DSpace Collection:
https://hdl.handle.net/10171/18869
2024-03-29T15:12:03ZGhrelin Reduces TNF-α-Induced Human Hepatocyte Apoptosis, Autophagy, and Pyroptosis: Role in Obesity-Associated NAFLD
https://hdl.handle.net/10171/68997
Title: Ghrelin Reduces TNF-α-Induced Human Hepatocyte Apoptosis, Autophagy, and Pyroptosis: Role in Obesity-Associated NAFLD
Abstract: Context: Human obesity is associated with increased circulating TNF-α, a proinflammatory cytokine that induces hepatocyte cell death.
Objective: The potential beneficial effects of acylated and desacyl ghrelin in the progression of nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis in obesity via the inhibition of TNF-α-induced hepatocyte apoptosis, autophagic cell death, and pyroptosis were investigated.
Design, settings, and participants: Plasma ghrelin isoforms and TNF-α were measured in 158 participants, and hepatocyte cell death was evaluated in liver biopsies from 76 patients with morbid obesity undergoing bariatric surgery with available liver echography and pathology analysis. The effect of acylated and desacyl ghrelin on basal and TNF-α-induced cell death was determined in vitro in human HepG2 hepatocytes.
Results: Circulating TNF-α and the acylated/desacyl ghrelin ratio were increased, whereas desacyl ghrelin levels were decreased in patients with obesity and NAFLD. Six months after bariatric surgery, decreased acylated/desacyl ghrelin levels, and improved hepatic function were found. Patients with obesity and type 2 diabetes showed increased hepatic ghrelin O-acyltransferase transcripts as well as an increased hepatic apoptosis, pyroptosis, and compromised autophagy. In HepG2 hepatocytes, acylated and desacyl ghrelin treatment reduced TNF-α-induced apoptosis, evidenced by lower caspase-8 and caspase-3 cleavage, as well as TUNEL-positive cells and pyroptosis, revealed by decreased caspase-1 activation and lower high-mobility group box 1 expression. Moreover, acylated ghrelin suppressed TNF-α-activated hepatocyte autophagy, as evidenced by a decreased LC3B-II/I ratio and increased p62 accumulation via AMPK/mTOR.
Conclusions: Ghrelin constitutes a protective factor against hepatocyte cell death. The increased acylated/desacyl ghrelin ratio in patients with obesity and NAFLD might constitute a compensatory mechanism to overcome TNF-α-induced hepatocyte apoptosis, autophagy, and pyroptosis.2019-01-01T00:00:00ZPrediction of effective humoral response to SARS‑CoV‑2 vaccines in healthy subjects by cortical thickness of post‑vaccination reactive lymphadenopathy
https://hdl.handle.net/10171/68382
Title: Prediction of effective humoral response to SARS‑CoV‑2 vaccines in healthy subjects by cortical thickness of post‑vaccination reactive lymphadenopathy
Abstract: Purpose To study the association between ultrasound cortical thickness in reactive post-vaccination lymph nodes and the
elicited humoral response and to evaluate the performance of cortical thickness as a predictor of vaccine effectiveness in
patients with and without a previous history of COVID-19 infection.
Methods A total of 156 healthy volunteers were recruited and followed prospectively after receiving two COVID-19 vaccination
doses using different protocols. Within a week after receiving the second dose, an axillary ultrasound of the ipsilateral
vaccinated arm was performed, and serial post-vaccination serologic tests (PVST) were collected. Maximum cortical
thickness was chosen as a nodal feature to analyze association with humoral immunity. Total antibodies quantified during
consecutive PVST in previously-infected patients and in coronavirus-naïve volunteers were compared (Mann–Whitney U
test). The association between hyperplastic-reactive lymph nodes and effective humoral response was studied (odds ratio).
The performance of cortical thickness in detecting vaccination effectiveness was evaluated (area under the ROC curve).
Results Significantly higher values for total antibodies were observed in volunteers with a previous history of COVID-19
infection (p < 0.001). The odds ratio associating immunized coronavirus-naïve volunteers after 90 and 180 days of the second
dose with a cortical thickness ≥ 3 mm was statistically significant (95% CI 1.52–6.97 and 95% CI 1.47–7.29, respectively).
