Breaking News
November 16, 2018 - Drug used to treat dizziness may slow down growth of triple-negative breast cancer
November 16, 2018 - AHA: Icosapent Ethyl Cuts CV Risk From Elevated Triglycerides
November 16, 2018 - ‘Orphan’ RNAs make cancer deadlier, but potentially easier to diagnose
November 16, 2018 - Air Cube touches down at hospital | News Center
November 16, 2018 - CRISPR-based tool shown to enhance cell-based immunotherapy
November 16, 2018 - Mechanisms that govern HIV latency differ in the gut and blood, finds study
November 16, 2018 - Researchers unravel mystery of NPM1 protein in acute myeloid leukemia
November 16, 2018 - High school students less likely to select milk, fruit for lunch when fruit juice is available
November 16, 2018 - Football coaches with great emotional competence are more successful
November 16, 2018 - Researchers awarded $10 million grant to address root causes of asthma in Puerto Rico
November 16, 2018 - Health Tip: Manage Morning Sickness
November 16, 2018 - Immunotherapy combination and chemotherapy show encouraging results in Phase II acute myeloid leukemia study
November 16, 2018 - ACC Latin America Conference brings experts to discuss latest cardiovascular science
November 16, 2018 - Pooled analysis of Intersect ENT’s steroid releasing implants in patients after frontal sinus surgery to be published
November 16, 2018 - Expectations about pain intensity can become self-fulfilling prophecies
November 16, 2018 - NIH awards $3.4 million to UC researchers to study gastrointestinal lymphatic system
November 16, 2018 - Scientist Dr David Taylor of MR Solutions is a finalist in the BMW i UK Tech Founder Awards
November 16, 2018 - Earlier treatment could help reverse autistic-like behavior in tuberous sclerosis
November 16, 2018 - Vegetables and salad may include bacteria that are resistant to antibiotics
November 16, 2018 - Autism linked to prolonged connection between brain regions
November 16, 2018 - Endocrine Society chooses four Diabetes Caucus leaders as winners of Diabetes Champion Award
November 16, 2018 - Brain and muscle cells found within kidney organoids
November 16, 2018 - Person’s sex hormones may play key role in trauma survival, finds study
November 16, 2018 - PTEN Genetic Test: MedlinePlus Lab Test Information
November 16, 2018 - Toxic metal pollution linked with development of autism spectrum disorder
November 16, 2018 - Calcified nodules in the retina increase risk for progression to late stages of AMD
November 16, 2018 - ZEISS teams up with arivis AG to offer complete 3D imaging solutions
November 16, 2018 - Georgia State professor receives $1.2 million grant to study how the brain controls eating behavior
November 16, 2018 - Specific bacterial toxins reduce number of cells suppressing immune response
November 16, 2018 - Review by ID physician improves outcomes for outpatient parenteral antimicrobial therapy
November 16, 2018 - Conditions that produce signs similar to arthritis
November 16, 2018 - New artificial intelligence-based method predicts treatment effectiveness
November 16, 2018 - AHA: Dapagliflozin Noninferior to Placebo for MACE in T2DM
November 16, 2018 - Surgery remains best treatment for appendicitis, Stanford study finds
November 16, 2018 - Non-surgical fistula creation system Ellipsys becomes key focus of attention at CiDA
November 16, 2018 - Researchers find no link between ‘allergy friendly’ dogs and lower risk of asthma
November 16, 2018 - Researchers elucidate new rules of connectivity of neurons in the neocortex
November 16, 2018 - Treating children with ‘bubble baby disease’
November 16, 2018 - Nexus announces availability of Arsenic Trioxide Injection in the US
November 16, 2018 - Researchers find metabolite shuttle between cells in the liver that may combat tissue fibrosis
