205 research outputs found
Constitutive Expression of Pluripotency-Associated Genes in Mesodermal Progenitor Cells (MPCs)
Background: We recently characterized a progenitor of mesodermal lineage (MPCs) from the human bone marrow of adults or umbilical cord blood. These cells are progenitors able to differentiate toward mesenchymal, endothelial and cardiomyogenic lineages. Here we present an extensive molecular characterization of MPCs, from bone marrow samples, including 39 genes involved in stem cell machinery, differentiation and cell cycle regulation. Methodology/Principal Findings: MPCs are cytofluorimetrically characterized and quantitative RT-PCR was performed to evaluate the gene expression profile, comparing it with MSCs and hESCs lines. Immunofluorescence and dot-blot analysis confirm qRT-PCR data. MPCs exhibit an increased expression of OCT4, NANOG, SALL4, FBX15, SPP1 and to a lesser extent c-MYC and KLF4, but lack LIN28 and SOX2. MPCs highly express SOX15. Conclusions/Significance: MPCs express many pluripotency-associated genes and show a peculiar Oct-4 molecular circuit. Understanding this unique molecular mechanism could lead to identifying MPCs as feasible, long telomeres, target cells for reprogramming with no up-regulation of the p53 pathway. Furthermore MPCs are easily and inexpensively harvested fro
Positron emission tomography response and minimal residual disease impact on progression-free survival in patients with follicular lymphoma. A subset analysis from the FOLL05 trial of the Fondazione Italiana Linfomi
The aim of the present study was to analyze the prognostic role of combined PET and BCL2/IGH analysis, performed at the EOT, in a subset study of the phase III trial FOLL05 (NCT00774826), in which patients with FL were randomized to R-CVP (rituximab plus cyclophosphamide, vincristine and prednisone), R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone) or R-FM (rituximab plus fludarabine and mitoxantrone).6 This study was conducted in compliance with the Declaration of Helsinki, was approved by the appropriate research ethics committee, and required each patient to provide written informed consent
Implications of KRAS mutations in acquired resistance to treatment in NSCLC
Rationale: KRAS is the most common and, simultaneously, the most ambiguous oncogene implicated in human cancer. Despite KRAS mutations were identified in Non Small Cell Lung Cancers (NSCLCs) more than 20 years ago, selective and specific inhibitors aimed at directly abrogating KRAS activity are not yet available. Nevertheless, many therapeutic approaches have been developed potentially useful to treat NSCLC patients mutated for KRAS and refractory to both standard chemotherapy and targeted therapies.
The focus of this review will be to provide an overview of the network related to the intricate molecular KRAS pathways, stressing on preclinical and clinical studies that investigate the predictive value of KRAS mutations in NSCLC patients.
Materials and Methods: A bibliographic search of the Medline database was conducted for articles published in English, with the keywords KRAS, KRAS mutations in non-small cell lung cancer, KRAS and tumorigenesis, KRAS and TKIs, KRAS and chemotherapy, KRAS and monoclonal antibody, KRAS and immunotherapy, KRAS and drugs, KRAS and drug resistance
Tympanic Membrane Collagen Expression by Dynamically Cultured Human Mesenchymal Stromal Cell/Star-Branched Poly(ε-Caprolactone) Nonwoven Constructs
The tympanic membrane (TM) primes the sound transmission mechanism due to special
fibrous layers mainly of collagens II, III, and IV as a product of TM fibroblasts, while type I is less
represented. In this study, human mesenchymal stromal cells (hMSCs) were cultured on star-branched
poly("-caprolactone) (*PCL)-based nonwovens using a TM bioreactor and proper dierentiating
factors to induce the expression of the TM collagen types. The cell cultures were carried out for
one week under static and dynamic conditions. Reverse transcriptase-polymerase chain reaction
(RT-PCR) and immunohistochemistry (IHC) were used to assess collagen expression. A Finite
Element Model was applied to calculate the stress distribution on the scaolds under dynamic
culture. Nanohydroxyapatite (HA) was used as a filler to change density and tensile strength of *PCL
scaolds. In dynamically cultured *PCL constructs, fibroblast surface marker was overexpressed, and
collagen type II was revealed via IHC. Collagen types I, III and IV were also detected. Von Mises
stress maps showed that during the bioreactor motion, the maximum stress in *PCL was double
that in HA/*PCL scaolds. By using a *PCL nonwoven scaold, with suitable physico-mechanical
properties, an oscillatory culture, and proper dierentiative factors, hMSCs were committed into
fibroblast lineage-producing TM-like collagens
Piezoelectric Signals in Vascularized Bone Regeneration
The demand for bone substitutes is increasing in Western countries. Bone graft substitutes aim to provide reconstructive surgeons with off-the-shelf alternatives to the natural bone taken from humans or animal species. Under the tissue engineering paradigm, biomaterial scaffolds can be designed by incorporating bone stem cells to decrease the disadvantages of traditional tissue grafts. However, the effective clinical application of tissue-engineered bone is limited by insufficient neovascularization. As bone is a highly vascularized tissue, new strategies to promote both osteogenesis and vasculogenesis within the scaffolds need to be considered for a successful regeneration. It has been demonstrated that bone and blood vases are piezoelectric, namely, electric signals are locally produced upon mechanical stimulation of these tissues. The specific effects of electric charge generation on different cells are not fully understood, but a substantial amount of evidence has suggested their functional and physiological roles. This review summarizes the special contribution of piezoelectricity as a stimulatory signal for bone and vascular tissue regeneration, including osteogenesis, angiogenesis, vascular repair, and tissue engineering, by considering different stem cell sources entailed with osteogenic and angiogenic potential, aimed at collecting the key findings that may enable the development of successful vascularized bone replacements useful in orthopedic and otologic surgery
