Publications

Obesity (OB) has become a serious health issue owing to its ever-increasing prevalence over the past few decades due to its contribution to severe metabolic and inflammatory disorders such as cardiovascular disease, type 2 diabetes, and cancer. The unbalanced energy metabolism in OB is associated with substantial epigenetic changes mediated by the gut microbiome (GM) structure and composition alterations. Remarkably, experimental evidence also indicates that OB-induced epigenetic modifications in adipocytes can lead to cellular "memory" alterations, predisposing individuals to weight regain after caloric restriction and subsequently inducing inflammatory pathways in the liver. Various environmental factors, especially diet, play key roles in the progression or prevention of OB and OB-related disorders by modulating the GM structure and composition and affecting epigenetic mechanisms. Here, we will first focus on the key role of epigenetic aberrations in the development of OB. Then, we discuss the association between abnormal alterations in the composition of the microbiome and OB and the interplays between the microbiome and the epigenome in the development of OB. Finally, we review promising strategies, including prebiotics, probiotics, a methyl-rich diet, polyphenols, and herbal foods for the prevention and/or treatment of OB via modulating the GM and their metabolites influencing the epigenome.

Eating disorders (EDs) are a heterogeneous class of increasing mental disorders that are characterized by disturbances in eating behaviors, body weight regulation, and associated psychological dysfunctions. These disorders create physiological imbalances that alter the diversity and composition of the gut microbiota. While evidence suggests that EDs can arise from epigenetic aberrations, alterations in gut microbial communities may also contribute to the development and/or persistence of EDs through epigenetic mechanisms. Understanding the interplay among gut microbial communities, epigenetic processes, and the risk of EDs provides opportunities for designing preventive and/or therapeutic interventions through gut microbiome modulation. This review highlights how microbiome-based therapeutics and specific dietary interventions can contribute to improving various subtypes of EDs by modulating gut microbial communities and mitigating epigenetic aberrations. First, we briefly review the literature on links between epigenetic aberrations and the pathophysiology of EDs. Second, we examine the potential role of the gut microbiome in the pathogenesis of EDs through epigenetic mechanisms. Next, we explore the associations between EDs and other psychiatric disorders, and examine the potential roles of the microbiome in their pathogenesis. Finally, we present evidence supporting the potential of microbiome-based therapeutics and specific dietary interventions to improve EDs through epigenetic modifications.

BACKGROUND: Colorectal cancer (CRC) is characterized by a pro-inflammatory microenvironment and features high-energy-supply molecules that assure tumor growth. A still less studied macromolecule is inorganic polyphosphate (iPolyP), a high-energy linear polymer that is ubiquitous in all forms of life. Made up of hundreds of repeated orthophosphate units, iPolyP is essential for a wide variety of functions in mammalian cells, including the regulation of proliferative signaling pathways. Some evidence has suggested its involvement in carcinogenesis, although more studies need to be pursued. Moreover, iPolyP regulates several homeostatic processes in animals, spanning from energy metabolism to blood coagulation and tissue regeneration.

RESULTS: In this study, we tested the role of iPolyP on CRC proliferation, using in vitro and ex vivo approaches, in order to evaluate its effect on tumor growth. We found that iPolyP is significantly increased in tumor tissues, derived from affected individuals enrolled in this study, compared to the corresponding peritumoral counterparts. In addition, iPolyP signaling occurs through the TRPM8 receptor, a well-characterized Na+ and Ca2+ ion channel often overexpressed in CRC and linked with poor prognosis, thus promoting CRC cell proliferation. The pharmacological inhibition of TRPM8 or RNA interference experiments performed in established CRC cell lines, such as Caco-2 and SW620, showed that the involvement of TRPM8 is essential, greater than that of the other two known iPolyP receptors, P2Y1 and RAGE. The presence of iPolyP drives cancer cells towards the mitotic phase of the cell cycle by enhancing the expression of ccnb1, which encodes the Cyclin B protein. In vitro 2D and 3D data reflected the ex vivo results, obtained by the generation of CRC-derived organoids, which increased in size.

CONCLUSIONS: These results indicate that iPolyP may be considered a novel and unexpected early biomarker supporting colorectal cancer cell proliferation.

One of the main causes of post-transplant-associated morbidity and mortality is cancer. The aims of the project were to study the neoplastic risk within the kidney transplant population and identify the determinants of this risk. A cohort of 462 renal transplant patients from 2010 to 2020 was considered. The expected incidence rates of post-transplant cancer development in the referenced population, the standardized incidence ratios (SIR) taking the Italian population as a comparison, and the absolute risk and the attributable fraction were extrapolated from these cohorts of patients. Kidney transplant recipients had an overall cancer risk of approximately three times that of the local population (SIR 2.8). A significantly increased number of cases were observed for Kaposi's sarcoma (KS) (SIR 195) and hematological cancers (SIR 6.8). In the first 3 years post-transplant, the risk to develop either KS or hematological cancers was four times higher than in the following years; in all cases of KS, the diagnosis was within 2 years from the transplant. Post-transplant immunosuppression represents the cause of 99% of cases of KS and 85% of cases of lymphomas, while only 39% is represented by solid tumors. Data related to the incidence, the percentages attributable to post-transplant immunosuppression, and the time of onset of neoplasms, particularly for KS and hematological tumors could help improve the management for the follow-up in these patients.

