Propiedades de la membrana y viabilidad celular: Importancia de la fluidez

Numerosos estudios sugieren que las vías de señalización y por ende la funcionalidad celular dependen de la organización de dominios en la membrana, que a su vez está determinada por la composición lipídica de la misma. El colesterol (Col) interviene en la regulación de la fluidez al particionar de manera selectiva en dominios específicos de la membrana, y se ha demostrado que su homeostasis es crucial para la viabilidad celular. Además, se sabe que el exceso de Col puede resultar citotóxico. Este lípido no puede ser degradado o utilizado como combustible, por lo que su exceso debe ser removido por aceptores o almacenado en compartimientos intracelulares. Las lipoproteínas de alta densidad (HDL) y en particular su apolipoproteína mayoritaria, la apoA-I, cumplen un rol fundamental en el transporte reverso del Col, que consiste en transportar el excedente desde los tejidos periféricos hacia el hígado para su eliminación en forma de sales biliares, o para ser redirigido desde los hepatocitos hacia los tejidos esteroidogénicos

Propiedades de la membrana y viabilidad celular: importancia de la fluidez

Numerosos estudios sugieren que las vías de señalización y por ende la funcionalidad celular dependen de la organización de dominios en la membrana, que a su vez está determinada por la composición lipídica de la misma. El colesterol (Col) interviene en la regulación de la fluidez al particionar de manera selectiva en dominios específicos de la membrana, y se ha demostrado que su homeostasis es crucial para la viabilidad celular. Además, se sabe que el exceso de Col puede resultar citotóxico. Este lípido no puede ser degradado o utilizado como combustible, por lo que su exceso debe ser removido por aceptores o almacenado en compartimientos intracelulares. Las lipoproteínas de alta densidad (HDL) y en particular su apolipoproteína mayoritaria, la apoA-I, cumplen un rol fundamental en el transporte reverso del Col, que consiste en transportar el excedente desde los tejidos periféricos hacia el hígado para su eliminación en forma de sales biliares, o para ser redirigido desde los hepatocitos hacia los tejidos esteroidogénicos.Universidad Nacional de La Plat

Association between progesterone concentration and endometrial gene expression in dairy cows

The objective of this study was to evaluate the association between progesterone concentration on Days 4 and 9 of the estrus cycle and endometrial transcriptome at Day 9 in lactating grazing dairy cows. Blood samples were obtained on Days 0, 4, and 9 for progesterone measurement by chemiluminescence. Cows were assigned to one of the following groups (n = 3 per group): cows with low physiological progesterone on Day 4, cows in anestrous, cows with high physiological progesterone on Day 4, and superovulated cows. Endometrial biopsy samples were obtained on Day 9 for RNA sequencing. Quality control and determination of differentially expressed genes (false discovery rate <0.05) were determined using the edgeR package for R software. We identified 3,042 differentially expressed genes among the 4 groups. Cows having high physiological progesterone and superovulated cows showed high similarities and clustered apart from those in anestrus or having low physiological progesterone. Functional analysis using Database for Annotation, Visualization, and Integrated Discovery revealed that endometrial genes upregulated by low progesterone concentration are enriched genes involved in the immune system and inflammatory response. Conversely, cows with high physiological progesterone concentration presented an endometrial transcriptome with similarities to cows with good genetic merit for fertility, showing upregulation of genes related to uterine relaxation–contraction, focal adhesion, GnRH signaling pathway, and epidermal growth factor–like related terms, suggesting a favorable embryo environment. In conclusion, our results support the concept that there is a threshold of progesterone concentration at the beginning of the luteal phase associated with endometrial expression of critical genes involved in the preparation of the uterine environment for embryo implantation.Facultad de Ciencias Veterinaria

Diagnosis of embryonic loss and very early detection of non-pregnant cows by Doppler ultrasound Summary