November 16, 2018 - AHA: PTSD Common Among Those Who Suffer Tear in the Aorta’s Wall
November 16, 2018 - Many RA patients’ pain related to central nervous system
November 16, 2018 - Changes in Himalayan gut microbiomes linked to diet
November 16, 2018 - Inhibition of prostaglandin E2 enhances ability to combat infectious colitis
November 16, 2018 - Chronic dry eye can slow reading rate and disrupt day to day tasks
November 16, 2018 - Researchers develop new drug molecule that inhibits inflammation
November 16, 2018 - Dementia symptoms peak in winter and spring, study finds
November 16, 2018 - Stanford tobacco researcher weighs in on JUUL
November 16, 2018 - Increasing omega-3 fatty acid intake during pregnancy reduces risk of premature birth, review finds
November 16, 2018 - Researchers find no link between infants waking up at night and later developmental problems
November 16, 2018 - Both parents and children agree about confidential medical services
November 16, 2018 - FDA warns against use of unapproved pain medications with implanted pumps
November 16, 2018 - Precision medicine-based approach to slow or reverse biologic drivers of Alzheimer’s disease
November 16, 2018 - Study provides new insight into norovirus outbreaks, may help guide efforts to develop vaccines
November 16, 2018 - Inexpensive, portable air purifier could help protect the heart from pollution
November 16, 2018 - New 15-minute scan could help diagnose brain damage in babies up to two years old
November 16, 2018 - Deep brain stimulation not effective for treating early Alzheimer’s
November 16, 2018 - Traditional chemotherapy superior to new alternative for oropharyngeal cancers | News Center
November 16, 2018 - What This Pond Protist Does With Its Genome Will Astound You
November 15, 2018 - Researchers develop tool that speeds up analysis and publication of biomedical data
November 15, 2018 - Scientists identify mechanism used by lung cancer cells to obtain glucose
November 15, 2018 - Abnormalities in development of the brain could be involved in onset of autism, finds new study
November 15, 2018 - Soy protein equally effective as animal protein in building muscle strength
November 15, 2018 - American Academy of Pediatrics, Nov. 2-6
November 15, 2018 - Dopamine drives early addiction to heroin
November 15, 2018 - Variance in gut microbiome in Himalayan populations linked to dietary lifestyle | News Center
November 15, 2018 - Reducing Cardiovascular Disease: The Amish Way
November 15, 2018 - King’s researchers launch charter to guide organizations to engage abuse survivors in research
November 15, 2018 - Enable Injections enters into development agreements with UCB and Apellis Pharmaceuticals
November 15, 2018 - TGen North collaborates with NARBHA Institute to advance human health
November 15, 2018 - Researchers discover molecular basis for therapeutic actions of an African folk medicine
November 15, 2018 - Human Cell Atlas study of early pregnancy shows how mother’s immune system is modified
November 15, 2018 - New guidelines for detecting and managing sarcopenia to be launched in the UK
November 15, 2018 - Researchers explore role of dietary composition on energy expenditure
November 15, 2018 - Elsevier launches Entellect™ Platform, unlocking value by creating AI-ready life sciences data
November 15, 2018 - Now that cannabis is legal in Canada, let’s use it to tackle the opioid crisis
November 15, 2018 - In the Spotlight: At the intersection of tech, health, and ethics
November 15, 2018 - Traditional Glaucoma Test Can Miss Severity of the Disease
November 15, 2018 - Researchers directly connect activities of genes with instinctive behavior in male cichlids
November 15, 2018 - Salk researchers report new methods to identify AD drug candidates with anti-aging properties
Genetically engineered 3-D human muscle transplant in a murine model

