Obesity is a metabolic state of energy excess and a risk factor for over a dozen cancer types. Because of the rising worldwide prevalence of obesity, decoding the mechanisms by which obesity promotes tumor initiation and early progression is a societal imperative and could broadly impact human health. Here, we review results from preclinical models that link obesity to cancer, using pancreatic adenocarcinoma as a paradigmatic example.
View Article and Find Full Text PDFExtracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells.
View Article and Find Full Text PDFObesity is a major modifiable risk factor for pancreatic ductal adenocarcinoma (PDAC), yet how and when obesity contributes to PDAC progression is not well understood. Leveraging an autochthonous mouse model, we demonstrate a causal and reversible role for obesity in early PDAC progression, showing that obesity markedly enhances tumorigenesis, while genetic or dietary induction of weight loss intercepts cancer development. Molecular analyses of human and murine samples define microenvironmental consequences of obesity that foster tumorigenesis rather than new driver gene mutations, including significant pancreatic islet cell adaptation in obesity-associated tumors.
View Article and Find Full Text PDFThe apicomplexan parasite is the primary agent of human babesiosis, a malaria-like illness and potentially fatal tick-borne disease. Unlike its close relatives, the agents of human malaria, develops within human and mouse red blood cells in the absence of a parasitophorous vacuole, and its secreted antigens lack trafficking motifs found in malarial secreted antigens. Here, we show that after invasion of erythrocytes, undergoes a major morphogenic change during which it produces an interlacement of vesicles (IOV); the IOV system extends from the plasma membrane of the parasite into the cytoplasm of the host erythrocyte.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2019
The positioning of chromosomes in the nucleus of a eukaryotic cell is highly organized and has a complex and dynamic relationship with gene expression. In the human malaria parasite , the clustering of a family of virulence genes correlates with their coordinated silencing and has a strong influence on the overall organization of the genome. To identify conserved and species-specific principles of genome organization, we performed Hi-C experiments and generated 3D genome models for five species and two related apicomplexan parasites.
View Article and Find Full Text PDFHuman babesiosis is an emerging tick-borne disease caused by apicomplexan parasites of the genus Clinical cases caused by have been associated with high parasite burden, severe pathology, and death. In both mice and hamsters, the parasite causes uncontrolled fulminant infections, which ultimately lead to death. Resolving these infections requires knowledge of biology, virulence, and susceptibility to anti-infectives, but little is known and further research is hindered by a lack of relevant model systems.
View Article and Find Full Text PDFBabesia microti and Babesia duncani are the main causative agents of human babesiosis in the United States. While significant knowledge about B. microti has been gained over the past few years, nothing is known about B.
View Article and Find Full Text PDFHuman babesiosis is an emerging zoonotic infectious disease caused by intraerythrocytic protozoan parasites of the genus Most cases of human babesiosis are caused by and often manifest in individuals over the age of 50 years or in patients with a compromised immune system. Patients who develop symptomatic infections usually experience months of asymptomatic infection after the acute infection has resolved. About one-fifth of -infected adults never develop symptoms.
View Article and Find Full Text PDFThe biosynthesis of the major acyl carrier Coenzyme A from pantothenic acid (PA) is critical for survival of Plasmodium falciparum within human erythrocytes. Accordingly, a PA analog α-PanAm showed potent activity against blood stage parasites in vitro; however, its efficacy in vivo and its mode of action remain unknown. We developed a new synthesis route for α-PanAm and showed that the compound is highly effective against blood stages of drug-sensitive and -resistant P.
View Article and Find Full Text PDFHuman babesiosis is a tick-borne multisystem disease caused by Babesia species of the apicomplexan phylum. Most clinical cases and fatalities of babesiosis are caused by Babesia microti Current treatment for human babesiosis consists of two drug combinations, atovaquone + azithromycin or quinine + clindamycin. These treatments are associated with adverse side effects and a significant rate of drug failure.
View Article and Find Full Text PDFIn nearly all non-photosynthetic cells, pantothenate (vitamin B5) transport and utilization are prerequisites for the synthesis of the universal essential cofactor Coenzyme A (CoA). Early studies showed that human malaria parasites rely on the uptake of pantothenate across the parasite plasma membrane for survival within erythrocytes. Recently, a P.
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