1,721,497 research outputs found
Analysis of Calcium homeostasis and PKC involvement in Pseudomonas aeruginosa infection.
No full textThe hypothesis underlying this proposal is that the comprehension of the mechanisms regulating intracellular second messengers in response to Pseudomonas aeruginosa may have a significant impact for development of novel therapies for treatment of inflammation in CF patients
Apoptosis and autophagy regulation at mitochondrial level: molecular mechanisms and effect of pathologic mutations
No full textMitochondria are relevant in cellular physiology, but also in promoting apoptotic cell-death and autophagy in response to specific signals. Mitochondrial
dysfunctions are involved in a variety of diseases, including cancer, neurodegeneration, chronic infections, inflammation, atherosclerosis and aging.
This projects joins four research groups with a common interest in understanding the mitochondrial pathways leading to such crucial cellular responses, focusing on
specific changes in mitochondrial physiology, dissecting the mitochondrial functions of specific genes of interest (p53, Ras, RET, VDAC, Parkin, PINK1, DJ-1 and
huntingtin) and analyzing in some detail the changes associated to models of neurodegeneration and cancer. Special emphasis will be given to the study of their role
in the mechanisms of regulation of apoptosis and autophagy as the unifying theme of this application.
We will:
1) dissect the role of p53 and p53-related proteins in mitochondrial apoptosis and autophagy, with a detailed investigation of the effects that p53 can exert on Ca2+
homeostasis and other parameters of mitochondrial physiology. While the mitochondrial function of p53 is established, it is not known if this function is shared by the
other p53-related proteins.
2) investigate the mitochondrial effects of Ras signalling in the regulation of apoptosis and autophagy, given its relevance for cell proliferation and survival. Both
wild-type Ras, as well as a series of tumor-associated oncogenic mutants will be used. This analysis promises to contribute to our knowledge of the broad cellular
consequences of Ras signalling in health and disease.
3) study the role of Voltage Dependent Anion Channels (VDACs) in regulating mitochondrial apoptosis and autophagy, since there are evidences of a functional
interaction between VDACs and the Ras-MEK signaling pathway. To gain insight into the molecular function and regulation of these channels, a proteomic approach
to map the protein interaction profile of selected VDACs will be implemented. The possible connection between mitochondrial outer membrane proteins, Ras and p53
will be studied, analysing whether VDACs can behave as receptors for these molecules, thus contributing to their recruitment to mitochondria, or if VDAC functions
are involved as downstream events in the mitochondrial responses induced by Ras and p53.
4) elucidate the mechanisms of apoptosis deregulation in cancer, focusing on oncocytic tumors, characterized by an abnormal amount of mitochondria due to mtDNA
mutations in complex I. It will be defined whether predisposition to tumorigenesis by a severe mitochondrial dysfunction may be related to activation of signalling
mechanisms leading to inhibition of cell death. In particular the involvement of mitochondrial biogenesis, autophagy and calcium homeostasis disturbance will be
determined. The function of the proto-oncogene receptor RET and its pro-apoptotic fragment, responsible for triggering cell death and promoting increased p53
levels, will also be studied, analysing in particular whether mitochondria are involved. Our preliminary studies have identified several proteins interacting with RET
pro-apoptotic fragment, including VDAC2 and AIP, which in turns binds Tom20: the functional consequences of this interaction will be further investigated.
5) investigate the role on mitochondrial Ca2+ and ATP of mitochondrial related proteins parkin, PINK1, DJ-1 and huntingtin (Htt), whose mutations are responsible
for Parkinson's and Huntington's disease. Special emphasis will be on their interaction with mitochondrial components, and on their modulation of apoptosis and
autophagy, two mechanisms of cell death probably involved in the selective loss of neuronal populations. In particular, for the PD-related proteins a possible
connection with the mitochondrial p53 pathway will be investigated. As for Htt, since emerging evidences suggest its interaction with the outer mitochondrial
membrane, probably through the PTP (which is still molecularly unknown) and/or its regulating proteins (VDAC, hexokinases, Cyclophilin etc.) efforts will be put on
identifying the nature of these interactions and their role on mitochondrial physiology.
In summary, this project addresses a number of relevant questions on the mitochondrial functions of crucial regulators of cell growth and proliferation (Ras, p53,
VDAC, RET), and aims to better define the molecular mechanisms coupling specific changes in mitochondrial physiology to fundamental cellular responses such as
apoptosis and autophagy. A detailed understanding of how these pathways are regulated could allow translation of this information into new approaches for the
treatment of a wide variety of diseases, in particular neurodegeneration and cancer
Autophagy modulation as target to develop novel pharmacological approaches for mitochondrial disorders
No full textThe overall goal of this project is to broaden our knowledge of the molecular interactions mediating the mitochondrial involvement
in autophagy with special attention to the possibility of designing novel pharmacological approaches to revert alterations
occurring in mitochondrial genetic disorders
PRRIITT Emilia Romagna Regional grant
No full textThis is a project on technology transfer in the biotech are
Mitochondria as target of redox-mediated cellular transformation and its regulation by effector proteins
No full textThe regulation of redox homeostasis is an important field of study in cancer research. Actually,
redox alterations is a mechanism that favours the clonal expansion of neoplastic cells. Thus, the
multi-step pathway of neoplastic progression often includes mutations of the genes encoding the
molecular machinery responsible of redox homeostasis.
In this project we will try to identify a “mitochondrial functional module” operating during redox
stress.
