Aditi Sinha - Academia.edu (original) (raw)

Papers by Aditi Sinha

Research paper thumbnail of Periostin as an early marker for elastin mediated vascular smooth muscle cell calcification

Cardiovascular System, 2013

ABSTRACT We provide evidence that the extracellular matrix protein, periostin, is strongly upregu... more ABSTRACT We provide evidence that the extracellular matrix protein, periostin, is strongly upregulated during in vitro and in vivo vascular smooth muscle cell calcification. RT-RCR and Western analyses demonstrate that upon stimulation with elastin peptides, rat aortic smooth muscle cells (RASMCs) exhibit a time-dependent increase in periostin expression, which is synergistically enhanced by the addition of transforming growth factor (TGF-β1). This increase was significantly attenuated by administering either lactose, an elastin-laminin receptor (ELR) antagonist, or the TGF-β1 receptor antagonist SB431542. As elastin peptides and TGF-β1 have been shown to contribute to RASMC calcification, the potential role of periostin in promoting RASMC calcification was further evaluated. Inhibition of periostin blocked RASMC calcification, whereas overexpression promoted calcification. This periostin-dependent calcification occurs, in part, through the regulation of osteogenic genes: alkaline phosphatase (ALP) and core binding factor 1 (Runx2/Cbfa-1). These data were further corroborated in a rat model of aortic calcific disease whereby periostin expression was confined to the calcified abdominal aorta.

Research paper thumbnail of Nanoparticle targeting to diseased vasculature for imaging and therapy

Nanomedicine: Nanotechnology, Biology and Medicine, 2014

Significant challenges remain in targeting drugs to diseased vasculature; most important being ra... more Significant challenges remain in targeting drugs to diseased vasculature; most important being rapid blood flow with high shear, limited availability of stable targets, and heterogeneity and recycling of cellular markers. We developed nanoparticles (NPs) to target degraded elastic lamina, a consistent pathological feature in vascular diseases. In-vitro organ and cell culture experiments demonstrated that these NPs were not taken up by cells, but instead retained within the extracellular space; NP binding was proportional to the extent of elastic lamina damage. With three well-established rodent models of vascular diseases such as aortic aneurysm (calcium chloride mediated aortic injury in rats), atherosclerosis (fat-fed apoE-/- mice), and vascular calcification (warfarin + vitamin K injections in rats), we show precise NPs spatial targeting to degraded vascular elastic lamina while sparing healthy vasculature when NPs were delivered systemically. Nanoparticle targeting degraded elastic lamina is attractive to deliver therapeutic or imaging agents to the diseased vasculature. This novel work focuses on nanoparticle targeting of degraded elastic lamina in a variety of diseases, including atherosclerosis, vascular calcification, and aneurysm formation, and demonstrates the feasibility to deliver therapeutic or imaging agents to the diseased vasculature.

Research paper thumbnail of Hydroxyapatite and calcified elastin induce osteoblast-like differentiation in rat aortic smooth muscle cells

Experimental Cell Research, 2014

Vascular calcification a b s t r a c t Vascular calcification can be categorized into two differe... more Vascular calcification a b s t r a c t Vascular calcification can be categorized into two different types. Intimal calcification related to atherosclerosis and elastin-specific medial arterial calcification (MAC). Osteoblast-like differentiation of vascular smooth muscle cells (VSMCs) has been shown in both types; however, how this relates to initiation of vascular calcification is unclear. We hypothesize that the initial deposition of hydroxyapatite-like mineral in MAC occurs on degraded elastin first and that causes osteogenic transformation of VSMCs. To test this, rat aortic smooth muscle cells (RASMCs) were cultured on hydroxyapatite crystals and calcified aortic elastin. Using RT-PCR and specific protein assays, we demonstrate that RASMCs lose their smooth muscle lineage markers like alpha smooth muscle actin (SMA) and myosin heavy chain (MHC) and undergo chondrogenic/osteogenic transformation. This is indicated by an increase in the expression of typical chondrogenic proteins such as aggrecan, collagen type II alpha 1(Col2a1) and bone proteins such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, when calcified conditions are removed, cells return to their original phenotype. Our data supports the hypothesis that elastin degradation and calcification precedes VSMCs 0 osteoblast-like differentiation.

