Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “MUSCLES”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Isorhynchophylline protects against pulmonary arterial hypertension and suppresses PASMCs proliferation

Highlights: • We focus on PASMCs proliferation in the pathogenesis of PAH. • Isorhynchophylline inhibited PASMCs proliferation and alleviated PAH. • IRN blocked PDGF-Rβ phosphorylation and its downstream signal transduction. • IRN regulated cyclins and CDKs to arrest cell cycle in the G0/G1 phase. • We reported IRN has the potential to be a candidate for PAH treatment. - Abstract: Increased pulmonary arterial smooth muscle cells (PASMCs) proliferation is a key pathophysiological component of pulmonary vascular remodeling in pulmonary arterial hypertension (PAH). Isorhynchophylline (IRN) is a tetracyclic oxindole alkaloid isolated from the Chinese herbal medicine Uncaria rhynchophylla. It has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether IRN can influence the development of PAH. Here we examined the effect of IRN on monocrotaline (MCT) induced PAH in rats. Our data demonstrated that IRN prevented MCT induced PAH in rats, as assessed by right ventricular (RV) pressure, the weight ratio of RV to (left ventricular + septum) and RV hypertrophy. IRN significantly attenuated the percentage of fully muscularized small arterioles, the medial wall thickness, and the expression of smooth muscle α-actin (α-SMA) and proliferating cell nuclear antigen (PCNA). In vitro studies, IRN concentration-dependently inhibited the platelet-derived growth factor (PDGF)-BB-induced proliferation of PASMCs. Fluorescence-activated cell-sorting analysis showed that IRN caused G0/G1 phase cell cycle arrest. IRN-induced growth inhibition was associated with downregulation of Cyclin D1 and CDK6 as well as an increase in p27Kip1 levels in PDGF-BB-stimulated PASMCs. Moreover, IRN negatively modulated PDGF-BB-induced phosphorylation of PDGF-Rβ, ERK1/2, Akt/GSK3β, and signal transducers and activators of transcription 3 (STAT3). These results demonstrate that IRN could inhibit PASMCs proliferation and attenuate pulmonary vascular remodeling after MCT induction. These beneficial effects were at least through the inhibition of PDGF-Rβ phosphorylation and its downstream signaling pathways. Therefore, IRN might be a potential candidate for the treatment of PAH.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Impact of methionine oxidation on calmodulin structural dynamics

Highlights: • We measured the distance distribution between two spin labels on calmodulin by DEER. • Two structural states, open and closed, were resolved at both low and high Ca. • Ca shifted the equilibrium toward the open state by a factor of 13. • Methionine oxidation, simulated by glutamine substitution, decreased the Ca effect. • These results have important implications for aging in muscle and other tissues. - Abstract: We have used electron paramagnetic resonance (EPR) to examine the structural impact of oxidizing specific methionine (M) side chains in calmodulin (CaM). It has been shown that oxidation of either M109 or M124 in CaM diminishes CaM regulation of the muscle calcium release channel, the ryanodine receptor (RyR), and that mutation of M to Q (glutamine) in either case produces functional effects identical to those of oxidation. Here we have used site-directed spin labeling and double electron–electron resonance (DEER), a pulsed EPR technique that measures distances between spin labels, to characterize the structural changes resulting from these mutations. Spin labels were attached to a pair of introduced cysteine residues, one in the C-lobe (T117C) and one in the N-lobe (T34C) of CaM, and DEER was used to determine the distribution of interspin distances. Ca binding induced a large increase in the mean distance, in concert with previous X-ray crystallography and NMR data, showing a closed structure in the absence of Ca and an open structure in the presence of Ca. DEER revealed additional information about CaM’s structural heterogeneity in solution: in both the presence and absence of Ca, CaM populates both structural states, one with probes separated by ∼4 nm (closed) and another at ∼6 nm (open). Ca shifts the structural equilibrium constant toward the open state by a factor of 13. DEER reveals the distribution of interprobe distances, showing that each of these states is itself partially disordered, with the width of each population ranging from 1 to 3 nm. Both mutations (M109Q and M124Q) decrease the effect of Ca on the structure of CaM, primarily by decreasing the closed-to-open equilibrium constant in the presence of Ca. We propose that Met oxidation alters CaM’s functional interaction with its target proteins by perturbing this Ca-dependent structural shift.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

