Biomedical subjects

Sergio Giunta

Publications and source records attributed to Sergio Giunta.

10 recordsLinked to original sources

PubMed2006

Is inflammaging an auto[innate]immunity subclinical syndrome?

The low-grade, chronic, systemic inflammatory state that characterizes the aging process (inflammaging) results from late evolutive-based expression of the innate immune system. Inflammaging is characterized by the complex set of five conditions which can be described as 1. low-grade, 2. controlled, 3. asymptomatic, 4. chronic, 5. systemic, inflammatory state, and fits with the antagonistic pleiotropy theory on the evolution of aging postulating that senescence is the late deleterious effect of genes (pro-inflammatory versus anti-inflammatory) that are beneficial in early life. Evolutionary programming of the innate immune system may act via selection on these genetic traits. Here I propose that the already acquired knowledge in this field may pave the way to a new chapter in the pathophysiology of autoimmunity: the auto-innate-immunity syndromes. Indeed, differently from the well known chapter of conventional autoimmune diseases and syndromes where the main actor is the adaptive immunity, inflammaging may constitute the subclinical paradigm of a new chapter of autoimmunity, namely that arising from an autoimmune inflammatory response of the innate-immune-system, an old actor of immunity and yet a new actor of autoimmunity, also acting as a major determinant of elderly frailty and age-associated diseases.

Journal Article↗

PubMed2006

Inflammaging and anti-inflammaging: a systemic perspective on aging and longevity emerged from studies in humans.

A large part of the aging phenotype, including immunosenescence, is explained by an imbalance between inflammatory and anti-inflammatory networks, which results in the low grade chronic pro-inflammatory status we proposed to call inflammaging. Within this perspective, healthy aging and longevity are likely the result not only of a lower propensity to mount inflammatory responses but also of efficient anti-inflammatory networks, which in normal aging fail to fully neutralize the inflammatory processes consequent to the lifelong antigenic burden and exposure to damaging agents. Such a global imbalance can be a major driving force for frailty and common age-related pathologies, and should be addressed and studied within an evolutionary-based systems biology perspective. Evidence in favor of this conceptualization largely derives from studies in humans. We thus propose that inflammaging can be flanked by anti-inflammaging as major determinants not only of immunosenescence but eventually of global aging and longevity.

Aging↗

PubMed2006

Transmission in vitro of hepatitis C virus from persistently infected human B-cells to hepatoma cells by cell-to-cell contact.

Virus cell-to-cell spread has been reported for many different viruses and may contribute to pathogenesis of viral disease. The role played by cell-to-cell contact in hepatitis C virus (HCV) transmission was studied in vitro by cell co-cultivation experiments. A human lymphoblastoid B-cell line, infected persistently with HCV in vitro (TO.FE(HCV)), was used as HCV donor [Serafino et al., 2003]; recipient cells were the human hepatoma HepG2 cell line. Both cell types were co-cultured for 48 hr to allow the cell-to-cell contacts. The hepatoma HepG2 cells are not permissive to free-virus infection, but they were infected successfully using TO.FE(HCV) cells as source of virus. The kinetics of viral RNA synthesis and the percentage of infected cells were compared in cell-mediated-and cell-free-viral infection. After co-cultivation, a consistent proportion of hepatoma cells replicated HCV and stably expressed viral antigens. Virus produced was infectious as demonstrated by the ability to reinfect fresh B-cells. This cell model shows that permissiveness to HCV infection can be achieved in vitro in non-permissive hepatoma cells by direct cell-to-cell contacts with infected human B-cells. This mechanism of virus spread may also play a pathogenic role in vivo.

B-Lymphocytes↗

PubMed2004

Transferrin neutralization of amyloid beta 25-35 cytotoxicity.

BACKGROUND: Fibrillar aggregates of amyloid beta 25-35 (Abeta(25-35)) form rapidly in vitro able to lyse human red blood cells (RBCs). Human sera, albumin, and apolipoprotein E (ApoE) each limit fibrillation and cytotoxicity. Potentially, these substances protect neurons from Abeta(1-40/42) aggregates. Transferrin (TF) is investigated in this study. METHODS: The Mattson red blood cells model was employed to determine whether co-incubation of transferrin and Abeta(25-35) prevented lysis. The formation of fibrillar Abeta(25-35) in the presence of transferrin was investigated using Congo red staining and spectrophotometric studies. RESULTS: We found that incubation of 20 muM Abeta(25-35) with physiologic levels of transferrin prevented red blood cells lysis and the formation of macro-aggregates. CONCLUSIONS: These in vitro results suggest that transferrin may limit fibrillar beta amyloid formation in vivo and cytotoxicity.

Adolescent↗

PubMed2003

Apolipoprotein E expression in localized prostate cancers.

Although prostate cancer has become the most common solid tumor diagnosed in men and the second leading cause of death due to malignancy, the progression of the disease is still somewhat unpredictable, until it becomes locally advanced or metastatic. The clinical problem to distinguish between dormant and progressive cancers is essential to patient care, as surgical and medical therapies have significant risk of morbidity and disability. Multiple gene expression in prostate cancer was surveyed by differential display cloning between the undifferentiated hormone refractory human prostate cancer cell line PC-3 (highly tumorigenic in nude mice) the hormone responsive LNCaP cell line (weakly tumorigenic in nude mice), and the poorly differentiated DU-145 cell line (moderately tumorigenic). ApoE mRNA was found to be highly expressed only in PC-3 cell-line. We further examined its protein expression by immunohistochemistry in 20 prostatectomy specimens and an association between Gleason score for each sample and ApoE expression was determined. ApoE expression correlates directly with the Gleason score in tissue sections, hormone independence as well as local and distant invasiveness. Prostatic intraepithelial neoplasias (PINs) adjacent to clinically manifested cancer were positive whereas more distant PINs were negative for ApoE. ApoE may represent a marker of more aggressive cells in human prostate cancers.