Genetically engineered 3-D human muscle transplant in a murine model

image_pdfDownload PDFimage_print
Vascular cell transduction and multicellular culturing strategy. Schematic representation of the diverse multicellular cultures examined: co-cultures and tri-cultures of naive or ANGPT-1 secreting endothelial cells with naive or VEGF-secreting SMCs and human myoblasts to generate 3D vascular networks within skeletal muscle constructs. Credit: Communications Biology, doi:10.1038/s42003-018-0161-0.

A growing need for tissues and organs in surgical reconstruction is addressed by the promising field of tissue engineering. For instance, muscle atrophy results from severe traumatic events including deep burns and cancer, requiring site/donor compatible surgical reconstruction. The existing ‘gold standard’ treatment in reconstructive surgery incorporates autologous flaps, although the technique is limited by low anatomical availability and donor site morbidity during clinical transplantation. As a clinically favorable alternative, tissue engineering presents strategies to engineer tissue grafts with improved quality and effectiveness. To maintain the viability of implants upon transplantation, increasing efforts are invested in designing pre-vascularized engineered tissue. Design examples include a multicellular culture of endothelial, mural and tissue-specific cells for self-assembly of vessel networks and cellular co-culture to build lasting, stable blood vessels to induce neovascularization within the host.

Recent studies have also demonstrated the possibility of engineering three-dimensional (3-D) muscle grafts from human cells (adult and differentiated) for seamless integration with native tissue upon transplantation. In parallel studies, a group of researchers showed that intra-arterial injections of adult venous endothelial cells proximal to an occluded artery in critical limb ischemia patients stimulated collateral expansion in Phase I and Phase Ib clinical trials.

The same multidisciplinary research team from the departments of Biomedical Engineering and Medicine now report on the development of a 3-D prevascularized engineered muscle containing human myoblasts (muscle cells) with genetically engineered endothelial cells and smooth muscle cells (SMCs), transplanted within a mouse host to enhance neovascularization and myogenesis. The outcomes are detailed in Nature Communications Biology, where Luba Perry and co-workers integrated myoblasts in endothelial cell-mural cell co-cultures as a tissue engineering strategy to increase the mechanical strength of transplanted tissue. The genetically modified vascular cells were cleared for clinical trials by the Food and Drug Administration (FDA), with potential for use in autologous vascularized tissue construction. The study showed promise for translating genetically engineered muscle in clinical settings to overcome autologous tissue shortage and accelerate host neovascularization for engineered grafts integration post-transplantation.

Images and schematics of the abdominal imaging window (AIW), a) schematic representation of the surgical procedure, b,c) top and bottom view of the AIW, d,e) lateral view of the AIW (scale bar = 10 mm), f) the AIW immediately post-transplantation in the abdominal muscle, the area of the implanted graft is seen in yellow dashes, g) the AIW 14 days post-implantation in the muscle, h) the graft integrated completely at 14 days post implantation in the muscle, i) the surgical procedure imaged with a mouse stabilized in a custom-made stabilizing imaging device (SID) for intravital confocal imaging. Credit: Communications Biology, doi:10.1038/s42003-018-0161-0.

The scientists seeded a multicellular culture of human angiopoietin 1 (ANGPT1) expressing endothelial cells (endothelial cellANGPT1) with human vascular endothelial growth factor (VEGF) expressing smooth muscle cells (SMCVEGF) and human myoblasts (hMyo) on 3-D polymer scaffolds to accelerate the vessel network formation and neovascularization in vitro and in vivo. Upon transplantation into mice with an abdominal wall defect, the host neovascularization was observed via an abdominal imaging window (AIW) for up to 14 days. To avoid transplant rejection, the study used immunodeficient mice for human graft integration. Since the cells used in the study were already FDA-approved for use in clinical trials, the findings may have significant implications in the construction of autologous, transplantable grafts for clinical integration and vascularization.

To genetically engineer the endothelial cell ANGPT1, adult endothelial cells were transduced with a retroviral vector to express ANGPT1 and then transduced with ZsGreen lentiviral particles. Adult SMCs were also similarly transduced with a retroviral vector to express VEGF165 (SMCVEGF) by replicating an established protocol. The expression of transgenes was determined via immunohistochemistry and enzyme linked immunosorbent assays (ELISAs).

In vitro vessel-like network stability. Representative 3D confocal images of whole-mount immunofluorescent scaffolds populated with endothelial cellANGPT1 (green), SMCsVEGF (red) and nuclei (blue). Credit: Communications Biology, doi:10.1038/s42003-018-0161-0.

Scaffolds were fabricated using 3-D porous poly-L-lactic acid (PLLA) and polylactic glycolic acid (PLGA) polymers with ranging pore sizes and porosity, replicating a previously described protocol. The authors investigated six multicellular cultures (co- and tri-culture cells) on separate scaffolds to generate 3-D vascular networks. Scaffolds were populated with diverse compositions of endothelial cellANGPT1, SMCsVEGF and primary human skeletal muscle cells (hMyo) visualized using immunofluorescence; endothelial cells were stained green, αSMA-positive cells stained red, and nuclei stained blue. The higher number of endothelial cells surrounded by αSMA-expressing mural cells suggested the formation of stable vessels.