In vivo cardiac glucose metabolism in the high-fat fed mouse: Comparison of euglycemic–hyperinsulinemic clamp derived measures of glucose uptake with a dynamic metabolomic flux profiling approach

Rationale: Cardiac metabolism is thought to be altered in insulin resistance and type 2 diabetes (T2D). Our understanding of the regulation of cardiac substrate metabolism and insulin sensitivity has largely been derived from ex vivo preparations which are not subject to the same metabolic regulation as in the intact heart in vivo. Studies are therefore required to examine in vivo cardiac glucose metabolism under physiologically relevant conditions. Objective: To determine the temporal pattern of the development of cardiac insulin resistance and to compare with dynamic approaches to interrogate cardiac glucose and intermediary metabolism in vivo. Methods and results: Studies were conducted to determine the evolution of cardiac insulin resistance in C57Bl/6 mice fed a high-fat diet (HFD) for between 1 and 16 weeks. Dynamic in vivo cardiac glucose metabolism was determined following oral administration of [U-{sup 13}C] glucose. Hearts were collected after 15 and 60 min and flux profiling was determined by measuring {sup 13}C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates. Cardiac insulin resistance, determined by euglycemic–hyperinsulinemic clamp, was evident after 3 weeks of HFD. Despite the presence of insulin resistance, in vivo cardiac glucose metabolism following oral glucose administration was not compromised in HFD mice. This contrasts our recent findings in skeletal muscle, where TCA cycle activity was reduced in mice fed a HFD. Similar to our report in muscle, glucose derived pyruvate entry into the TCA cycle in the heart was almost exclusively via pyruvate dehydrogenase, with pyruvate carboxylase mediated anaplerosis being negligible after oral glucose administration. Conclusions: Under experimental conditions which closely mimic the postprandial state, the insulin resistant mouse heart retains the ability to stimulate glucose metabolism. - Highlights: • Insulin clamp was used to determine the evolution of cardiac insulin resistance. • Clamp measures were compared to a dynamic metabolomics approach. • The clamp revealed the presence of cardiac insulin resistance after 3 weeks of HFD. • Cardiac glucose metabolism was not affected by HFD during an oral glucose challenge.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Myostatin inhibits eEF2K-eEF2 by regulating AMPK to suppress protein synthesis

Growth of skeletal muscle is dependent on the protein synthesis, and the rate of protein synthesis is mainly regulated in the stage of translation initiation and elongation. Myostatin, a member of the transforming growth factor-β (TGF-β) superfamily, is a negative regulator of protein synthesis. C2C12 myotubes was incubated with 0, 0.01, 0.1, 1, 2, 3 μg/mL myostatin recombinant protein, and then we detected the rates of protein synthesis by the method of SUnSET. We found that high concentrations of myostatin (2 and 3 μg/mL) inhibited protein synthesis by blocking mTOR and eEF2K-eEF2 pathway, while low concentration of myostatin (0.01, 0.1 and 1 μg/mL) regulated eEF2K-eEF2 pathway activity to block protein synthesis without affected mTOR pathway, and myostatin inhibited eEF2K-eEF2 pathway through regulating AMPK pathway to suppress protein synthesis. It provided a new mechanism for myostatin regulating protein synthesis and treating muscle atrophy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Modulation of hyaluronan polymer size regulates proliferation of perimysial fibroblasts in thyroid eye disease

