Functional differences in visceral and subcutaneous fat pads originate from differences in the adipose stem cell.

Metabolic pathologies mainly originate from adipose tissue (AT) dysfunctions. AT differences are associated with fat-depot anatomic distribution in subcutaneous (SAT) and visceral omental (VAT) pads. We address the question whether the functional differences between the two compartments may be present early in the adipose stem cell (ASC) instead of being restricted to the mature adipocytes. Using a specific human ASC model, we evaluated proliferation/differentiation of ASC from abdominal SAT-(S-ASC) and VAT-(V-ASC) paired biopsies in parallel as well as the electrophysiological properties and functional activity of ASC and their in vitro-derived adipocytes. A dramatic difference in proliferation and adipogenic potential was observed between the two ASC populations, S-ASC having a growth rate and adipogenic potential significantly higher than V-ASC and giving rise to more functional and better organized adipocytes. To our knowledge, this is the first comprehensive electrophysiological analysis of ASC and derived-adipocytes, showing electrophysiological properties, such as membrane potential, capacitance and K(+)-current parameters which confirm the better functionality of S-ASC and their derived adipocytes. We document the greater ability of S-ASC-derived adipocytes to secrete adiponectin and their reduced susceptibility to lipolysis. These features may account for the metabolic differences observed between the SAT and VAT. Our findings suggest that VAT and SAT functional differences originate at the level of the adult ASC which maintains a memory of its fat pad of origin. Such stem cell differences may account for differential adipose depot susceptibility to the development of metabolic dysfunction and may represent a suitable target for specific therapeutic approaches.

Inflammatory response in human skeletal muscle cells: CXCL10 as a potential therapeutic target.

Inflammatory myopathies (IMs) are systemic diseases characterized by a T helper (Th) 1 type inflammatory response and cell infiltrates within skeletal muscles. The mainstay of treatment is drugs aimed at suppressing the immune system - corticosteroids and immunosuppressants. About 25% of patients are non-responders. Skeletal muscle cells seem actively involved in the immune-inflammatory response and not only a target; understanding the molecular bases of IMs might help drug development strategies. Within muscles the interaction between the chemokine interferon (IFN)γ inducible 10 kDa protein, CXCL10 or IP-10, and its specific receptor CXCR3, present on Th1 type infiltrating cells, likely plays a pivotal role, potentially offering the opportunity for therapeutic intervention. We aimed to clarify the involvement of human skeletal muscle cells in inflammatory processes in terms of CXCL10 secretion, to elucidate the engaged molecular mechanism(s) and, finally, to evaluate muscular cell responses, if any, to some immunosuppressants routinely used in IM treatment, such as methylprednisolone, methotrexate, cyclosporin A and Infliximab. We first isolated and characterized human fetal skeletal muscle cells (Hfsmc), which expressed the specific lineage markers and showed the competence to react in the context of an in vitro alloresponse. CXCL10 protein secretion by Hfsmc was similarly induced by the inflammatory cytokines interferon (IFN)γ and tumor necrosis factor (TNF)α, above undetectable control levels, through the activation of Stat1 and NF-kB pathways, respectively; CXCL10 secretion was significantly magnified by cytokine combination, and this synergy was associated to a significant up-regulation of TNFαRII; cytokine-induced CXCL10 secretion was considerably affected only by Infliximab. Our data suggested that human skeletal muscle cells might actively self-promote muscular inflammation by eliciting CXCL10 secretion, which is known to amplify Th1 cell tissue infiltration in vivo. In conclusion, we sustain that pharmacological targeting of CXCL10 within muscular cells might contribute to keep in control pro-Th1 polarization of the immune/inflammatory response.

Gonadotropin-releasing hormone modulates cholesterol synthesis and steroidogenesis in SH-SY5Y cells.

