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Peta KT, Durandt C, van Heerden MB, Joubert AM, Pepper MS, Ambele MA. Effect of 2-methoxyestradiol on mammary tumor initiation and progression. Cancer Rep (Hoboken) 2024; 7:e2068. [PMID: 38600057 PMCID: PMC11006714 DOI: 10.1002/cnr2.2068] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/04/2024] [Accepted: 03/24/2024] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND The anti-cancer agent 2-methoxyestradiol (2-ME) has been shown to have anti-proliferative and anti-angiogenic properties. Previously, the effect of 2-ME on early- and late-stage breast cancer (BC) was investigated in vivo using a transgenic mouse model (FVB/N-Tg(MMTV-PyVT)) of spontaneous mammary carcinoma. Anti-tumor effects were observed in late-stage BC with no effect on early-stage BC. Given the contrasting results obtained from the different BC stages, we have now investigated the effect of 2-ME when administered before the appearance of palpable tumors. METHODS Each mouse received 100 mg/kg 2-ME on day 30 after birth, twice per week for 28 days, while control mice received vehicle only. Animals were terminated on day 59. Lung and mammary tissue were obtained for immunohistochemical analysis of CD163 and CD3 expression, and histological examination was performed to analyze tumor necrosis. Additionally, blood samples were collected to measure plasma cytokine levels. RESULTS 2-ME increased tumor mass when compared to the untreated animals (p = .0139). The pro-tumorigenic activity of 2-ME was accompanied by lower CD3+ T-cell numbers in the tumor microenvironment (TME) and high levels of the pro-inflammatory cytokine interleukin (IL)-1β. Conversely, 2-ME-treatment resulted in fewer CD163+ cells detectable in the TME, increased levels of tumor necrosis, increased IL-10 plasma levels, and low IL-6 and IL-27 plasma levels. CONCLUSION Taken together, these findings suggest that 2-ME promotes early-stage BC development.
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Affiliation(s)
- Kimberly T. Peta
- Department of Immunology, Institute for Cellular and Molecular Medicine, South African Medical Research Council, Extramural Unit for Stem Cell Research and Therapy, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Chrisna Durandt
- Department of Immunology, Institute for Cellular and Molecular Medicine, South African Medical Research Council, Extramural Unit for Stem Cell Research and Therapy, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Marlene B. van Heerden
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Anna M. Joubert
- Department of Physiology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Michael S. Pepper
- Department of Immunology, Institute for Cellular and Molecular Medicine, South African Medical Research Council, Extramural Unit for Stem Cell Research and Therapy, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Melvin A. Ambele
- Department of Immunology, Institute for Cellular and Molecular Medicine, South African Medical Research Council, Extramural Unit for Stem Cell Research and Therapy, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
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Grobbelaar S, Mercier AE, van den Bout I, Durandt C, Pepper MS. Considerations for enhanced mesenchymal stromal/stem cell myogenic commitment in vitro. Clin Transl Sci 2024; 17:e13703. [PMID: 38098144 PMCID: PMC10787211 DOI: 10.1111/cts.13703] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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] [Received: 08/14/2023] [Revised: 11/16/2023] [Accepted: 12/09/2023] [Indexed: 01/15/2024] Open
Abstract
The generation of tissue from stem cells is an alluring concept as it holds a number of potential applications in clinical therapeutics and regenerative medicine. Mesenchymal stromal/stem cells (MSCs) can be isolated from a number of different somatic sources, and have the capacity to differentiate into adipogenic, osteogenic, chondrogenic, and myogenic lineages. Although the first three have been extensively investigated, there remains a paucity of literature on the latter. This review looks at the various strategies available in vitro to enhance harvested MSC commitment and differentiation into the myogenic pathway. These include chemical inducers, myogenic-enhancing cell culture substrates, and mechanical and dynamic culturing conditions. Drawing on information from embryonic and postnatal myogenesis from somites, satellite, and myogenic progenitor cells, the mechanisms behind the chemical and mechanical induction strategies can be studied, and the sequential gene and signaling cascades can be used to monitor the progression of myogenic differentiation in the laboratory. Increased understanding of the stimuli and signaling mechanisms in the initial stages of MSC myogenic commitment will provide tools with which we can enhance their differentiation efficacy and advance the process to clinical translation.
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Affiliation(s)
- Simone Grobbelaar
- Department of Physiology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
- Institute for Cellular and Molecular Medicine, Department of Immunology, and South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Anne E. Mercier
- Department of Physiology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Iman van den Bout
- Department of Physiology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
- Centre for Neuroendocrinology, Department of Immunology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Chrisna Durandt
- Institute for Cellular and Molecular Medicine, Department of Immunology, and South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Michael S. Pepper
- Institute for Cellular and Molecular Medicine, Department of Immunology, and South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
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Hendricks CL, Mellet J, Durandt C, Brittain D, Pepper MS. Haematopoietic stem-cell transplantation in an HIV endemic area: time to consider donors exposed to or living with HIV. Lancet HIV 2023; 10:e742-e749. [PMID: 37837978 DOI: 10.1016/s2352-3018(23)00198-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 07/24/2023] [Accepted: 07/31/2023] [Indexed: 10/16/2023]
Abstract
South Africa has more than 8 million people living with HIV. However, the number of patients undergoing haematopoietic stem-cell transplantation (HSCT) in South Africa is far below the target number. Donor numbers are insufficient to meet demand. Both HSCT and solid organ transplantation have proved successful in people living with HIV. Solid organ transplantation also has good outcomes when both donors and recipients have HIV. This Personal View explores the possible inclusion of people living with HIV and umbilical cord blood from HIV-negative infants exposed to HIV as donor sources for HSCT. Beyond the risk of HIV transmission, additional complications must be considered, such as delayed or inadequate immune reconstitution and an increased risk of haematological abnormalities and malignancies. Interactions between antiretroviral drugs and drugs used in the conditioning regimen, as well as the need to maintain virological suppression when gastrointestinal absorption deteriorates, are additional complicating factors. The process also requires more stringent ethical processes to be in place to minimise physical and emotional harm. However, in an HIV endemic country, people living with HIV or donors exposed to HIV must be considered as part of a multidisciplinary collaborative effort to provide more patients with the opportunity to have a life-saving HSCT.
