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Kaiser M, Rodriguez-Menocal L, Badiavas EV. Role of Extracellular Vesicles in Stem Cell Therapy. Curr Stem Cell Res Ther 2024; 19:629-635. [PMID: 35786194 DOI: 10.2174/1574888x17666220630162836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/22/2022]
Abstract
Burn wounds are a major source of morbidity and mortality in both the military and civilian settings. Research about the pathophysiology of thermal injury has revealed possible interventions that can aid this process to reduce scarring and wound contracture. Bone Marrow derived Mesenchymal Stem Cells (BM-MSCs) have been an exciting topic in research for many years. They have been shown to facilitate wound healing and tissue regeneration, two areas that are vital in the healing process, especially in burn wounds. More recently the discovery of Extracellular Vesicles (EVs) has allowed us to further characterize the immunomodulatory roles and understand the cellular pathways implicated in wound healing. The purpose of this review is to discuss the role of EVs in wound healing, and to propose that EVs are the main mechanism that deliver cellular materials to target cells to coordinate wound healing following tissue injury.
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Affiliation(s)
- Michael Kaiser
- Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Evangelos V Badiavas
- Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, Florida, United States
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Rodriguez-Menocal L, Davis SC, Guzman W, Gil J, Valdes J, Solis M, Higa A, Natesan S, Schulman CI, Christy RJ, Badiavas EV. Model to Inhibit Contraction in Third-Degree Burns Employing Split-Thickness Skin Graft and Administered Bone Marrow-Derived Stem Cells. J Burn Care Res 2023; 44:302-310. [PMID: 36048023 DOI: 10.1093/jbcr/irac119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Indexed: 11/14/2022]
Abstract
Third-degree burns typically result in pronounced scarring and contraction in superficial and deep tissues. Established techniques such as debridement and grafting provide benefit in the acute phase of burn therapy, nevertheless, scar and contraction remain a challenge in deep burns management. Our ambition is to evaluate the effectiveness of novel cell-based therapies, which can be implemented into the standard of care debridement and grafting procedures. Twenty-seven third-degree burn wounds were created on the dorsal area of Red Duroc pig. After 72 h, burns are surgically debrided using a Weck knife. Split-thickness skin grafts (STSGs) were then taken after debridement and placed on burn scars combined with bone marrow stem cells (BM-MSCs). Biopsy samples were taken on days 17, 21, and 45 posttreatment for evaluation. Histological analysis revealed that untreated control scars at 17 days are more raised than burns treated with STSGs alone and/or STSGs with BM-MSCs. Wounds treated with skin grafts plus BM-MSCs appeared thinner and longer, indicative of reduced contraction. qPCR revealed some elevation of α-SMA expression at day 21 and Collagen Iα2 in cells derived from wounds treated with skin grafts alone compared to wounds treated with STSGs + BM-MSCs. We observed a reduction level of TGFβ-1 expression at days 17, 21, and 45 in cells derived from wounds treated compared to controls. These results, where the combined use of stem cells and skin grafts stimulate healing and reduce contraction following third-degree burn injury, have a potential as a novel therapy in the clinic.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery/Interdisciplinary/Stem Cell Institute, University of Miami School of Medicine, Miami, Florida, USA
| | - Stephen C Davis
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Wellington Guzman
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery/Interdisciplinary/Stem Cell Institute, University of Miami School of Medicine, Miami, Florida, USA
| | - Joel Gil
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Jose Valdes
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Michael Solis
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Alexander Higa
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Shanmugasundaram Natesan
- Extremity Trauma and Regenerative Medicine Program, US Army Institute of Surgical Research, Texas, USA
| | - Carl I Schulman
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, Florida, USA
| | - Robert J Christy
- Extremity Trauma and Regenerative Medicine Program, US Army Institute of Surgical Research, Texas, USA
| | - Evangelos V Badiavas
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery/Interdisciplinary/Stem Cell Institute, University of Miami School of Medicine, Miami, Florida, USA
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3
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Wieder E, Kolonias D, Itamura H, Rodriguez-Menocal L, Wang TP, Badiavas E, Komanduri KV. Mesenchymal Stem Cell Derived Extracellular Vesicles Regulate Murine Gvhd. Transplant Cell Ther 2022. [DOI: 10.1016/s2666-6367(22)00526-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schulman CI, Namias N, Pizano L, Rodriguez-Menocal L, Aickara D, Guzman W, Candanedo A, Maranda E, Beirn A, Badiavas EV. The effect of mesenchymal stem cells improves the healing of burn wounds: a phase 1 dose-escalation clinical trial. Scars Burn Heal 2022; 8:20595131211070783. [PMID: 35781931 PMCID: PMC9247372 DOI: 10.1177/20595131211070783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background Stem cell therapy holds promise to improve healing and stimulate tissue
regeneration after burn injury. Preclinical evidence has supported this;
however, clinical studies are lacking. We examined the application of bone
marrow-derived mesenchymal stem cells (BM-MSC) to deep second-degree burn
injuries using a two-dose escalation protocol. Methods Ten individuals aged 18 years or older with deep second-degree burn wounds
were enrolled. The first five patients were administered 2.5 × 10³
BM-MSC/cm2 to their wounds. After safety of the initial dose
level was assessed, a second group of five patients was treated with a
higher concentration of 5 × 10³ allogeneic BM-MSC/cm2. Safety was
assessed clinically and by evaluating cytokine levels in mixed recipient
lymphocyte/donor BM-MSC reactions (INFγ, IL-10 and TNFα). At each visit, we
performed wound measurements and assessed wounds using a Patient and
Observer Scar Assessment Scale (POSAS). Results All patients responded well to treatment, with 100% closure of wounds and
minimal clinical evidence of fibrosis. No adverse reactions or evidence of
rejection were observed for both dose levels. Patients receiving the first
dose concentration had a wound closure rate of 3.64 cm2/day.
