.

Systemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease with a wide range of clinical expressions. The kidney is often affected, usually within 5 years of the onset of SLE, and lupus nephropathy (LN) carries a high risk for increased morbidity. The clinical heterogeneity of the disease is accompanied by complex disturbances affecting the immune system with inflammation and tissue damage due to loss of tolerance to nuclear antigens and the deposition of immune complexes in tissues. Several studies have reported that in human SLE, there is an important role of the Type-I-interferons (INF) system suggested by the upregulation of INF-inducible genes observed in serial gene expression microarray studies. This review aims to describe the transduction pathways of Type-I-interferons, in particular INFα, and its immune-regulatory function in the pathogenesis of SLE and, in particular, in LN. In addition, recent novelties concerning biologic therapy in LN will be discussed.

Pathological diagnosis of Coronavirus-related nephropathy: insight from postmortem studies.

A novel coronavirus pneumonia first occurred in Wuhan, China in early December 2019; the causative agent was identified and named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the World Health Organization (WHO), and the resulting disease termed coronavirus disease 2019 (COVID-19), according to the WHO coronavirus disease situation reports. This condition has spread rapidly all over the world and caused more than 125 million cases globally, with more than 2 million related deaths. Two previous outbreaks due to zoonotic coronaviruses have occurred in the last 20 years, namely the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), causing high morbidity and mortality in human populations upon crossing the species barriers. SARS-CoV-2, SARS-CoV, and MERS-CoV show several similarities in pathogenicity and clinical presentations, the latter ranging from asymptomatic infection to severe acute respiratory distress syndrome (ARDS) and multiorgan impairment. Acute kidney injury (AKI) has been commonly reported in patients with CoV infections; therefore, pathological analysis of renal parenchyma in these patients has been carried out in order to improve knowledge about underlying mechanisms. Viral infection has been demonstrated in the renal tubular epithelial cells by electron microscopy (EM), immunohistochemistry (IHC), and in situ hybridization (ISH), although with conflicting results. Light microscopy (LM) changes have been described in the renal parenchyma primarily in the form of acute renal tubular damage, possibly due to direct viral cytopathic effect and immune-mediated mechanisms such as cytokine storm syndrome. In this review, we describe and discuss the spectrum of histological, ultrastructural, and molecular findings in SARS-CoV, MERS-CoV, and SARS-CoV-2-related renal pathology obtained from postmortem studies, as well as intrinsic limitations and pitfalls of current diagnostic techniques.

CD40 Cross-Linking Induces Migration of Renal Tumor Cell through Nuclear Factor of Activated T Cells (NFAT) Activation.

CD40 crosslinking plays an important role in regulating cell migration, adhesion and proliferation in renal cell carcinoma (RCC). CD40/CD40L interaction on RCC cells activates different intracellular pathways but the molecular mechanisms leading to cell scattering are not yet clearly defined. Aim of our study was to investigate the main intracellular pathways activated by CD40 ligation and their specific involvement in RCC cell migration. CD40 ligation increased the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun NH (2)-terminal kinase (JNK) and p38 MAPK. Furthermore, CD40 crosslinking activated different transcriptional factors on RCC cell lines: AP-1, NFkB and some members of the Nuclear Factor of Activated T cells (NFAT) family. Interestingly, the specific inhibition of NFAT factors by cyclosporine A, completely blocked RCC cell motility induced by CD40 ligation. In tumor tissue, we observed a higher expression of NFAT factors and in particular an increased activation and nuclear migration of NFATc4 on RCC tumor tissues belonging to patients that developed metastases when compared to those who did not. Moreover, CD40-CD40L interaction induced a cytoskeleton reorganization and increased the expression of integrin ß1 on RCC cell lines, and this effect was reversed by cyclosporine A and NFAT inhibition. These data suggest that CD40 ligation induces the activation of different intracellular signaling pathways, in particular the NFATs factors, that could represent a potential therapeutic target in the setting of patients with metastatic RCC.

Recurrent Glomerulonephritis after Renal Transplantation: The Clinical Problem.

