In Vitro Identification of New Transcriptomic and miRNomic Profiles Associated with Pulmonary Fibrosis Induced by High Doses Everolimus: Looking for New Pathogenetic Markers and Therapeutic Targets.

The administration of Everolimus (EVE), a mTOR inhibitor used in transplantation and cancer, is often associated with adverse effects including pulmonary fibrosis. Although the underlying mechanism is not fully clarified, this condition could be in part caused by epithelial to mesenchymal transition (EMT) of airway cells. To improve our knowledge, primary bronchial epithelial cells (BE63/3) were treated with EVE (5 and 100 nM) for 24 h. EMT markers (α-SMA, vimentin, fibronectin) were measured by RT-PCR. Transepithelial resistance was measured by Millicell-ERS ohmmeter. mRNA and microRNA profiling were performed by Illumina and Agilent kit, respectively. Only high dose EVE increased EMT markers and reduced the transepithelial resistance of BE63/3. Bioinformatics showed 125 de-regulated genes that, according to enrichment analysis, were implicated in collagen synthesis/metabolism. Connective tissue growth factor (CTGF) was one of the higher up-regulated mRNA. Five nM EVE was ineffective on the pro-fibrotic machinery. Additionally, 3 miRNAs resulted hyper-expressed after 100 nM EVE and able to regulate 31 of the genes selected by the transcriptomic analysis (including CTGF). RT-PCR and western blot for MMP12 and CTGF validated high-throughput results. Our results revealed a complex biological network implicated in EVE-related pulmonary fibrosis and underlined new potential disease biomarkers and therapeutic targets.

Everolimus-induced epithelial to mesenchymal transition (EMT) in bronchial/pulmonary cells: when the dosage does matter in transplantation.

BACKGROUND: Everolimus (EVE) is a mammalian target of rapamycin inhibitor (mTOR-I) widely used in transplantation that may determine some severe adverse events, including pulmonary fibrosis. The pathogenic mechanism of mTOR-I-associated pulmonary toxicity is still unclear, but epithelial to mesenchymal transition (EMT) of bronchial/pulmonary cells may play a role. METHODS: Three cell lines-human type II pneumocyte-derived A549, normal bronchial epithelial, and bronchial epithelial homozygous for the delta F508 cystic fibrosis-causing mutation-were treated with EVE or tacrolimus at different concentrations. Real-time polymerase chain reaction and immunofluorescence were used to evaluate mRNA and protein levels of EMT markers (alpha-SMA, vimentin, fibronectin). Subsequently, in 13 EVE- and 13 tacrolimus-treated patients we compared the rate of lung fibrosis, estimated by an arbitrary pulmonary fibrosis index score (PFIS). RESULTS: Biomolecular experiments demonstrated that high doses of EVE (100 nM) up-regulated EMT markers in all cell lines at both gene- and protein level. High concentrations of EVE were also able to reduce the mRNA levels of epithelial markers (E-cadherin and ZO-1) and to induce the phosphorylation of AKT. In the in vivo part of the study, PFIS was significantly higher in the EVE-group than the tacrolimus-group (p = 0.03) and correlated with trough levels (R2 = 0.35). CONCLUSIONS: Our data reveal, for the first time, a dose-dependent EVE-induced EMT in airway cells. They suggest that clinicians should employ, wherever possible, low dosages of mTOR-Is in transplant recipients, assessing periodically their pulmonary function.

Mitochondria: a new therapeutic target in chronic kidney disease.

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.

[Pharmacogenetics: a promising tool to personalize immunosuppressive therapy in renal transplantation]. / Farmacogenetica: un possibile strumento per la personalizzazione della terapia immunosoppressiva nel trapianto renale.