Patients receiving the second dose concentration demonstrated a wound
closure rate of 10.47 cm2/day. The difference in healing rates
between the two groups was not found to be statistically significant
(P = 0.17). Conclusion BM-MSC appear beneficial in optimising wound healing in patients with deep
second-degree burn wounds. Adverse outcomes were not observed when
administering multiple doses of allogeneic BM-MSC. Lay Summary Thermal injuries are a significant source of morbidity and mortality,
constituting 5%–20% of all injuries and 4% of all deaths. Despite overall
improvements in the management of acutely burned patients, morbidities
associated with deeper burn injuries remain commonplace. Burn patients are
too often left with significant tissue loss, scarring and contractions
leading to physical loss of function and long-lasting psychological and
emotional impacts. In previous studies, we have demonstrated the safety and efficacy of
administering bone marrow-derived mesenchymal stem cells (BM-MSC) to chronic
wounds with substantial improvement in healing and evidence of tissue
regeneration. In this report, we have examined the application of BM-MSC to
deep second-degree burn injuries in patients. The aim of the present phase I/II clinical trial was to examine the safety
and efficacy of administering allogeneic BM-MSC to deep second-degree burns.
We utilised two different dose levels at concentrations 2.5 × 103
and 5 × 103 cells/cm2. Patients with deep
second-degree burn wounds up to 20% of the total body surface area were
eligible for treatment. Allogeneic BM-MSC were applied to burn wounds
topically or by injection under transparent film dressing <7 days after
injury. Patients were followed for at least six months after treatment. Using two dose levels allowed us to gain preliminary information as to
whether different amounts of BM-MSC administered to burn wounds will result
in significant differences in safety/ clinical response. Once the safety and
dose-response analysis were completed, we evaluated the efficacy of
allogeneic stem cell therapy in the treatment of deep second-degree burn
wounds. In this study, we examined the role of allogeneic BM-MSC treatment in
patients with deep second-degree burn injuries, in a dose-dependent manner.
No significant related adverse events were reported. Safety was evaluated
both clinically and by laboratory-based methods. Efficacy was assessed
clinically through evidence of re-pigmentation, hair follicle restoration
and regenerative change. While these findings are encouraging, more studies
will be needed to better establish the benefit of BM-MSC in the treatment of
burn injuries.
