Human Adult Renal Progenitor Cells Prevent Cisplatin-Nephrotoxicity by Inducing CYP1B1 Overexpression and miR-27b-3p Down-Regulation through Extracellular Vesicles.

Cisplatin is one of the most effective chemotherapeutic agents strongly associated with nephrotoxicity. Tubular adult renal progenitor cells (tARPC) can regenerate functional tubules and participate in the repair processes after cisplatin exposition. This study investigated the molecular mechanisms underlying the protective effect of tARPC on renal epithelium during cisplatin nephrotoxicity. By performing a whole-genome transcriptomic analysis, we found that tARPC, in presence of cisplatin, can strongly influence the gene expression of renal proximal tubular cell [RPTEC] by inducing overexpression of CYP1B1, a member of the cytochrome P450 superfamily capable of metabolizing cisplatin and of hypoxia/cancer-related lncRNAs as MIR210HG and LINC00511. Particularly, tARPC exerted renoprotection and regeneration effects via extracellular vesicles (EV) enriched with CYP1B1 and miR-27b-3p, a well-known CYP1B1 regulatory miRNA. The expression of CYP1B1 by tARPC was confirmed by analyzing biopsies of cisplatin-treated renal carcinoma patients that showed the colocalization of CYP1B1 with the tARPC marker CD133. CYP1B1 was also overexpressed in urinary EV purified from oncologic patients that presented nephrotoxicity episodes after cisplatin treatment. Interestingly CYP1B1 expression significantly correlated with creatinine and eGFR levels. Taken together, our results show that tARPC are able to counteract cisplatin-induced nephrotoxicity via CYP1B1 release through EV. These findings provide a promising therapeutic strategy for nephrotoxicity risk assessment that could be related to abundance of renal progenitors.

The Long Non-coding RNA HOTAIR Controls the Self-renewal, Cell Senescence, and Secretion of Anti-aging Protein α-Klotho in Human Adult Renal Progenitor Cells.

The long non-coding RNAs (lncRNA) play an important role in several biological processes, including some renal diseases. Nevertheless, little is known about lncRNA that are expressed in the healthy kidneys and involved in renal cell homeostasis and development, and even less is known about lncRNA involved in the maintenance of human adult renal stem/progenitor cells (ARPCs) that have been shown to be very important for renal homeostasis and repair processes. Through a whole-genome transcriptome screening, we found that the HOTAIR lncRNA is highly expressed in renal progenitors and potentially involved in cell cycle and senescence biological processes. By CRISPR/Cas9 genome editing, we generated HOTAIR knockout ARPC lines and established a key role of this lncRNA in ARPC self-renewal properties by sustaining their proliferative capacity and limiting the apoptotic process. Intriguingly, the HOTAIR knockout led to the ARPC senescence and to a significant decrease in the CD133 stem cell marker expression which is an inverse marker of ARPC senescence and can regulate renal tubular repair after the damage. Furthermore, we found that ARPCs expressed high levels of the α-Klotho anti-aging protein and especially 2.6-fold higher levels compared to that secreted by renal proximal tubular cells (RPTECs). Finally, we showed that HOTAIR exerts its function through the epigenetic silencing of the cell cycle inhibitor p15 inducing the trimethylation of the histone H3K27. Altogether, these results shed new light on the mechanisms of regulation of these important renal cells and may support the future development of precision therapies for kidney diseases.

Adult Renal Stem/Progenitor Cells Can Modulate T Regulatory Cells and Double Negative T Cells.

Adult Renal Stem/Progenitor Cells (ARPCs) have been recently identified in the human kidney and several studies show their active role in kidney repair processes during acute or chronic injury. However, little is known about their immunomodulatory properties and their capacity to regulate specific T cell subpopulations. We co-cultured ARPCs activated by triggering Toll-Like Receptor 2 (TLR2) with human peripheral blood mononuclear cells for 5 days and 15 days and studied their immunomodulatory capacity on T cell subpopulations. We found that activated-ARPCs were able to decrease T cell proliferation but did not affect CD8+ and CD4+ T cells. Instead, Tregs and CD3+ CD4- CD8- double-negative (DN) T cells decreased after 5 days and increased after 15 days of co-culture. In addition, we found that PAI1, MCP1, GM-CSF, and CXCL1 were significantly expressed by TLR2-activated ARPCs alone and were up-regulated in T cells co-cultured with activated ARPCs. The exogenous cocktail of cytokines was able to reproduce the immunomodulatory effects of the co-culture with activated ARPCs. These data showed that ARPCs can regulate immune response by inducing Tregs and DN T cells cell modulation, which are involved in the balance between immune tolerance and autoimmunity.

Urinary exosomal shuttle RNA: Promising cancer diagnosis biomarkers of lower urinary tract.

