A ZNRF3-dependent Wnt/ß-catenin signaling gradient is required for adrenal homeostasis.

Spatiotemporal control of Wnt signaling is essential for the development and homeostasis of many tissues. The transmembrane E3 ubiquitin ligases ZNRF3 (zinc and ring finger 3) and RNF43 (ring finger protein 43) antagonize Wnt signaling by promoting degradation of frizzled receptors. ZNRF3 and RNF43 are frequently inactivated in human cancer, but the molecular and therapeutic implications remain unclear. Here, we demonstrate that adrenocortical-specific loss of ZNRF3, but not RNF43, results in adrenal hyperplasia that depends on Porcupine-mediated Wnt ligand secretion. Furthermore, we discovered a Wnt/ß-catenin signaling gradient in the adrenal cortex that is disrupted upon loss of ZNRF3. Unlike ß-catenin gain-of-function models, which induce high Wnt/ß-catenin activation and expansion of the peripheral cortex, ZNRF3 loss triggers activation of moderate-level Wnt/ß-catenin signaling that drives proliferative expansion of only the histologically and functionally distinct inner cortex. Genetically reducing ß-catenin dosage significantly reverses the ZNRF3-deficient phenotype. Thus, homeostatic maintenance of the adrenal cortex is dependent on varying levels of Wnt/ß-catenin activation, which is regulated by ZNRF3.

The adrenal capsule is a signaling center controlling cell renewal and zonation through Rspo3.

Adrenal glands are zonated endocrine organs that are essential in controlling body homeostasis. How zonation is induced and maintained and how renewal of the adrenal cortex is ensured remain a mystery. Here we show that capsular RSPO3 signals to the underlying steroidogenic compartment to induce ß-catenin signaling and imprint glomerulosa cell fate. Deletion of RSPO3 leads to loss of SHH signaling and impaired organ growth. Importantly, Rspo3 function remains essential in adult life to ensure replenishment of lost cells and maintain the properties of the zona glomerulosa. Thus, the adrenal capsule acts as a central signaling center that ensures replacement of damaged cells and is required to maintain zonation throughout life.

Culture of the human pilosebaceous unit, hair follicle and sebaceous gland.

Terence Kealey first pioneered the isolation and organ maintenance of human eccrine and sebaceous glands in the early to mid-1980. This led to subsequent methods describing the isolation and culture of human hair follicles, the human pilosebaceous unit as well as the sebaceous duct. The importance of these models in the study of the biology of human skin glands and appendages has been demonstrated in numerous publications and their importance as models for animal replacement, refinement and reduction (3Rs) is increasingly important. In particular, in vitro (ex vivo) hair follicle culture has played a significant part in helping elucidate the role of signalling molecules in regulating hair growth and hair fibre formation and has been especially useful in understanding metabolic aspects of hair growth. However, obtaining sufficient numbers of hair follicles is becoming increasingly difficult as plastic surgery becomes less invasive and smaller skin samples provided. There is therefore an urgent requirement for the next generation of in vitro models using cell lines and tissue engineering, and this has led to the development of immortalised cell lines as well as attempts to model hair follicle embryogenesis in vitro and development of skin on a chip.

Design and realization of a normothermic perfusion system for laboratory tests on pig liver.

Ex vivo testing is a fundamental step in the development of new medical devices; indeed without it, it is impossible to proceed with in vivo tests. At the University of Florence, a robotic tool for microwave thermal ablation is under development. Up to now, the thermoablation tests for the validation of the tool were carried out on non-perfused ex vivo livers, providing results that inevitably differ from those obtainable with an in vivo liver. The aim is to design, and consequently create, a compact and transportable system which allows to perfuse a swine liver with physiological solution and heparin. This device should also allow the organ to be transported from the explantation place to the laboratory, keeping it under normothermal condition. The perfusor was designed to simulate the physiological flow within the liver in the most realistic way possible. The design, construction, and optimization of the perfusor have been addressed using the physiological values of hepatic flow and pressure identified in the literature, neglecting in the first instance any load losses. Therefore, open circuit tests were conducted, validated through perfusion tests on freshly explanted pig liver; during these tests, the surface temperature of the organ was recorded using an infrared camera, and the fluid temperature was verified using an immersion probe. The perfusion test showed a good alignment with the open circuit tests, demonstrating the validity of the simplifications adopted to treat the complex vascular structure of the liver.

