Allogenic tissue-specific decellularized scaffolds promote long-term muscle innervation and functional recovery in a surgical diaphragmatic hernia model

Congenital diaphragmatic hernia (CDH) is a neonatal defect in which the diaphragm muscle does not develop properly, thereby raising abdominal organs into the thoracic cavity and impeding lung development and function. Large diaphragmatic defects require correction with prosthetic patches to close the malformation. This treatment leads to a consequent generation of unwelcomed mechanical stress in the repaired diaphragm and hernia recurrences, thereby resulting in high morbidity and significant mortality rates. We proposed a specific diaphragm-derived extracellular matrix (ECM) as a scaffold for the treatment of CDH. To address this strategy, we developed a new surgical CDH mouse model to test the ability of our tissue-specific patch to regenerate damaged diaphragms. Implantation of decellularized diaphragmatic ECM-derived patches demonstrated absence of rejection or hernia recurrence, in contrast to the performance of a commercially available synthetic material. Diaphragm-derived ECM was able to promote the generation of new blood vessels, boost long-term muscle regeneration, and recover host diaphragmatic function. In addition, using a GFP\u202f+\u202fSchwann cell mouse model, we identified re-innervation of implanted patches. These results demonstrated for the first time that implantation of a tissue-specific biologic scaffold is able to promote a regenerating diaphragm muscle and overcome issues commonly related to the standard use of prosthetic materials

CircRNAs are here to stay: A perspective on the MLL recombinome

Chromosomal translocations harbored by cancer genomes are important oncogenic drivers. In MLL rearranged acute leukemia (MLLre) MLL/KMT2A fuses with over 90 partner genes. Mechanistic studies provided clues of MLL fusion protein leukemogenic potential, but models failed to fully recapitulate the disease. Recently, expression of oncogenic fusion circular RNAs (f-circ) by MLL-AF9 fusion was proven. This discovery, together with emerging data on the importance and diversity of circRNAs formed the incentive to study the circRNAs of the MLL recombinome. Through interactions with other RNAs, such as microRNAs, and with proteins, circRNAs regulate cellular processes also related to cancer development. CircRNAs can translate into functional peptides too. MLL and most of the 90 MLL translocation partners do express circRNAs and exploration of our RNA-seq dataset of sorted blood cell populations provided new data on alternative circular isoform generation and expression variability of circRNAs of the MLL recombinome. Further, we provided evidence that rearrangements of MLL and three of the main translocation partner genes can impact circRNA expression, supported also by preliminary observations in leukemic cells. The emerging picture underpins the view that circRNAs are worthwhile to be considered when studying MLLre leukemias and provides a new perspective on the impact of chromosomal translocations in cancer cells at large

Extracellular ATP is increased by release of ATP-loaded microparticles triggered by nutrient deprivation

Rationale: Caloric restriction improves the efficacy of anti-cancer therapy. This effect is largely dependent on the increase of the extracellular ATP concentration in the tumor microenvironment (TME). Pathways for ATP release triggered by nutrient deprivation are largely unknown. Methods: The extracellular ATP (eATP) concentration was in vivo measured in the tumor microenvironment of B16F10-inoculated C57Bl/6 mice with the pmeLuc probe. Alternatively, the pmeLuc-TG-mouse was used. Caloric restriction was in vivo induced with hydroxycitrate (HC). B16F10 melanoma cells or CT26 colon carcinoma cells were in vitro exposed to serum starvation to mimic nutrient deprivation. Energy metabolism was monitored by Seahorse. Microparticle release was measured by ultracentrifugation and by Nanosight. Results: Nutrient deprivation increases eATP release despite the dramatic inhibition of intracellular energy synthesis. Under these conditions oxidative phosphorylation was dramatically impaired, mitochondria fragmented and glycolysis and lactic acid release were enhanced. Nutrient deprivation stimulated a P2X7-dependent release of ATP-loaded, mitochondria-containing, microparticles as well as of naked mitochondria. Conclusions: Nutrient deprivation promotes a striking accumulation of eATP paralleled by a large release of ATP-laden microparticles and of naked mitochondria. This is likely to be a main mechanism driving the accumulation of eATP into the TME

T Regulatory Lymphocytes Function Increased, by Induction Of Ho-1, Improves Type-1 Cardio-Renal Syndrome

Rationale: Type-1 cardio-renal syndrome (CRS) is characterized by an acute kidney dysfunction due to renal arteriolar vasoconstriction following an acute worsening of cardiac function. It is well know that HO-1 upregulation has a cardio protective and renoprotective function mediated by anti-oxidative, anti-inflammatory, anti-apoptotic and vasodilating effects. An alteration of T-lymphocyte-related immune response seems to be one of the potential mechanisms involved in type-1 CRS. Objective: The aim of this study was to assess 1) if HO-1 upregulation could be a therapeutic target for type 1 CRS and 2) the role of T-lymphocytes in HO-1 induced effects on renal function in type 1 CRS. Methods: Post-ischemic heart failure was induced by left anterior coronary artery ligation in C57Bl6 and SCID (T lymphocytes deficient) mice. Animals were divided into 4 groups: sham, myocardial infarction (MI), MI treated with HO-1 inducer cobalt protoporphyrin (CoPP) with and without the HO activity inhibitor stannous mesoporphyrin (SnMP). All mice underwent echocardiography (fractional area shortening, FAS) and renal Doppler sonography (intrarenal pulsatility index, PI) 30 days after surgery. Results: Heart function was significantly reduced in MI groups (C57: FAS: sham 0.36\ub10.06, MI 0.26\ub10.04, p<0.05; SCID: FAS: sham 0.34\ub10.04, MI: 0.24\ub10.04, p<0.01) and PI was significantly increased in MI groups compared to sham groups (C57: PI: sham 0.98\ub10.05, MI: 1.12\ub10.11, p<0.05; SCID: PI: sham 0.72\ub10.08, MI 1.37\ub10.37, p<0.05). HO-1 induction improved heart function in both C57 and SCID mice but only in SCID mice was a significant improvement of renal vasoconstriction observed (SCID; PI: MI+CoPP 0.9\ub10.19 p<0.05). In SCID mice SnMP treatment reversed the effect of CoPP on heart function and renal vasoconstriction. Conclusion: Our novel study showed that T lymphocyte mediated immunity is involved in type 1 CRS and upregulation of HO-1, in this setting, could be a therapeutic target for improving type 1 CRS. Author Disclosures: P. Pesce: None. D. Sacerdoti: None. M. Boldrin: None. R. Rezzani: None. N.G. Abraham: None. Key Words: Renal circulation \u2022 Heart failure \u2022 Immunologic factors \u2022 Oxidative stres