Highlights: • IGF-1 and PH20 modulate HA polymer size. • HA polymer size regulates fibroblast proliferation. • Mitogenic effect of HA is mediated by membrane potential alteration. In active thyroid eye disease (TED), the extraocular muscles feature excessive hyaluronan (HA) accumulation and increased fibroblast proliferation. To investigate the effects of HA on proliferation, we cultured perimysial fibroblasts from extraocular muscles of active TED patients, and adopted IGF-1 and PH20 as modulators for HA concentration and HA polymer size. Based on the results, IGF-1 increased HA concentration, promoted high molecular weight HA (HMW-HA) proportion and stimulated fibroblast proliferation. Hyaluronidase PH20 decreased HA concentration, but caused HMW-HA accumulation and exaggerating proliferation as well. Combined treatment with both reagents resulted in retention of low molecular weight HA (LMW-HA), and suppressed fibroblast proliferation. Pearson correlation demonstrated no significance between HA concentration and proliferation. Mitogenic investigation unveiled the stimulatory effects of HMW-HA via membrane depolarization and inhibitive effects of LMW-HA via membrane hyperpolarization. Our findings offer insights into the essential role of HA molecular weight during TED pathogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

The inhibition of the effect and mechanism of vascular intimal hyperplasia in Tiam1 knockout mice

Highlights: • Tiam1 was highly expressed in the neointimal layer of the ligated carotid artery. • The intimal hyperplasia in Tiam1 KO mice after the ligation decreased. • PDGF-induced proliferation of HASMCs were inhibited with Tiam1 knockdown. • Rac1 involved in the migration of HASMCs that Tiam1 promoted. T-Cell Lymphoma Invasion and Metastasis 1 (Tiam1) is a specific nucleotide exchange factor (GEF) that can activate Rho-like GTPase and Rac1 and regulate various cellular processes, including cell cycle progression and cell migration. The roles of Tiam1 in vascular intimal hyperplasia, especially in vascular smooth muscle cell proliferation and migration, are not fully understood. In this study, we investigated the effect of Tiam1 on vascular intimal hyperplasia in a carotid artery ligation model and human aortic smooth muscle cells (HASMCs). We found that the expression of Tiam1 was up-regulated in the neointima of carotid artery ligation mice and that Tiam1{sup −/−} mice following carotid artery ligation had less neointimal formation compared with wild type mice. Knockdown of Tiam1 by siRNA markedly attenuated PDGF-induced migration and proliferation in HASMCs by inhibiting the activation of Rac1. Therefore, these results suggest that Tiam1 is an important regulator of intima hyperplasia. It may regulate vascular intimal hyperplasia through the activation of Rac1.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Occult Pelvic Lymph Node Involvement in Bladder Cancer: Implications for Definitive Radiation

Purpose: To inform radiation treatment planning for clinically staged, node-negative bladder cancer patients by identifying clinical factors associated with the presence and location of occult pathologic pelvic lymph nodes. Methods and Materials: The records of patients with clinically staged T1-T4N0 urothelial carcinoma of the bladder undergoing radical cystectomy and pelvic lymphadenectomy at a single institution were reviewed. Logistic regression was used to evaluate associations between preoperative clinical variables and occult pathologic pelvic or common iliac lymph nodes. Percentages of patient with involved lymph node regions entirely encompassed within whole bladder (perivesicular nodal region), small pelvic (perivesicular, obturator, internal iliac, and external iliac nodal regions), and extended pelvic clinical target volume (CTV) (small pelvic CTV plus common iliac regions) were calculated. Results: Among 315 eligible patients, 81 (26%) were found to have involved pelvic lymph nodes at the time of surgery, with 38 (12%) having involved common iliac lymph nodes. Risk of occult pathologically involved lymph nodes did not vary with clinical T stage. On multivariate analysis, the presence of lymphovascular invasion (LVI) on preoperative biopsy was significantly associated with occult pelvic nodal involvement (odds ratio 3.740, 95% confidence interval 1.865-7.499, P<.001) and marginally associated with occult common iliac nodal involvement (odds ratio 2.307, 95% confidence interval 0.978-5.441, P=.056). The percentages of patients with involved lymph node regions entirely encompassed by whole bladder, small pelvic, and extended pelvic CTVs varied with clinical risk factors, ranging from 85.4%, 95.1%, and 100% in non-muscle-invasive patients to 44.7%, 71.1%, and 94.8% in patients with muscle-invasive disease and biopsy LVI. Conclusions: Occult pelvic lymph node rates are substantial for all clinical subgroups, especially patients with LVI on biopsy. Extended coverage of pelvic lymph nodes up to the level of the common iliac nodes may be warranted in subsets of patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Dose-Escalation Study for Cardiac Radiosurgery in a Porcine Model

