Estudios genéticos en Bacillus Thuringiensis : transformación, mutagénesis y clonado molecular

Fil: Rubinstein, Clara Patricia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Mouse models for V103I and I251L gain of function variants of the human MC4R display decreased adiposity but are not protected against a hypercaloric diet

Objective: The melanocortin 4 receptor (MC4R) is a G protein-coupled receptor that plays major roles in the central control of energy balance. Loss-of-function mutations of MC4R constitute the most common monogenic cause of early-onset extreme obesity in humans, whereas gain-offunction mutations appear to be protective. In particular, two relatively frequent alleles carrying the non-synonymous coding mutations V103I or I251L are associated with lower risks of obesity and type-2 diabetes. Although V103I and I251L MC4Rs showed more efficient signalling in transfected cells, their specific effects in live animals remain unexplored. Here, we investigated whether the introduction of V103I and I251L mutations into the mouse MC4R leads to a lean phenotype and provides protection against an obesogenic diet. Methods: Using CRISPR/Cas9, we generated two novel strains of mice carrying single-nucleotide mutations into the mouse Mc4r which are identical to those present in V103I and I251L MCR4 human alleles, and studied their phenotypic outcomes in mice fed with normal chow or a high-fat diet. In particular, we measured body weight progression, food intake and adiposity. In addition, we analysed glucose homeostasis through glucose and insulin tolerance tests. Results: We found that homozygous V103I females displayed shorter longitudinal length and decreased abdominal white fat, whereas homozygous I251L females were also shorter and leaner due to decreased weight in all white fat pads examined. Homozygous Mc4rV103I/V103I and Mc4rI251L/I251L mice of both sexes showed improved glucose homeostasis when challenged in a glucose tolerance test, whereas Mc4rI251L/I251L females showed improved responses to insulin. Despite being leaner and metabolically more efficient, V103I and I251L mutants fed with a hypercaloric diet increased their fasting glucose levels and adiposity similar to their wild-type littermates. Conclusions: Our results demonstrate that mice carrying V103I and I251L MC4R mutations displayed gain-of-function phenotypes that were more evident in females. However, hypermorphic MC4R mutants were as susceptible as their control littermates to the obesogenic and diabetogenic effects elicited by a long-term hypercaloric diet, highlighting the importance of healthy feeding habits even under favourable genetic conditions.Fil: Rojo, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Mccarthy, Clara Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Raingo, Jesica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. University of Michigan; Estados Unido

Selective disruption of dopamine D2 receptors in pituitary lactotropes increases body weight and adiposity in female mice

Prolactin, a pleiotropic hormone secreted by lactotropes, has reproductive and metabolic functions. Chronically elevated prolactin levels increase food intake, but in some hyperprolactinemic states such as in the global dopamine D2 receptor (D2R) knockout mouse, food intake is not increased. Here, we conduct a cell-specific genetic dissection study using conditional mutant mice that selectively lack D2Rs from pituitary lactotropes (lacDrd2KO) to evaluate the role of elevated prolactin levels without any confounding effect of central D2Rs on motor and reward mechanisms related to food intake. LacDrd2KO female mice exhibited chronic hyperprolactinemia, pituitary hyperplasia, and a preserved GH axis. In addition, lacDrd2KO female but not male mice evidenced increased food intake by three months of age and, from five months onwards their body weights were heavier. A marked increment in fat depots, adipocyte size, serum triglyceride and non-esterified fatty acid levels, and a decrease in lipolytic enzymes in adipose tissue were evidenced. Furthermore, lacDrd2KO female mice had glucose intolerance but a preserved response to insulin. In the hypothalamus Npy mRNA expression was increased, and Pomc and Ppo mRNA levels were unaltered (in contrast to results in global D2R knockout mouse). Thus, the orexigenic effect of prolactin, and its action on hypothalamic Npy expression were fully evidenced, leading to increased food intake and adiposity. Our results highlight the metabolic role of prolactin and illustrate the value of studying cell-specific mutant mice to disentangle patho-physiological mechanisms otherwise masked in null allele mutants or in animals treated with pervasive pharmacological agents.Fil: Pérez Millán, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Luque, Guillermina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Ramirez, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Noain, Daniela Maria Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Ornstein, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Becu, Damasia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Central Dopamine D2 Receptors Regulate Growth-HormoneDependent Body Growth and Pheromone Signaling to Conspecific Males