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Affiliation(s)
- Carl I Schulman
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, FL, USA
| | - Nicholas Namias
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, FL, USA
| | - Louis Pizano
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, FL, USA
| | - Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery. Leonard M Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Miami, FL, USA
| | - Divya Aickara
- Department of Dermatology and Cutaneous Surgery. Leonard M Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Miami, FL, USA
| | - Wellington Guzman
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, FL, USA
| | - Ambar Candanedo
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, FL, USA
| | - Eric Maranda
- Department of Dermatology and Cutaneous Surgery. Leonard M Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Miami, FL, USA
| | - Audrey Beirn
- Department of Dermatology and Cutaneous Surgery. Leonard M Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Miami, FL, USA
| | - Evangelos V Badiavas
- Department of Dermatology and Cutaneous Surgery. Leonard M Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Miami, FL, USA
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McBride JD, Rodriguez-Menocal L, Candanedo A, Guzman W, Garcia-Contreras M, Badiavas EV. Dual mechanism of type VII collagen transfer by bone marrow mesenchymal stem cell extracellular vesicles to recessive dystrophic epidermolysis bullosa fibroblasts. Biochimie 2018; 155:50-58. [DOI: 10.1016/j.biochi.2018.04.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 04/06/2018] [Indexed: 01/08/2023]
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6
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Rodriguez-Menocal L, Davis SS, Becerra S, Salgado M, Gill J, Valdes J, Candanedo A, Natesan S, Solis M, Guzman W, Higa A, Schulman CI, Christy RJ, Waibel J, Badiavas EV. Assessment of Ablative Fractional CO2 Laser and Er:YAG Laser to Treat Hypertrophic Scars in a Red Duroc Pig Model. J Burn Care Res 2018; 39:954-962. [DOI: 10.1093/jbcr/iry012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
| | - Stephen S Davis
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - Sandra Becerra
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, Florida
| | - Marcela Salgado
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
| | - Joel Gill
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - Jose Valdes
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - Ambar Candanedo
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
| | - Shanmugasundaram Natesan
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, Florida
| | - Michael Solis
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - Wellington Guzman
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
| | - Alex Higa
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
| | - Carl I Schulman
- Extremity Trauma and Regenerative Medicine Program, US Army Institute of Surgical Research, Chambers Pass, Fort Sam Houston, Texas
| | - Robert J Christy
- Department of Surgery, Ryder Trauma Center, University of Miami School of Medicine, Miami, Florida
| | - Jill Waibel
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
| | - Evangelos V Badiavas
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida
- Interdisciplinary Stem Cell Institute, University of Miami School of Medicine, Miami, Florida
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Cui T, Jimenez JJ, Block NL, Badiavas EV, Rodriguez-Menocal L, Vila Granda A, Cai R, Sha W, Zarandi M, Perez R, Schally AV. Agonistic analogs of growth hormone releasing hormone (GHRH) promote wound healing by stimulating the proliferation and survival of human dermal fibroblasts through ERK and AKT pathways. Oncotarget 2018; 7:52661-52672. [PMID: 27494841 PMCID: PMC5288139 DOI: 10.18632/oncotarget.11024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/23/2016] [Indexed: 12/22/2022] Open
Abstract
Decreased or impaired proliferation capability of dermal fibroblasts interferes with successful wound healing. Several growth factors tested failed to fully restore the growth of fibroblasts, possibly due to their rapid degradation by proteases. It is therefore critical to find new agents which have stimulatory effects on fibroblasts while being highly resistant to degradation. In such a scenario, the activities of two agonistic analogs of growth hormone releasing hormone (GHRH), MR-409 and MR-502, were evaluated for their impact on proliferation and survival of primary human dermal fibroblasts. In vitro, both analogs significantly stimulated cell growth by more than 50%. Under serum-depletion induced stress, fibroblasts treated with MR-409 or MR-502 demonstrated better survival rates than control. These effects can be inhibited by either PD98059 or wortmannin. Signaling through MEK/ERK1/2 and PI3K/AKT in an IGF-1 receptor-independent manner is required. In vivo, MR-409 promoted wound closure. Animals treated topically with MR-409 healed earlier than controls in a dose-dependent manner. Histologic examination revealed better wound contraction and less fibrosis in treated groups. In conclusion, MR-409 is a potent mitogenic and anti-apoptotic factor for primary human dermal fibroblasts. Its beneficial effects on wound healing make it a promising agent for future development.
