Climacostol reduces tumour progression in a mouse model of melanoma via the p53-dependent intrinsic apoptotic programme

Climacostol, a compound produced by the ciliated protozoan Climacostomum virens, displayed cytotoxic properties in vitro. This study demonstrates that it has anti-tumour potential. Climacostol caused a reduction of viability/proliferation of B16-F10 mouse melanoma cells, a rapidly occurring DNA damage, and induced the intrinsic apoptotic pathway characterised by the dissipation of the mitochondrial membrane potential, the translocation of Bax to the mitochondria, the release of Cytochrome c from the mitochondria, and the activation of Caspase 9-dependent cleavage of Caspase 3. The apoptotic mechanism of climacostol was found to rely on the up-regulation of p53 and its targets Noxa and Puma. In vivo analysis of B16-F10 allografts revealed a persistent inhibition of tumour growth rate when melanomas were treated with intra-tumoural injections of climacostol. In addition, it significantly improved the survival of transplanted mice, decreased tumour weight, induced a remarkable reduction of viable cells inside the tumour, activated apoptosis and up-regulated the p53 signalling network. Importantly, climacostol toxicity was more selective against tumour than non-tumour cells. The anti-tumour properties of climacostol and the molecular events associated with its action indicate that it is a powerful agent that may be considered for the design of pro-apoptotic drugs for melanoma therapy

Inequality, Fiscal Capacity and the Political Regime: Lessons from the Post-Communist Transition

Using panel data for twenty-seven post-communist economies between 1987-2003, we examine the nexus of relationships between inequality, fiscal capacity (defined as the ability to raise taxes efficiently) and the political regime. Investigating the impact of political reform we find that full political freedom is associated with lower levels of income inequality. Under more oligarchic (authoritarian) regimes, the level of inequality is conditioned by the state’s fiscal capacity. Specifically, oligarchic regimes with more developed fiscal systems are able to defend the prevailing vested interests at a lower cost in terms of social injustice. This empirical finding is consistent with the model developed by Acemoglu (2006). We also find that transition countries undertaking early macroeconomic stabilisation now enjoy lower levels of inequality; we confirm that education fosters equality and the suggestion of Commander et al (1999) that larger countries are prone to higher levels of inequality.http://deepblue.lib.umich.edu/bitstream/2027.42/57211/1/wp831 .pd

Miro: A molecular switch at the center of mitochondrial regulation

The orchestration of mitochondria within the cell represents a critical aspect of cell biology. At the center of this process is the outer mitochondrial membrane protein, Miro. Miro coordinates diverse cellular processes by regulating connections between organelles and the cytoskeleton that range from mediating contacts between the endoplasmic reticulum and mitochondria to the regulation of both actin and microtubule motor proteins. Recently, a number of cell biological, biochemical, and protein structure studies have helped to characterize the myriad roles played by Miro. In addition to answering questions regarding Miro’s function, these studies have opened the door to new avenues in the study of Miro in the cell. This review will focus on summarizing recent findings for Miro’s structure, function, and activity while highlighting key questions that remain unanswered.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155476/1/pro3839.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155476/2/pro3839_am.pd

Impact of Drp1 activation and fission induction in the pathogenesis of DMD progression

Loss of function mutations in DMD gene encoding for dystrophin protein cause Duchenne Muscular Dystrophy (DMD) a severe progressive neuromuscular disease. Despite remarkable progress has been made in genetic approaches to restore dystrophin, or its function, new therapeutic strategies are needed. In this view, muscle weakness in DMD is thought to be dependent, at least in part, on damaged mitochondria and compromised bioenergetics. Consistently mitochondria are an attractive target for therapeutic interventions. Dystrophic fibers show marked mitochondria fragmentation, however, few studies have addressed the relevance of mitochondrial shape in the muscle damage progression. Accordingly, we generated a DMD mouse model with intrinsically fluorescent mitochondria, the mdx-PhAM mouse, to precisely define mitochondrial dynamics during DMD progression and we confirmed the existence of a less interconnected mitochondrial network in mdx single fibers by 3- dimensional reconstruction. In agreement, Western blot experiments showed a significant upregulation of pro-fission proteins, Drp1 and its receptors, in mdx muscles starting from 3 months of age, suggesting the shifting of mitochondrial dynamics towards Drp1-mediated mitochondrial fission. This can potentially contributes to DMD pathological fibrosis and inflammation by triggering the activation of specific signaling pathways, such as inflammation by DAMPs (mtDNA) release and UPR response. Therefore, to assess the relevance of Drp1-dependent fission enhancement in DMD pathogenesis we treated mdx mice with MDIVI-1, a specific Drp1 inhibitor. We have obtained encouraging results as for muscle functionality and phenotype, thus confirming the relevance of Drp1 as a therapeutic target in DMD