Research paper thumbnail of Efficacy of Reversal of Aortic Calcification by Chelating Agents

Calcified Tissue International, 2013

Elastin-specific medial vascular calcification, termed ''Monckeberg's sclerosis,'' has been recog... more Elastin-specific medial vascular calcification, termed ''Monckeberg's sclerosis,'' has been recognized as a major risk factor for various cardiovascular events. We hypothesize that chelating agents, such as disodium ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and sodium thiosulfate (STS) might reverse elastin calcification by directly removing calcium from calcified tissues into soluble calcium complexes. We assessed the chelating ability of EDTA, DTPA, and STS on removal of calcium from hydroxyapatite (HA) powder, calcified porcine aortic elastin, and calcified human aorta in vitro. We show that both EDTA and DTPA could effectively remove calcium from HA and calcified tissues, while STS was not effective. The tissue architecture was not altered during chelation. In the animal model of aortic elastin-specific calcification, we further show that local periadventitial delivery of EDTA loaded in to poly(lactic-co-glycolic acid) nanoparticles regressed elastin-specific calcification in the aorta. Collectively, the data indicate that elastin-specific medial vascular calcification could be reversed by chelating agents.

Research paper thumbnail of Prevention of Abdominal Aortic Aneurysm Progression by Targeted Inhibition of Matrix Metalloproteinase Activity with Batimastat-Loaded Nanoparticles

Circulation research, Jan 6, 2015

Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of ... more Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of development and progression of abdominal aortic aneurysms (AAA). Systemic treatments of MMP inhibitors have shown effectiveness in animal models but it did not translate to clinical success either due low doses used or systemic side-effects of MMP inhibitors. We propose a targeted nanoparticle based delivery of MMP inhibitor at very low doses to the AAA site. Such therapy will be an attractive option for preventing expansion of aneurysms in patients without systemic side effects. Our previous study showed that poly D, L-lactide (PLA) nanoparticles (NPs) conjugated with an anti-elastin antibody could be targeted to the site of an aneurysm in a rat model of AAA. In the study reported here, we tested whether such targeted NPs could deliver the MMP inhibitor batimastat (BB-94) to the site of an aneurysm and prevent aneurysmal growth. PLA NPs were loaded with BB-94 and conjugated with an elas...

Research paper thumbnail of Periostin as an early marker for elastin mediated vascular smooth muscle cell calcification

Cardiovascular System, 2013

ABSTRACT We provide evidence that the extracellular matrix protein, periostin, is strongly upregu... more ABSTRACT We provide evidence that the extracellular matrix protein, periostin, is strongly upregulated during in vitro and in vivo vascular smooth muscle cell calcification. RT-RCR and Western analyses demonstrate that upon stimulation with elastin peptides, rat aortic smooth muscle cells (RASMCs) exhibit a time-dependent increase in periostin expression, which is synergistically enhanced by the addition of transforming growth factor (TGF-β1). This increase was significantly attenuated by administering either lactose, an elastin-laminin receptor (ELR) antagonist, or the TGF-β1 receptor antagonist SB431542. As elastin peptides and TGF-β1 have been shown to contribute to RASMC calcification, the potential role of periostin in promoting RASMC calcification was further evaluated. Inhibition of periostin blocked RASMC calcification, whereas overexpression promoted calcification. This periostin-dependent calcification occurs, in part, through the regulation of osteogenic genes: alkaline phosphatase (ALP) and core binding factor 1 (Runx2/Cbfa-1). These data were further corroborated in a rat model of aortic calcific disease whereby periostin expression was confined to the calcified abdominal aorta.

Research paper thumbnail of Nanoparticle targeting to diseased vasculature for imaging and therapy

Nanomedicine: Nanotechnology, Biology and Medicine, 2014

Significant challenges remain in targeting drugs to diseased vasculature; most important being ra... more Significant challenges remain in targeting drugs to diseased vasculature; most important being rapid blood flow with high shear, limited availability of stable targets, and heterogeneity and recycling of cellular markers. We developed nanoparticles (NPs) to target degraded elastic lamina, a consistent pathological feature in vascular diseases. In-vitro organ and cell culture experiments demonstrated that these NPs were not taken up by cells, but instead retained within the extracellular space; NP binding was proportional to the extent of elastic lamina damage. With three well-established rodent models of vascular diseases such as aortic aneurysm (calcium chloride mediated aortic injury in rats), atherosclerosis (fat-fed apoE-/- mice), and vascular calcification (warfarin + vitamin K injections in rats), we show precise NPs spatial targeting to degraded vascular elastic lamina while sparing healthy vasculature when NPs were delivered systemically. Nanoparticle targeting degraded elastic lamina is attractive to deliver therapeutic or imaging agents to the diseased vasculature. This novel work focuses on nanoparticle targeting of degraded elastic lamina in a variety of diseases, including atherosclerosis, vascular calcification, and aneurysm formation, and demonstrates the feasibility to deliver therapeutic or imaging agents to the diseased vasculature.