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Affiliation(s)
- Candice Laverne Hendricks
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Juanita Mellet
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Chrisna Durandt
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - David Brittain
- Alberts Cellular Therapy, Netcare Pretoria East Hospital, Pretoria, South Africa
| | - Michael Sean Pepper
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
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Peta KT, Durandt C, van Heerden MB, Joubert AM, Pepper MS, Ambele MA. Effect of 2-methoxyestradiol treatment on early- and late-stage breast cancer progression in a mouse model. Cell Biochem Funct 2023; 41:898-911. [PMID: 37649158 PMCID: PMC10947225 DOI: 10.1002/cbf.3842] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/27/2023] [Accepted: 08/17/2023] [Indexed: 09/01/2023]
Abstract
The prevalence of breast cancer (BC) continues to increase and is the leading cause of cancer deaths in many countries. Numerous in vitro and in vivo studies have demonstrated that 2-methoxyestradiol (2-ME) has antiproliferative and antiangiogenic effects in BC, thereby inhibiting tumour growth and metastasis. We compared the effect of 2-ME in early- and late-stage BC using a transgenic mouse model-FVB/N-Tg(MMTV-PyVT)-of spontaneously development of aggressive mammary carcinoma with lung metastasis. Mice received 100 mg/kg 2-ME treatment immediately when palpable mammary tumours were identified (early-stage BC; Experimental group 1) and 28 days after palpable mammary tumours were detected (late-stage BC; Experimental group 2). 2-ME was administered via oral gavage three times a week for 28 days after initiation of treatment, whereas control mice received the vehicle containing 10% dimethyl sulfoxide and 90% sunflower oil for the same duration as the treatment group. Mammary tumours were measured weekly over the 28 days and at termination, blood, mammary and lung tissue were collected for analysis. Mice with a tumour volume threshold of 4000 mm3 were killed before the treatment regime was completed. 2-ME treatment of early-stage BC led to lower levels of mammary tumour necrosis, whereas tumour mass and volume were increased. Additionally, necrotic lesions and anti-inflammatory CD163-expressing cells were more frequent in pulmonary metastatic tumours in this group. In contrast, 2-ME treatment of late-stage BC inhibited tumour growth over the 28-day period and resulted in increased CD3+ cell number and tumour necrosis. Furthermore, 2-ME treatment slowed down pulmonary metastasis but did not increase survival of late-stage BC mice. Besides late-stage tumour necrosis, none of the other results were statistically significant. This study demonstrates that 2-ME treatment has an antitumour effect on late-stage BC, however, with no increase in survival rate, whereas the treatment failed to demonstrate any benefit in early-stage BC.
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Affiliation(s)
- Kimberly T. Peta
- Department of Immunology, Institute for Cellular and Molecular Medicine; South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy; Faculty of Health SciencesUniversity of PretoriaArcadiaSouth Africa
| | - Chrisna Durandt
- Department of Immunology, Institute for Cellular and Molecular Medicine; South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy; Faculty of Health SciencesUniversity of PretoriaArcadiaSouth Africa
| | - Marlene B. van Heerden
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Anna M. Joubert
- Department of Physiology, School of Medicine, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
| | - Michael S. Pepper
- Department of Immunology, Institute for Cellular and Molecular Medicine; South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy; Faculty of Health SciencesUniversity of PretoriaArcadiaSouth Africa
| | - Melvin A. Ambele
- Department of Immunology, Institute for Cellular and Molecular Medicine; South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy; Faculty of Health SciencesUniversity of PretoriaArcadiaSouth Africa
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Faculty of Health SciencesUniversity of PretoriaPretoriaSouth Africa
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Herd CL, Mellet J, Mashingaidze T, Durandt C, Pepper MS. Consequences of HIV infection in the bone marrow niche. Front Immunol 2023; 14:1163012. [PMID: 37497228 PMCID: PMC10366613 DOI: 10.3389/fimmu.2023.1163012] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/21/2023] [Indexed: 07/28/2023] Open
Abstract
Dysregulation of the bone marrow niche resulting from the direct and indirect effects of HIV infection contributes to haematological abnormalities observed in HIV patients. The bone marrow niche is a complex, multicellular environment which functions primarily in the maintenance of haematopoietic stem/progenitor cells (HSPCs). These adult stem cells are responsible for replacing blood and immune cells over the course of a lifetime. Cells of the bone marrow niche support HSPCs and help to orchestrate the quiescence, self-renewal and differentiation of HSPCs through chemical and molecular signals and cell-cell interactions. This narrative review discusses the HIV-associated dysregulation of the bone marrow niche, as well as the susceptibility of HSPCs to infection by HIV.
