Publications by authors named "David Majerowicz"

Article Synopsis
  • * Lycopene nanomicelles show strong anti-inflammatory and anticancer effects by inhibiting pro-inflammatory pathways and promoting cancer cell death, alongside improving liver health.
  • * Although promising, the research also highlights the need for further investigation into the effects of lycopene on lipid metabolism and emphasizes the importance of safety evaluations for potential clinical use.
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Lipophorin is the primary lipoprotein present in the hemolymph of insects, responsible for the lipids' transport between organs. It interacts with specific sites on cell membranes in an essential process for transferring lipids. The lipophorin receptor is the protein responsible for the interaction between lipophorin and cell membranes.

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Intracellular levels of NAD   regulate metabolism, among other ways, through enzymes that use NAD   as a substrate, capable of inducing catabolic processes, such as lipid oxidation, glucose uptake, and mitochondrial activity. In several model organisms, administering precursor compounds for NAD  synthesis increases its levels, improves lipid and glucose homeostasis, and reduces weight gain. However, evidence of the effects of these precursors on human patients needs to be better evaluated.

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Plasma 25-dihydroxyvitamin D levels appear reduced in patients with obesity or type 2 diabetes, as reported in several observational studies. However, the association between these reduced hormone levels and metabolic parameters is unclear. In any case, vitamin D supplementation in patients with Metabolic Syndrome is standard.

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Insects need to transport lipids through the aqueous medium of the hemolymph to the organs in demand, after they are absorbed by the intestine or mobilized from the lipid-producing organs. Lipophorin is a lipoprotein present in insect hemolymph, and is responsible for this function. A single gene encodes an apolipoprotein that is cleaved to generate apolipophorin I and II.

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In nearly every species of insect, embryonic development takes place outside of the mother's body and is entirely dependent on the elements that the mother had previously stored within the eggs. It is well known that the follicle cells (FCs) synthesize the eggshell (chorion) components during the process of choriogenesis, the final step of oogenesis before fertilization. These cells have developed a specialization in the massive production of chorion proteins, which are essential for the protection and survival of the embryo.

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FGF21 is a hormone produced primarily by the liver with several metabolic functions, such as induction of heat production, control of glucose homeostasis, and regulation of blood lipid levels. Due to these actions, several laboratories have developed FGF21 analogs to treat patients with metabolic disorders such as obesity and diabetes. Here, we performed a systematic review and meta-analysis of randomized controlled trials that used FGF21 analogs and analyzed metabolic outcomes.

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Autophagy and the ubiquitin-proteasome system (UPS) are important cellular mechanisms that coordinate protein degradation essential for proteostasis. P62/SQSTM1 is a receptor cargo protein able to deliver ubiquitinated targets to the proteasome proteolytic complex and/or to the autophagosome. In the insect vector of Chagas disease, Rhodnius prolixus, previous works have shown that the knockdown of different autophagy-related genes (ATGs) and ubiquitin-conjugating enzymes resulted in abnormal oogenesis phenotypes and embryo lethality.

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The energy stored in fatty acids is essential for several critical activities of insects, such as embryogenesis, oviposition, and flight. is an obligatory hematophagous hemipteran and vector of Chagas disease, and it feeds infrequently on very large blood meals. As digestion slowly occurs, lipids are synthesized and accumulate in the fat body, mainly as triacylglycerol, in lipid droplets.

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Trypanosoma rangeli is a protozoan parasite that infects triatomines and mammals in the Americas, producing mixed infections with Trypanosoma cruzi, the etiological agent of Chagas disease. The former parasite is not pathogenic to humans, but has different levels of pathogenicity, as well as causing physiological and behavioral alterations, to its invertebrate hosts. In this study, we measured locomotory activity, and the glyceride accumulation profile in the hemolymph and fat body, as well as the expression of key genes related to triglyceride metabolism, of Rhodnius prolixus nymphs infected with T.

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The high reproductive rates of insects contribute significantly to their ability to act as vectors of a variety of vector-borne diseases. Therefore, it is strategically critical to find molecular targets with biotechnological potential through the functional study of genes essential for insect reproduction. The ubiquitin-proteasome system is a vital degradative pathway that contributes to the maintenance of regular eukaryotic cell proteostasis.