Glomerulonephritis (GN) continues to be one of the main causes of end-stage kidney disease (ESKD) with an incidence rating from 10.5% to 38.2%. Therefore, recurrent GN, previously considered to be a minor contributor to graft loss, is the third most common cause of graft failure 10 years after renal transplantation. However, the incidence, pathogenesis, and natural course of recurrences are still not completely understood. This review focuses on the most frequent diseases that recur after renal transplantation, analyzing rate of recurrence, epidemiology and risk factors, pathogenesis and bimolecular mechanisms, clinical presentation, diagnosis, and therapy, taking into consideration the limited data available in the literature. First of all, the risk for recurrence depends on the type of glomerulonephritis. For example, recipient patients with anti-glomerular basement membrane (GBM) disease present recurrence rarely, but often exhibit rapid graft loss. On the other hand, recipient patients with C3 glomerulonephritis present recurrence in more than 50% of cases, although the disease is generally slowly progressive. It should not be forgotten that every condition that can lead to chronic graft dysfunction should be considered in the differential diagnosis of recurrence. Therefore, a complete workup of renal biopsy, including light, immunofluorescence and electron microscopy study, is essential to provide the diagnosis, excluding alternative diagnosis that may require different treatment. We will examine in detail the biomolecular mechanisms of both native and transplanted kidney diseases, monitoring the risk of recurrence and optimizing the available treatment options.

Altered Phosphorylation of Cytoskeleton Proteins in Peripheral Blood Mononuclear Cells Characterizes Chronic Antibody-Mediated Rejection in Kidney Transplantation.

Chronic antibody-mediated rejection (CAMR) is the major cause of kidney transplant failure. The molecular mechanisms underlying this event are still poorly defined and this lack of knowledge deeply influences the potential therapeutic strategies. The aim of our study was to analyze the phosphoproteome of peripheral blood mononuclear cells (PBMCs), to identify cellular signaling networks differentially activated in CAMR. Phosphoproteins isolated from PBMCs of biopsy proven CAMR, kidney transplant recipients with normal graft function and histology and healthy immunocompetent individuals, have been investigated by proteomic analysis. Phosphoproteomic results were confirmed by Western blot and PBMCs' confocal microscopy analyses. Overall, 38 PBMCs samples were analyzed. A differential analysis of PBMCs' phosphoproteomes revealed an increase of lactotransferrin, actin-related protein 2 (ARPC2) and calgranulin-B in antibody-mediated rejection patients, compared to controls. Increased expression of phosphorylated ARPC2 and its correlation to F-actin filaments were confirmed in CAMR patients. Our results are the first evidence of altered cytoskeleton organization in circulating immune cells of CAMR patients. The increased expression of phosphorylated ARPC2 found in the PBMCs of our patients, and its association with derangement of F-actin filaments, might suggest that proteins regulating actin dynamics in immune cells could be involved in the mechanism of CAMR of kidney grafts.

LPS removal reduces CD80-mediated albuminuria in critically ill patients with Gram-negative sepsis.

LPS-induced sepsis is a leading cause of acute kidney injury (AKI) in critically ill patients. LPS may induce CD80 expression in podocytes with subsequent onset of proteinuria, a risk factor for progressive chronic kidney disease (CKD) frequently observed after AKI. This study aimed to investigate the therapeutic efficacy of LPS removal in decreasing albuminuria through the reduction of podocyte CD80 expression. Between January 2015 and December 2017, 70 consecutive patients with Gram-negative sepsis-induced AKI were randomized to either have coupled plasma filtration and adsorption (CPFA) added to the standard care ( n = 35) or not ( n = 35). To elucidate the possible relationship between LPS-induced renal damage, proteinuria, and CD80 expression in Gram sepsis, a swine model of LPS-induced AKI was set up. Three hours after LPS infusion, animals were treated or not with CPFA for 6 h. Treatment with CPFA significantly reduced serum cytokines, C-reactive protein, procalcitonin, and endotoxin levels in patients with Gram-negative sepsis-induced AKI. CPFA significantly lowered also proteinuria and CD80 urinary excretion. In the swine model of LPS-induced AKI, CD80 glomerular expression, which was undetectable in control pigs, was markedly increased at the podocyte level in LPS-exposed animals. CPFA significantly reduced LPS-induced proteinuria and podocyte CD80 expression in septic pigs. Our data indicate that LPS induces albuminuria via podocyte expression of CD80 and suggest a possible role of timely LPS removal in preventing the maladaptive repair of the podocytes and the consequent increased risk of CKD in sepsis-induced AKI.