Neurosteroids are involved in Central Nervous System development, brain functionality and neuroprotection but little is known about regulators of their biosynthesis. Recently gonadotropins, Gonadotropin-releasing Hormone (GnRH) and their receptors have been localized in different brain regions, such as hippocampus and cortex. Using human neuronal-like cells we found that GnRH up-regulates the expression of key genes of cholesterol and steroid synthesis when used in a narrow range around 1.0 nM. The expression of Hydroxysterol D24-reductase (seladin-1/DHCR24), that catalyzes the last step of cholesterol biosynthesis, is increased by 50% after 90 min of incubation with GnRH. StAR protein and P450 side chain cleavage (P450scc) are up-regulated by 3.3 times after 90 min and by 3.5 times after 3 h, respectively. GnRH action is mediated by LH and 1.0 nM GnRH enhances the expression of LHß as well. A two fold increase of cell cholesterol is induced after 90 min of GnRH incubation and 17ß-estradiol (E2) production is increased after 24, 48 and 72 h. These data indicate for the first time that GnRH regulates both cholesterol and steroid biosynthesis in human neuronal-like cells and suggest a new physiological role for GnRH in the brain.

Peroxisome-proliferator-activated receptor gamma (PPARgamma) is required for modulating endothelial inflammatory response through a nongenomic mechanism.

Besides their well-known anti-diabetic effects, the peroxisome-proliferator-activated receptor gamma (PPARgamma) thiazolidinedione ligands (TZD) have been suggested to also display anti-inflammatory properties. The receptor role in mediating such effects is far from being elucidated. Here, we demonstrated that PPARgamma is necessary for TZD to interfere with TNFalpha and IFNgamma inflammatory activity in human endothelial cells. Different PPARgamma ligands similarly inhibit cytokinic stimulation of IFNgamma-inducible-protein-of-10-kDa (IP10) secretion in a dose-dependent manner and prevent the induced phosphorylation/activation of extracellular-signaling-regulated-kinases (ERK1/2). To further confirm the PPARgamma role in mediating both rapid and long term anti-inflammatory effects of its ligands, we evaluated RGZ inhibitory action in PPARgamma-silenced and -overexpressing cells. PPARgamma-silencing results in a reversion of RGZ inhibitory activity on cyto/chemokine secretions and rapid ERK phosphorylation. Conversely, receptor overexpression significantly increases RGZ inhibitory activity. Finally, PPARgamma-overexpression results in a reduction of ERK1/2 phosphorylation and inflammatory secretions in response to TNFalpha and IFNgamma even in the absence of RGZ, suggesting a restraining effect controlled by endogenous ligands. In conclusion, our data provide the first evidence that PPARgamma is involved in the anti-inflammatory action of TZD in endothelial cells, not only by modulating cyto/chemokine secretions but also by restraining ERK activation through a novel rapid nongenomic mechanism.

Comparison between VDR analogs and current immunosuppressive drugs in relation to CXCL10 secretion by human renal tubular cells.

During kidney allograft rejection, CXC chemokine ligand 10 (CXCL10)-CXC chemokine receptor 3 (CXCR3) trafficking between peripheral blood and tissues initiates alloresponse and perpetuates a self-inflammatory loop; thus, CXCL10-CXCR3 axis could represent a pharmacologic target. In this perspective, immunosuppressors targeting graft-resident cells, beside immune cells, could be very advantageous. Vitamin D receptor (VDR) agonists exhibit considerable immunomodulatory properties. This study aimed to investigate whether elocalcitol and BXL-01-0029 could decrease the expression of CXCL10 in activated renal tubular cells in vitro and thus be useful in kidney allograft rejection treatment. Experiments were performed in human tubular renal cells stimulated with interferon-gamma + tumor necrosis factor-alpha with and without VDR agonists, tacrolimus, sirolimus, hydrocortisone, methylprednisolone, cyclosporin A and mycophenolate mofetil. CXCL10 protein secretion and gene expression were measured by ELISA and by quantitative PCR. Specific inhibitors were used to investigate intracellular pathways involved in tubular cells activation. For IC(50) determination and comparison, dose-response curves with VDR agonists, tacrolimus and mycophenolic acid were performed. Elocalcitol and BXL-01-0029 inhibited CXCL10 secretion by renal cells, without affecting cell viability, while almost all the immunosuppressors were found to be ineffective, except for tacrolimus and mycophenolate mofetil. BXL-01-0029 was the most potent drug and, notably, it was found to be capable of allowing reduction in tacrolimus-inhibitory doses. Our data suggest that BXL-01-0029 could potentially be a dose-reducing agent for conventional immunosuppressors in kidney rejection management.