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Affiliation(s)
- Tengjiao Cui
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA.,Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joaquin J Jimenez
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Norman L Block
- Department of Pathology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Evangelos V Badiavas
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Medicine, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Medicine, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ailin Vila Granda
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Renzhi Cai
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA.,Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Wei Sha
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA.,Department of Medicine, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Marta Zarandi
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA
| | - Roberto Perez
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA
| | - Andrew V Schally
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA.,South Florida VA Foundation for Research and Education, Veterans Affairs Medical Center, Miami, FL, USA.,Department of Pathology, University of Miami Miller School of Medicine, Miami, FL, USA.,Division of Hematology/Oncology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.,Division of Endocrinology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.,Department of Medicine, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA.,Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA
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8
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McBride JD, Rodriguez-Menocal L, Guzman W, Candanedo A, Garcia-Contreras M, Badiavas EV. Bone Marrow Mesenchymal Stem Cell-Derived CD63 + Exosomes Transport Wnt3a Exteriorly and Enhance Dermal Fibroblast Proliferation, Migration, and Angiogenesis In Vitro. Stem Cells Dev 2017; 26:1384-1398. [PMID: 28679315 DOI: 10.1089/scd.2017.0087] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Wnts are secreted glycoproteins that regulate stem cell self-renewal, differentiation, and cell-to-cell communication during embryonic development and in adult tissues. Bone marrow mesenchymal stem cells (BM-MSCs) have been shown to stimulate dermis repair and regeneration; however, it is unclear how BM-MSCs may modulate downstream Wnt signaling. While recent reports implicate that Wnt ligands and Wnt messenger RNAs (such as Wnt4) exist within the interior compartment of exosomes, it has been debated whether or not Wnts exist on the exterior surface of exosomes to travel in the extracellular space. To help answer this question, we utilized flow cytometry of magnetic beads coated with anti-CD63 antibodies and found, for the first time, that Wnt3a protein is detectable exteriorly on CD63+ exosomes derived from BM-MSCs over-secreting Wnt3a into serum-free conditioned media (Wnt3a CM). Our data suggest that CD63+ exosomes significantly help transport exterior Wnt3a signal to recipient cells to promote fibroblast and endothelial functions. During purification of exosomes, we unexpectedly found that use of ultracentrifugation alone significantly decreased the ability to detect exteriorly bound Wnt3a on CD63+ exosomes, however, polyethylene glycol (PEG)-mediated exosome-enrichment before exosome-purification (with ultracentrifugation into a sucrose cushion) resulted in exosomes more likely to retain exterior Wnt3a detectability and downstream Wnt/beta-catenin activity. Our findings indicate the important role that purification methods may have on stem cell-derived Wnt-exosome activity in downstream assays. The ability for BM-MSC Wnt3a CM and exosomes to stimulate dermal fibroblast proliferation and migration, and endothelial angiogenesis in vitro, was significantly decreased after CD63+-exosome depletion or knockdown of Wnt coreceptor LRP6 in recipient cells, suggesting both are required for optimal Wnt-exosome activity in our system. Thus, BM-MSC-derived CD63+ exosomes are a significant carrier of exterior Wnt3a within high Wnt environments, resulting in downstream fibroblast proliferation, migration, and angiogenesis in vitro.
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Affiliation(s)
- Jeffrey D McBride
- 1 Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine , Miami, Florida.,2 Interdisciplinary Stem Cell Institute , Miami, Florida
| | - Luis Rodriguez-Menocal
- 1 Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine , Miami, Florida.,2 Interdisciplinary Stem Cell Institute , Miami, Florida
| | - Wellington Guzman
- 1 Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine , Miami, Florida.,2 Interdisciplinary Stem Cell Institute , Miami, Florida
| | - Ambar Candanedo
- 1 Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine , Miami, Florida.,2 Interdisciplinary Stem Cell Institute , Miami, Florida
| | | | - Evangelos V Badiavas
- 1 Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine , Miami, Florida.,2 Interdisciplinary Stem Cell Institute , Miami, Florida
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Abstract
Extracellular vesicles (exosomes, microvesicles, and apoptotic bodies) are ubiquitous in human tissues, circulation, and body fluids. Of these vesicles, exosomes are of growing interest among investigators across multiple fields, including dermatology. The characteristics of exosomes, their associated cargo (nucleic acids, proteins, and lipids), and downstream functions are vastly different, depending on the cell origin. Here, we review concepts in extracellular vesicle biology, with a focus on exosomes, highlighting recent studies in the field of dermatology. Furthermore, we highlight emerging technical issues associated with isolating and measuring exosomes. Extracellular vesicles, including exosomes, have immediate potential for serving as biomarkers and therapeutics in dermatology over the next decade.
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Affiliation(s)
- Jeffrey D McBride
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA; Interdisciplinary Stem Cell Institute, Miami, Florida, USA
| | - Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA; Interdisciplinary Stem Cell Institute, Miami, Florida, USA
| | - Evangelos V Badiavas
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida, USA; Interdisciplinary Stem Cell Institute, Miami, Florida, USA.