Competition between adult males for limited resources such as food and receptive females is shaped by the male pattern of pituitary growth hormone (GH) secretion that determines body size and the production of urinary pheromones involved in male-to-male aggression. In the brain, dopamine (DA) provides incentive salience to stimuli that predict the availability of food and sexual partners. Although the importance of the GH axis and central DA neurotransmission in social dominance and fitness is clearly appreciated, the two systems have always been studied unconnectedly. Here we conducted a cell-specific genetic dissection study in conditional mutant mice that selectively lack DA D2 receptors (D2R) from pituitary lactotropes (lacDrd2KO) or neurons (neuroDrd2KO). Whereas lacDrd2KO mice developed a normal GH axis, neuroDrd2KO mice displayed fewer somatotropes; reduced hypothalamic Ghrh expression, pituitary GH content, and serum IGF-I levels; and exhibited reduced body size and weight. As a consequence of a GH axis deficit, neuroDrd2KO adult males excreted low levels of major urinary proteins and their urine failed to promote aggression and territorial behavior in control male challengers, in contrast to the urine taken from control adult males. These findings reveal that central D2Rs mediate a euroendocrineexocrine cascade that controls the maturation of the GH axis and downstream signals that are critical for fitness, social dominance, and competition between adult males.Fil: Noain, Daniela Maria Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Pérez Millán, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Bello Gay, Estefania Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Luque, Guillermina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Casas Cordero, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Gelman, Diego Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Peper, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Isabel Garcia-tornadu. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Malcolm J Low. Michigan State University; Estados Unidos;Fil: Becu, Damasia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; Argentin

Design of whey protein nanostructures for incorporation and release of nutraceutical compounds in food

Whey proteins are widely used as nutritional and functional ingredients in formulated foods because they are relative inexpensive, generally recognized as safe (GRAS) ingredient and possess important biological, physical and chemical functionalities. Denaturation and aggregation behavior of these proteins is of particular relevance toward manufacture of novel nanostructures with a number of potential uses. When these processes are properly engineered and controlled, whey proteins may be formed into nanohydrogels, nanofibrils or nanotubes and be used as carrier of bioactive compounds. This review intends to discuss the latest understandings of nanoscale phenomena of whey protein denaturation and aggregation that may contribute for the design of protein nanostructures. Whey protein aggregation and gelation pathways under different processing and environmental conditions such as microwave heating, high voltage and moderate electrical fields, high pressure, temperature, pH and ionic strength were critically assessed. Moreover, several potential applications of nanohydrogels, nanofibrils and nanotubes for controlled release of nutraceutical compounds (e.g. probiotics, vitamins, antioxidants and peptides) were also included. Controlling the size of protein networks at nanoscale through application of different processing and environmental conditions can open perspectives for development of nanostructures with new or improved functionalities for incorporation and release of nutraceuticals in food matrices.Oscar L. Ramos, Ricardo N. Pereira and Clara Fuci~nos gratefully acknowledge their Post-Doctoral grants (SFRH/BPD/80766/2011, SFRH/BPD/ 81887/2011, and SFRH/BPD/87910/2012, respectively) to the Fundação para a Ciência e Tecnologia (FCT, Portugal). All authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project “BioEnv— Biotechnology and Bioengineering for a sustainable world”, REF. NORTE07-0124-FEDER-000048, co-funded by Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER