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Nel S, Durandt C, Murdoch C, Pepper MS. Determinants of Dental Pulp Stem Cell Heterogeneity. J Endod 2022; 48:1232-1240. [PMID: 35809811 DOI: 10.1016/j.joen.2022.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022]
Abstract
INTRODUCTION The aim of this review is to provide a narrative review on the determinants of dental pulp stem cell (DPSC) heterogeneity that may affect the regenerative properties of these cells. METHODS PubMed, Scopus and Medline (Ovid) literature searches were done on human dental pulp stem cell (hDPSC) heterogeneity. The focus was on human dental pulp stem cells (hDPSCs) with a primary focus on DPSC heterogeneity. RESULTS DPSCs display significant heterogeneity as illustrated by the various subpopulations reported, including differences in proliferation and differentiation capabilities and the impact of various intrinsic and extrinsic factors. CONCLUSIONS The lack of consistent and reliable results in the clinical setting may be due to the heterogeneous nature of DPSC populations. Standardization in isolation techniques and in criteria to characterize DPSCs should lead to less variability in results reported and improve comparison of findings between studies. Single-cell RNA sequencing holds promise in elucidating DPSC heterogeneity and may contribute to the establishment of standardized techniques.
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Affiliation(s)
- Sulette Nel
- Department of Oral Pathology and Oral Biology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, South Africa.
| | - Chrisna Durandt
- Institute for Cellular and Molecular Medicine (ICMM), Department of Immunology, and SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Candice Murdoch
- Institute for Cellular and Molecular Medicine (ICMM), Department of Immunology, and SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Michael S Pepper
- Institute for Cellular and Molecular Medicine (ICMM), Department of Immunology, and SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, South Africa
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Damerell V, Ambele MA, Salisbury S, Neumann-Mufweba A, Durandt C, Pepper MS, Prince S. The c-Myc/TBX3 Axis Promotes Cellular Transformation of Sarcoma-Initiating Cells. Front Oncol 2022; 11:801691. [PMID: 35145908 PMCID: PMC8821881 DOI: 10.3389/fonc.2021.801691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/30/2021] [Indexed: 11/23/2022] Open
Abstract
Sarcomas are highly aggressive cancers of mesenchymal origin whose clinical management is highly complex. This is partly due to a lack of understanding of the molecular mechanisms underpinning the transformation of mesenchymal stromal/stem cells (MSCs) which are presumed to be the sarcoma-initiating cells. c-Myc is amplified/overexpressed in a range of sarcomas where it has an established oncogenic role and there is evidence that it contributes to the malignant transformation of MSCs. T-box transcription factor 3 (TBX3) is upregulated by c-Myc in a host of sarcoma subtypes where it promotes proliferation, tumor formation, migration, and invasion. This study investigated whether TBX3 is a c-Myc target in human MSCs (hMSCs) and whether overexpressing TBX3 in hMSCs can phenocopy c-Myc overexpression to promote malignant transformation. Using siRNA, qRT-PCR, luciferase reporter and chromatin-immunoprecipitation assays, we show that c-Myc binds and directly activates TBX3 transcription in hMSCs at a conserved E-box motif. When hMSCs were engineered to stably overexpress TBX3 using lentiviral gene transfer and the resulting cells characterised in 2D and 3D, the overexpression of TBX3 was shown to promote self-renewal, bypass senescence, and enhance proliferation which corresponded with increased levels of cell cycle progression markers (cyclin A, cyclin B1, CDK2) and downregulation of the p14ARF/MDM2/p53 tumor suppressor pathway. Furthermore, TBX3 promoted the migratory and invasive ability of hMSCs which associated with increased levels of markers of migration (Vimentin, SLUG, SNAIL, TWIST1) and invasion (MMP2, MMP9). Transcriptomic analysis revealed that genes upregulated upon TBX3 overexpression overlapped with c-myc targets, were involved in cell cycle progression, and were associated with sarcomagenesis. Together, the data described indicate that the c-Myc/TBX3 oncogenic molecular pathway may be a key mechanism that transforms hMSCs into sarcomas.
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Affiliation(s)
- Victoria Damerell
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Melvin Anyasi Ambele
- Department of Immunology and SAMRC Extramural Unit for Stem Research and Therapy, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine, University of Pretoria, Pretoria, South Africa
- Department of Oral Pathology and Oral Biology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Shanel Salisbury
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Alexis Neumann-Mufweba
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Chrisna Durandt
- Department of Immunology and SAMRC Extramural Unit for Stem Research and Therapy, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine, University of Pretoria, Pretoria, South Africa
| | - Michael Sean Pepper
- Department of Immunology and SAMRC Extramural Unit for Stem Research and Therapy, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine, University of Pretoria, Pretoria, South Africa
| | - Sharon Prince
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- *Correspondence: Sharon Prince,
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Mollentze J, Durandt C, Pepper MS. An In Vitro and In Vivo Comparison of Osteogenic Differentiation of Human Mesenchymal Stromal/Stem Cells. Stem Cells Int 2021; 2021:9919361. [PMID: 34539793 PMCID: PMC8443361 DOI: 10.1155/2021/9919361] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/23/2021] [Accepted: 08/20/2021] [Indexed: 12/11/2022] Open
Abstract
The use of stem cells in regenerative medicine, including tissue engineering and transplantation, has generated a great deal of enthusiasm. Mesenchymal stromal/stem cells (MSCs) can be isolated from various tissues, most commonly, bone marrow but more recently adipose tissue, dental pulp, and Wharton's jelly, to name a few. MSCs display varying phenotypic profiles and osteogenic differentiating capacity depending and their site of origin. MSCs have been successfully differentiated into osteoblasts both in vitro an in vivo but discrepancies exist when the two are compared: what happens in vitro does not necessarily happen in vivo, and it is therefore important to understand why these differences occur. The osteogenic process is a complex network of transcription factors, stimulators, inhibitors, proteins, etc., and in vivo experiments are helpful in evaluating the various aspects of this osteogenic process without distractions and confounding variables. With that in mind, the results of in vitro experiments need to be carefully considered and interpreted with caution as they do not perfectly replicate the conditions found within living organisms. This is where in vivo experiments help us better understand interactions that might occur in the osteogenic process that cannot be replicated in vitro. Potentially, these differences could also be exploited to develop an optimal MSC cell therapeutic product that can be used for bone disorders. There are many bone disorders, most of which cause a great deal of discomfort. Clinically acceptable protocols could be developed in which MSCs are used to aid in bone regeneration providing relief for patients with chronic pain. The aim of this review is to examine the differences between studies conducted in vitro and in vivo with regard to the osteogenic process to better define the gaps in current osteogenic research. By better understanding osteogenic differentiation, we can better define treatment strategies for various bone disorders.