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ATP synthase plays an essential role in mitochondrial metabolism, being responsible for the production of ATP in oxidative phosphorylation. However, recent results have shown that it may also be present in the cell membrane, involved in lipophorin binding to its receptors. Here, we used a functional genetics approach to investigate the roles of ATP synthase in lipid metabolism in the kissing bug Rhodnius prolixus.

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Insects have become essential models in studying human metabolic diseases, mainly due to their low maintenance cost and available tools. Both mutations and modified diets induce metabolic states similar to human obesity and diabetes. Here, we explore the effect of a high-calorie, high-fat diet on the metabolism of the beetle Tribolium castaneum.

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Insects are unable to synthesize cholesterol and depend on the presence of sterols in the diet for cell membrane composition and hormone production. Thus, cholesterol absorption, transport, and metabolism are potential targets for vector and pest control strategies. Here, we investigate the dietary cholesterol absorption and tissue distribution in the kissing bug using radiolabeled cholesterol.

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The fly genome contains a single ortholog of the evolutionarily conserved transcription factor hepatocyte nuclear factor 4 (HNF4), a broadly and constitutively expressed member of the nuclear receptor superfamily. Like its mammalian orthologs, Drosophila HNF4 (dHNF4) acts as a critical regulator of fatty acid and glucose homeostasis. Because of its role in energy storage and catabolism, the insect fat body controls non-autonomous organs including the ovaries, where lipid metabolism is essential for oogenesis.

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In insects, lipids are stored in the fat body mainly as triacylglycerol. Lipids can be directly provided by digestion and incorporated from the hemolymph, or synthesized de novo from other substrates such as carbohydrates and amino acids. The first step in de novo lipid synthesis is catalyzed by acetyl-CoA carboxylase (ACC), which carboxylates acetyl-CoA to form malonyl-CoA.

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The acyl-CoA-binding proteins (ACBP) act by regulating the availability of acyl-CoA in the cytoplasm and must have essential functions in lipid metabolism. The genome of the kissing-bug Rhodnius prolixus encodes five proteins of this family, but little is known about them. In this study we investigated the expression and function of RpACBP-5.

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Obesity is a severe worldwide epidemic. Obesity comorbidities, such as type 2 diabetes mellitus, hypertension, and atherosclerosis, are costly for patients and governments. The treatment of obesity involves several facets, including lifestyle changes, bariatric surgery, and pharmacotherapy.

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More than a third of the world population is at constant risk of contracting some insect-transmitted disease, such as Dengue fever, Zika virus disease, malaria, Chagas' disease, African trypanosomiasis, and others. Independent of the life cycle of the pathogen causing the disease, the insect vector hematophagous habit is a common and crucial trait for the transmission of all these diseases. This lifestyle is unique, as hematophagous insects feed on blood, a diet that is rich in protein but relatively poor in lipids and carbohydrates, in huge amounts and low frequency.

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Phosphofructokinase (PFK) is a key regulatory enzyme of glycolysis, being considered the pacemaker of this pathway. In mammals, this enzyme exists as three different isoforms, PFKM, PFKL and PFKP, presenting different regulatory and catalytic properties. The expression of these isoforms is tissue-specific and vary according to the cell differentiation and signalization.

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Obesity and diabetes are metabolic diseases and they are increasing in prevalence. The dynamics of gene expression associated with these diseases is fundamental to identifying genes involved in related biological processes. qPCR is a sensitive technique for mRNA quantification and the most commonly used method in gene-expression studies.

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Background: Mosquitoes feed on plant-derived fluids such as nectar and sap and are exposed to bioactive molecules found in this dietary source. However, the role of such molecules on mosquito vectorial capacity is unknown. Weather has been recognized as a major determinant of the spread of dengue, and plants under abiotic stress increase their production of polyphenols.

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The kissing bug Rhodnius prolixus is both an important vector of Chagas' disease and an interesting model for investigation into the field of physiology, including lipid metabolism. The publication of this insect genome will bring a huge amount of new molecular biology data to be used in future experiments. Although this work represents a promising scenario, a preliminary analysis of the sequence data is necessary to identify and annotate the genes involved in lipid metabolism.

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The acyl-CoA-binding proteins (ACBP) constitute a family of conserved proteins that bind acyl-CoA with high affinity and protect it from hydrolysis. Thus, ACBPs may have essential roles in basal cellular lipid metabolism. The genome of the insect Rhodnius prolixus encodes five ACBP genes similar to those described for other insect species.

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Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼ 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect.

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