The best AUC result was obtained comparing antibody secretion of coronavirus-naïve volunteers at 180 days (0.738).
Conclusions Ultrasound cortical thickness of reactive lymph nodes in coronavirus-naïve patients may reflect antibody production
and a long-term effective humoral response elicited by vaccination.
Clinical relevance statement In coronavirus-naïve patients, ultrasound cortical thickness of post-vaccination reactive lymphadenopathy
shows a positive association with protective antibody titers against SARS-CoV-2, especially in the long term,
providing new insights into previous publications.2023-01-01T00:00:00ZImpact of ultra-low temperature long-term storage on the preanalytical variability of twentyone common biochemical analytes
https://hdl.handle.net/10171/68378
Title: Impact of ultra-low temperature long-term storage on the preanalytical variability of twentyone common biochemical analytes
Abstract: Objectives: Retrospective studies frequently assume analytes
long-term stability at ultra-low temperatures. However,
these storage conditions, common among biobanks
and research, may increase the preanalytical variability,
adding a potential uncertainty to the measurements. This
study is aimed to evaluate long-term storage stability of
different analytes at <−70 °C and to assess its impact on the
reference change value formula.
Methods: Twenty-one analytes commonly measured in
clinical laboratories were quantified in 60 serum samples.
Samples were immediately aliquoted and frozen at <−70 °C,
and reanalyzed after 11 ± 3.9 years of storage. A change in
concentration after storage was considered relevant if the
percent deviation from the baseline measurement was
significant and higher than the analytical performance
specifications.
Results: Preanalytical variability (CVP) due to storage,
determined by the percentage deviation, showed a
noticeable dispersion. Changes were relevant for alanine
aminotransferase, creatinine, glucose, magnesium, potassium,
sodium, total bilirubin and urate. No significant
differences were found in aspartate aminotransferase,
calcium, carcinoembryonic antigen, cholesterol, C-reactive
protein, direct bilirubin, free thryroxine, gammaglutamyltransferase,
lactate dehydrogenase, prostatespecific
antigen, triglycerides, thyrotropin, and urea. As
nonnegligible, CVP must remain included in reference
change value formula, which was modified to consider
whether one or two samples were frozen.
Conclusions: After long-term storage at ultra-low temperatures,
there was a significant variation in some
analytes that should be considered. We propose that
reference change value formula should include the CVP
when analyzing samples stored in these conditions.2022-01-01T00:00:00ZComparison of six commercial serum exosome isolation methods suitable for clinical laboratories. Effect in cytokine analysis
https://hdl.handle.net/10171/68375
Title: Comparison of six commercial serum exosome isolation methods suitable for clinical laboratories. Effect in cytokine analysis
Abstract: Background: Exosomes are nanovesicles released by cells
that can be detected in blood. Exosomes contain several
molecules, such as cytokines that have potential utility
as disease biomarkers. The aim of the present work is to
compare six different commercial kits suitable for the
clinical laboratory in relation to the efficiency and purity
of exosome isolation, and their effect in subsequent
cytokines analysis.
Methods: Serum exosomes were obtained from 10
volunteers
using six commercial kits: exoEasy, ExoQuick,
Exo-spin, ME kit, ExoQuick Plus and Exo-Flow. Exosome
concentrations and size distributions were quantified by
nanoparticle tracking analysis. Exosome markers CD63,
CD9 and TSG101 were determined by Western blot. ApoB
and albumin were measured using nephelometry. S100A9,
CXCL5 and CXCL12 were measured using a Luminex assay.
Results: The concentration of particles obtained between
different kits varied by a factor of 100. There was no correlation
in particle concentrations extracted between
different kits, except between ExoQuick and Exo-Flow.
The highest exosome purity was achieved with ExoQuick
Plus and exoEasy, while the lowest were achieved with
ME and ExoQuick. Albumin was present in all exosome
extracts analyzed and ApoB in all except those extracted
with Exo-Flow and ME. Cytokine detection varied depending
on the purification kit used and there was no correlation
in cytokine concentrations between samples obtained
with different kits.
Conclusions: Both the sample and the type of commercial
kit used affect the efficiency and purity of exosome isolation.
In addition, the exosome purification method deeply
affects the capability to detect and quantify cytokines.2019-01-01T00:00:00Z