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Affiliation(s)
- Jamie Mollentze
- Institute for Cellular and Molecular Medicine, Department of Immunology; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Chrisna Durandt
- Institute for Cellular and Molecular Medicine, Department of Immunology; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Michael S. Pepper
- Institute for Cellular and Molecular Medicine, Department of Immunology; SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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White M, Feucht UD, Duffley E, Molokoane F, Durandt C, Cassol E, Rossouw T, Connor KL. Does in utero HIV exposure and the early nutritional environment influence infant development and immune outcomes? Findings from a pilot study in Pretoria, South Africa. Pilot Feasibility Stud 2020; 6:192. [PMID: 33308322 PMCID: PMC7730756 DOI: 10.1186/s40814-020-00725-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 02/22/2020] [Accepted: 11/11/2020] [Indexed: 03/08/2023] Open
Abstract
Background As mother-to-child transmission of HIV decreases, and the population of infants who are born HIV-exposed, but uninfected (HEU) continues to rise, there is a growing need to understand the development and health outcomes of infants who are HEU to ensure that they have the healthiest start to life. Methods In a prospective cohort pilot study at Kalafong Hospital, Pretoria, South Africa, we aimed to determine if we could recruit new mothers living with HIV on antiretrovirals (ART; n = 20) and not on ART (n = 20) and new mothers without HIV (n = 20) through our clinics to study the effects of HEU on growth and immune- and neurodevelopment in infants in early life, and test the hypothesis that infants who were HEU would have poorer health outcomes compared to infants who were HIV-unexposed, uninfected (HUU). We also undertook exploratory analyses to investigate relationships between the early nutritional environment, food insecurity and infant development. Infant growth, neurodevelopment (Guide for Monitoring Child Development [GMCD]) and levels of monocyte subsets (CD14, CD16 and CCR2 expression [flow cytometry]) were measured in infants at birth and 12 weeks (range 8–16 weeks). Results We recruited 33 women living with HIV on ART and 22 women living without HIV within 4 days of delivery from June to December 2016. Twenty-one women living with HIV and 10 without HIV returned for a follow-up appointment at 12 weeks postpartum. The high mobility of this population presented major challenges to participant retention. Preliminary analyses revealed lower head circumference and elevated CCR2+ (% and median fluorescence intensity) on monocytes at birth among infants who were HEU compared to HUU. Maternal reports of food insecurity were associated with lower maternal nutrient intakes at 12 weeks postpartum and increased risk of stunting at birth for infants who were HEU, but not infants who were HUU. Conclusions Our small feasibility pilot study suggests that HEU may adversely affect infant development, and further, infants who are HEU may be even more vulnerable to the programming effects of suboptimal nutrition in utero and postnatally. This pilot and preliminary analyses have been used to inform our research questions and protocol in our ongoing, full-scale study.
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Affiliation(s)
- Marina White
- Department of Health Sciences, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Ute D Feucht
- Paediatrics, University of Pretoria, Pretoria, GP 0002, South Africa.,Research Centre for Maternal, Fetal, Newborn & Child Health Care Strategies, University of Pretoria, Pretoria, GP 0002, South Africa.,Maternal and Infant Health Care Strategies Unit, South African Medical Council, Pretoria, South Africa
| | - Eleanor Duffley
- Department of Health Sciences, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Felicia Molokoane
- Research Centre for Maternal, Fetal, Newborn & Child Health Care Strategies, University of Pretoria, Pretoria, GP 0002, South Africa.,Maternal and Infant Health Care Strategies Unit, South African Medical Council, Pretoria, South Africa.,Obstetrics and Gynaecology, University of Pretoria, Pretoria, GP, 0002, South Africa
| | - Chrisna Durandt
- South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, Pretoria, GP 0002, South Africa.,Institute for Cellular and Molecular Medicine, Department of Immunology, University of Pretoria, Pretoria, GP 0002, South Africa
| | - Edana Cassol
- Department of Health Sciences, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Theresa Rossouw
- Institute for Cellular and Molecular Medicine, Department of Immunology, University of Pretoria, Pretoria, GP 0002, South Africa
| | - Kristin L Connor
- Department of Health Sciences, Carleton University, Ottawa, ON, K1S 5B6, Canada.