Los productores lecheros enfrentan grandes desafíos que amenazan los resultados económicos del sistema, siendo la eficiencia reproductiva uno de los principales factores para tener en cuenta. Para alcanzar el objetivo de un parto por año/vaca y mantener así la rentabilidad del tambo, es primordial lograr la mayor cantidad de vacas inseminadas en el menor tiempo posible. Tanto las vacas que fallan en la concepción como aquellas que padecen de pérdidas embrionarias son en las que hay que focalizar los esfuerzos para detectarlas e inseminarlas nuevamente en forma rápida y de esta manera acortar el intervalo de tiempo entre el parto y la nueva concepción. Los objetivos de este estudio fueron 1) validar la ultrasonografía (USG) Doppler para la detección de vacas no gestantes a los 19-20 d post-IA y 2) determinar las pérdidas embrionarias entre los 19 y 34 días de gestación en vacas de tambo. Al día 19-20 post IA, se evaluó la perfusión sanguínea del cuerpo lúteo (CL-FS) por USG Doppler en modo color y en modo power en todas las vacas ingresadas en el estudio (n= 131). En la misma visita también se evaluó la ecotextura uterina mediante USG en modo B para determinar si dicha evaluación podría aportar datos que mejoraran el diagnóstico de no-preñez al día 19-20 post IA. Además, se obtuvieron muestras de sangre para la medición de progesterona (P4) y para determinar la expresión de genes relacionados con la gestación temprana (genes estimulados por el interferón tau; ISG) mediante PCR en tiempo real. Finalmente se realizó el diagnóstico de gestación a los 33-34 d post-IA mediante USG en modo B. El modo Color de la USG Doppler mostró alta precisión para detectar vacuidad al pie de la vaca usando la categoría ≤1 (escala 0-4) en todos los cuadrantes del CL. La tasa de no-preñez diagnosticada USG Doppler a los 19-20 d post-IA fue de 38,9 % (51/131), mientras que el 62,6 % (82/131)Dairy producers face important challenges threatening the system's financial results, making reproductive efficiency one of the most important. To achieve the goal of a calving per cow/year and thus maintain the profitability of the dairy, it is essential to achieve a high number of inseminated cows in the shortest possible time. Cows that fail to conceive and those that suffer embryo loss are the ones that we should focus on detecting and inseminating them promptly, shortening the time interval between calving and new conception. The objectives of this study were 1) to assess the ultrasound (USG) Doppler for the detection of non-pregnant cows at 19- 20 d post-IA and 2) to determine the embryo loss between 19-34 d of pregnancy in dairy cows. In all cows included in the study (n=131), the corpus luteum (CL-FS) perfusion was assessed by the color and the power mode of the Doppler USG. In addition, the uterine echotexture was evaluated by USG mode B to predict if, including this information, the precision of the USG Doppler at 19-20 d post AI improved. At the same time, blood samples were collected to measure progesterone (P4) and to determine the expression of genes related to early pregnancy (interferon-stimulated genes; ISG) by real-time PCR. Finally, the pregnancy diagnosis was performed at 33-36 d after IA using USG mode B. Color mode showed higher precision in detecting non-pregnant cows using category ≤1 (scale 0-4) in all CL quadrants. The non-pregnancy rate at 19-20 d post-AI was 38,9% (51/131) by CL-FS Doppler USG. In contrast, the non-pregnancy rate at 33-34d post-AI was 62,6 (82/131) by B-mode USG based on the lack of embryo visualization. The presence of a thick endometrial layer and the visualization of the uterine stratum vascular at 19-20 d post-AI was related to the non-pregnancy diagnosis at 33-34 d post-AI (p1ng/ml at 19-20 d post-AI, we detected that 28,1% of the cows potentially lost the pregnancy between 19-34 d. Doppler USG allowed the detection of non-pregnant cows between 19-20 d post-AI, and the additional B-mode ultrasound evaluation of the uterine echo structure improved the detection of non-pregnant cows. The early diagnosis using these techniques is a valuable and quick tool to be implemented in resynchronization protocols to minimize open days.Fil: Lorenti, N. S.. Practica Privada; ArgentinaFil: Madoz, Laura Vanina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rearte, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; ArgentinaFil: Quintero Rodriguez, Luis Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; ArgentinaFil: Migliorisi, Ana Lorena. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; ArgentinaFil: Jaureguiberry, María. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; ArgentinaFil: Gabler, C.. Freie Universität Berlin; AlemaniaFil: Drillich, M.. University of Veterinary Medicine; AustriaFil: de la Sota, Rodolfo Luzbel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Teriogenología; Argentin