Interferon-alpha, -beta and -gamma induce CXCL9 and CXCL10 secretion by human thyrocytes: modulation by peroxisome proliferator-activated receptor-gamma agonists.

It has been hypothesized that interferon (IFN) alpha and beta cause autoimmune thyroid dysfunctions by changing the Th1/Th2 balance, but the mechanisms involved are not yet known. The aims of this study were: (a) to test the effect of IFNalpha, IFNbeta and IFNgamma on the secretion of the Th1 chemokines CXCL9 and CXCL10, in "primary cultures of human thyroid follicular cells" (TFC); (b) to assess the effect of PPARgamma activation on CXCL9 and CXCL10 secretion. In TFC, CXCL9 and CXCL10 were undetectable in the supernatant. IFNgamma, IFNalpha and IFNbeta, dose dependently induced CXCL9 and CXCL10 release. TNFalpha alone had no effect. The combination of each of the IFNs with TNFalpha had a significant synergistic effect on CXCL9 and CXCL10 secretion. Treatment of TFC with rosiglitazone dose dependently inhibited the IFNs-stimulated CXCL9 and CXCL10 release. Compared with IFNalpha and IFNbeta, IFNgamma was the most potent stimulus of CXCL9 and CXCL10 secretion. In conclusion, IFNalpha, IFNbeta, IFNgamma and TNFalpha (synergistically with IFNs) dose-dependently induce the release of CXCL9 and CXCL10 by TFC, suggesting that this process may be related, at least in part, to the appearance of thyroid dysfunction during IFNs therapy. Furthermore, PPARgamma activation partially inhibits this process.

Peroxisome proliferator-activated receptor gamma (PPARgamma): Is the genomic activity the only answer?

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily of transcription factors, widely expressed in the organism, including adipose, vascular and immune cells. Besides the well-known role in lipid/glycidic homeostasis, PPARgamma has also recently emerged as a key regulator of inflammatory and immune responses. Besides the natural ligands, more potent synthetic agonists of PPARgamma have been developed, including thiazolidinediones (TZDs), currently used in type 2 diabetes treatment, which also exert anti-inflammatory and anti-neoplastic effects. PPARgamma mechanism of action has focused considerable attention over the years. This receptor was initially shown to act on gene expression through a direct transcription and an indirect transrepression activity, mainly associated with metabolic and anti-inflammatory effects. Different post-translational modifications of the receptor can modulate PPARgamma activity. More recently, rapid nongenomic activity of TZDs affecting post-translation modifications of extranuclear proteins involved in cell signaling, has been reported. In particular, PPARgamma can physically interact with protein kinases resulting in a compartment specific recruitment and activity modulation of these enzymes. Among them, ERK can be positively/negatively regulated by PPARgamma ligands, as in endothelial cells, where TZDs exert anti-inflammatory effects through a novel mechanism involving a rapid inhibition of ERK1/2 phosphorylation/activation. Finally, some of the TZD anti-tumor effects seem to be PPARgamma-independent, raising the possibility that alternative receptors can act through extranuclear nongenomic pathways. In conclusion, different mechanisms of action of PPARgamma seem to coexist in an interacting functional network in the cell, concurring in mediating both pharmacological and natural ligand effects.

High pretransplant serum levels of CXCL9 are associated with increased risk of acute rejection and graft failure in kidney graft recipients.

Several clinical and experimental models have underlined the role of the CXCR3-binding chemokines in the immune-mediated kidney diseases. This study aimed to investigate the predictive value of measuring pretransplant CXCL9 levels for acute rejection (AR) onset and kidney transplantation outcome. Pretransplantation serum levels of CXCL9 were tested retrospectively in 252 kidney graft recipients, whose stratification in two groups according to CXCL9 levels (<272.1 pg/ml vs. >272.1 pg/ml) showed highly significant differences in 5-year survival rates (97.7% vs. 73.3%; P < 0.001). Multivariate analysis demonstrated that among the analysed variables, CXCL9 [relative risk (RR) 11.708] and AR (RR 3.604) had the highest predictive power of graft loss. Accordingly, patients with AR (254.4 + or - 22.1; P < 0.05) and, even more, those with anti-thymoglobulin (ATG)-treated AR also showed increased pretransplant serum CXCL9 levels (319.3 + or - 28.1, P < 0.001). Moreover, CXCL9 expression and distribution were investigated in tissue specimens obtained from 10 patients affected by AR, and wide CXCL9 expression was detected not only in infiltrating inflammatory cells but also in vascular and tubular structures. Measurement of pretransplant serum CXCL9 levels might represent the tracking of a clinically useful parameter to identify subjects at high risk of AR and graft failure. These findings might be used for the individualization of immunosuppressive therapies.