Purpose: To perform a proof-of-principle dose-escalation study to radiosurgically induce scarring in cardiac muscle tissue to block veno-atrial electrical connections at the pulmonary vein antrum, similar to catheter ablation. Methods and Materials: Nine mini-pigs underwent pretreatment magnetic resonance imaging (MRI) evaluation of heart function and electrophysiology assessment by catheter measurements in the right superior pulmonary vein (RSPV). Immediately after examination, radiosurgery with randomized single-fraction doses of 0 and 17.5-35 Gy in 2.5-Gy steps were delivered to the RSPV antrum (target volume 5-8 cm{sup 3}). MRI and electrophysiology were repeated 6 months after therapy, followed by histopathologic examination. Results: Transmural scarring of cardiac muscle tissue was noted with doses ≥32.5 Gy. However, complete circumferential scarring of the RSPV was not achieved. Logistic regressions showed that extent and intensity of fibrosis significantly increased with dose. The 50% effective dose for intense fibrosis was 31.3 Gy (odds ratio 2.47/Gy, P<.01). Heart function was not affected, as verified by MRI and electrocardiogram evaluation. Adjacent critical structures were not damaged, as verified by pathology, demonstrating the short-term safety of small-volume cardiac radiosurgery with doses up to 35 Gy. Conclusions: Radiosurgery with doses >32.5 Gy in the healthy pig heart can induce circumscribed scars at the RSPV antrum noninvasively, mimicking the effect of catheter ablation. In our study we established a significant dose-response relationship for cardiac radiosurgery. The long-term effects and toxicity of such high radiation doses need further investigation in the pursuit of cardiac radiosurgery for noninvasive treatment of atrial fibrillation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Mapping {sup 15}O Production Rate for Proton Therapy Verification

Purpose: This work was a proof-of-principle study for the evaluation of oxygen-15 ({sup 15}O) production as an imaging target through the use of positron emission tomography (PET), to improve verification of proton treatment plans and to study the effects of perfusion. Methods and Materials: Dynamic PET measurements of irradiation-produced isotopes were made for a phantom and rabbit thigh muscles. The rabbit muscle was irradiated and imaged under both live and dead conditions. A differential equation was fitted to phantom and in vivo data, yielding estimates of {sup 15}O production and clearance rates, which were compared to live versus dead rates for the rabbit and to Monte Carlo predictions. Results: PET clearance rates agreed with decay constants of the dominant radionuclide species in 3 different phantom materials. In 2 oxygen-rich materials, the ratio of {sup 15}O production rates agreed with the expected ratio. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using {sup 15}O decay constant, whereas the live thigh activity decayed faster. Most importantly, the {sup 15}O production rates agreed within 2% (P>.5) between conditions. Conclusions: We developed a new method for quantitative measurement of {sup 15}O production and clearance rates in the period immediately following proton therapy. Measurements in the phantom and rabbits were well described in terms of {sup 15}O production and clearance rates, plus a correction for other isotopes. These proof-of-principle results support the feasibility of detailed verification of proton therapy treatment delivery. In addition, {sup 15}O clearance rates may be useful in monitoring permeability changes due to therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Carbon black nanoparticles induce biphasic gene expression changes associated with inflammatory responses in the lungs of C57BL/6 mice following a single intratracheal instillation