Inflammation induces osteoclast differentiation from peripheral mononuclear cells in chronic kidney disease patients: crosstalk between the immune and bone systems.

Background: Inflammation and immune system alterations contribute to bone damage in many pathologies by inducing the differentiation of osteoclasts (OCs), the bone resorbing cells. This link is largely unexplored in chronic kidney disease (CKD) and haemodialysis (HD) patients, in which reduced renal function is accompanied by an increased inflammatory state and skeletal abnormality. Methods: We used ex vivo culture experiments to investigate the osteoclastogenic potential of peripheral blood mononuclear cells (PBMCs) of CKD and HD patients, focusing on immune cell subsets and inflammatory cytokines such as LIGHT and receptor activator of nuclear factor κB ligand (RANKL). Results: We observed spontaneous osteoclastogenesis with a significant increase in OC formation and bone resorbing activity in late-stage CKD and HD patients when compared with early-stage CKD patients and healthy donors, likely due to an increased expression of RANKL and LIGHT (homologous to Lymphotoxins exhibiting Inducible expression and competing with herpes simplex virus Glycoprotein D for herpes virus entry mediator [HVEM], a receptor expressed by T lymphocytes) in PBMCs. Specific inhibition of these cytokines in PBMCs isolated from CKD stages 3b-5 and HD patients induced the reduction of OC formation in vitro. The phenotypic characterization of peripheral blood cells revealed a significant increase of OC precursors (CD14+CD11b+CD51/61+) and CD14+CD16+ monocytes in advanced CKD and HD patients compared with the control group. Conclusions: Our results suggest that circulating inflammatory monocytes from advanced CKD or HD patients trans differentiate into OCs in vitro and play a relevant role in mineral bone disorders and that LIGHT and RANKL represent new potential therapeutic targets in these settings.

TRIM8 restores p53 tumour suppressor function by blunting N-MYC activity in chemo-resistant tumours.

BACKGROUND: TRIM8 plays a key role in controlling the p53 molecular switch that sustains the transcriptional activation of cell cycle arrest genes and response to chemotherapeutic drugs. The mechanisms that regulate TRIM8, especially in cancers like clear cell Renal Cell Carcinoma (ccRCC) and colorectal cancer (CRC) where it is low expressed, are still unknown. However, recent studies suggest the potential involvement of some microRNAs belonging to miR-17-92 and its paralogous clusters, which could include TRIM8 in a more complex pathway. METHODS: We used RCC and CRC cell models for in-vitro experiments, and ccRCC patients and xenograft transplanted mice for in vivo assessments. To measure microRNAs levels we performed RT-qPCR, while steady-states of TRIM8, p53, p21 and N-MYC were quantified at protein level by Western Blotting as well as at transcript level by RT-qPCR. Luciferase reporter assays were performed to assess the interaction between TRIM8 and specific miRNAs, and the potential effects of this interaction on TRIM8 expression. Moreover, we treated our cell models with conventional chemotherapeutic drugs or tyrosine kinase inhibitors, and measured their response in terms of cell proliferation by MTT and colony suppression assays. RESULTS: We showed that TRIM8 is a target of miR-17-5p and miR-106b-5p, whose expression is promoted by N-MYC, and that alterations of their levels affect cell proliferation, acting on the TRIM8 transcripts stability, as confirmed in ccRCC patients and cell lines. In addition, reducing the levels of miR-17-5p/miR-106b-5p, we increased the chemo-sensitivity of RCC/CRC-derived cells to anti-tumour drugs used in the clinic. Intriguingly, this occurs, on one hand, by recovering the p53 tumour suppressor activity in a TRIM8-dependent fashion and, on the other hand, by promoting the transcription of miR-34a that turns off the oncogenic action of N-MYC. This ultimately leads to cell proliferation reduction or block, observed also in colon cancer xenografts overexpressing TRIM8. CONCLUSIONS: In this paper we provided evidence that TRIM8 and its regulators miR-17-5p and miR-106b-5 participate to a feedback loop controlling cell proliferation through the reciprocal modulation of p53, miR-34a and N-MYC. Our experiments pointed out that this axis is pivotal in defining drug responsiveness of cancers such ccRCC and CRC.

miR-29b and miR-198 overexpression in CD8+ T cells of renal cell carcinoma patients down-modulates JAK3 and MCL-1 leading to immune dysfunction.