Renal transplantation is the gold standard therapy for patients affected by end stage renal disease. It is a clinical condition characterized by severe biological/biochemical alterations that requires renal replacement therapy to ensure patients survival. In most cases, it is followed by a significant improvement of patients quality of life, reduction in medical expenses and prolongation of life. However, to reach these positive clinical effects, patients need to take several immunosuppressive medications (calcineurin inhibitors, mTOR inhibitors and antimetabolites) characterized by a narrow therapeutic index, that, in some cases, could cause important adverse effects. To avoid toxicities and adverse drug reactions, immunosuppressors should be correctly administered, according to the blood trough levels. Nevertheless, in most of the times, this methodology to adjust drug doses gives inadequate and non-reproducible results. Additionally, as largely described, inherited differences in drug metabolism and disposition and genetic variability in therapeutic targets (e.g. receptors) need to be taken into account because of their role in modulating drug effects and toxicities. Therefore, worldwide researchers are working together to identify biomarkers, useful to personalize therapy based on genetic characteristics of patients. In this context, we believe that the omics techniques could represent a future powerful instruments that, whether employed routinely, could help to reach this objective.

Personalization of the immunosuppressive treatment in renal transplant recipients: the great challenge in "omics" medicine.

Renal transplantation represents the most favorable treatment for patients with advanced renal failure and it is followed, in most cases, by a significant enhancement in patients' quality of life. Significant improvements in one-year renal allograft and patients' survival rates have been achieved over the last 10 years primarily as a result of newer immunosuppressive regimens. Despite these notable achievements in the short-term outcome, long-term graft function and survival rates remain less than optimal. Death with a functioning graft and chronic allograft dysfunction result in an annual rate of 3%-5%. In this context, drug toxicity and long-term chronic adverse effects of immunosuppressive medications have a pivotal role. Unfortunately, at the moment, except for the evaluation of trough drug levels, no clinically useful tools are available to correctly manage immunosuppressive therapy. The proper use of these drugs could potentiate therapeutic effects minimizing adverse drug reactions. For this purpose, in the future, "omics" techniques could represent powerful tools that may be employed in clinical practice to routinely aid the personalization of drug treatment according to each patient's genetic makeup. However, it is unquestionable that additional studies and technological advances are needed to standardize and simplify these methodologies.

[Extra-renal adverse effects of mTOR inhibitors: know them to optimize their use in renal transplantation]. / Effetti avversi extra-renali degli inibitori di mTOR: conoscerli per ottimizzare l'utilizzo di questi farmaci nel trapianto renale.

The mammalian target of rapamycin inhibitors (mTOR-I) sirolimus and everolimus represents a class of immunosuppressive drugs largely used in renal transplantation. The main mechanism of action of these drugs is the inhibition of the mammalian target of rapamycin (mTOR), a regulatory protein kinase involved in lymphocyte proliferation. Additionally, the inhibition of the crosstalk among mTORC1, mTORC2 and PI3K confers the anti-neoplastic activities of these drugs. Because of their specific pharmacological characteristics and their relative lack of nephrotoxicity, these inhibitors are a valid option to calcineurine inhibitors (CNIs) for maintenance immunosuppression in renal transplant recipients with chronic allograft damage. However, as other immunosuppressive drugs, mTOR-I may induce the development of several adverse effects (e.g., pulmonary toxicity, hematological disorders, dismetabolism, lymphedema) that need to be early diagnosed and treated to avoid severe illness in renal transplant patients. All these side effects are most of the time reversible and dose related. Therefore, it is unquestionable that these particular drugs should be administered at the lowest dose able to maintain relatively low trough levels, in order to increase their importance and specific therapeutic effects minimizing or avoiding drug toxicities. Utilization of low dosages of mTOR-I should be encouraged not only in CNI-combined schemas, but also when administered alone in CNI-free immunosuppressive protocol.

mTOR inhibitors and renal allograft: Yin and Yang.