Inhalation of carbon black nanoparticles (CBNPs) causes pulmonary inflammation; however, time course data to evaluate the detailed evolution of lung inflammatory responses are lacking. Here we establish a time-series of lung inflammatory response to CBNPs. Female C57BL/6 mice were intratracheally instilled with 162 μg CBNPs alongside vehicle controls. Lung tissues were examined 3 h, and 1, 2, 3, 4, 5, 14, and 42 days (d) post-exposure. Global gene expression and pulmonary inflammation were assessed. DNA damage was evaluated in bronchoalveolar lavage (BAL) cells and lung tissue using the comet assay. Increased neutrophil influx was observed at all time-points. DNA strand breaks were increased in BAL cells 3 h post-exposure, and in lung tissues 2–5 d post-exposure. Approximately 2600 genes were differentially expressed (± 1.5 fold; p ≤ 0.05) across all time-points in the lungs of exposed mice. Altered transcript levels were associated with immune-inflammatory response and acute phase response pathways, consistent with the BAL profiles and expression changes found in common respiratory infectious diseases. Genes involved in DNA repair, apoptosis, cell cycle regulation, and muscle contraction were also differentially expressed. Gene expression changes associated with inflammatory response followed a biphasic pattern, with initial changes at 3 h post-exposure declining to base-levels by 3 d, increasing again at 14 d, and then persisting to 42 d post-exposure. Thus, this single CBNP exposure that was equivalent to nine 8-h working days at the current Danish occupational exposure limit induced biphasic inflammatory response in gene expression that lasted until 42 d post-exposure, raising concern over the chronic effects of CBNP exposure. - Highlights: • A single exposure to CBNPs induced expression changes in over 2600 genes in mouse lungs. • Altered genes were associated with immune-inflammatory and acute phase responses. • Several genes were involved in DNA repair, apoptosis, and muscle contraction. • Effects of a single exposure to CBNPs lasted until 42 d post-exposure. • A single exposure to CBNPs induced a biphasic inflammatory response in gene expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

TW-01, a piperazinedione-derived compound, inhibits Ras-mediated cell proliferation and angioplasty-induced vascular restenosis

Purpose: Vascular smooth muscle cell (VSMC) proliferation plays a critical role in the pathogenesis of atherosclerosis and restenosis. This study investigated piperazinedione derived compound TW-01-mediated inhibitory effects on VSMC proliferation and intimal hyperplasia. Methods: Cell proliferation was determined using [{sup 3}H]-thymidine incorporation and MTT assay; cell cycle distribution was measured using flow cytometry; proteins and mRNA expression were determined using western blotting and RT-PCR analyses; DNA binding activity of nuclear factor-κB (NF-κB), as measured using enzyme-linked immunosorbent assays (ELISA); in vivo effects of TW-01 were determined using balloon angioplasty in the rat. Results: TW-01 significantly inhibited cell proliferation. At the concentrations used, no cytotoxic effects were observed. Three predominant signaling pathways were inhibited by TW-01: (a) extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) activation and its downstream effectors of c-fos, c-jun, and c-myc; (b) DNA binding activity of nuclear factor-κB (NF-κB); and, (c) Akt/protein kinase B (PKB) and cell cycle progression. Furthermore, TW-01 also inhibited Ras activation, a shared upstream event of each of these signaling cascades. In vascular injury studies, oral administration of TW-01 significantly suppressed intimal hyperplasia induced by balloon angioplasty. Conclusion: The present study suggests that TW-01 might be a potential candidate for atherosclerosis treatment. - Highlights: • TW-01significantly inhibits vascular smooth muscle cell proliferation. • TW-01 inhibits ERK, Akt and Ras pathway and DNA binding activity of NF-κB. • TW-01 significantly suppresses intimal hyperplasia induced by balloon angioplasty. • TW-01 might be a potential candidate for atherosclerosis treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