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10
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Maranda E, Rodriguez-Menocal L, Badiavas E. Role of Mesenchymal Stem Cells in Dermal Repair in Burns and Diabetic Wounds. Curr Stem Cell Res Ther 2016; 12:61-70. [DOI: 10.2174/1574888x11666160714115926] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 06/27/2016] [Accepted: 07/10/2016] [Indexed: 12/15/2022]
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11
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Shabbir A, Cox A, Rodriguez-Menocal L, Salgado M, Van Badiavas E. Mesenchymal Stem Cell Exosomes Induce Proliferation and Migration of Normal and Chronic Wound Fibroblasts, and Enhance Angiogenesis In Vitro. Stem Cells Dev 2015; 24:1635-47. [PMID: 25867197 DOI: 10.1089/scd.2014.0316] [Citation(s) in RCA: 430] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Although chronic wounds are common and continue to be a major cause of morbidity and mortality, treatments for these conditions are lacking and often ineffective. A large body of evidence exists demonstrating the therapeutic potential of mesenchymal stem cells (MSCs) for repair and regeneration of damaged tissue, including acceleration of cutaneous wound healing. However, the exact mechanisms of wound healing mediated by MSCs are unclear. In this study, we examined the role of MSC exosomes in wound healing. We found that MSC exosomes ranged from 30 to 100-nm in diameter and internalization of MSC exosomes resulted in a dose-dependent enhancement of proliferation and migration of fibroblasts derived from normal donors and chronic wound patients. Uptake of MSC exosomes by human umbilical vein endothelial cells also resulted in dose-dependent increases of tube formation by endothelial cells. MSC exosomes were found to activate several signaling pathways important in wound healing (Akt, ERK, and STAT3) and induce the expression of a number of growth factors [hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF1), nerve growth factor (NGF), and stromal-derived growth factor-1 (SDF1)]. These findings represent a promising opportunity to gain insight into how MSCs may mediate wound healing.
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Affiliation(s)
- Arsalan Shabbir
- Department of Dermatology and Cutaneous Surgery, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine , Miami, Florida
| | - Audrey Cox
- Department of Dermatology and Cutaneous Surgery, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine , Miami, Florida
| | - Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine , Miami, Florida
| | - Marcela Salgado
- Department of Dermatology and Cutaneous Surgery, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine , Miami, Florida
| | - Evangelos Van Badiavas
- Department of Dermatology and Cutaneous Surgery, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine , Miami, Florida
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12
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Rodriguez-Menocal L, Shareef S, Salgado M, Shabbir A, Van Badiavas E. Role of whole bone marrow, whole bone marrow cultured cells, and mesenchymal stem cells in chronic wound healing. Stem Cell Res Ther 2015; 6:24. [PMID: 25881077 PMCID: PMC4414366 DOI: 10.1186/s13287-015-0001-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 02/02/2015] [Accepted: 02/02/2015] [Indexed: 01/29/2023] Open
Abstract
Introduction Recent evidence has shown that bone marrow cells play critical roles during the inflammatory, proliferative and remodeling phases of cutaneous wound healing. Among the bone marrow cells delivered to wounds are stem cells, which can differentiate into multiple tissue-forming cell lineages to effect, healing. Gaining insight into which lineages are most important in accelerating wound healing would be quite valuable in designing therapeutic approaches for difficult to heal wounds. Methods In this report we compared the effect of different bone marrow preparations on established in vitro wound healing assays. The preparations examined were whole bone marrow (WBM), whole bone marrow (long term initiating/hematopoietic based) cultured cells (BMC), and bone marrow derived mesenchymal stem cells (BM-MSC). We also applied these bone marrow preparations in two murine models of radiation induced delayed wound healing to determine which had a greater effect on healing. Results Angiogenesis assays demonstrated that tube formation was stimulated by both WBM and BMC, with WBM having the greatest effect. Scratch wound assays showed higher fibroblast migration at 24, 48, and 72 hours in presence of WBM as compared to BM-MSC. WBM also appeared to stimulate a greater healing response than BMC and BM-MSC in a radiation induced delayed wound healing animal model. Conclusions These studies promise to help elucidate the role of stem cells during repair of chronic wounds and reveal which cells present in bone marrow might contribute most to the wound healing process.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, 1501 NW 10th Street, Suite 924, Miami, FL, 33136, USA.
| | - Shahjahan Shareef
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, 1501 NW 10th Street, Suite 924, Miami, FL, 33136, USA.
| | - Marcela Salgado
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, 1501 NW 10th Street, Suite 924, Miami, FL, 33136, USA.
| | - Arsalan Shabbir
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, 1501 NW 10th Street, Suite 924, Miami, FL, 33136, USA.
| | - Evangelos Van Badiavas
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, 1501 NW 10th Street, Suite 924, Miami, FL, 33136, USA.