To investigate the influence of ANGPT1 and VEGF overexpression on vessel maturation, the vascularized constructs were stained for collagen IV and vascular endothelial (VE) cadherin. The results demonstrated a higher percentage of collagen IV-wrapped vessels.

In vitro vessel-like maturity. Representative confocal images of whole-mount immunofluorescent scaffolds populated with tricultures (Endothelial cells – green, collagen positive cells – red, nuclei – blue). Credit: Communications Biology, doi:10.1038/s42003-018-0161-0.

Once ANGPT1-overexpressing endothelial cells were found to increase both the length and maturity of the vessel-like networks formed in vitro, the effect on host vascularization was examined upon transplantation. For in vivo investigations, the scientists used a previously established rectus abdominis muscle defect nude mouse model. The engineered muscles included those formed from a naive endothelial cell-SMC-myoblasts tri-culture as the control, alongside muscles formed from endothelial cellANGPT1, SMCVEGF and myoblasts tri-culture as the test, implanted four days after seeding. Both groups showed highly effective host-graft integration 14 days post implantation.

In vivo neovascularization, a) representative confocal images of the graft obtained through the AIW for control vs. test grafts (green: human endothelial cells-ZsGreen, red: TRITC dextran, blue: mouse CD31), b) representative confocal large-magnification images of grafts with native or ANGPT1 and VEGF expressing tricultures (scale bar – 100 µm) c) representative image of TRITC-dextran circulating in transplanted scaffolds and its respective AngioTool analysis; vessel skeletons are in red, vessel borders in yellow and vessel junctions in blue, d) AngioTool quantitated total vessel length of both functional and non-functional mouse blood vessels. Data are expressed as box-and-whisker plots, e) AngioTool-quantified total vessel length of functional blood vessels, d) AngioTool-quantified total vessel length of implanted endothelial cells (ECs) (control and test), implanted ECs were mostly noticeable in the control grafts, while those in the test grafts were barely noticeable at days 4-14. Credit: Communications Biology, doi:10.1038/s42003-018-0161-0.

By as early as four days after implantation, the host vessel invaded into both graft types, although the progression and coverage were faster in the ANGPT-1- and VEGF-expressing test grafts. After 14 days of transplantation, the test grafts were more densely populated with host vasculature than the control triculture grafts; by this time, the implanted scaffold vasculature for either graft was no longer visible. At four to 14 days post-transplantation, the total length of the vessels in constructs were calculated using the AngioTool software, with greater vessel length seen in ANGPT1- and VEGF- expressing grafts compared to the controls. Images of hematoxylin and eosin (H&E) stains of transplanted grafts indicated they were perfused and functional comparable to physiological vessel density of the surrounding native muscle by day 14. Muscle fibers formed around and inside the graft area within the same timeline, covering a larger area in the test grafts compared to the controls to indicate superior myogenesis.

The detailed construction of a genetically engineered, vascularized muscle tissue can be translated to engineer other types of vascularized tissue by integrating tissue-specific cell types. The ability to derive such cells from elderly patients is of great importance as they can be transplanted without rejection. The regulatory challenges along the bench-to-bedside route of autologous engineered tissue products present a challenge, accompanied with the time-length for cell culture, which must be accounted for. Engineered muscles should be further optimized to better mimic native muscle tissue, followed by animal studies in larger animal models—alongside comparisons between different donor cells, prior to translating the genetically engineered vascularized 3-D muscle grafts to a clinical setting.


Explore further:
New approach reduces immune response to tissue engineered vascular grafts

More information:
Luba Perry et al. Genetically engineered human muscle transplant enhances murine host neovascularization and myogenesis, Communications Biology (2018). DOI: 10.1038/s42003-018-0161-0

Luba Perry et al. Elderly Patient-Derived Endothelial Cells for Vascularization of Engineered Muscle, Molecular Therapy (2017). DOI: 10.1016/j.ymthe.2017.02.011

Naoto Koike et al. Creation of long-lasting blood vessels, Nature (2004). DOI: 10.1038/428138a

Journal reference:
Molecular Therapy

Nature

Tagged with:

About author

Related Articles