Rosiglitazone impairs proliferation of human adrenocortical cancer: preclinical study in a xenograft mouse model.

Adrenocortical carcinoma (ACC) is a rare aggressive tumor with a poor prognosis. The lack of a specific and effective medical treatment is due to the poor knowledge of the mechanisms underlying tumor growth. Research on potential drugs able to specifically interfere with tumor proliferation is essential to develop more efficacious therapies. We evaluated for the first time the in vivo effect of rosiglitazone (RGZ), an anti-diabetic drug with in vitro anti-tumor properties, on ACC proliferation in a xenograft model obtained by s.c. injection of human ACC H295R cells in athymic mice. When the tumor size reached 5 mm, animals were allocated to 5 mg/kg RGZ- or water-treated groups. Tumor volume was measured twice a week. A significant reduction of tumor growth in RGZ versus control (control) group was observed and was already maximal following 17 day treatment (1-T/C=75.4% (43.7-93.8%)). After 31 days of treatment, mice were killed and tumor analyzed. Tumor histological evaluation revealed characteristics of invasiveness, richness in small vessels and mitotic figures in control group, while RGZ group tumors presented non infiltrating borders, few vessels, and many apoptotic bodies. Tumor immunohistochemistry showed that Ki-67 was reduced in RGZ versus control group. Quantitative real-time RT-PCR demonstrated a significant reduction in the expression of angiogenic (VEGF), vascular (CD31), proliferation (BMI-1), and anti-apoptotic (Bcl-2) genes in RGZ versus control group tumors. The same inhibitory effects were confirmed in in vitro RGZ-treated H295R. Our findings support and expand the role of RGZ in controlling ACC proliferation and angiogenesis in vivo and in vitro.

Seladin-1 and testicular germ cell tumours: new insights into cisplatin responsiveness.

The molecular basis for the exquisite sensitivity of testicular germ cell tumours of adolescents and adults (TGCTs), ie seminomas and non-seminomatous germ cell tumours, to chemo/radiotherapy has not been fully clarified so far. It has been suggested that it may be dependent on factors involved in the regulation of apoptosis. Seladin-1 is a multi-functional protein involved in various biological processes, including apoptosis. The aim of our study was to assess the expression of seladin-1 in different histological types of TGCTs, known to have varying treatment sensitivity, in order to establish whether this protein may influence cisplatin responsiveness in vitro. Seladin-1 expression levels, both at the mRNA and at the protein level, were higher in the adjacent normal parenchyma than in the pathological counterparts. In tumoural tissues, the level of expression differed among TGCT histological types. The highest tumour-expression level was found in teratoma, whereas the lowest was detected in seminoma, corresponding to the different chemo/and radiosensitivities of these tumour types. In common with other cancers, in TGCT-derived cell lines seladin-1 showed anti-apoptotic properties through inhibition of caspase-3 activation. We confirmed our results using a non-seminomatous cell line model (NT2) before and after differentiation with retinoic acid. Significantly higher seladin-1 expression was observed in the differentiated derivatives (teratoma) and an inverse relationship was found between seladin-1 expression and the amount of cleaved caspase-3. Seladin-1 silencing or overexpression in this cell line supports involvement of seladin-1 in cisplatin responsiveness. Seladin-1 silencing was associated with greater cisplatin responsiveness demonstrated by decreased cell viability and increased expression of apoptotic markers. In contrast, overexpression of seladin-1 was associated with a higher survival rate and a clear anti-apoptotic effect. In conclusion, we have demonstrated for the first time an important role for seladin-1 in the biology of TGCTs and provided new insights into cisplatin responsiveness of these tumours.