EGF–FGF{sub 2} stimulates the proliferation and improves the neuronal commitment of mouse epidermal neural crest stem cells (EPI-NCSCs)

Epidermal neural crest stem cells (EPI-NCSCs), which reside in the bulge of hair follicles, are attractive candidates for several applications in cell therapy, drug screening and tissue engineering. As suggested remnants of the embryonic neural crest (NC) in an adult location, EPI-NCSCs are able to generate a wide variety of cell types and are readily accessible by a minimally invasive procedure. Since the combination of epidermal growth factor (EGF) and fibroblast growth factor type 2 (FGF{sub 2}) is mitogenic and promotes the neuronal commitment of various stem cell populations, we examined its effects in the proliferation and neuronal potential of mouse EPI-NCSCs. By using a recognized culture protocol of bulge whiskers follicles, we were able to isolate a population of EPI-NCSCs, characterized by the migratory potential, cell morphology and expression of phenotypic markers of NC cells. EPI-NCSCs expressed neuronal, glial and smooth muscle markers and exhibited the NC-like fibroblastic morphology. The treatment with the combination EGF and FGF{sub 2}, however, increased their proliferation rate and promoted the acquisition of a neuronal-like morphology accompanied by reorganization of neural cytoskeletal proteins βIII-tubulin and nestin, as well as upregulation of the pan neuronal marker βIII-tubulin and down regulation of the undifferentiated NC, glial and smooth muscle cell markers. Moreover, the treatment enhanced the response of EPI-NCSCs to neurogenic stimulation, as evidenced by induction of GAP43, and increased expression of Mash-1 in neuron-like cell, both neuronal-specific proteins. Together, the results suggest that the combination of EGF–FGF2 stimulates the proliferation and improves the neuronal potential of EPI-NCSCs similarly to embryonic NC cells, ES cells and neural progenitor/stem cells of the central nervous system and highlights the advantage of using EGF–FGF{sub 2} in neuronal differentiation protocols. - Highlights: • EPI-NCSCs express undifferentiated NC and lineage-specific markers. • EGF–FGF{sub 2} supports in vitro expansion of EPI-NCSCs. • EGF–FGF{sub 2} promotes acquisition of neuron-like morphology by EPI-NCSCs. • EGF–FGF{sub 2} up regulates the expression of the pan-neuronal marker βIII-tubulin. • EGF–FGF{sub 2} enhances the response of EPI-NCSCs to neurogenic stimulation in vitro.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

A new cell-based assay to evaluate myogenesis in mouse myoblast C2C12 cells

The development of the efficient screening system of detecting compounds that promote myogenesis and prevent muscle atrophy is important. Mouse C2C12 cells are widely used to evaluate myogenesis but the procedures of the assay are not simple and the quantification is not easy. We established C2C12 cells expressing the N-terminal green fluorescence protein (GFP) and the C-terminal GFP (GFP1–10 and GFP11 cells). GFP1–10 and GFP11 cells do not exhibit GFP signals until they are fused. The signal intensity correlates with the expression of myogenic markers and myofusion. Myogenesis-promoting reagents, such as insulin-like growth factor-1 (IGF1) and β-guanidinopropionic acid (GPA), enhance the signals, whereas the poly-caspase inhibitor, z-VAD-FMK, suppresses it. GFP signals are observed when myotubes formed by GFP1–10 cells are fused with single nuclear GFP11 cells, and enhanced by IGF1, GPA, and IBS008738, a recently-reported myogenesis-promoting reagent. Fusion between myotubes formed by GFP1–10 and GFP11 cells is associated with the appearance of GFP signals. IGF1 and GPA augment these signals, whereas NSC23766, Rac inhibitor, decreases them. The conditioned medium of cancer cells suppresses GFP signals during myogenesis and reduces the width of GFP-positive myotubes after differentiation. Thus the novel split GFP-based assay will provide the useful method for the study of myogenesis, myofusion, and atrophy. - Highlights: • C2C12 cells expressing split GFP proteins show GFP signals when mix-cultured. • The GFP signals correlate with myogenesis and myofusion. • The GFP signals attenuate under the condition that muscle atrophy is induced.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Polymer microfiber meshes facilitate cardiac differentiation of c-kit{sup +} human cardiac stem cells