SRT2104, a new specific SIRT1 activator, promotes muscle recovery enhancing mitochondrial metabolism in DMD

Duchenne Muscular Dystrophy (DMD) is an X-linked degenerative genetic disease caused by mutations of the DMD gene encoding dystrophin protein. While remarkable progress has been made in genetic approaches to restore dystrophin or its function, targeting secondary pathological mechanisms remains an important issue to address. SIRT1 belongs to a class of NAD+-dependent class III deacetylase that controls several key cellular processes. Different attempts have been done to increase SIRT1 activation in mdx mice, however, despite the initial promise, the current opinion reveals the need for developing better and more selective activators of sirtuins. Among these, the SRT2104 molecule is the most advanced in clinical studies. We have challenged the effects of SRT2104 administration in mdx mice and 12 weeks of SRT2104 supplementation with the diet improved muscle performance and muscle phenotype. SRT2104 administration also boosted muscle OxPhos capacity, as further confirmed by respiratory complexes’ activity, supporting the idea of SRT2104 as a good metabolic enhancer. To mechanistically characterize the SRT2104 mode of action, a series of molecular dynamics simulations have been performed on the available structures of SIRT1. They support the idea that a conformational selection mechanism is responsible of the activity of SRT2104, i.e., the open inactive conformation of the protein explores a more compact intermediate state that is stabilized by the drug, then converted into its active form. We have further investigated SRT2104 action by exploring the proteomic profiles of muscles throughquantitativemassspectrometry,revealingtheSRT2104-dependentenhancementof the muscle contraction system. Moreover, we have also characterized the acetylated landscape of mdx muscle after SRT2104 administration pointing out some interesting deacetylated metabolicenzymes,thereforebothapproachesprovedmuscleimprovements and specific metabolic effects of the drug

Ovarian cancer molecular pathology.

Peer reviewe

SARS-CoV-2 hampers dopamine production in iPSC-derived dopaminergic neurons

An increasing number of patients experiences prolonged symptoms, whose profile and timeline remain uncertain, a condition that has been defined as post COVID. The majority of recovered hospitalized patients manifests at least one persistent symptom even sixty days after the first clinical manifestation's onset. Particularly, in light of the COVID-19-related symptomatology, it has been hypothesized that SARS-CoV-2 might affect the dopamine pathway. However, no scientific evidence has been produced so far. To this end, human iPSC-derived dopaminergic neurons were infected with EU, Delta and Omicron SARS-CoV-2 variants. The infection with EU and Delta variants, but not with Omicron, results in a reduced intracellular content and extracellular release of dopamine. Indeed, the tyrosine hydroxylase was found to be significantly upregulated at the mRNA level, while being greatly reduced at the protein level. The major downstream synthetic enzyme DOPA-decarboxylase and the dopamine transporter were significantly downregulated both at the mRNA and protein level. Notably, in vitro SARS-CoV-2 infection was also associated with an altered MAP2 and TAU expression and with an increased presence of neuronal stress markers. These preliminary observations suggest that the dopamine metabolism and production are affected by SARS-CoV-2, partially explaining some of the neurological symptoms manifested