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Rodriguez-Menocal L, Salgado M, Davis S, Waibel J, Shabbir A, Cox A, Badiavas EV. Percutaneous bone marrow transplantation using fractional ablative Erbium:YAG laser. PLoS One 2014; 9:e93004. [PMID: 24667438 PMCID: PMC3965514 DOI: 10.1371/journal.pone.0093004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 02/27/2014] [Indexed: 01/06/2023] Open
Abstract
Topical application of therapeutic agents has been a mainstay in Dermatology for the treatment of skin disorders but is not commonly used for systemic delivery. For a topically applied agent to reach distant body sites it must first overcome the barrier function of the skin and then penetrate into deeper structures before reaching the systemic circulation. This has limited the use of topically applied agents to those having specific charge, solubility and size restrictions. Pretreatment of the skin with ablative fractional laser appears to enhance the uptake of some topically applied drugs but the ability to effectively deliver agents to distant sites is largely unproven. In this report we used a fractional ablative Erb:YAG (Erbium/Yttrium Aluminum Garnet) laser to facilitate the transfer of bone marrow stem cells through the skin in a murine bone marrow transplant model. Chimerism could be detected in the peripheral blood of recipient C57BL/6 mice that were pretreated with ablative fractional laser and had topically applied enhanced green fluorescent protein (GFP) labeled bone marrow cells from syngeneic donor transgenic mice. This study indicates that fractional laser can be used to deliver stem cells through the skin and remain functionally intact.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Interdiscipinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Marcela Salgado
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Interdiscipinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Stephen Davis
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jill Waibel
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Arsalan Shabbir
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Audrey Cox
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Evangelos V. Badiavas
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Interdiscipinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Rodriguez-Menocal L, Faridi MH, Martinez L, Shehadeh LA, Duque JC, Wei Y, Mesa A, Pena A, Gupta V, Pham SM, Vazquez-Padron RI. Macrophage-derived IL-18 and increased fibrinogen deposition are age-related inflammatory signatures of vascular remodeling. Am J Physiol Heart Circ Physiol 2014; 306:H641-53. [PMID: 24414074 DOI: 10.1152/ajpheart.00641.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging has been associated with pathological vascular remodeling and increased neointimal hyperplasia. The understanding of how aging exacerbates this process is fundamental to prevent cardiovascular complications in the elderly. This study proposes a mechanism by which aging sustains leukocyte adhesion, vascular inflammation, and increased neointimal thickness after injury. The effect of aging on vascular remodeling was assessed in the rat balloon injury model using microarray analysis, immunohistochemistry, and LINCOplex assays. The injured arteries in aging rats developed thicker neointimas than those in younger animals, and this significantly correlated with a higher number of tissue macrophages and increased vascular IL-18. Indeed, IL-18 was 23-fold more abundant in the injured vasculature of aged animals compared with young rats, while circulating levels were similar in both groups of animals. The depletion of macrophages in aged rats with clodronate liposomes ameliorated vascular accumulation of IL-18 and significantly decreased neointimal formation. IL-18 was found to inhibit apoptosis of vascular smooth muscle cells (VSMC) and macrophages, thus favoring both the formation and inflammation of the neointima. In addition, injured arteries of aged rats accumulated 18-fold more fibrinogen-γ than those of young animals. Incubation of rat peritoneal macrophages with immobilized IL-18 increased leukocyte adhesion to fibrinogen and suggested a proinflammatory positive feedback loop among macrophages, VSMC, and the deposition of fibrinogen during neointimal hyperplasia. In conclusion, our data reveal that concentration changes in vascular cytokine and fibrinogen following injury in aging rats contribute to local inflammation and postinjury neointima formation.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Surgery and Vascular Biology Institute, University of Miami Miller School of Medicine, Miami, Florida
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Brentnall M, Rodriguez-Menocal L, De Guevara RL, Cepero E, Boise LH. Caspase-9, caspase-3 and caspase-7 have distinct roles during intrinsic apoptosis. BMC Cell Biol 2013; 14:32. [PMID: 23834359 PMCID: PMC3710246 DOI: 10.1186/1471-2121-14-32] [Citation(s) in RCA: 767] [Impact Index Per Article: 69.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 06/17/2013] [Indexed: 12/15/2022] Open
Abstract
Background Apoptosis is a form of programmed cell death that is regulated by the Bcl-2 family and caspase family of proteins. The caspase cascade responsible for executing cell death following cytochrome c release is well described; however the distinct roles of caspases-9, -3 and -7 during this process are not completely defined. Results Here we demonstrate several unique functions for each of these caspases during cell death. Specific inhibition of caspase-9 allows for efficient release of cytochrome c, but blocks changes in mitochondrial morphology and ROS production. We show that caspase-9 can cleave Bid into tBid at amino acid 59 and that this cleavage of Bid is required for ROS production following serum withdrawal. We also demonstrate that caspase-3-deficient MEFs are less sensitive to intrinsic cell death stimulation, yet have higher ROS production. In contrast, caspase-7-deficient MEFs are not resistance to intrinsic cell death, but remain attached to the ECM. Conclusions Taken together, these data suggest that caspase-9 is required for mitochondrial morphological changes and ROS production by cleaving and activating Bid into tBid. After activation by caspase-9, caspase-3 inhibits ROS production and is required for efficient execution of apoptosis, while effector caspase-7 is required for apoptotic cell detachment.