Over 40,000 patients in the United States are estimated to suffer from end-stage liver disease and acute hepatic failure, for which liver transplantation is the only available therapy. Human primary hepatocytes (HPH) have not been employed as a therapeutic tool due to the difficulty in growing and expanding them in vitro, their sensitivity to cold temperatures, and tendency to dedifferentiate following two-dimensional culture. The differentiation of human-induced pluripotent stem cells (hiPSCs) into liver organoids (LO) has emerged as a potential alternative to orthotropic liver transplantation (OLT). However, several factors limit the efficiency of liver differentiation from hiPSCs, including a low proportion of differentiated cells capable of reaching a mature phenotype, the poor reproducibility of existing differentiation protocols, and insufficient long-term viability in vitro and in vivo. This review will analyze various methodologies being developed to improve hepatic differentiation from hiPSCs into liver organoids, paying particular attention to the use of endothelial cells as supportive cells for their further maturation. Here, we demonstrate why differentiated liver organoids can be used as a research tool for drug testing and disease modeling, or employed as a bridge for liver transplantation following liver failure.

Human induced pluripotent stem cells (hiPSCs) represent a powerful tool for the generation of specialized cells to be used in regenerative medicine as well as hepatocellular repopulation tool to treat liver metabolic diseases such as nonalcoholic steatohepatitis (NASH). Here we describe a strategy to obtain fully functional liver organoids from hiPSCs in a scalable manner. Our approach uses a two-step process, with a first step involving the scalable formation of homogeneous and uniform-sized human embryoid bodies (hEBs), followed by the application of a four-step liver differentiation protocol for the derivation of liver organoids that possess all the features of primary human hepatocytes. This chapter will also illustrate the characterization of the liver organoids by directed biomolecular techniques.

Human-induced pluripotent stem cells (hiPSCs) constitute a great source to generate specialized cells that can be employed in cell replacement therapy for a number of degenerative diseases. In this chapter, I describe a strategy to mass-produce fully functional hepatocyte organoids using hiPSCs interlaced with human adipose microvascular endothelial cells (HAMEC). Our unique technology employs a two-step strategy, consisting of the scalable generation of nearly spherical uniform-sized human embryoid bodies (hEBs), and the subsequent employment of a four-step hepatocyte differentiation approach for the generation of hepatocyte organoids that display all the characteristics of human primary hepatocytes. In this chapter, we also describe methodologies to characterize the hepatocyte organoids by using different biomolecular assays.

Liver involvement after abdominal blunt trauma must be expected, and in up to 30% of cases, spleen, kidney, and pancreas injuries may coexist. Whenever hemodynamics conditions do not contraindicate the overcoming of the ancient dogma according to which exploratory laparotomy should be performed after every major abdominal trauma, a CT scan has to clarify the liver lesions so as to determine the optimal management strategy. Except for complete vascular avulsion, no liver trauma grade precludes nonoperative management. Every attempt to treat the injured liver by avoiding a strong surgical approach may be considered. Each time, a nonoperative management (NOM) consisting of a basic "wait and see" attitude combined with systemic support and blood replacement are inadequate. Embolization should be considered to stop the bleeding. Percutaneous drainage of collections, endoscopic retrograde cholangiopancreatography (ERCP) with papilla sphincterotomy or stent placement and percutaneous transhepatic biliary drainage (PTBD) may avoid, or at least delay, surgical reconstruction or resection until systemic and hepatic inflammatory remodeling are resolved. The pathophysiological principle sustaining these leanings is based on the opportunity to limit the further release of cell debris fragments acting as damage-associated molecular patterns (DAMPs) and the following stress response associated with the consequent immune suppression after trauma. The main goal will be a faster recovery combined with limited cell death of the liver through the ischemic events that may directly follow the trauma, exacerbated by hemostatic procedures and surgery, in order to reduce the gross distortion of a regenerated liver.

A laparoscopic approach is suggested with the highest grade of recommendation for acute cholecystitis, perforated gastroduodenal ulcers, acute appendicitis, gynaecological disorders, and non-specific abdominal pain (NSAP). To date, the main qualities of laparoscopy for these acute surgical scenarios are clearly stated: quicker surgery, faster recovery and shorter hospital stay. For the remaining surgical emergencies, as well as for abdominal trauma, the role of laparoscopy is still a matter of debate. Patients might benefit from a laparoscopic approach only if performed by experienced teams and surgeons which guarantee a high standard of care. More precisely, laparoscopy can limit damage to the tissue and could be effective for the reduction of the overall amount of cell debris, which is a result of the intensity with which the immune system reacts to the injury and the following symptomatology. In fact, these fragments act as damage-associated molecular patterns (DAMPs). DAMPs, as well as pathogen associated molecular patterns (PAMPs), are recognised by both surface and intracellular receptors of the immune cells and activate the cascade which, in critically ill surgical patients, is responsible for a deranged response. This may result in the development of progressive and multiple organ dysfunctions, manifesting with acute respiratory distress syndrome (ARDS), coagulopathy, liver dysfunction and renal failure. In conclusion, none of the emergency surgical scenarios preclude laparoscopy, provided that the surgical tactic could ensure sufficient cleaning of the abdomen in addition to resolving the initial tissue damage caused by the "trauma".

Organoids formed from human induced pluripotent stem cells (hiPSCs) could be a limitless source of functional tissue for transplantations in many organs. Unfortunately, fine-tuning differentiation protocols to form large quantities of hiPSC organoids in a controlled, scalable, and reproducible manner is quite difficult and often takes a very long time. Recently, we introduced a new approach of rapid organoid formation from dissociated hiPSCs and endothelial cells using microfabricated cell-repellent microwell arrays. This approach, when combined with real-time label-free Raman spectroscopy of biochemical composition changes and confocal light scattering spectroscopic microscopy of chromatin transition, allows for monitoring live differentiating organoids without the need to sacrifice a sample, substantially shortening the time of protocol fine-tuning. We used this approach to both culture and monitor homogeneous liver organoids that have the main functional features of the human liver and which could be used for cell transplantation liver therapy in humans.