BACKGROUND: Prostate and bladder cancers continue to be the first and fourth most common cancers in men worldwide; thus there is an urgent need for more accurate biomarkers that can detect these types of cancer in a non-invasive way. Liquid biopsy is a new non-invasive tool for diagnosis and with a virtually unlimited supply urine is even more attractive resource since urinary exosomes have been discovered to contain RNAs that are hallmarks of cancer. It is challenging to assay those secreting lower amounts of molecules. METHODS: This review, based on articles identified through a PubMed/MEDLINE search, comprehensively summarizes state of the art approaches used in the discovery and validation of exosomal RNA biomarkers purified from the urine for lower urinary tract cancer. RESULTS: The combination of PCA3 and ERG has shown a relatively good improvement in diagnostic performance; examples of other potential biomarkers and the methods utilized in their discovery are also discussed in this review. CONCLUSIONS: Of these last markers, to date there are still few data to implement these for routine diagnosis.

Surgical complications of renal transplantation: ultrasound diagnosis.

OBJECTIVE: Ultrasound is the principal imaging technique for the evaluation of a renal allograft; it is a safe imaging technique to assess the structure of the graft and its perfusion without the need for intravenous contrast or ionizing radiation. The evaluation of kidney transplant complications is easy due to its presence in the iliac fossa lying anterior to the external iliac vessels. Complications may be classified as medical and surgical; the latter are classified in urologic, vascular and general surgical complications. MATERIALS AND METHODS: Our experience on surgical complications in kidney recipients from donors, on the role of ultrasound in the diagnosis of these complications and their impact on the graft and patient survival rates is reported. RESULTS: Ultrasonography represents a safe imaging technique to assess the structure of the graft and its perfusion without the use of ionizing radiation and iodinated contrast medium, and a quick, accurate method for the evaluation of complications. CONCLUSIONS: Although it possesses limitations and is ultimately operator dependent, ultrasound is considered an excellent tool for the assessment of the kidney transplant and in our experience it represents the main imaging technique used in the evaluation of graft complications.

Unusual solitary metastasis of the ciliary body in renal cell carcinoma.

Renal cell carcinoma (RCC) usually metastasizes to the lung, liver, bone; ocular metastasis is uncommon. We describe a rare case of metachronous ciliary RCC metastasis in a 42-year-old man who had undergone left radical nephrectomy for conventional RCC (pT3aN0M0, G2 Fuhrman) 6 years earlier. Solitary metastasis of the left eye presented with inflammatory symptoms, but examination of the fundus and bulbar ultrasound revealed a small mass of the ciliary body. Initial radiotherapy was unsuccessful and definitive treatment consisted of ocular enucleation with radical result and no further evidence of local and distant disease. Ocular metastasis of RCC is rare, can appear years after treating the primary tumor and should not be excluded in RCC follow-up. As for other RCC solitary metastasis, the best option remains the radical surgical approach.

[Doppler color ultrasonography in the assessment of double kidney transplantation]. / L'eco-colorDoppler nella valutazione del doppio trapianto di rene.

OBJECTIVE: In our Transplant Centre, in the last three years, twelve patients with chronic kidney disease underwent a "double kidney" transplant according to Masson technique. Our purpose is the evaluation of ultrasonography and echo-colorDoppler ultrasound in the diagnosis of possible clinical and surgical complications of "double kidney" transplant. PATIENTS AND METHODS: The "double kidney" transplant inclusion criteria are the following: donor age > 70 yrs; glomerulosclerosis > 20%; histological score (according to Kandinsky) > 4 and < 6. In our centre, from January 1998 to December 2001, we made 68 kidney transplantations from marginal donors, 12 of them were "double transplant". Mean donor age was 74.3 +/- 5.3 (70-82). Renal function was determined by detection of serum creatinine; every single patient underwent to ultrasonography evaluation of grafts during follow-up. RESULTS: Mean follow-up is 10 +/- 4.6 months (6-18); mean value of donor's serum creatinine 1.5 +/- 0.6 mg/dl. Delayed Graft Function (DGF) rate was 50%; no case of Primary Non Function (PNF) and Acute Rejection was found. Patients with DGF (group A) had a Resistance Index (IR) > 0.80 (mean 0.82); patients without DGF (group B) had an IR < 0.80 (mean 0.68 and 0.65) (p < 0.05). All patients underwent an eco colorDoppler evaluation after 3 and 6 months; in both groups (A and B) IR was, respectively, 0.75 and 0.71. Surgical adverse events were 41.6% (5/12): 3 urinary obstructions; 1 thrombosis of renal vein; 1 pelvic lymphocele. In all these patients the first diagnostic step was ultrasonography. Ultrasonography, in "double transplant" as in single one, have a very important role in post-transplant evaluation of DGF and surgical complications.