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Affiliation(s)
- Matthew Brentnall
- Departments of Hematology and Medical Oncology and Cell Biology, Winship Cancer Institute of Emory University, 1365 Clifton Road NE Bldg:C, Rm:4012, Atlanta, GA 30322, USA
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Rodriguez-Menocal L, Salgado M, Ford D, Van Badiavas E. Stimulation of skin and wound fibroblast migration by mesenchymal stem cells derived from normal donors and chronic wound patients. Stem Cells Transl Med 2012. [PMID: 23197781 DOI: 10.5966/sctm.2011-0029] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Chronic wounds continue to be a major cause of morbidity for patients and an economic burden on the health care system. Novel therapeutic approaches to improved wound healing will need, however, to address cellular changes induced by a number of systemic comorbidities seen in chronic wound patients, such as diabetes, chronic renal failure, and arterial or venous insufficiency. These effects likely include impaired inflammatory cell migration, reduced growth factor production, and poor tissue remodeling. The multifunctional properties of bone marrow-derived mesenchymal stem cells (MSCs), including their ability to differentiate into various cell types and capacity to secrete factors important in accelerating healing of cutaneous wounds, have made MSCs a promising agent for tissue repair and regeneration. In this study we have used an in vitro scratch assay procedure incorporating labeled MSCs and fibroblasts derived from normal donors and chronic wound patients in order to characterize the induction of mobilization when these cells are mixed. A modified Boyden chamber assay was also used to examine the effect of soluble factors on fibroblast migration. These studies suggest that MSCs play a role in skin wound closure by affecting dermal fibroblast migration in a dose-dependent manner. Deficiencies were noted, however, in chronic wound patient fibroblasts and MSCs as compared with those derived from normal donors. These findings provide a foundation to develop therapies targeted specifically to the use of bone marrow-derived MSCs in wound healing and may provide insight into why some wounds do not heal.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Dermatology and Cutaneous Surgery, Leonard M. Miller School of Medicine, University of Miami, Interdisciplinary Stem Cell Institute, Florida, USA
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Abstract
AIMS The aim of this study was to investigate the mechanisms by which nicotine increases vascular smooth muscle cell (VSMC) proliferation and post-injury neointimal formation. METHODS AND RESULTS Vascular injury was inflicted in the right iliac artery of nicotine-treated and control rats. Nicotine increased post-injury VSMC proliferation (Ki67(+) cells) and neointimal formation (neointima/media ratio, 0.42 ± 0.23 vs. 0.14 ± 0.07, P= 0.02). To determine the mechanisms by which nicotine exacerbates VSMC proliferation, cultured cells were exposed to nicotine, and signalling pathways leading to cell proliferation were studied. Nicotine activated extracellular signal-regulated kinase (ERK) 1/2 in a dose- and time-dependent manner. The blockade of this signalling axis abolished nicotine-mediated proliferation. Functional nicotinic acetylcholine receptors and Ca(2+) influx were necessary for ERK1/2 activation and nicotine-induced mitogenesis in VSMCs. Downstream to ERK1/2, nicotine induced the phosphorylation of Ets-like gene 1 in a timely co-ordinated manner with the up-regulation of the atherogenic transcription factor, early growth response 1 (Egr-1). The treatment of balloon-injured arteries with a lentivirus vector carrying a short hairpin RNA against Egr-1 abolished the deleterious effect of nicotine on vascular remodelling. CONCLUSION Nicotine acts through its receptors in VSMC to activate the ERK-Egr-1 signaling cascade that induces cell proliferation and exacerbates post-injury neointimal development.