On-Chain Global Maintenance Services

Facility management deals with all activities that are not core business for a company and are consequently outsourced to specilized companies. Maintenance is a fundamental activity in facility management and it is often handled by Global Maintenance Services (GMS) where some maintenance activities are delegated by the company to service providers and are remunerated according to measurable results expressed as Key Performance Indicators. In this context, it would be desirable to have information systems trustable by all involved actors. In this paper, we discuss the design of a blockchain solution capable to support a GMS on-chain. We first introduce the GMS concept and how it is related to the Principal-Agent relationship, then we show a reference architecture to implement GMS on-chain. We discuss a use case of on-chain GMS in a hospital showing how smart contracts and oracles can be used in this context. We present the advantages of this approach and we discuss the open problems for realizing a proof-of-concep

Acid Sphingomyelinase Downregulation Enhances Mitochondrial Fusion and Promotes Oxidative Metabolism in a Mouse Model of Melanoma

Melanoma is the most severe type of skin cancer. Its unique and heterogeneous metabolism, relying on both glycolysis and oxidative phosphorylation, allows it to adapt to disparate conditions. Mitochondrial function is strictly interconnected with mitochondrial dynamics and both are fundamental in tumour progression and metastasis. The malignant phenotype of melanoma is also regulated by the expression levels of the enzyme acid sphingomyelinase (A-SMase). By modulating at transcriptional level A-SMase in the melanoma cell line B16-F1 cells, we assessed the effect of enzyme downregulation on mitochondrial dynamics and function. Our results demonstrate that A-SMase influences mitochondrial morphology by affecting the expression of mitofusin 1 and OPA1. The enhanced expression of the two mitochondrial fusion proteins, observed when A-SMase is expressed at low levels, correlates with the increase of mitochondrial function via the stimulation of the genes PGC-1alpha and TFAM, two genes that preside over mitochondrial biogenesis. Thus, the reduction of A-SMase expression, observed in malignant melanomas, may determine their metastatic behaviour through the stimulation of mitochondrial fusion, activity and biogenesis, conferring a metabolic advantage to melanoma cells

The natural compound climacostol as a prodrug strategy based on pH activation for efficient delivery of cytotoxic small agents

We synthesized and characterized MOMO as a new small molecule analog of the cytotoxic natural product climacostol efficiently activated in mild extracellular acidosis. The synthesis of MOMO had a key step in the Wittig olefination for the construction of the carbon-carbon double bond in the alkenyl moiety of climacostol. The possibility of obtaining the target (Z)-alkenyl MOMO derivative in very good yield and without presence of the less active (E)-diastereomer was favored from the methoxymethyl ether (MOM)-protecting group of hydroxyl functions in aromatic ring of climacostol aldehyde intermediate. Of interest, the easy removal of MOM-protecting group in a weakly acidic environment allowed us to obtain a great quantity of climacostol in biologically active (Z)-configuration. Results obtained in free-living ciliates that share the same micro-environment of the climacostol natural producer Climacostomum virens demonstrated that MOMO is well-tolerated in a physiological environment, while its cytotoxicity is rapidly and efficiently triggered at pH 6.3. In addition, the cytostatic vs. cytotoxic effects of acidified-MOMO can be modulated in a dose-dependent manner. In mouse melanoma cells, MOMO displayed a marked pH-sensitivity since its cytotoxic and apoptotic effects become evident only in mild extracellular acidosis. Data also suggested MOMO being preferentially activated in the unique extra-acidic microenvironment that characterizes tumoural cells. Finally, the use of the model organism Drosophila melanogaster fed with an acidic diet supported the efficient activity and oral delivery of MOMO molecule in vivo. MOMO affected oviposition of mating adults and larvae eclosion. Reduced survival of flies was due to lethality during the larval stages while emerging larvae retained their ability to develop into adults. Interestingly, the gut of eclosed larvae exhibited an extended damage (cell death by apoptosis) and the brain tissue was also affected (reduced mitosis), demonstrating that orally activated MOMO efficiently targets different tissues of the developing fly. These results provided a proof-of-concept study on the pH-dependence of MOMO effects. In this respect, MOM-protection emerges as a potential prodrug strategy which deserves to be further investigated for the generation of efficient pH-sensitive small organic molecules as pharmacologically active cytotoxic compounds