Rapamycin does not adversely affect intrahepatic islet engraftment in mice and improves early islet engraftment in humans.

Objective: In this study we examined the effect of rapamycin (RAPA), a key component of the immunosuppressive regimen in clinical islet transplantation, on islet engraftment and function in vivo. Methods and results: Diabetic C57BL/6 or BALB/C recipient mice were transplanted with 350 syngeneic islets through the portal vein (PV-Tx; C57BL/6 n = 60; BALB/C n = 22) and treated with once-daily oral RAPA (1 mg/kg) or vehicle. No differences in post-transplant blood glucose concentrations and glucose tolerance were observed between RAPA-and vehicle-treated mice. The impact of RAPA on human islet engraftment was assessed in 10 patients with type 1 diabetes treated with 0.1 mg/kg/day rapamycin before islet transplantation. Compared to non pre-treated islet transplant recipents (n = 12), RAPA pre-treated patients had increased blood RAPA concentrations (p = 0.006) and fasting C-peptide concentrations (p = 0.005) in the two weeks post-transplant. RAPA pre-treatment was associated with a reduction in chemokines CCL2 and CCL3 concentrations pre-transplant (p < 0.01), and a dampened chemokine response (p = 0.005) post-transplant. Concordantly, in vitro RAPA inhibited the secretion of CCL2 and CCL3 by monocytes. Conclusion: Rapamycin does not adversely affect intrahepatic islet engraftment in the mouse, and potentially improves islet engraftment in humans by an anti-inflammatory mechanism

Human pancreatic islet preparations release HMGB1: (ir)relevance for graft engraftment.

High levels of donor-derived high-mobility group box 1 (HMGB1) protein have been associated with poor islet graft outcome in mouse models. The aim of our work was to determine whether HMGB1 released by human islets had independent proinflammatory effects that influence engraftment in humans. Human islet preparations contained and released HMGB1 in different amounts, as determined by Western blot and ELISA (median 17 pg/ml/IEQ/24 h; min–max 0–211, n = 74). HMGB1 release directly correlated with brain death, donor hyperamilasemia, and factors related to the pancreas digestion procedure (collagenase and digestion time). HMGB1 release was significantly positively associated with the release of other cytokines/chemokines, particularly with the highly released "proinflammatory" CXCL8/IL-8, CXCL1/GRO-α, and the IFN-γ-inducible chemokines CXCL10/IP-10 and CXCL9/MIG. HMGB1 release was not modulated by Toll-like receptor 2, 3, 4, 5, and 9 agonists or by exposure to IL-1β. When evaluated after islet transplantation, pretransplant HMGB1 release was weakly associated with the activation of the coagulation cascade (evaluated as serum cross-linked fibrin products), but not with the immediate posttransplant inflammatory response. Concordantly, HMGB1 did not affect short-term human islet function. Our data show that human islet HMGB1 release is a sign of "damaged" islets, although without any independent direct role in graft failure

Allo Beta Cell transplantation: specific features, unanswered questions, and immunological challenge

Type 1 diabetes (T1D) presents a persistent medical challenge, demanding innovative strategies for sustained glycemic control and enhanced patient well-being. Beta cells are specialized cells in the pancreas that produce insulin, a hormone that regulates blood sugar levels. When beta cells are damaged or destroyed, insulin production decreases, which leads to T1D. Allo Beta Cell Transplantation has emerged as a promising therapeutic avenue, with the goal of reinstating glucose regulation and insulin production in T1D patients. However, the path to success in this approach is fraught with complex immunological hurdles that demand rigorous exploration and resolution for enduring therapeutic efficacy. This exploration focuses on the distinct immunological characteristics inherent to Allo Beta Cell Transplantation. An understanding of these unique challenges is pivotal for the development of effective therapeutic interventions. The critical role of glucose regulation and insulin in immune activation is emphasized, with an emphasis on the intricate interplay between beta cells and immune cells. The transplantation site, particularly the liver, is examined in depth, highlighting its relevance in the context of complex immunological issues. Scrutiny extends to recipient and donor matching, including the utilization of multiple islet donors, while also considering the potential risk of autoimmune recurrence. Moreover, unanswered questions and persistent gaps in knowledge within the field are identified. These include the absence of robust evidence supporting immunosuppression treatments, the need for reliable methods to assess rejection and treatment protocols, the lack of validated biomarkers for monitoring beta cell loss, and the imperative need for improved beta cell imaging techniques. In addition, attention is drawn to emerging directions and transformative strategies in the field. This encompasses alternative immunosuppressive regimens and calcineurin-free immunoprotocols, as well as a reevaluation of induction therapy and recipient preconditioning methods. Innovative approaches targeting autoimmune recurrence, such as CAR Tregs and TCR Tregs, are explored, along with the potential of stem stealth cells, tissue engineering, and encapsulation to overcome the risk of graft rejection. In summary, this review provides a comprehensive overview of the inherent immunological obstacles associated with Allo Beta Cell Transplantation. It offers valuable insights into emerging strategies and directions that hold great promise for advancing the field and ultimately improving outcomes for individuals living with diabetes