BACKGROUND: Mammalian microRNAs (miR) regulate the expression of genes relevant for the development of adaptive and innate immunity against cancer. Since T cell dysfunction has previously been reported in patients with renal cell carcinoma (RCC; clear cell type), we aimed to analyze these immune cells for genetic and protein differences when compared to normal donor T cells freshly after isolation and 35 days after in vitro stimulation (IVS) with HLA-matched RCC tumor cells. METHODS: We investigated gene expression profiles of tumor-reactive CD8(+) T cells obtained from RCC patient and compared with their HLA-matched healthy sibling donors using a microarray approach. In addition, miRNAs analysis was performed in a validation cohort of peripheral blood CD8(+) T cells from 25 RCC patients compared to 15 healthy volunteers. RESULTS: We observed that CD8(+) T cells from RCC patients expressed reduced levels of anti-apoptotic and proliferation-associated gene products when compared with normal donor T cells both pre- and post-IVS. In particular, JAK3 and MCL-1 were down-regulated in patient CD8(+) T cells versus their normal counterparts, likely due to defective suppressor activity of miR-29b and miR-198 in RCC CD8(+) T cells. Indeed, specific inhibition of miR-29b or miR-198 in peripheral blood mononuclear cells (PBMCs) isolated from RCC patients, resulted in the up-regulation of JAK3 and MCL-1 proteins and significant improvement of cell survival in vitro. CONCLUSIONS: Our results suggest that miR-29b and miR-198 dysregulation in RCC patient CD8(+) T cells is associated with dysfunctional immunity and foreshadow the development of miR-targeted therapeutics to correct such T cell defects in vivo.

A type I interferon signature characterizes chronic antibody-mediated rejection in kidney transplantation.

Chronic antibody-mediated rejection (CAMR) represents the main cause of kidney graft loss. To uncover the molecular mechanisms underlying this condition, we characterized the molecular signature of peripheral blood mononuclear cells (PBMCs) and, separately, of CD4(+) T lymphocytes isolated from CAMR patients, compared to kidney transplant recipients with normal graft function and histology. We enrolled 29 patients with biopsy-proven CAMR, 29 stable transplant recipients (controls), and 8 transplant recipients with clinical and histological evidence of interstitial fibrosis/tubular atrophy. Messenger RNA and microRNA profiling of PBMCs and CD4(+) T lymphocytes was performed using Agilent microarrays in eight randomly selected patients per group from CAMR and control subjects. Results were evaluated statistically and by functional pathway analysis (Ingenuity Pathway Analysis) and validated in the remaining subjects. In PBMCs, 45 genes were differentially expressed between the two groups, most of which were up-regulated in CAMR and were involved in type I interferon signalling. In the same patients, 16 microRNAs were down-regulated in CAMR subjects compared to controls: four were predicted modulators of six mRNAs identified in the transcriptional analysis. In silico functional analysis supported the involvement of type I interferon signalling. To further confirm this result, we investigated the transcriptomic profiles of CD4(+) T lymphocytes in an independent group of patients, observing that the activation of type I interferon signalling was a specific hallmark of CAMR. In addition, in CAMR patients, we detected a reduction of circulating BDCA2(+) dendritic cells, the natural type I interferon-producing cells, and their recruitment into the graft along with increased expression of MXA, a type I interferon-induced protein, at the tubulointerstitial and vascular level. Finally, interferon alpha mRNA expression was significantly increased in CAMR compared to control biopsies. We conclude that type I interferon signalling may represent the molecular signature of CAMR.

Thrombin may modulate dendritic cell activation in kidney transplant recipients with delayed graft function.