The tetraspanin Tspan15 is an essential subunit of an ADAM10 scissor complex

A disintegrin and metalloprotease 10 (ADAM10) is a transmembrane protein essential for embryonic development, and its dysregulation underlies disorders such as cancer, Alzheimer's disease, and inflammation. ADAM10 is a molecular scissor that proteolytically cleaves the extracellular region from >100 substrates, including Notch, amyloid precursor protein, cadherins, growth factors, and chemokines. ADAM10 has been recently proposed to function as six distinct scissors with different substrates, depending on its association with one of six regulatory tetraspanins, termed TspanC8s. However, it remains unclear to what degree ADAM10 function critically depends on a TspanC8 partner, and a lack of monoclonal antibodies specific for most TspanC8s has hindered investigation of this question. To address this knowledge gap, here we designed an immunogen to generate the first monoclonal antibodies targeting Tspan15, a model TspanC8. The immunogen was created in an ADAM10-knockout mouse cell line stably overexpressing human Tspan15, because we hypothesized that expression in this cell line would expose epitopes that are normally blocked by ADAM10. Following immunization of mice, this immunogen strategy generated four Tspan15 antibodies. Using these antibodies, we show that endogenous Tspan15 and ADAM10 co-localize on the cell surface, that ADAM10 is the principal Tspan15-interacting protein, that endogenous Tspan15 expression requires ADAM10 in cell lines and primary cells, and that a synthetic ADAM10/Tspan15 fusion protein is a functional scissor. Furthermore, two of the four antibodies impaired ADAM10/Tspan15 activity. These findings suggest that Tspan15 directly interacts with ADAM10 in a functional scissor complex

Breakthrough SARS-CoV-2 infections among patients with cancer following two and three doses of COVID-19 mRNA vaccines: a retrospective observational study from the COVID-19 and Cancer Consortium

BACKGROUND: Breakthrough SARS-CoV-2 infections following vaccination against COVID-19 are of international concern. Patients with cancer have been observed to have worse outcomes associated with COVID-19 during the pandemic. We sought to evaluate the clinical characteristics and outcomes of patients with cancer who developed breakthrough SARS-CoV-2 infections after 2 or 3 doses of mRNA vaccines. METHODS: We evaluated the clinical characteristics of patients with cancer who developed breakthrough infections using data from the multi-institutional COVID-19 and Cancer Consortium (CCC19; NCT04354701). Analysis was restricted to patients with laboratory-confirmed SARS-CoV-2 diagnosed in 2021 or 2022, to allow for a contemporary unvaccinated control population; potential differences were evaluated using a multivariable logistic regression model after inverse probability of treatment weighting to adjust for potential baseline confounding variables. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) are reported. The primary endpoint was 30-day mortality, with key secondary endpoints of hospitalization and ICU and/or mechanical ventilation (ICU/MV). FINDINGS: The analysis included 2486 patients, of which 564 and 385 had received 2 or 3 doses of an mRNA vaccine prior to infection, respectively. Hematologic malignancies and recent receipt of systemic anti-neoplastic therapy were more frequent among vaccinated patients. Vaccination was associated with improved outcomes: in the primary analysis, 2 doses (aOR: 0.62, 95% CI: 0.44-0.88) and 3 doses (aOR: 0.20, 95% CI: 0.11-0.36) were associated with decreased 30-day mortality. There were similar findings for the key secondary endpoints of ICU/MV (aOR: 0.60, 95% CI: 0.45-0.82 and 0.37, 95% CI: 0.24-0.58) and hospitalization (aOR: 0.60, 95% CI: 0.48-0.75 and 0.35, 95% CI: 0.26-0.46) for 2 and 3 doses, respectively. Importantly, Black patients had higher rates of hospitalization (aOR: 1.47, 95% CI: 1.12-1.92), and Hispanic patients presented with higher rates of ICU/MV (aOR: 1.61, 95% CI: 1.06-2.44). INTERPRETATION: Vaccination against COVID-19, especially with additional doses, is a fundamental strategy in the prevention of adverse outcomes including death, among patients with cancer. FUNDING: This study was partly supported by grants from the National Cancer Institute grant number P30 CA068485 to C-YH, YS, SM, JLW; T32-CA236621 and P30-CA046592 to C.R.F; CTSA 2UL1TR001425-05A1 to TMW-D; ACS/FHI Real-World Data Impact Award, P50 MD017341-01, R21 CA242044-01A1, Susan G. Komen Leadership Grant Hunt to MKA. REDCap is developed and supported by Vanderbilt Institute for Clinical and Translational Research grant support (UL1 TR000445 from NCATS/NIH)