Leber's Hereditary Optic Neuropathy: A Report on Novel mtDNA Pathogenic Variants

Leber's hereditary optic neuropathy (LHON) is due to missense point mutations affecting mitochondrial DNA (mtDNA); 90% of cases harbor the m.3460G&gt;A, m.11778G&gt;A, and m.14484T&gt;C primary mutations. Here, we report and discuss five families with patients affected by symptomatic LHON, in which we found five novel mtDNA variants. Remarkably, these mtDNA variants are located in complex I genes, though without strong deleterious effect on respiration in cellular models: this finding is likely linked to the tissue specificity of LHON. This study observes that in the case of a strong clinical suspicion of LHON, it is recommended to analyze the whole mtDNA sequence, since new rare mtDNA pathogenic variants causing LHON are increasingly identified

Lack of in vivo genotoxic effect of dried whole Aloe ferox juice

&lt;p&gt;Aloe ferox Mill is widely used as a traditional herbal medicine for the treatment of a broad spectrum of illnesses given its laxative, anti-inflammatory, bitter tonic, anti-oxidant, antimicrobial and anti-cancer properties. Using the in vivo alkaline comet assay in animals (OECD 489), this study investigated the potential in vivo genotoxicity of dried Aloe ferox juice at dose levels of 500, 1000, and 2000 mg/kg/day in mice. Aloe ferox showed no genotoxic activity in preparations of single cells from the colon of the treated Hsd:ICR (CD-1) male mice. No statistically significant increase in DNA migration over the negative control was observed by analysis of variance for both comet parameters, tail moment and tail intensity, apart from the positive control ethyl methanesulphonate that induced clear and statistically significant increases in DNA migration parameters over the concurrent controls. The new reported scientific evidence unequivocally demonstrates that dried Aloe ferox juice containing hydroxyanthracene derivatives does not induce DNA damage in preparations of single cells from colon in in vivo comet genotoxicity studies. This suggests that the hyperplastic changes and mucosal hyperplasia observed after long-term administration of Aloe vera non-decolourised whole leaf extract may be attributed to an epigenetic effect of the material under investigation.&lt;/p&gt

Lack of genotoxicity of rhubarb (rhizome) in the Ames and micronucleus in vitro tests

&lt;p&gt;Aloe ferox Mill is widely used as a traditional herbal medicine for the treatment of a broad spectrum of illnesses given its laxative, anti-inflammatory, bitter tonic, anti-oxidant, antimicrobial and anti-cancer properties. Using the in vivo alkaline comet assay in animals (OECD 489), this study investigated the potential in vivo genotoxicity of dried Aloe ferox juice at dose levels of 500, 1000, and 2000 mg/kg/day in mice. Aloe ferox showed no genotoxic activity in preparations of single cells from the colon of the treated Hsd:ICR (CD-1) male mice. No statistically significant increase in DNA migration over the negative control was observed by analysis of variance for both comet parameters, tail moment and tail intensity, apart from the positive control ethyl methanesulphonate that induced clear and statistically significant increases in DNA migration parameters over the concurrent controls. The new reported scientific evidence unequivocally demonstrates that dried Aloe ferox juice containing hydroxyanthracene derivatives does not induce DNA damage in preparations of single cells from colon in in vivo comet genotoxicity studies. This suggests that the hyperplastic changes and mucosal hyperplasia observed after long-term administration of Aloe vera non-decolourised whole leaf extract may be attributed to an epigenetic effect of the material under investigation.&lt;/p&gt

Vittorio Grevi - Scritti per il <<Corriere>> 1988-2010

Il volume contiene una selezione ragionata - preceduta da una prefazione di Virginio Rognoni - degli articoli di argomento giuridico scritti da Vittorio Grevi per Il Corriere della Sera nell'arco di tempo compreso tra il 1988 e il 2010, completata dall'indice generale di tutti gli articoli pubblicati, e dall'indice dei nomi citati

Calcineurin inhibitor-free immunosuppressive regimen in type 1 diabetes patients receiving islet transplantation: single-group phase 1/2 trial

Our final objective is to develop an adoptive therapy with tolerogenic donor-specific type 1 T regulatory cells for patients with type 1 diabetes undergoing islet transplantation. The achievement of this objective depends on the availability of an immunosuppressive treatment compatible with the survival, function, and expansion of type 1 T regulatory cells