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du Plessis L, Bonato M, Durandt C, Cloete SWP, Soley JT. Sperm macrocephaly syndrome in the ostrich Struthio camelus: morphological characteristics and implications for motility. Reprod Fertil Dev 2018; 31:712-723. [PMID: 30458919 DOI: 10.1071/rd18242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/23/2018] [Indexed: 12/12/2022] Open
Abstract
Sperm macrocephaly syndrome (SMS) is characterised by a high percentage of spermatozoa with enlarged heads and multiple tails, and is related to infertility. Although this multiple sperm defect has been described in other mammalian species, little is known about this anomaly in birds. Morphological examination of semen from nine South African black ostriches (Struthio camelus var. domesticus) involved in an AI trial revealed the variable presence of spermatozoa with large heads and multiple tails. Ultrastructural features of the defect were similar to those reported in mammals except that the multiple tails were collectively bound within the plasmalemma. The tails were of similar length and structure to those of normal spermatozoa, and the heads were 1.6-fold longer, emphasising the uniformity of the anomaly across vertebrate species. Flow cytometry identified these cells as diploid and computer-aided sperm analysis revealed that they swim slower but straighter than normal spermatozoa, probably due to the increased drag of the large head and constrained movement of the merged multiple tails. The high incidence of this defect in one male ostrich indicates that, although rare, SMS can occur in birds and may potentially have an adverse effect on breeding programs, particularly for endangered species.
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Affiliation(s)
- L du Plessis
- Electron Microscope Unit, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | - M Bonato
- Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
| | - C Durandt
- Department of Immunology, Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, SAMRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, South Africa
| | - S W P Cloete
- Department of Animal Sciences, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
| | - J T Soley
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
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Anderson R, Theron AJ, Nel JG, Durandt C, Cholo MC, Feldman C, Tintinger GR. Clofazimine, but Not Isoniazid or Rifampicin, Augments Platelet Activation in vitro. Front Pharmacol 2018; 9:1335. [PMID: 30515097 PMCID: PMC6255828 DOI: 10.3389/fphar.2018.01335] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 09/25/2018] [Accepted: 10/30/2018] [Indexed: 12/22/2022] Open
Abstract
Although the inclusion of the cationic amphiphilic, anti-mycobacterial agent, clofazimine, in the chemotherapeutic regimens of patients with multidrug-resistant tuberculosis (TB) has contributed to improved outcomes, concerns remain about the cardiotoxic potential of this agent. Accordingly, the current study was undertaken with the primary objective of investigating the effects of clofazimine, on the reactivity of human platelets in vitro, a seemingly unexplored, mechanism of cardiotoxicity. Platelet-rich plasma (PRP) prepared from the blood of healthy, adult humans was treated with clofazimine (0.625–10 mg/L), or the primary anti-TB agents, isoniazid and rifampicin (at final concentrations of 5 and 10 mg/L), followed by addition of either adenosine 5′-diphosphate (ADP) or thrombin and measurement of platelet activation according to the magnitude of expression of CD62P (P-selectin), as well as the CD62P-mediated formation of heterotypic neutrophil:platelet (NP) aggregates, using flow cytometry. Clofazimine, but neither isoniazid nor rifampicin, caused dose-related potentiation of both ADP- and thrombin-activated expression of CD62P by platelets, achieving statistical significance at threshold concentrations of 0.625 and 2.5 mg/L, respectively, as well as significant formation of N:P aggregates. These stimulatory effects of clofazimine on platelet activation were partly attenuated by pre-treatment of PRP with the membrane-stabilizing agent, α-tocopherol, possibly consistent with a membrane-disruptive mechanism. In conclusion, clofazimine, at concentrations within the therapeutic range, augments platelet activation in vitro, probably by a mechanism linked to membrane destabilization. If operative in vivo, these pro-thrombotic activities of clofazimine may predispose for development of microvascular occlusion, exacerbating an already existing high risk for development of TB-associated cardiovascular disease.
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Affiliation(s)
- Ronald Anderson
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Annette J Theron
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Jan G Nel
- Department of Haematology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Tshwane Academic Division, National Health Laboratory Service, Pretoria, South Africa
| | - Chrisna Durandt
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Moloko C Cholo
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Charles Feldman
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gregory R Tintinger
- Department of Internal Medicine, Faculty of Health Sciences, Steve Biko Academic Hospital, University of Pretoria, Pretoria, South Africa
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Dessels C, Durandt C, Pepper MS. Comparison of human platelet lysate alternatives using expired and freshly isolated platelet concentrates for adipose-derived stromal cell expansion. Platelets 2018; 30:356-367. [PMID: 29553865 DOI: 10.1080/09537104.2018.1445840] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 01/09/2023]
Abstract
Pooled human platelet lysate (pHPL) has been used to expand adipose-derived stromal cells (ASCs) and can be formulated using fresh or expired buffy coats (BCs) which are then resuspended in either plasma or an additive solution. Not much is known about the effects that expired products and additive solutions have on ASC expansion, and the need for quality control and release criteria has been expressed. This pilot study compared proliferation, cell size, morphology and immunophenotype of ASCs expanded in the different pHPL alternatives versus foetal bovine serum (FBS). Quality control criteria were assessed prior to and during the manufacture of the pHPL alternatives. ASCs were then expanded in 1%, 2.5%, 5% or 10% of the different pHPL alternatives or in 10% FBS. Cell size, morphology, cell number and immunophenotype were measured using microscopy and flow cytometry. The majority of the pHPL alternatives were within the recommended ranges for the quality control criteria. ASCs expanded in the pHPL alternatives were smaller in size, displayed a tighter spindle-shaped morphology, increased cell growth and had a similar immunophenotype (with the exception of CD34 and CD36) when compared to ASCs expanded in FBS. Here we report on the effects that expired BC products and additive solutions have on ASC expansion. When taken together, our findings indicate that all of the pHPL alternatives can be considered to be suitable replacements for FBS for ASC expansion, and that expired BC products can be used as an alternative to fresh BC products.