Growing bone tissue-engineered niches with graded osteogenicity: an in vitro method for biomimetic construct assembly
The traditional bone tissue-engineering approach exploits mesenchymal stem cells ( MSCs) to be seeded once only on three-dimensional (3D) scaffolds, hence, differentiated for a certain period of time and resulting in a homogeneous osteoblast population at the endpoint. However, after achieving terminal osteodifferentiation, cell viability is usually markedly compromised. On the other hand, naturally occurring osteogenesis results from the coexistence of MSC progenies at distinct differentiative stages in the same microenvironment. This diversification also enables long-term viability of the mature tissue. We report an easy and tunable in vitro method to engineer simple osteogenic cell niches in a biomimetic fashion. The niches were grown via periodic reseeding of undifferentiated MSCs on MSC/scaffold constructs, the latter undergoing osteogenic commitment. Timefractioning of the seeded cell number during differentiation time of the constructs allowed graded osteogenic cell populations to be grown together on the same scaffolds (i.e., not only terminally differentiated osteoblasts). In such cell-dynamic systems, the overall differentiative stage of the constructs could also be tuned by varying the cell density seeded at each inoculation. In this way, we generated two different biomimetic niche models able to host good reservoirs of preosteoblasts and other osteoprogenitors after 21 culture days. At that time, the niche type resulting in 40.8% of immature osteogenic progenies and only 59.2% of mature osteoblasts showed a calcium content comparable to the constructs obtained with the traditional culture method (i.e., 100.03 – 29.30 vs. 78.51 – 28.50 pg/cell, respectively; p = not significant), the latter colonized only by fully differentiated osteoblasts showing exhausted viability. This assembly method for tissue-engineered constructs enabled a set of important parameters, such as viability, colonization, and osteogenic yield of the MSCs to be balanced on 3D scaffolds, thus achieving biomimetic in vitro models with graded osteogenicity, which are more complex and reliable than those currently used by tissue engineers
Evaluation of Haematological and Immunological Parameters of the ASFV Lv17/WB/Rie1 Strain and Its Derived Mutant Lv17/WB/Rie1/d110-11L against ASFV Challenge Infection in Domestic Pigs
African swine fever virus (ASFV) is the etiological agent of a haemorrhagic disease that threatens the global pig industry. There is an urgency to develop a safe and efficient vaccine, but the knowledge of the immune–pathogenetic mechanisms behind ASFV infection is still very limited. In this paper, we evaluated the haematological and immunological parameters of domestic pigs vaccinated with the ASFV Lv17/WB/Rie1 strain or its derived mutant Lv17/WB/Rie1/d110-11L and then challenged with virulent Armenia/07 ASFV. Circulating levels of C-reactive protein (CRP), 13 key cytokines and 11 haematological parameters were evaluated throughout the study. Lv17/WB/Rie1 triggered an inflammatory response, with increased levels of CRP and pro-inflammatory cytokines, and induced lymphopenia, thrombocytopenia and a decline in red blood cell (RBC) parameters, although this was transitory. Lv17/WB/Rie1/d110-11L triggered only transitory thrombocytopenia and a mild inflammatory reaction, with no increase in serum levels of pro-inflammatory cytokines, but it raised IL-1Ra levels. Both strains counteracted several adverse reactions elicited by virulent challenge, like thrombocytopenia, a decline in RBC parameters, and inflammation. Within this paper, we provided a deep portrayal of the impact of diverse ASFV strains on the domestic pig’s immune system. A better understanding of these immune–pathological mechanisms would help to design suitable vaccines against this disease
Development of tissue-engineered constructs for ossicular chain replacement
Ossicular chain (OC) is the bony part of middle ear dedicated to sound transmission. Chronic inflammations, infections and traumas occurring in the lifespan result in a set of severe diseases known as “conductive hearing loss”. To recover an acceptable hearing threshold, the damaged OC have to be surgically replaced with artificial prostheses. However, despite many efforts aimed at fabricating optimal replacements, all the synthetic prostheses are subject to extrusion, i.e., a type of rejection due to lack of biointegration. For these reasons, it is necessary to envision novel strategies for the OC substitution. In recent years, we have proposed an approach for OC reconstruction based on tissue engineering (TE), in which mesenchymal stromal cells (MSCs) are cultured under osteogenic differentiation regimen on bioresorbable 3D scaffolds up to obtain new bone substitutes with appropriate shape and dimensions (Danti et al., 2009; Danti et al., 2010). In this study, human MSCs were osteo-differentiated on different types of OC scaffolds fabricated in our laboratories. TE constructs were analyzed via biochemical assays, molecular biology and histo-morphological methods. An extensive analysis on native ossicles was performed to compare the results obtained in the constructs with the mature tissues. The results showed that the cells were viable, colonized the scaffolds and produced extracellular matrix molecules at intra- and extra-cellular level. MSC differentiation towards the osteogenic lineage was demonstrated by the production of mineralized matrix and specific osteogenic markers. Moreover, we assessed that all the investigated molecules were also expressed in the native tissues, even if at different expression levels, indicating that it was obtained a preliminary step for the creation of TE constructs to be employed, in perspective, as OC substitutes in the otologic surgery
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