Molecular mechanisms underlying the pro-inflammatory synergistic effect of tumor necrosis factor alpha and interferon gamma in human microvascular endothelium.

Tumor necrosis factor alpha (TNFalpha) and interferon gamma (IFNgamma) are among the most potent cytokines involved in orchestrating the inflammation response. The molecular mechanisms implicated in the synergism between cytokines are still poorly characterized. We demonstrate that both cytokines dose-dependently stimulate IFNgamma-inducible-protein-of-10-kDa (IP-10) secretion in human microvascular endothelial cells (HMEC-1), showing a potent synergism which is not restricted to IP-10, but is also evident for monokine-induced-by-IFNgamma (MIG) and IL-6 secretion. Immunofluorescence analysis reveals that TNFalpha and IFNgamma converge on a rapid phosphorylation of ERK, which however results in a different subcellular compartmentalization of the activated enzyme in response to the two cytokines. Differences in the subcellular recruitment of ERK in response to IFNgamma and TNFalpha are responsible for generating different ERK downstream signaling, which can thus synergize on the secretion of IP-10 as well as of other cytokines/chemokines. The importance of ERK activation in mediating the synergism of the two cytokines is further confirmed by the inhibitory effect of the anti-diabetic drug rosiglitazone and ERK blockers on IP-10, MIG and IL-6 secretion. A further mechanism of synergism involving the reciprocal upregulation of TNFalpha-RII and of IFNgamma-R, in response to IFNgamma and TNFalpha, respectively, was revealed by flow cytometry and quantitative real time RT-PCR analysis.

Characterization of human adult stem-cell populations isolated from visceral and subcutaneous adipose tissue.

Adipose tissue is a dynamic endocrine organ with a central role in metabolism regulation. Functional differences in adipose tissue seem associated with the regional distribution of fat depots, in particular in subcutaneous and visceral omental pads. Here, we report for the first time the isolation of human adipose-derived adult stem cells from visceral omental and subcutaneous fat (V-ASCs and S-ASCs, respectively) from the same subject. Immunophenotyping shows that plastic culturing selects homogeneous cell populations of V-ASCs and S-ASCs from the corresponding stromal vascular fractions (SVFs), sharing typical markers of mesenchymal stem cells. Electron microscopy and electrophysiological and real-time RT-PCR analyses confirm the mesenchymal stem nature of both V-ASCs and S-ASCs, while no significant differences in a limited pattern of cytokine/chemokine expression can be detected. Similar to S-ASCs, V-ASCs can differentiate in vitro toward adipogenic, osteogenic, chondrogenic, muscular, and neuronal lineages, as demonstrated by histochemical, immunofluorescence, real-time RT-PCR, and electrophysiological analyses, suggesting the multipotency of such adult stem cells. Our data demonstrate that both visceral and subcutaneous adipose tissues are a source of pluripotent stem cells with multigermline potential. However, the visceral rather than the subcutaneous ASC could represent a more appropriate in vitro cell model for investigating the molecular mechanisms implicated in the pathophysiology of metabolic disorders such as obesity.

Pretransplant positivity for circulating thyroid antibodies and graft survival in patients undergoing kidney transplant.

BACKGROUND: Thyroid disturbances are common in kidney graft recipients and they may influence graft function. CXC chemokine ligand 10 plays a role in both autoimmune thyroiditis and graft rejection. Thyroid antibody (Ab) positivity has been regarded as a marker of imbalance of the immune system. AIM: To relate pretransplant positivity for antithyroperoxidase (TPO) Ab and antithyroglobulin (Tg) Ab with kidney graft outcome. METHODS: Pretransplant thyroid antibodies were measured in 211 kidney graft recipients. RESULTS: The 5-year death-censored graft survival rate was 91.5%. Pretransplant circulating Tg Ab and TPO Ab were detected in 12 (5.7%) and 13 (6.2%) patients, respectively. Lifetime analysis showed similar 5-year graft survival rates in patients negative or positive for Tg Ab and TPO Ab (91.5 vs. 91.7% for Tg Ab and 91.9 vs. 84.6% for TPO Ab). However, patients with pretransplant positivity for TPO Ab showed a significantly lower 5-year graft survival when early graft loss (12 months after transplant) was excluded (84.6 and 96.8% for TPO Ab+ and TPO Ab- patients, respectively; p < 0.05). Occurrence of acute rejection and chronic allograft nephropathy was unrelated to thyroid Ab positivity. Serum CXC chemokine ligand 10 levels were similar independent of Tg Ab and TPO Ab positivity. CONCLUSION: Pretransplant positivity for TPO Ab may affect long-term graft survival in kidney graft recipients independent of occurrence of acute rejections and chronic allograft nephropathy.