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Affiliation(s)
- Carla Dessels
- a Institute for Cellular and Molecular Medicine, Department of Immunology, SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences , University of Pretoria , Pretoria , South Africa
| | - Chrisna Durandt
- a Institute for Cellular and Molecular Medicine, Department of Immunology, SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences , University of Pretoria , Pretoria , South Africa
| | - Michael S Pepper
- a Institute for Cellular and Molecular Medicine, Department of Immunology, SAMRC Extramural Unit for Stem Cell Research and Therapy, Faculty of Health Sciences , University of Pretoria , Pretoria , South Africa
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13
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Nel JG, Durandt C, Theron AJ, Tintinger GR, Pool R, Richards GA, Mitchell TJ, Feldman C, Anderson R. Pneumolysin mediates heterotypic aggregation of neutrophils and platelets in vitro. J Infect 2017; 74:599-608. [PMID: 28267572 DOI: 10.1016/j.jinf.2017.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/17/2017] [Accepted: 02/24/2017] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Platelets orchestrate the inflammatory activities of neutrophils, possibly contributing to pulmonary and myocardial damage during severe pneumococcal infection. This study tested the hypothesis that the pneumococcal toxin, pneumolysin (Ply), activates production of platelet-activating factor (PAF) and thromboxane A2 (TxA2) by neutrophils, these bioactive lipids being potential mediators of neutrophil:platelet (NP) networking. METHODS The effects of recombinant Ply (10-80 ng mL-1) on the production of PAF and TxA2 by isolated neutrophils were measured using ELISA procedures, and NP aggregation by flow cytometry. RESULTS Exposure of neutrophils to Ply induced production of PAF and, to a lesser extent, TxA2, achieving statistical significance at ≥20 ng mL-1 of the toxin. In the case of NP interactions, Ply promoted heterotypic aggregation which was dependent on upregulation of P-selectin (CD62P) and activation of protease-activated receptor 1 (PAR1), attaining statistical significance at ≥10 ng mL-1 of the toxin, but did not involve either PAF or TxA2. CONCLUSION Ply induces synthesis of PAF and TxA2, by human neutrophils, neither of which appears to contribute to the formation of NP heterotypic aggregates in vitro, a process which is seemingly dependent on CD62P and PAR1. These pro-inflammatory activities of Ply may contribute to the pathogenesis of pulmonary and myocardial injury during severe pneumococcal infection.
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Affiliation(s)
- Jan G Nel
- Department of Haematology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa.
| | - Chrisna Durandt
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Unit for Stem Cell Research, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Annette J Theron
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Gregory R Tintinger
- Department of Internal Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Roger Pool
- Department of Haematology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; Tshwane Academic Division of the National Health Laboratory Service, Pretoria, South Africa
| | - Guy A Richards
- Department of Critical Care, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa; Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Timothy J Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Charles Feldman
- Division of Pulmonology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa
| | - Ronald Anderson
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa; Institute for Cellular and Molecular Medicine, South African Medical Research Council Unit for Stem Cell Research, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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14
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de Villiers D, Potgieter M, Ambele MA, Adam L, Durandt C, Pepper MS. The Role of Reactive Oxygen Species in Adipogenic Differentiation. Adv Exp Med Biol 2017; 1083:125-144. [PMID: 29139087 DOI: 10.1007/5584_2017_119] [Citation(s) in RCA: 23] [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] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Interest in reactive oxygen species and adipocyte differentiation/adipose tissue function is steadily increasing. This is due in part to a search for alternative avenues for combating obesity, which results from the excess accumulation of adipose tissue. Obesity is a major risk factor for complex disorders such as cancer, type 2 diabetes, and cardiovascular diseases. The ability of mesenchymal stromal/stem cells (MSCs) to differentiate into adipocytes is often used as a model for studying adipogenesis in vitro. A key focus is the effect of both intra- and extracellular reactive oxygen species (ROS) on adipogenesis. The consensus from the majority of studies is that ROS, irrespective of the source, promote adipogenesis.The effect of ROS on adipogenesis is suppressed by antioxidants or ROS scavengers. Reactive oxygen species are generated during the process of adipocyte differentiation as well as by other cell metabolic processes. Despite many studies in this field, it is still not possible to state with certainty whether ROS measured during adipocyte differentiation are a cause or consequence of this process. In addition, it is still unclear what the exact sources are of the ROS that initiate and/or drive adipogenic differentiation in MSCs in vivo. This review provides an overview of our understanding of the role of ROS in adipocyte differentiation as well as how certain ROS scavengers and antioxidants might affect this process.