Human Apolipoprotein A-I-Derived Amyloid: Its Association with Atherosclerosis

Amyloidoses constitute a group of diseases in which soluble proteins aggregate and deposit extracellularly in tissues. Nonhereditary apolipoprotein A-I (apoA-I) amyloid is characterized by deposits of nonvariant protein in atherosclerotic arteries. Despite being common, little is known about the pathogenesis and significance of apoA-I deposition. In this work we investigated by fluorescence and biochemical approaches the impact of a cellular microenvironment associated with chronic inflammation on the folding and pro-amyloidogenic processing of apoA-I. Results showed that mildly acidic pH promotes misfolding, aggregation, and increased binding of apoA-I to extracellular matrix elements, thus favoring protein deposition as amyloid like-complexes. In addition, activated neutrophils and oxidative/proteolytic cleavage of the protein give rise to pro amyloidogenic products. We conclude that, even though apoA-I is not inherently amyloidogenic, it may produce non hereditary amyloidosis as a consequence of the pro-inflammatory microenvironment associated to atherogenesis

Genomic epidemiology of third-generation cephalosporin-resistant Escherichia coli from Argentinian pig and dairy farms reveals animal-specific patterns of co-resistance and resistance mechanisms

Control measures are being introduced globally to reduce the prevalence of antibiotic resistance (ABR) in bacteria on farms. However, little is known about the current prevalence and molecular ecology of ABR in bacterial species with the potential to be key opportunistic human pathogens, such as Escherichia coli, on South American farms. Working with 30 dairy cattle farms and 40 pig farms across two provinces in central-eastern Argentina, we report a comprehensive genomic analysis of third-generation cephalosporin-resistant (3GC-R) E. coli, which were recovered from 34.8% (cattle) and 47.8% (pigs) of samples from fecally contaminated sites. Phylogenetic analysis revealed substantial diversity suggestive of long-term horizontal and vertical transmission of 3GC-R mechanisms. CTX-M-15 and CTX-M-2 were more often produced by isolates from dairy farms, while CTX-M-8 and CMY-2 and co-carriage of amoxicillin/clavulanate resistance and florfenicol resistance were more common in isolates from pig farms. This suggests different selective pressures for antibiotic use in these two animal types. We identified the β-lactamase gene blaROB, which has previously only been reported in the family Pasteurellaceae, in 3GC-R E. coli. blaROB was found alongside a novel florfenicol resistance gene, ydhC, also mobilized from a pig pathogen as part of a new composite transposon. As the first comprehensive genomic survey of 3GC-R E. coli in Argentina, these data set a baseline from which to measure the effects of interventions aimed at reducing on-farm ABR and provide an opportunity to investigate the zoonotic transmission of resistant bacteria in this region

Occurrence of Norovirus, Rotavirus, Hepatitis a Virus, and Enterovirus in Berries in Argentina

Berries have been implicated as the probable vehicle of infection in multiple outbreaks of norovirus and hepatitis A virus (HAV). These foods often receive minimal or no processing and may be exposed to virus contamination at each stage of production. In an increasingly globalized world, berries have a wide distribution and can give rise to the spread of diseases in distant parts of the world. With the aim of describing the virological quality of the berries cultivated in Argentina, a total of 184 soft fruits of different varieties (strawberries, blueberries, raspberries, blackberries, currants, pomegranate arils, cassis, and elder) were collected during the periods 2016-2018 and 2020. Viral particles were eluted and concentrated by polyethylene glycol precipitation according to ISO 15216-2:2019 guidelines. Genome detection of norovirus (NoV) genogroups I (GI) and II (GII), HAV, rotavirus, and enterovirus was performed by real-time RT-PCR with TaqMan probes. Positive samples were amplified by conventional RT-PCR and the amplicons were purified and sequenced in both directions. Phylogenetic analysis was performed using the Neighbor-Joining method based on the evolutionary model Kimura-2-parameters. NoV GII.6 was detected in 1/184 (0.5%) of the soft fruits, corresponding to a raspberry sample obtained during the fall of 2017. No presence of other human enteric viruses was found in the other berries analyzed. The collected data are the first in Argentina in relation to the prevalence of enteric viruses in berries and is useful as reference data for a risk assessment of soft fruits as vehicles of foodborne pathogenic viruses.This work was supported by the National Agency for Scientific and Technical Promotion (PICT 2018-04224). J.M.O. and P.B. are members of the researcher career program of CONICET, Argentina. V.E.P. is a recipient of a CONICET fellowship.Peer reviewe