Globular adiponectin induces differentiation and fusion of skeletal muscle cells.

The growing interest in skeletal muscle regeneration is associated with the opening of new therapeutic strategies for muscle injury after trauma, as well as several muscular degenerative pathologies, including dystrophies, muscular atrophy, and cachexia. Studies focused on the ability of extracellular factors to promote myogenesis are therefore highly promising. We now report that an adipocyte-derived factor, globular adiponectin (gAd), is able to induce muscle gene expression and cell differentiation. gAd, besides its well-known ability to regulate several metabolic functions in muscle, including glucose uptake and consumption and fatty acid catabolism, is able to block cell cycle entry of myoblasts, to induce the expression of specific skeletal muscle markers such as myosin heavy chain or caveolin-3, as well as to provoke cell fusion into multinucleated syncytia and, finally, muscle fibre formation. gAd exerts its pro-differentiative activity through redox-dependent activation of p38, Akt and 5'-AMP-activated protein kinase pathways. Interestingly, differentiating myoblasts are autocrine for adiponectin, and the mimicking of pro-inflammatory settings or exposure to oxidative stress strongly increases the production of the hormone from differentiating cells. These data suggest a novel function of adiponectin, directly coordinating the myogenic differentiation program and serving an autocrine function during skeletal myogenesis.

New insights on the neuroprotective role of sterols and sex steroids: the seladin-1/DHCR24 paradigm.

In 2000 a new gene, i.e. seladin-1 (for selective Alzheimer's disease indicator-1) was identified and found to be down regulated in vulnerable brain regions in Alzheimer's disease. Seladin-1 was considered a novel neuroprotective factor, because of its anti-apoptotic properties. Subsequently, it has been demonstrated that seladin-1 corresponds to the gene that encodes 3-beta-hydroxysterol delta-24-reductase (DHCR24), that catalyzes the synthesis of cholesterol from desmosterol. There is evidence that cholesterol plays a fundamental role in maintaining brain homeostasis. Because of its enzymatic activity, seladin-1/DHCR24 has been considered the human homolog of the plant protein DIMINUTO/DWARF1, that is involved in the synthesis of sterol plant hormones. We have recently demonstrated that seladin-1/DHCR24 is a fundamental mediator of the protective effects of estrogens in the brain. This review describes how this protein interacts with cholesterol and estrogens, thus generating a neuroprotective network, that might open new possibilities in the prevention/treatment of neurodegenerative diseases.

The CXCR4/CXCL12 axis in endometrial cancer.

Chemokines and their receptors seem to act as important regulators of the metastatic cascade. CXCL12 and its receptor CXCR4 were shown to be involved in human cancer progression. There is increasing evidences suggesting that the expression of CXCR4 in human cancers is correlated with poor patient prognosis and that CXCR4 neutralization can prevent metastases in vivo. Here we tested the role of the CXCR4/CXCL12 axis in a neoplasia with a reduced risk of metastatic progression, such as human endometrial cancer. CXCR4 and CXCL12 mRNA expression was measured in 41 endometrial cancers and in corresponding not affected tissues. The expression of CXCR4 was predominant in endometrial cancer (P = 0.035) whereas CXCL12 was overexpressed in normal mucosae (P = 0.002). CXCR4 expression (P = 0.035), but not CXCL12, was significantly related to cancer differentiation. Endometrial cancer cells (HEC1A) were able to generate diffuse metastases in peritoneum, lung and liver of CD-1 nude mice, but the simultaneous treatment with a neutralizing anti-CXCR4 monoclonal antibody dramatically reduced the number and the size of metastases in the animals. In conclusion, our data seem to indicate that the CXCR4-CXCL12 axis can play a role in the progression of endometrial carcinoma and that specific therapies with antagonists of chemokines receptors could be of help in the treatment of metastatic patients.