The possibility that mitochondria could act as targets of redox alterations during tumoral cell
transformation is an intriguing hypothesis supported by some considerations: mitochondria are the
major source and the most proximal targets of reactive oxygen species and they regulate stress
response and apoptosis, moreover agents perturbing mitochondrial Ca2+ homeostasis change the
susceptibility of the cells to apoptosis. However, the mechanism by which mitochondria participate
in the redox-dependent cellular neoplastic transformation is still unclear. The elucidation of these
signalling pathways is the focus of this grant application. The work will focus on the identification
of a “mitochondrial functional module” acting during redox stress. Much of a cell’s activity is in
fact organized as a module composed by interacting molecules. In particular we will try to identify
the molecules involved in mitochondrial Ca2+ homeostasis during redox changes (such as oxidant,
reducing or antioxidants treatments) and the relevance of this regulation for the modulation of
organelle function and cell fate.
To this end we will pursue the preliminary results already obtained on the effects of redox stress on
mitochondrial Ca2+ homeostasis, by investigating on the one hand their consequences on global
cellular Ca2+ homeostasis, on the other the role of these changes on the sensitivity to apoptosis
induced by different stimuli. We will then investigate the intracellular effectors of the redox
mediated signals focusing on proteins interacting with the mitochondria. We will also investigate,
by a variety of experimental approaches, the molecular mechanisms underlying the participation of
these organelles during redox stress in different tumors. Finally, when a mitochondrial functional
module will be identified, the expression profile of the proteins involved will be evaluated in
normal and neoplastic cells. In these studies, we will employ a variety of experimental approaches
that allow to image intracellular organelle structure, Ca2+ signals and effector proteins in living
cells, including novel techniques (e.g. use of specifically targeted recombinant probes). Thus, in this
grant proposal, we will combine the experimental approaches, the scientific know-how of the PI and
the fundamental support from different external collaborators that ensure unique experience and
expertise in all the fields, essentials for a new and young research unit. In conclusion, we believe
that the identification of the “mitochondrial functional module” acting during redox-dependent
neoplastic cellular transformation, with the elucidation of the intracellular targets and the molecules
involved, can potentially reveal new pharmacological targets and allow in vitro test of the efficacy
of pharmaceutical treatments to better identify the appropriate in vivo therapy
Involvement of mitochondrial proteins in autophagy: a possible link with mitochondrial disorders
No full textThe overall goal of this project is to broaden our knowledge of the molecular interactions
mediating the mitochondrial involvement in autophagy with special attention to the possibility of
designing novel pharmacological approaches to revert alterations occurring in mitochondrial
genetic disorders
Intracellular Ca2+ homeostasis and mitochondria in oligodendrocytes during oxidative stress and their role in apoptotic cell death
No full textThe application proposes a comprehensive and
detailed investigation of the effects of ROS on oligodendrocytes. With a combination of techniques,
we will study a variety of events, which may be linked to mitochondrial function/dysfunction; this
in oligodendrocytes in physiological conditions, or in conditions mimicking inflammation and
oxidative stress
Mitochondrial calcium signalling and organelle dysfunction in mitochondrial diseases: molecular determinants and regulatory mechanisms
No full textThe project addresses mitochondrial calcium (Ca2+) signalling and its regulation, with the aim of understanding how these events participate in the pathogenesis of mitochondrial disorders and can be targeted by novel drugs. Ca2+ is an important and complex messenger in the organelle, regulating processes as diverse as metabolic stimulation and pro-apoptotic structural alterations. In response to a large number of external stimuli, Ca2+ flows into the cell, and reaches mitochondria. Amplitude and timing of the Ca2+ flux (a sort of “Ca2+ signature”) determines an effect that can range from a number of cell activities (contraction, secretion, etc.) to its death. Dynamics and final outcome of mitochondrial Ca2+ signals depend on their 3D structure and other regulatory influences (kinases, redox state).
The project i) utilizes a variety of experimental approaches for identifying the mitochondrial Ca2+ transporters and associated proteins, thus obtaining novel drug targets ii) investigates the regulatory mechanism that may operate in physiological and pathological conditions, focusing on redox state iii) analyses the mitochondrial Ca2+ effects of a specific mitochondrial disease, the Leber’s hereditary Optic Neuropathy (LHON). Preliminary studies indicate that this is a very promising line of research
Mitochondria-associated membranes (MAMs) and pathologies
No full textDue to their typical filamentous architecture, both mitochondria and endoplasmic reticulum (ER) establish tight connections with other intracellular organelles, including nucleus and plasma-membrane, thereby modulating a wide range of cellular processes
Modulation of mitochondrial permeability transition pores in reperfusion injury: Mechanisms and therapeutic approaches
No full textIschemia/reperfusion injury is attracting continuous interest in science for two reasons: because it affects several clinical conditions and because it has been identified, albeit in broad terms, the molecular entity becoming activated by the reperfusion damage paradoxes. Indeed, calcium, oxygen-dependent oxidative stress and pH would activate conformational changes in the mitochondrial cristae embedded F1/FO ATP synthase, allowing the formation of pores in the inner mitochondrial membrane thus increasing its permeability. This is a key determinant for mitochondrial stress, cell death and tissue dysfunction. Targeting each of these factors has never contributed to improved clinical outcome of the patients affected by reperfusion damage; now, the focus on the PTP opening could represent the closest target to solve this pathway made by extensive cell death when the tissues become revascularized. In this review, we summarized last knowledge about the structure, the modulation and the therapeutic targeting of the PTP, focusing on ATP synthase and cardiac ischemia/reperfusion.From research conducted over the last 10 years, it emerges that c subunit of ATP synthase, and in general this multiprotein complex, has a key role in the PTP activity in the ischemic cardiac disease. Its expression and conformational changes inside mitochondria are the culprits of an exacerbated reperfusion injury both at in vitro level and in human studies. The possibility to target c subunit and PTP opening for future therapeutic approaches as adjuvants to conventional therapies is also discussed.imag
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