Severe pandemic 2009 H1N1 influenza disease due to pathogenic immune complexes

Fil: Monsalvo, Ana Clara. Fundacion INFANT, Buenos Aires; Argentina.Fil: Batalle, Juan P. Fundacion INFANT, Buenos Aires; Argentina.Fil: Lopez, M Florencia. Fundacion INFANT, Buenos Aires; Argentina.Fil: Krause, Jens C. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Klemenc, Jennifer. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Hernandez, Johanna Zea. . Fundacion INFANT, Buenos Aires; Argentina.Fil: Maskin, Bernardo. Hospital Nacional Prof. Alejandro Posadas, Buenos Aires; Argentina.Fil: Bugna, Jimena. Fundacion INFANT, Buenos Aires; Argentina.Fil: Rubinstein, Carlos. Hospital Dr Federico Abete, Malvinas Argentinas, Buenos Aires; Argentina.Fil: Aguilar, Leandro. Hospital Dr Federico Abete, Malvinas Argentinas, Buenos Aires; Argentina.Fil: Dalurzo, Liliana. Hospital Italiano, Buenos Aires; Argentina.Fil: Libster, Romina. Fundacion INFANT, Buenos Aires; Argentina.Fil: Savy, Vilma. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Baumeister, Elsa. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Aguilar, Liliana. Hospital Nacional Prof. Alejandro Posadas, Buenos Aires; Argentina.Fil: Cabral, Graciela. Hospital Nacional Prof. Alejandro Posadas, Buenos Aires; Argentina.Fil: Font, Julia. Hospital Nacional Prof. Alejandro Posadas, Buenos Aires; Argentina.Fil: Solari, Liliana. Hospital Nacional Prof. Alejandro Posadas, Buenos Aires; Argentina.Fil: Weller, Kevin P. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Johnson, Joyce. Department of Pathology, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Echavarria, Marcela. Department of Microbiology, CEMIC, Buenos Aires; Argentina.Fil: Edwards, Kathryn M. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Chappell, James D. Department of Pathology, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Crowe, James E. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Williams, John V. Department of Pediatrics, Vanderbilt University, Nashville, TN; Estados Unidos.Fil: Melendi, Guillermina A. Fundacion INFANT, Buenos Aires; Argentina.Fil: Polack, Fernando P. Fundacion INFANT, Buenos Aires; Argentina.Pandemic influenza viruses often cause severe disease in middle-aged adults without preexisting comorbidities. The mechanism of illness associated with severe disease in this age group is not well understood. Here we find preexisting serum antibodies that cross-react with, but do not protect against, 2009 H1N1 influenza virus in middle-aged adults. Nonprotective antibody is associated with immune complex-mediated disease after infection. We detected high titers of serum antibody of low avidity for H1-2009 antigen, and low-avidity pulmonary immune complexes against the same protein, in severely ill individuals. Moreover, C4d deposition--a marker of complement activation mediated by immune complexes--was present in lung sections of fatal cases. Archived lung sections from middle-aged adults with confirmed fatal influenza 1957 H2N2 infection revealed a similar mechanism of illness. These observations provide a previously unknown biological mechanism for the unusual age distribution of severe cases during influenza pandemics