Predictive role of pretransplant serum CXCL10 for cardiac acute rejection.

BACKGROUND: The detection of acute rejection in heart transplantation remains an important feature of transplant management, especially in the early phase. Frequent surveillance with endomyocardial biopsy is necessary, even though it is an invasive procedure and carries a certain risk. Hence, noninvasive biomarkers able to predict acute rejection could be a further helpful tool in patient management. The interferon-gamma-inducible chemokine CXCL10 is required for initiation and development of graft failure caused by acute or chronic rejection. It has been reported that CXCL10 serum level is predictive of graft loss in kidney graft recipients. In the present study, we investigated whether pretransplant CXCL10 serum level may be a predictive noninvasive biomarker in heart transplant (HTx) recipients, as well. METHODS: Sera from 143 patients undergoing orthotopic heart transplantation were collected before surgery and tested for CXCL10 and CCL22 and compared with serum samples from healthy subjects. RESULTS: We found that basal CXCL10 serum levels in HTx recipients were significantly higher than in healthy subjects, whereas no difference was seen in CCL22 levels. Among HTx recipients, CXCL10 serum levels of rejectors were significantly higher than in nonrejectors. Our results showed that CXCL10 was a significant independent risk factor of several variables and had the highest predictive value for early acute heart rejection, with 160 pg/mL cutoff value. CONCLUSIONS: In HTx recipients, measurement of pretransplant CXCL10 serum levels could be a clinically useful tool for predicting cardiac acute rejection, especially in the early posttransplant period.

Regeneration of glomerular podocytes by human renal progenitors.

Depletion of podocytes, common to glomerular diseases in general, plays a role in the pathogenesis of glomerulosclerosis. Whether podocyte injury in adulthood can be repaired has not been established. Here, we demonstrate that in the adult human kidney, CD133+CD24+ cells consist of a hierarchical population of progenitors that are arranged in a precise sequence within Bowman's capsule and exhibit heterogeneous potential for differentiation and regeneration. Cells localized to the urinary pole that expressed CD133 and CD24, but not podocyte markers (CD133+CD24+PDX- cells), could regenerate both tubular cells and podocytes. In contrast, cells localized between the urinary pole and vascular pole that expressed both progenitor and podocytes markers (CD133+CD24+PDX+) could regenerate only podocytes. Finally, cells localized to the vascular pole did not exhibit progenitor markers, but displayed phenotypic features of differentiated podocytes (CD133-CD24-PDX+ cells). Injection of CD133+CD24+PDX- cells, but not CD133+CD24+PDX+ or CD133-CD24- cells, into mice with adriamycin-induced nephropathy reduced proteinuria and improved chronic glomerular damage, suggesting that CD133+CD24+PDX- cells could potentially treat glomerular disorders characterized by podocyte injury, proteinuria, and progressive glomerulosclerosis.

Low serum and peritoneal fluid concentration of interferon-gamma-induced protein-10 (CXCL10) in women with endometriosis.

OBJECTIVE: To evaluate serum and peritoneal fluid concentrations of interferon-gamma-inducible protein-10 (CXCL10), a chemokine involved in local immune function, in women with endometriosis. DESIGN: Prospective study. SETTING: Division of Obstetrics and Gynecology, University of Siena. PATIENT(S): A total of 147 women were divided in two groups: women with (n = 77) and without (n = 70) endometriosis. INTERVENTION(S): Serum and peritoneal fluid were collected from all patients undergoing laparoscopy. MAIN OUTCOME MEASURE(S): CXCL10 concentrations were measured by a specific ELISA. RESULT(S): Serum CXCL10 concentrations in women with endometriosis were significantly lower than in those without endometriosis. No statistically significant difference between women with early endometriosis and those with advanced endometriosis was found. CXCL10 concentrations in peritoneal fluid of women with advanced endometriosis were significantly lower than in that of women with an early stage of, or without, endometriosis. CONCLUSION(S): The decreased concentrations of CXCL10 in serum and peritoneal fluid of women with endometriosis indicate an impaired immune activity in women with endometriosis.