Electrospun microfiber meshes have been shown to support the proliferation and differentiation of many types of stem cells, but the phenotypic fate of c-kit{sup +} human cardiac stem cells (hCSCs) have not been explored. To this end, we utilized thin (~5 µm) elastomeric meshes consisting of aligned 1.7 µm diameter poly (ester-urethane urea) microfibers as substrates to examine their effect on hCSC viability, morphology, proliferation, and differentiation relative to cells cultured on tissue culture polystyrene (TCPS). The results showed that cells on microfiber meshes displayed an elongated morphology aligned in the direction of fiber orientation, lower proliferation rates, but increased expressions of genes and proteins majorly associated with cardiomyocyte phenotype. The early (NK2 homeobox 5, Nkx2.5) and late (cardiac troponin I, cTnI) cardiomyocyte genes were significantly increased on meshes (Nkx=2.5 56.2±13.0, cTnl=2.9±0.56,) over TCPS (Nkx2.5=4.2±0.9, cTnl=1.6±0.5, n=9, p<0.05 for both groups) after differentiation. In contrast, expressions of smooth muscle markers, Gata6 and myosin heavy chain (SM-MHC), were decreased on meshes. Immunocytochemical analysis with cardiac antibody exhibited the similar pattern of above cardiac differentiation. We conclude that aligned microfiber meshes are suitable for guiding cardiac differentiation of hCSCs and may facilitate stem cell-based therapies for treatment of cardiac diseases. - Highlights: • First study to characterize c-kit{sup +} human cardiac stem cells on microfiber meshes. • Microfiber meshes seem reducing cell proliferation, but no effect on cell viability. • Microfiber meshes facilitate the elongation of human cardiac stem cells in culture. • Cardiac but not smooth muscle differentiation were enhanced on microfiber meshes. • Microfiber meshes may be used as cardiac patches in cell-based cardiac therapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Atractylenolide I restores HO-1 expression and inhibits Ox-LDL-induced VSMCs proliferation, migration and inflammatory responses in vitro

Pathogenesis of atherosclerosis is characterized by the proliferation and migration of vascular smooth muscle cells (VSMCs) and inflammatory lesions. The aim of this study is to elucidate the effect of atractylenolide I (AO-I) on smooth muscle cell inflammation, proliferation and migration induced by oxidized modified low density lipoprotein (Ox-LDL). Here, We found that atractylenolide I inhibited Ox-LDL-induced VSMCs proliferation and migration in a dose-dependent manner, and decreased the production of inflammatory cytokines and the expression of monocyte chemoattractant protein-1 (MCP-1) in VSMCs. The study also identified that AO-I prominently inhibited p38-MAPK and NF-κB activation. More importantly, the specific heme oxygenase-1 (HO-1) inhibitor zinc protoporphyrin (ZnPP) IX partially abolished the beneficial effects of atractylenolide I on Ox-LDL-induced VSMCs. Furthermore, atractylenolide I blocked the foam cell formation in macrophages induced by Ox-LDL. In summary, inhibitory roles of AO-I in VSMCs proliferation and migration, lipid peroxidation and subsequent inflammatory responses might contribute to the anti-atherosclerotic property of AO-I. - Highlights: • AO-I inhibited Ox-LDL-induced VSMCs proliferation and migration. • AO-I alleviated inflammatory response via inhibiting TNF-α, IL-6 and NO production. • AO-I restored HO-1 expression and down-regulated PCNA expression. • MCP-1 overexpression is potentially regulated by NF-κB and p38 MAPK pathway. • AO-I possesses strong anti-lipid peroxidation effect.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