Clinical outcome of kidney transplantation from DBD donors complicated with acute kidney injury / 器官移植

Objective To evaluate the clinical outcome of kidney transplantation from donation after brain death (DBD) donors complicated with acute kidney injury (AKI). Methods Clinical data of 216 DBD donors were retrospectively analyzed, and they were divided into the AKI group (n=69) and control group (n=147) according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Donors in the AKI group were further divided into the KDIGO stage 1 and stage 2-3 subgroups. One hundred and thirty-five recipients were assigned into the AKI group and 288 recipients in the control group. Postoperative recovery of renal function and clinical outcomes of the recipients were recorded. The risk factors of delayed graft function (DGF) were identified. Results The highest serum creatinine (Scr) level, Scr level before procurement, the highest blood sodium level and blood sodium level before procurement in the AKI group were higher than those in the control group. The application duration of vasopressors in the AKI group was longer than that in the control group. In the AKI group, the amount of fluid resuscitation within 48 h was higher, the HCO3− level at admission was lower, and the incidence of diabetes insipidus and hypotension was higher than those in the control group. The highest Scr level and the Scr level before procurement in KDIGO stage 2-3 donors were significantly higher than those in KDIGO stage 1 counterparts (all P<0.05). Compared with the control group, the incidence of DGF and acute rejection was higher, the proportion of continuous renal replacement therapy was higher, the Scr level within postoperative 90 d was higher, and the urine amount within postoperative 3 d was less than those of recipients in the AKI group. Compared with KDIGO stage 1 recipients, KDIGO stage 2-3 recipients had higher Scr levels at postoperative 3, 4, 5 and 15 d, and less urine amount at postoperative 2 d (all P<0.05). Univariate analysis showed that donor age, the highest Scr level, the highest blood sodium level and the amount of fluid resuscitation within 48 h were the risk factors for DGF in recipients after kidney transplantation. Multivariate analysis showed that donor age was the independent risk factor for DGF in recipients after kidney transplantation (all P<0.05). Conclusions For the application of DBD donors complicated with AKI, active organ maintenance should be performed to alleviate AKI. It exerts no effect upon graft function and survival rate at postoperative 6 months, which may achieve equivalent efficacy as non-AKI donors and may be used as a source of extended criteria donor kidneys.

Experience of clinical efficacy of renal transplantation from donors of donation after brain death complicated with acute kidney injury / 器官移植

Objective To summarize the clinical efficacy of renal transplantation from donors of donation after brain death (DBD) complicated with acute kidney injury (AKI). Methods Fifty-nine DBD donors successfully undergoing renal transplantation were recruited in this investigation. According to the Scr level upon admission of intensive care unit (ICU), DBD donors were divided into the AKI group (n=14) and control group (n=45). A total of 101 recipients were assigned into the AKI group (n=23) and control group (n=78) correspondingly. The organ donation conditions of 59 donors were summarized. Main parameters of the donors before organ procurement were statistically compared between two groups. Postoperative kidney function, hospitalization condition and clinical outcomes of the recipients were statistically compared between two groups. Results Among 59 donors, 14 cases (24%) suffered from AKI. Two donors received continuous renal replacement therapy during organ maintenance. Compared with the donors in the control group, the APACHE Ⅱ score of the donors was significantly higher (P<0.05), the incidence of central diabetes insipidus was considerably higher (P<0.01), the Scr levels at admission of ICU and before organ procurement were significantly higher (both P<0.01) and the amount of urine at 24 h before organ procurement was dramatically less in the AKI group (P<0.01).Compared with the recipients in the control group, the Scr levels at postoperative 2 and 3 d were significantly higher (both P<0.05), the length of hospital stay was considerably longer (P<0.01) and the hospitalization expanse was significantly higher in the AKI group (P<0.05). No statistical significance was observed in the postoperative delayed recovery of renal graft function, incidence of acute rejection, infection and rehabilitation dialysis in the recipients between two groups (all P>0.05). At 3 months after transplantation, the recipients in two groups were discharged and the graft survival rate was 100%. Conclusions For renal transplantation from DBD donors complicated with AKI, active measures should be taken to maintain the organ and relieve the AKI, which yields similar clinical efficacy to renal transplantation from non-AKI donors and widens the origin of kidney graft.