Mammalian target of rapamycin inhibitors (mTOR-I), everolimus and sirolimus, are immunosuppressive drugs extensively used in renal transplantation. Their main mechanism of action is the inhibition of cell signaling through the PI3 K/Akt/mTOR pathway. This interesting mechanism of action confers to these medications both great immunosuppressive potential and important anti-neoplastic properties. Although the clinical utility of this drug category, as with other antineoplastic/immunosuppressants, is clear, the use of mTOR-I commonly results in the development of several complications. In particular, these agents may determine severe renal toxicity that, as recent studies report, seems clearly correlated to dose and duration of drug use. The mTOR-I-induced renal allograft spectrum of toxicity includes the enhanced incidence of delayed graft function, nephrotoxicity in particular when co-administered with calcineurin inhibitors (CNI) and onset of proteinuria. The latter effect appears highly frequent in patients undergoing mTOR-I treatment and significantly associated with a rapid graft lost. The damage leading to this complication interests both the glomerular and tubular area. mTOR-I cause an inhibition of proliferation in podocytes and the epithelial-to-mesenchymal transition in tubular cells. Interestingly, all these side effects are mostly reversible and dose related. Therefore, it is unquestionable that these particular drugs should be administered at the lowest dose able to maintain relatively low trough levels, in order to maximize their important and specific therapeutic effects while minimizing or avoiding drug toxicities. Utilization of low dosages of mTOR-I should be encouraged not only in CNI-combined schemas, but also when administered alone in a CNI-free immunosuppressive protocol.

Monoclonal antibody therapy and renal transplantation: focus on adverse effects.

A series of monoclonal antibodies (mAbs) are commonly utilized in renal transplantation as induction therapy (a period of intense immunosuppression immediately before and following the implant of the allograft), to treat steroid-resistant acute rejections, to decrease the incidence and mitigate effects of delayed graft function, and to allow immunosuppressive minimization. Additionally, in the last few years, their use has been proposed for the treatment of chronic antibody-mediated rejection, a major cause of late renal allograft loss. Although the exact mechanism of immunosuppression and allograft tolerance with any of the currently used induction agents is not completely defined, the majority of these medications are targeted against specific CD proteins on the T or B cells surface (e.g., CD3, CD25, CD52). Moreover, some of them have different mechanisms of action. In particular, eculizumab, interrupting the complement pathway, is a new promising treatment tool for acute graft complications and for post-transplant hemolytic uremic syndrome. While it is clear their utility in renal transplantation, it is also unquestionable that by using these highly potent immunosuppressive agents, the body loses much of its innate ability to mount an adequate immune response, thereby increasing the risk of severe adverse effects (e.g., infections, malignancies, haematological complications). Therefore, it is extremely important for clinicians involved in renal transplantation to know the potential side effects of monoclonal antibodies in order to plan a correct therapeutic strategy minimizing/avoiding the onset and development of severe clinical complications.

Systemic and nonrenal adverse effects occurring in renal transplant patients treated with mTOR inhibitors.

The mammalian target of rapamycin inhibitors (mTOR-I), sirolimus and everolimus, are immunosuppressive drugs largely used in renal transplantation. The main mechanism of action of these drugs is the inhibition of the mammalian target of rapamycin (mTOR), a regulatory protein kinase involved in lymphocyte proliferation. Additionally, the inhibition of the crosstalk among mTORC1, mTORC2, and PI3K confers the antineoplastic activities of these drugs. Because of their specific pharmacological characteristics and their relative lack of nephrotoxicity, these inhibitors are valid option to calcineurine inhibitors (CNIs) for maintenance immunosuppression in renal transplant recipients with chronic allograft nephropathy. However, as other immunosuppressive drugs, mTOR-I may induce the development of several adverse effects that need to be early recognized and treated to avoid severe illness in renal transplant patients. In particular, mTOR-I may induce systemic nonnephrological side effects including pulmonary toxicity, hematological disorders, dysmetabolism, lymphedema, stomatitis, cutaneous adverse effects, and fertility/gonadic toxicity. Although most of the adverse effects are dose related, it is extremely important for clinicians to early recognize them in order to reduce dosage or discontinue mTOR-I treatment avoiding the onset and development of severe clinical complications.

Hairy cell leukemia in kidney transplantation: lesson from a rare disorder.