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Affiliation(s)
- Danielle de Villiers
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Marnie Potgieter
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Center for Microbial Ecology and Genomics, Department of Genetics, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Melvin A Ambele
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Oral Pathology and Oral Biology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ladislaus Adam
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Chrisna Durandt
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Michael S Pepper
- Department of Immunology and Institute for Cellular and Molecular Medicine; SAMRC Extramural Unit for Stem Cell Research and Therapy; Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
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15
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Nel JG, Durandt C, Theron AJ, Tintinger GR, Mitchell TJ, Feldman C, Anderson R. S47 Pneumolysin promotes neutrophil: platelet aggregation in vitro. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.53] [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: 11/04/2022]
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16
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van Vollenstee FA, Jackson C, Hoffmann D, Potgieter M, Durandt C, Pepper MS. Human adipose derived mesenchymal stromal cells transduced with GFP lentiviral vectors: assessment of immunophenotype and differentiation capacity in vitro. Cytotechnology 2016; 68:2049-60. [PMID: 26815002 PMCID: PMC5023578 DOI: 10.1007/s10616-016-9945-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 01/12/2016] [Indexed: 12/13/2022] Open
Abstract
Adipose derived mesenchymal stromal/stem cells (ASCs) are a heterogeneous population characterized by (a) their ability to adhere to plastic; (b) immunophenotypic expression of certain cell surface markers, while lacking others; and (c) the capacity to differentiate into lineages of mesodermal origin including osteocytes, chondrocytes and adipocytes. The long-term goal is to utilize these cells for clinical translation into cell-based therapies. However, preclinical safety and efficacy need to be demonstrated in animal models. ASCs can also be utilized as biological vehicles for vector-based gene delivery systems, since they are believed to home to sites of inflammation and infection in vivo. These factors motivated the development of a labelling system for ASCs using lentiviral vector-based green fluorescent protein (GFP) transduction. Human ASCs were transduced with GFP-expressing lentiviral vectors. A titration study determined the viral titer required to transduce the maximum number of ASCs. The effect of the transduced GFP lentiviral vector on ASC immunophenotypic expression of surface markers as well as their ability to differentiate into osteocytes and adipocytes were assessed in vitro. A transduction efficiency in ASC cultures of approximately 80 % was observed with an MOI of ~118. No significant immunophenotypic differences were observed between transduced and non-transduced cells and both cell types successfully differentiated into adipocytes and osteocytes in vitro. We obtained >80 % transduction of ASCs using GFP lentiviral vectors. Transduced ASCs maintained plastic adherence, demonstrated ASC immunophenotype and the ability to differentiate into cells of the mesodermal lineage. This GFP-ASC transduction technique offers a potential tracking system for future pre-clinical studies.
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Affiliation(s)
- Fiona A van Vollenstee
- Department of Immunology, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine and MRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, P.O. Box 2034, Pretoria, 0001, South Africa
| | - Carlo Jackson
- Department of Immunology, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine and MRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, P.O. Box 2034, Pretoria, 0001, South Africa
| | - Danie Hoffmann
- Plastic and Reconstructive Surgeon, Private Practice, Pretoria, South Africa
| | - Marnie Potgieter
- Department of Immunology, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine and MRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, P.O. Box 2034, Pretoria, 0001, South Africa
| | - Chrisna Durandt
- Department of Immunology, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine and MRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, P.O. Box 2034, Pretoria, 0001, South Africa
| | - Michael S Pepper
- Department of Immunology, Faculty of Health Sciences, Institute for Cellular and Molecular Medicine and MRC Extramural Unit for Stem Cell Research and Therapy, University of Pretoria, P.O. Box 2034, Pretoria, 0001, South Africa.
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17
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Nel JG, Theron AJ, Durandt C, Tintinger GR, Pool R, Mitchell TJ, Feldman C, Anderson R. Pneumolysin activates neutrophil extracellular trap formation. Clin Exp Immunol 2016; 184:358-67. [PMID: 26749379 DOI: 10.1111/cei.12766] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/14/2015] [Accepted: 12/23/2015] [Indexed: 02/06/2023] Open
Abstract
The primary objective of the current study was to investigate the potential of the pneumococcal toxin, pneumolysin (Ply), to activate neutrophil extracellular trap (NET) formation in vitro. Isolated human blood neutrophils were exposed to recombinant Ply (5-20 ng ml(-1) ) for 30-90 min at 37°C and NET formation measured using the following procedures to detect extracellular DNA: (i) flow cytometry using Vybrant® DyeCycle™ Ruby; (ii) spectrofluorimetry using the fluorophore, Sytox(®) Orange (5 μM); and (iii) NanoDrop(®) technology. These procedures were complemented by fluorescence microscopy using 4', 6-diamino-2-phenylindole (DAPI) (nuclear stain) in combination with anti-citrullinated histone monoclonal antibodies to visualize nets. Exposure of neutrophils to Ply resulted in relatively rapid (detected within 30-60 min), statistically significant (P < 0·05) dose- and time-related increases in the release of cellular DNA impregnated with both citrullinated histone and myeloperoxidase. Microscopy revealed that NETosis appeared to be restricted to a subpopulation of neutrophils, the numbers of NET-forming cells in the control and Ply-treated systems (10 and 20 ng ml(-1) ) were 4·3 (4·2), 14.3 (9·9) and 16·5 (7·5), respectively (n = 4, P < 0·0001 for comparison of the control with both Ply-treated systems). Ply-induced NETosis occurred in the setting of retention of cell viability, and apparent lack of involvement of reactive oxygen species and Toll-like receptor 4. In conclusion, Ply induces vital NETosis in human neutrophils, a process which may either contribute to host defence or worsen disease severity, depending on the intensity of the inflammatory response during pneumococcal infection.