β-catenin is important for the development of an insulin responsive pool of GLUT4 glucose transporters in 3T3-L1 adipocytes

GLUT4 is unique among specialized glucose transporters in being exclusively expressed in muscle and adipocytes. In the absence of insulin the distribution of GLUT4 is preferentially intracellular and insulin stimulation results in the movement of GLUT4 containing vesicles to the plasma membrane. This process is responsible for the insulin stimulation of glucose uptake in muscle and fat. While signalling pathways triggering the translocation of GLUT4 are well understood, the mechanisms regulating the intracellular retention of GLUT4 are less well understood. Here we report a role for β-catenin in this process. In 3T3-L1 adipocytes in which β-catenin is depleted, the levels of GLUT4 at and near the plasma membrane rise in unstimulated cells while the subsequent increase in GLUT4 at the plasma membrane upon insulin stimulation is reduced. Small molecule approaches to acutely activate or inhibit β-catenin give results that support the results obtained with siRNA and these changes are accompanied by matching changes in glucose transport into these cells. Together these results indicate that β-catenin is a previously unrecognized regulator of the mechanisms that control the insulin sensitive pool of GLUT4 transporters inside these adipocyte cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Dexamethasone reduces the formation of thoracic aortic aneurysm and dissection in a murine model

Highlights: • Dexamethasone attenuated thoracic aortic aneurysm and dissection in a mouse model. • Dexamethasone reduced infiltration of inflammatory cell and apoptosis of vascular smooth muscle cell and fibroblast. • Dexamethasone partly alleviated degradation of collagen and phenotype switch. • DEX might ameliorate thoracic aortic aneurysm and dissection by suppressing NF-κB signaling pathway. Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening vascular disease with no effective pharmaceutical therapies currently available. Inflammation plays a key role in the progression of aneurysms. Dexamethasone (DEX), a synthetic glucocorticoid, has showed alleviating effects on cells in vitro from TAAD patients. Here we performed a study aiming at investigating the protective role of DEX in a β-aminopropionitrile monofumarate (BAPN)-induced TAAD mouse model. DEX (dose: 0.04 mg/kg/day) treatment significantly reduced the aortic diameter and inhibited TAAD formation. DEX reduced infiltration of macrophages and neutrophils, apoptosis of vascular smooth muscle cells (VSMCs), expression of metalloproteinase 2/9, and extracellular matrix degradation in BAPN-treated TAAD mice. Furthermore, DEX therapy downregulated the expression of p-p65 in macrophages and VSMCs, which suggested that DEX might ameliorate BAPN-induced TAAD by suppressing NF-κB signaling. Therefore, DEX therapy attenuates the progression of BAPN-induced TAAD murine model and could be used as an effective adjuvant therapy for treating TAAD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

CRISPR/Cas correction of muscular dystrophies

Muscular dystrophies are a heterogeneous group of monogenic neuromuscular disorders which lead to progressive muscle loss and degeneration of the musculoskeletal system. The genetic causes of muscular dystrophies are well characterized, but no effective treatments have been developed so far. The discovery and application of the CRISPR/Cas system for genome editing offers a new path for disease treatment with the potential to permanently correct genetic mutations. The post-mitotic and multinucleated features of skeletal muscle provide an ideal target for CRISPR/Cas therapeutic genome editing because correction of a subpopulation of nuclei can provide benefit to the whole myofiber. In this review, we provide an overview of the CRISPR/Cas system and its derivatives in genome editing, proposing potential CRISPR/Cas-based therapies to correct diverse muscular dystrophies, and we discuss challenges for translating CRISPR/Cas genome editing to a viable therapy for permanent correction of muscular dystrophies.

60 APPLIED LIFE SCIENCES↗