BACKGROUND: Coagulation and complement activation represent key events in ischaemia-reperfusion-induced renal injury leading to delayed graft function (DGF). It is still unclear whether the coagulation cascade may also influence the acquired immunity. The aim of the present study was to investigate the expression of protease-activated receptor 1 (PAR-1), the main thrombin receptor, by graft-infiltrating dendritic cells (DCs), and to evaluate whether thrombin may influence DCs complement production and T-cell response. METHODS: PAR-1, BDCA1, CD11c, BDCA4, fibrin, C3c and C3d protein expression were evaluated by confocal microscopy. Cultured DCs were obtained incubating monocytes (Ms) with IL-4 and GM-CSF. DC maturation was obtained with IFN-g+sCD40L or with a cytokine cocktail (IL-1b, TNF-a, PGE2, IL-6). PAR1 protein expression on cultured DC was evaluated by flow-cytometry. Complement receptors, C3, IL12/IL17p40 and IL10 gene expression was evaluated by qPCR. T cell phenotype was evaluated by ELISPOT. IFN-g protein presence was evaluated by ELISA. RESULTS: PAR-1 was expressed by infiltrating myeloid DCs in pre-transplant and in DGF biopsies. In DGF grafts, myeloid DCs localized within fibrin and C3d deposits and expressed C3c. In vitro, PAR-1 protein expression was increased in monocyte-derived immature DCs and in cytokine-induced mature DCs compared to monocytes. PAR-1 activation caused a time-dependent increase in C3 and complement receptors expression. Moreover, thrombin stimulation, while reducing interleukin-10 mRNA abundance, induced interleukin-12/IL-17 p40 gene expression, and promoted C3a ability to increase interleukin-12/IL17 mRNA abundance. These changes in the DCs' cytokine pattern influenced their ability to induce interferon-g production by T cells, suggesting the activation of a T helper-1 bias. CONCLUSION: Our data suggest that PAR-1 is expressed by DCs in DGF grafts and its activation may induce complement production and a Th1 bias. This observation suggests a potential pathogenic link between DGF and acquired allo-response leading to graft damage.

Interplay between SOX9, ß-catenin and PPARγ activation in colorectal cancer.

Colorectal carcinogenesis relies on loss of homeostasic mechanisms regulating cell proliferation, differentiation and survival. These cell processes have been reported to be influenced independently by transcription factors activated downstream of the Wnt pathway, such as SOX9 and ß-catenin, and by the nuclear receptor PPARγ. The purpose of this study was to explore the expression levels and functional link between SOX9, ß-catenin and PPARγ in the pathogenesis of colorectal cancer (CRC). We evaluated SOX9, ß-catenin and PPARγ expression levels on human CRC specimens by qPCR and immunoblot detection. We tested the hypothesis that PPARγ activation might affect SOX9 and ß-catenin expression using four colon cancer cell lines (CaCo2, SW480, HCT116, and HT29 cells). In CRC tissues SOX9 resulted up-regulated at both mRNA and protein levels when compared to matched normal mucosa, ß-catenin resulted up-regulated at protein levels, while PPARG mRNA and PPARγ protein levels were down-regulated. A significant relationship was observed between high PPARG and SOX9 expression levels in the tumor tissue and female gender (p=0.005 and p=0.04, respectively), and between high SOX9 expression in the tumor tissue and age (p=0.04) and microsatellite instability (MSI), in particular with MSI-H (p=0.0002). Moreover, treatment with the synthetic PPARγ ligand rosiglitazone induced different changes of SOX9 and ß-catenin expression and subcellular localization in the colon cancer cell lines examined. In conclusion, SOX9, ß-catenin and PPARγ expression levels are deregulated in the CRC tissue, and in colon cancer cell lines ligand-dependent PPARγ activation unevenly influences SOX9 and ß-catenin expression and subcellular localization, suggesting a variable mechanistic role in colon carcinogenesis.

Rapamycin induces ILT3(high)ILT4(high) dendritic cells promoting a new immunoregulatory pathway.

ILT3(high)ILT4(high) dendritic cells (DCs) may cause anergy in CD4(+)CD45RO(+)CD25(+) T cells transforming them into regulatory T cells (Tregs). Here, we tested whether chronic exposure to rapamycin may modulate this immunoregulatory pathway in renal transplant recipients. Forty renal transplant patients with biopsy-proven chronic allograft nephropathy and receiving calcineurin inhibitors were randomly assigned to either calcineurin inhibitor dose reduction or withdrawal with rapamycin introduction. At conversion and 2 years thereafter, we measured the rapamycin effects on circulating DCs (BDCA1/BDCA2 and ILT3/ILT4 expression), CD4(+)/CD25(high)/Foxp3(+) Tregs, CD8(+)/CD28(-) T cells, and the Th1/Th2 balance in graft biopsies. In rapamycin-treated patients, peripheral BDCA2(+) cells were significantly increased along with ILT3/ILT4(+) DCs. The number of circulating CD4(+)/CD25(high)/Foxp3(+)/CTLA4(+) Tregs, CD8(+)CD28(-) T cells, and HLA-G serum levels were higher in the rapamycin-treated group. The number of ILT3/ILT4(+)BDCA2(+) DC was directly and significantly correlated with circulating Tregs and CD8(+)CD28(-) T cells. ILT3/ILT4 expression was increased in kidney biopsies at the end of the study period along with a significant bias toward a Th2 response within the graft only in the rapamycin-treated patients. Thus, rapamycin induces the upregulation of ILT3 and ILT4 on the DC surface, and this effect is associated with an increase in the number of Tregs and expansion of the CD8(+)CD28(-) T cell population. This suggests that mTOR inhibition may promote a novel immunoregulatory pathway.