We report here on the diagnosis and successful treatment of a case of hairy cell leukemia (HCL) that arose 15 years after kidney transplantation in a 51-year-old patient. As soon as the diagnosis was made, HCL was treated with 2-CDA, obtaining complete hematological remission. Immunosuppression with the calcineurin inhibitor cyclosporin was maintained, and the graft was preserved. In kidney transplant recipients supported with immunosuppressive drugs, post-transplant lymphoproliferative diseases (PTLDs) are frequent and typically related to immunosuppression via a loss of control of infectious/EBV-related proliferative stimuli. To date, HCL has not been considered among PTLDs. Recently, however, the oncogenic mutation V600E of the BRAF protein kinase has been found to be a hallmark of HCL, and calcineurin inhibitors have been shown to interfere with signaling downstream of V600E BRAF early on by counteracting senescence-associated mechanisms that protect against the oncogenic potential of the mutated kinase. Such a biochemical link between the oncogene-dependent signaling and calcineurin inhibitor activities suggests that HCL in transplanted patients might be a peculiar type of PTLD based on the presence of a specific mutation. This mechanism might also be involved in other neoplasias bearing the same or similar mutations, such as melanoma and non-melanoma skin cancer.

[Post-renal transplant pregnancy: a project to plan carefully]. / Gravidanza post-trapianto: un progetto da pianificare.

Kidney transplant is the best treatment for end-stage renal disease (ESRD) as it improves the quality of life and reduces the mortality risk for most patients compared with maintenance dialysis. Additionally, evidence from the literature suggests that renal function, endocrine status and libido rapidly improve after kidney transplant, and one in 50 women of childbearing age become pregnant. Therefore, it seems clear that pregnancy after transplant is a great challenge for physicians involved in this field. The available information on pregnancy outcomes is largely derived from case reports and single-center series, which are unlikely to be representative. Moreover, poor results are less likely to be reported. Many of the reports on long-term outcome show the results of past medical, obstetric, and neonatal care, which may be very different from current practice. Attempts are being made to provide more up-to-date, representative data through national transplantation pregnancy registries. A great number of researchers worldwide have analyzed the biological and endocrinological machinery associated with this event. Additionally, several strategies have been introduced to avoid unplanned pregnancies and to minimize maternal and fetal complications in renal transplant recipients. It seems evident that the return to fertility soon after transplant is often associated with unplanned pregnancy, which can expose both mother and fetus to considerable risks. This underpins the necessity to recommend contraceptive counseling and start clinical follow-up in order to early identify possible pregnancy-related risk factors. In general, pregnancy should not be recommended within the first year after kidney transplant because the risk of acute rejection is greatest and immunosuppressive therapy the most aggressive. It should be planned when organ function and immunosuppressive therapy are stabilized and there is no sign of rejection, hypertension, or chronic infection. Additionally, renal transplant patients and their physicians together must try to identify the best timing, carry out pre-pregnancy screening, and delineate clinical follow-up and future pharmacological programs to minimize or avoid serious maternal and fetal complications. Finally, additional studies are needed to better understand the physiology associated with this condition, improve the pharmacological approach, and analyze the complex ethical and social implications of this important aspect of renal transplantation.

Unusual renal presentation of Fabry disease in a female patient.

BACKGROUND: A 29-year-old white woman with a family history of Fabry disease was referred to a nephrology clinic with hypertension and nephropathy. Her renal function was below normal (serum creatinine level 141 micromol/l; estimated glomerular filtration rate 41 ml/min/1.73 m2) with no proteinuria or albuminuria. INVESTIGATIONS: Medical history, physical examination, leukocyte alpha-galactosidase A assay, laboratory tests (for antinuclear antibodies, antineutrophil cytoplasmic antibodies, lupus anticoagulant, anticardiolipin antibodies, complement and cryoglobulin), ophthalmological examination, echocardiography, brain magnetic resonance angiography, renal ultrasonography, renal color echo-Doppler scan, renal magnetic resonance angiography, renal angiography and renal biopsy. DIAGNOSIS: Diffuse sclero-atrophic renal tissue changes and widespread renal arterio-arteriolosclerotic changes secondary to Fabry disease. TREATMENT: Angiotensin-converting-enzyme inhibitors and maintenance treatment with agalsidase-beta, 1 mg/kg body weight, every 2 weeks.