RESUMO
Progeroid murine models represent an emerging tool to investigate mechanisms of aging in an expedient and efficient manner. One prominent mechanism of aging is the accumulation of DNA damage and subsequent increase in cellular senescence, leading to age related pathologies. Ercc1-/Δ hypomorphic mice, which have a reduced level of the ERCC1-XPF DNA repair endonuclease complex, accumulate spontaneously occurring endogenous DNA damage similar to naturally aged mice, but at a faster rate. The resulting genomic damage gives rise to a senescent cell burden that is comparable to that of a naturally aged mouse. In fact, the expression of senescence and senescence-associated secretory phenotype (SASP) markers in 4-5-month-old Ercc1-/Δ mice, along with other measurements of senescence, were equivalent and never exceeded the extent of that found in naturally aged mice. Furthermore, many features of both natural murine aging and human aging are present in Ercc1-/Δ mice. An emerging use of these mice is the ability to study age-related signaling pathways, including identifying different types of senescent cells and their key senescent cell anti-apoptotic pathways (SCAPs). Most importantly, this model represents a rapid, cost-effective mouse model for the evaluation in vivo of senolytic drugs and other gerotherapeutics.
Assuntos
Envelhecimento/genética , Apoptose/genética , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Endonucleases/genética , Camundongos , Envelhecimento/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Senescência Celular/genética , Síndrome de Cockayne/genética , Síndrome de Cockayne/fisiopatologia , Dano ao DNA/genética , Flavonóis/farmacologia , Xeroderma Pigmentoso/genética , Xeroderma Pigmentoso/fisiopatologiaRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, lethal malignancy that invades adjacent vasculatures and spreads to distant sites before clinical detection. Although invasion into the peripancreatic vasculature is one of the hallmarks of PDAC, paradoxically, PDAC tumors also exhibit hypovascularity. How PDAC tumors become hypovascular is poorly understood. We describe an organotypic PDAC-on-a-chip culture model that emulates vascular invasion and tumor-blood vessel interactions to better understand PDAC-vascular interactions. The model features a 3D matrix containing juxtaposed PDAC and perfusable endothelial lumens. PDAC cells invaded through intervening matrix, into vessel lumen, and ablated the endothelial cells, leaving behind tumor-filled luminal structures. Endothelial ablation was also observed in in vivo PDAC models. We also identified the activin-ALK7 pathway as a mediator of endothelial ablation by PDAC. This tumor-on-a-chip model provides an important in vitro platform for investigating the process of PDAC-driven endothelial ablation and may provide a mechanism for tumor hypovascularity.
Assuntos
Receptores de Ativinas Tipo I/metabolismo , Células Endoteliais/metabolismo , Neoplasias Pancreáticas/metabolismo , Transdução de Sinais/fisiologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Biomimética/métodos , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular , Linhagem Celular Tumoral , Células Endoteliais/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Invasividade Neoplásica/patologia , Neoplasias Pancreáticas/patologia , Neoplasias PancreáticasRESUMO
OBJECTIVES: The morphogenetic events that occur during angiogenic sprouting involve several members of the Rho family of GTPases, including Cdc42. However, the precise roles of Cdc42 in angiogenic sprouting have been difficult to elucidate owing to the lack of models to study these events in vitro. Here, we aim to identify the roles of Cdc42 in branching morphogenesis in angiogenesis. METHODS: Using a 3D biomimetic model of angiogenesis in vitro, where endothelial cells were seeded inside a cylindrical channel within collagen gel and sprouted from the channel in response to a defined biochemical gradient of angiogenic factors, we inhibited Cdc42 activity with a small molecule inhibitor ML141 and examined the effects of Cdc42 on the morphogenetic processes of angiogenic sprouting. RESULTS: We find that partial inhibition of Cdc42 had minimal effects on directional migration of endothelial cells, but led to fewer branching events without affecting the length of these branches. We also observed that antagonizing Cdc42 reduced collective migration in favor of single cell migration. Additionally, Cdc42 also regulated the initiation of filopodial extensions in endothelial tip cells. CONCLUSIONS: Our findings suggest that Cdc42 can affect multiple morphogenetic processes during angiogenic sprouting and ultimately impact the architecture of the vasculature.