Two dimensional gel phosphoproteome of peripheral blood mononuclear cells: comparison between two enrichment methods.

BACKGROUND: Protein phosphorylation is considered a key event in signal transduction. Peripheral blood mononuclear cells (PBMCs) are a critical component of the immune system. The analysis of PBMCs phosphoproteome might help elucidate the signaling pathways essential to their biological role in health, immunological diseases and cancer. Enrichment of phosphoproteins becomes a prerequisite for phosphoproteome analysis and conventionally requires a multi-step procedure and sophisticated equipments. In this study, we standardized 2D-PAGE phosphoproteome analysis of PBMCs and compared two phosphoprotein enrichment methods, lanthanum chloride precipitation and affinity micro-column. Further, the different specificity for PBMCs phosphorylated proteins of each method was investigated. RESULTS: PBMCs were isolated from fresh whole blood of ten healthy donors. PBMCs phosphoproteins were enriched either by phosphoprotein precipitation using lanthanum chloride, with an overall yield of 8.9 ± 4.7%, or by using an affinity micro-column, with a lower yield of 3.2 ± 1.6% (p = 0.05). Image analysis of Sypro-stained analytical 2D-PAGE gels detected 554 ± 68 protein spots for the lanthanum pattern [inter-assay coefficient of variation (CV) = 27.0%, intra-assay CV = 10.7%] and 575 ± 35 protein spots for the micro-column pattern (inter-assay CV = 26.8%; intra-assay CV = 11.0%) (p = 0.6), with 57% match of the spots detected by the 2 approaches. 1D gel electrophoresis and western blot analyses of the supernatants suggested a better lanthanum ions capability to deplete phosphoproteins in a PBMCs protein lysate compared to the affinity micro-column. On the other hand, 1D gel electrophoresis analysis of dephosphorylated PBMCs protein lysate revealed a relatively higher unspecificity for the lanthanum ions compared to affinity micro-column. Filamin-A, coronin 1A, pyruvate kinase isozymes M1/M2 and ficolin-1 were considerably more expressed in the lanthanum phosphoprotein pattern. Interestingly, ficolin-1 had not been reported in 2DE-PBMCs proteome profiles so far. CONCLUSION: Our results describe the differences and the validity of phosphoprotein enrichment methods and provide two successful and complementary approaches for the 2DE phosphoproteome analysis of PBMCs.

Dendritic Cells: A Bridge between Tolerance Induction and Cancer Development in Transplantation Setting.

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting cells crucial for fostering allograft tolerance while simultaneously supporting host defense against infections and cancer. Within the tumor microenvironment, DCs can either mount an immune response against cancer cells or foster immunotolerance, presenting a dual role. In immunocompromised individuals, posttransplant malignancies pose a significant health concern, with DCs serving as vital players in immune responses against cancer cells. Both recipient- and donor-derived DCs play a critical role in the rejection process, infiltrating the transplanted organ and sustaining T-cell responses. The use of immunosuppressive drugs represents the predominant approach to control this immunological barrier in transplanted organs. Evidence has shed light on the immunopharmacology of these drugs and novel strategies for manipulating DCs to promote allograft survival. Therefore, comprehending the mechanisms underlying this intricate microenvironment and the effects of immunosuppressive therapy on DCs is crucial for developing targeted therapies to reduce graft failure rates. This review will delve into the fundamental immunobiology of DCs and provide a detailed exploration of their clinical significance concerning alloimmune responses and posttransplant malignancies.