Research paper thumbnail of Hydroxyapatite and calcified elastin induce osteoblast-like differentiation in rat aortic smooth muscle cells

Experimental Cell Research, 2014

Vascular calcification a b s t r a c t Vascular calcification can be categorized into two differe... more Vascular calcification a b s t r a c t Vascular calcification can be categorized into two different types. Intimal calcification related to atherosclerosis and elastin-specific medial arterial calcification (MAC). Osteoblast-like differentiation of vascular smooth muscle cells (VSMCs) has been shown in both types; however, how this relates to initiation of vascular calcification is unclear. We hypothesize that the initial deposition of hydroxyapatite-like mineral in MAC occurs on degraded elastin first and that causes osteogenic transformation of VSMCs. To test this, rat aortic smooth muscle cells (RASMCs) were cultured on hydroxyapatite crystals and calcified aortic elastin. Using RT-PCR and specific protein assays, we demonstrate that RASMCs lose their smooth muscle lineage markers like alpha smooth muscle actin (SMA) and myosin heavy chain (MHC) and undergo chondrogenic/osteogenic transformation. This is indicated by an increase in the expression of typical chondrogenic proteins such as aggrecan, collagen type II alpha 1(Col2a1) and bone proteins such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, when calcified conditions are removed, cells return to their original phenotype. Our data supports the hypothesis that elastin degradation and calcification precedes VSMCs 0 osteoblast-like differentiation.

Research paper thumbnail of Efficacy of Reversal of Aortic Calcification by Chelating Agents

Calcified Tissue International, 2013

Elastin-specific medial vascular calcification, termed ''Monckeberg's sclerosis,'' has been recog... more Elastin-specific medial vascular calcification, termed ''Monckeberg's sclerosis,'' has been recognized as a major risk factor for various cardiovascular events. We hypothesize that chelating agents, such as disodium ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and sodium thiosulfate (STS) might reverse elastin calcification by directly removing calcium from calcified tissues into soluble calcium complexes. We assessed the chelating ability of EDTA, DTPA, and STS on removal of calcium from hydroxyapatite (HA) powder, calcified porcine aortic elastin, and calcified human aorta in vitro. We show that both EDTA and DTPA could effectively remove calcium from HA and calcified tissues, while STS was not effective. The tissue architecture was not altered during chelation. In the animal model of aortic elastin-specific calcification, we further show that local periadventitial delivery of EDTA loaded in to poly(lactic-co-glycolic acid) nanoparticles regressed elastin-specific calcification in the aorta. Collectively, the data indicate that elastin-specific medial vascular calcification could be reversed by chelating agents.

Research paper thumbnail of Prevention of Abdominal Aortic Aneurysm Progression by Targeted Inhibition of Matrix Metalloproteinase Activity with Batimastat-Loaded Nanoparticles

Circulation research, Jan 6, 2015

Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of ... more Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of development and progression of abdominal aortic aneurysms (AAA). Systemic treatments of MMP inhibitors have shown effectiveness in animal models but it did not translate to clinical success either due low doses used or systemic side-effects of MMP inhibitors. We propose a targeted nanoparticle based delivery of MMP inhibitor at very low doses to the AAA site. Such therapy will be an attractive option for preventing expansion of aneurysms in patients without systemic side effects. Our previous study showed that poly D, L-lactide (PLA) nanoparticles (NPs) conjugated with an anti-elastin antibody could be targeted to the site of an aneurysm in a rat model of AAA. In the study reported here, we tested whether such targeted NPs could deliver the MMP inhibitor batimastat (BB-94) to the site of an aneurysm and prevent aneurysmal growth. PLA NPs were loaded with BB-94 and conjugated with an elas...