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Affiliation(s)
- Roberto I Vazquez-Padron
- Department of Surgery and Vascular Biology Institute, University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 7147A, Miami, FL 33136, USA
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Rodriguez-Menocal L, Wei Y, Pham SM, St-Pierre M, Li S, Webster K, Goldschmidt-Clermont P, Vazquez-Padron RI. A novel mouse model of in-stent restenosis. Atherosclerosis 2009; 209:359-66. [PMID: 19875114 DOI: 10.1016/j.atherosclerosis.2009.09.071] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 09/15/2009] [Accepted: 09/26/2009] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND AIMS In-stent restenosis (ISR) is the major complication that occurs after percutaneous coronary interventions to facilitate coronary revascularization. Herein we described a simple and cost-effective model, which reproduces important features of ISR in the mouse. METHODS AND RESULTS Microvascular bare metal stents were successfully implanted in the abdominal aorta of atherosclerotic ApoE-null mice. Patency of implanted stents was interrogated using ultrasound biomicroscopy. Aortas were harvested at different time points after implantation and processed for histopathological analysis. Thrombus formation was histologically detected after 1 day. Leukocyte adherence and infiltration were evident after 7 days and decreased thereafter. Neointimal formation, neointimal thickness and luminal stenosis simultaneously increased up to 28 days after stent implantation. Using multichannel fluorescence molecular tomography (FMT) for spatiotemporal resolution of MMP activities, we observed that MMP activity in the stented aorta of Apo-E null mice was 2-fold higher than that of wild-type mice. Finally, we compared neointimal formation in response to stenting in two genetically different mouse strains. In-stent neointimas in FVB/NJ mice were 2-fold thicker than in C57BL/6J mice (p=0.002). CONCLUSION We have developed a model that can take advantage of the multiple genetic resources available for the mouse to study the mechanisms of in-stent restenosis.
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Affiliation(s)
- Luis Rodriguez-Menocal
- University of Miami Miller School of Medicine, 1600 NW 10th Avenue, RMSB 7147A, Miami, FL 33136, United States
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Rodriguez-Menocal L, St-Pierre M, Wei Y, Khan S, Mateu D, Calfa M, Rahnemai-Azar AA, Striker G, Pham SM, Vazquez-Padron RI. The origin of post-injury neointimal cells in the rat balloon injury model. Cardiovasc Res 2008; 81:46-53. [DOI: 10.1093/cvr/cvn265] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Vazquez-Padron RI, Rodriguez-Menocal L, Mateu D, Wei Y, Salgar S, Li S, Pham SM. QS370. Vascular Injury Causes Early-Onset Apoptosis of Medial Vascular Smooth Muscle Cells. J Surg Res 2008. [DOI: 10.1016/j.jss.2007.12.623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Recently a metacaspase, encoded by YCA1, has been implicated in a primitive form of apoptosis or programmed cell death in yeast. Previously it had been shown that over-expression of mammalian pro-apoptotic proteins can induce cell death in yeast, but the mechanism of how cell death occurred was not clearly established. More recently, it has been shown that DNA or oxidative damage, or other cell cycle blocks, can result in cell death that mimics apoptosis in higher cells. Also, in fission yeast deletion of genes required for triacylglycerol synthesis leads to cell death and expression of apoptotic markers. A metacaspase sharing greater than 40% identity to budding yeast Yca1 has been identified in fission yeast, however, its role in programmed cell death is not yet known. Analysis of the genetic pathways that influence cell death in yeast may provide insights into the mechanisms of apoptosis in all eukaryotic organisms.
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Affiliation(s)
- Luis Rodriguez-Menocal
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, P.O. Box 016129, Miami, FL 33101-6129, USA
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Feng W, Rodriguez-Menocal L, Tolun G, D'Urso G. Schizosacchromyces pombe Dpb2 binds to origin DNA early in S phase and is required for chromosomal DNA replication. Mol Biol Cell 2003; 14:3427-36. [PMID: 12925774 PMCID: PMC181578 DOI: 10.1091/mbc.e03-02-0088] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Genetic evidence suggests that DNA polymerase epsilon (Pol epsilon) has a noncatalytic essential role during the early stages of DNA replication initiation. Herein, we report the cloning and characterization of the second largest subunit of Pol epsilon in fission yeast, called Dpb2. We demonstrate that Dpb2 is essential for cell viability and that a temperature-sensitive mutant of dpb2 arrests with a 1C DNA content, suggesting that Dpb2 is required for initiation of DNA replication. Using a chromatin immunoprecipitation assay, we show that Dpb2, binds preferentially to origin DNA at the beginning of S phase. We also show that the C terminus of Pol epsilon associates with origin DNA at the same time as Dpb2. We conclude that Dpb2 is an essential protein required for an early step in DNA replication. We propose that the primary function of Dpb2 is to facilitate assembly of the replicative complex at the start of S phase. These conclusions are based on the novel cell cycle arrest phenotype of the dpb2 mutant, on the previously uncharacterized binding of Dpb2 to replication origins, and on the observation that the essential function of Pol epsilon is not dependent on its DNA synthesis activity.
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Affiliation(s)
- Wenyi Feng
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33101-6129, USA
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