Aged↗

PubMed2002

Albumin protects human red blood cells against Abeta25-35-induced lysis more effectively than ApoE.

Inhibition of the lysis of human red blood cells (RBCs) exposed to amyloid peptide Abeta25-35 is an model for screening natural and synthetic substances potentially protective against amyloid damage. In this system, human serum and a component, namely apolipoprotein E (apoE), completely prevent RBC lysis. This report demonstrates that albumin, another serum component, is 8-fold more protective: a concentration of 12.5 microg/ml protects RBCs against 20 microM-Abeta25-35, and prevents the formation of fibrillar Abeta25-35 aggregates stainable by Congo Red. The biological relevance of these findings is suggested by the following: (1) a large fraction ( approximately 90%) of circulating Abeta1-42 is bound to albumin; (2) albumin immunoreactivity is present in brain amyloid plaques; and (3) incubation of Abeta with albumin rapidly decreases detectable levels of free Abeta suggesting epitope masking. The results add new and important functional consequences to the amyloid-albumin relationship and imply that experimental systems investigating Abeta cytotoxicity should consider the protective interaction of albumin.

Albumins↗

PubMed2002

Is there a future for clinical laboratories? Experience in the Marche Region, Italy.

The government of the Marche Region has approved an Act called the "Regional Health Plan" establishing rules for the organization and development of healthcare. The main aim of the general plan is to rationalize the activities of medical laboratories first by making up an inventory of existing facilities and tests performed, and by classifying laboratories on the basis of their specialization and the complexity of tests that they perform.Moreover, the possible role of point-of-care testing and the need for clinical advice by laboratory professionals has also been debated.

Clinical Laboratory Techniques↗

PubMed2002

Beta-amyloid fragment 25-35 selectively damages platelets from patients with Alzheimer's disease.

In order to analyze the metabolic response of AD patient platelets to beta-amyloid, we have carried out fluorimetric measurements of intracellular calcium and an ultrastructural survey of platelets exposed to the beta-amyloid active fragment 25-35 (betaA(25-35)). Since it is not possible to analyze directly the damaged neurons in AD, the study of peripheral blood cells, especially platelets, may be of great value for the investigation of the toxic effects of beta-amyloid on AD neuronal cells.

Alzheimer Disease↗

PubMed2002

In vitro apolipoprotein E protects human red blood cells against lysis induced by amyloid-beta (AP) fragment 25-35.

Mattson et al. (9) demonstrated lysis of human red blood cells (RBC) exposed to amyloid peptide Abeta(25-35), a new experimental model for amyloid-beta toxicity. Lysis resulted from poreformation in the RBC membranes and was completely prevented by concurrent exposure to Congo red We demonstrate that human serum, purified ApoE from human plasma, and recombinant isoforms of ApoE neutralize the Abeta(25-35) cytotoxicity: the E2 and E4 isoforms were marginally more effective than E3. Second, we demonstrate that Abeta(25-35) forms fibrils in the reaction mixtures using electron-microscopy. Together these results suggest that the RBC model might be useful in preliminary identification of natural and synthetic substances able to protect against amyloid-beta cytotoxic effects due to fibrillar Abeta(25-35). Such compounds would be candidate molecules for testing in neuronal systems.

Adult↗

PubMedDate not supplied

Is the simian virus SV40 associated with idiopathic focal segmental glomerulosclerosis in humans?

BACKGROUND: Glomerulosclerosis was reported in mice transgenic for the simian polyomavirus SV40 early region that contains the transforming sequences encoding the SV40 large T-antigen (TAG). This was discovered when an SV40 epidemic occurred following the use of contaminated polio vaccines during 1955-1963, and led to investigations that showed an association between SV40 infection and tumors in humans. We investigated the possible association of SV40 infection and idiopathic focal segmental glomerulosclerosis (FSGS). METHODS: The study was performed in 17 Bouin-fixed, paraffin-embedded renal biopsies from FSGS patients and 10 matched biopsies from patients with IgA glomerulonephritis; all patients had undergone polio vaccination in the early 1960s. Extracted DNA was polymerase chain reaction (PCR) amplified using SV.for3/SV.rev primers and GabE1/GabE2 primers; both sets of primers map in the region of SV40 TAG sequences, and amplify a fragment of respectively 105-bp and 135-bp. The biopsies considered were those in which the DNA was sufficiently intact to allow amplification of a fragment of 102-bp of the ApoE gene. RESULTS: Three FSGS and none of the IgA biopsies were positive for the SV.for3/SV.rev fragment. Conversely, amplification with GabE1/GabE2 primers did not lead to any specific product in either the IgA or FSGS biopsies. Restriction fragment length polymorphism and sequencing analyses revealed that the positive results obtained with the SV.for3/SV.rev primers were due to amplicons generated by multiple dimerization of forward and reverse primers. CONCLUSIONS: With the limited number of patients investigated, this study excludes the hypothesis that SV40 is associated with idiopathic FSGS.

Antigens, Polyomavirus Transforming↗