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Affiliation(s)
| | - A J Theron
- Department of Immunology, Faculty of Health Sciences, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service.,South African Medical Research Council Unit for Stem Cell Research, Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria
| | - C Durandt
- South African Medical Research Council Unit for Stem Cell Research, Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria
| | - G R Tintinger
- Department of Internal Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - R Pool
- Department of Haematology
| | - T J Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - C Feldman
- Division of Pulmonology, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg and Charlotte Maxeke Academic Hospital, Johannesburg, South Africa
| | - R Anderson
- South African Medical Research Council Unit for Stem Cell Research, Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria
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Abstract
Abstract The human innate immune system is indispensable for protection against potentially invasive microbial and viral pathogens, either neutralising them or containing their spread until effective mobilisation of the slower, adaptive (specific), immune response. Until fairly recently, it was believed that the human innate immune system possessed minimal discriminatory activity in the setting of a rather limited range of microbicidal or virucidal mechanisms. However, recent discoveries have revealed that the innate immune system possesses an array of novel pathogen recognition mechanisms, as well as a resourceful and effective alternative mechanism of phagocyte (predominantly neutrophil)-mediated, anti-infective activity known as NETosis. The process of NETosis involves an unusual type of programmed, purposeful cell death, resulting in the extracellular release of a web of chromatin heavily impregnated with antimicrobial proteins. These structures, known as neutrophil extracellular traps (NETs), immobilise and contribute to the eradication of microbial pathogens, ensuring that the anti-infective potential of neutrophils is sustained beyond the lifespan of these cells. The current review is focused on the mechanisms of NETosis and the role of this process in host defence. Other topics reviewed include the potential threats to human health posed by poorly controlled, excessive formation of NETs, specifically in relation to development of autoimmune and cardiovascular diseases, as well as exacerbation of acute and chronic inflammatory disorders of the airways.
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19
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Durandt C, van Vollenstee FA, Dessels C, Kallmeyer K, de Villiers D, Murdoch C, Potgieter M, Pepper MS. Novel flow cytometric approach for the detection of adipocyte subpopulations during adipogenesis. J Lipid Res 2016; 57:729-42. [PMID: 26830859 PMCID: PMC4808761 DOI: 10.1194/jlr.d065664] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 12/02/2015] [Indexed: 12/17/2022] Open
Abstract
The ability of mesenchymal stromal cells (MSCs) to differentiate into adipocytes provides a cellular model of human origin to study adipogenesis in vitro. One of the major challenges in studying adipogenesis is the lack of tools to identify and monitor the differentiation of various subpopulations within the heterogeneous pool of MSCs. Cluster of differentiation (CD)36 plays an important role in the formation of intracellular lipid droplets, a key characteristic of adipocyte differentiation/maturation. The objective of this study was to develop a reproducible quantitative method to study adipocyte differentiation by comparing two lipophilic dyes [Nile Red (NR) and Bodipy 493/503] in combination with CD36 surface marker staining. We identified a subpopulation of adipose-derived stromal cells that express CD36 at intermediate/high levels and show that combining CD36 cell surface staining with neutral lipid-specific staining allows us to monitor differentiation of adipose-derived stromal cells that express CD36intermediate/high during adipocyte differentiation in vitro. The gradual increase of CD36intermediate/high/NRpositive cells during the 21 day adipogenesis induction period correlated with upregulation of adipogenesis-associated gene expression.
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Affiliation(s)
- Chrisna Durandt
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Fiona A van Vollenstee
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Carla Dessels
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Karlien Kallmeyer
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Danielle de Villiers
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Candice Murdoch
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Marnie Potgieter
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Michael S Pepper
- Institute for Cellular and Molecular Medicine, South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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20
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Dodgen TM, Hochfeld WE, Fickl H, Asfaha SM, Durandt C, Rheeder P, Drögemöller BI, Wright GEB, Warnich L, Labuschagne CDJ, van Schalkwyk A, Gaedigk A, Pepper MS. Introduction of the AmpliChip CYP450 Test to a South African cohort: a platform comparative prospective cohort study. BMC Med Genet 2013; 14:20. [PMID: 23356658 PMCID: PMC3605304 DOI: 10.1186/1471-2350-14-20] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/18/2013] [Indexed: 02/02/2023]
Abstract
Background Adverse drug reactions and lack of therapeutic efficacy associated with currently prescribed pharmacotherapeutics may be attributed, in part, to inter-individual variability in drug metabolism. Studies on the pharmacogenetics of Cytochrome P450 (CYP) enzymes offer insight into this variability. The objective of this study was to compare the AmpliChip CYP450 Test® (AmpliChip) to alternative genotyping platforms for phenotype prediction of CYP2C19 and CYP2D6 in a representative cohort of the South African population. Methods AmpliChip was used to screen for thirty-three CYP2D6 and three CYP2C19 alleles in two different cohorts. As a comparison cohort 2 was then genotyped using a CYP2D6 specific long range PCR with sequencing (CYP2D6 XL-PCR + Sequencing) platform and a PCR-RFLP platform for seven CYP2C19 alleles. Results Even though there was a low success rate for the AmpliChip, allele frequencies for both CYP2D6 and CYP2C19 were very similar between the two different cohorts. The CYP2D6 XL-PCR + Sequencing platform detected CYP2D6*5 more reliably and could correctly distinguish between CYP2D6*2 and *41 in the Black African individuals. Alleles not covered by the AmpliChip were identified and four novel CYP2D6 alleles were also detected. CYP2C19 PCR-RFLP identified CYP2C19*9,*15, *17 and *27 in the Black African individuals, with *2, *17 and *27 being relatively frequent in the cohort. Eliminating mismatches and identifying additional alleles will contribute to improving phenotype prediction for both enzymes. Phenotype prediction differed between platforms for both genes. Conclusion Comprehensive genotyping of CYP2D6 and CYP2C19 with the platforms used in this study, would be more appropriate than AmpliChip for phenotypic prediction in the South African population. Pharmacogenetically important novel alleles may remain undiscovered when using assays that are designed according to Caucasian specific variation, unless alternate strategies are utilised.
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Affiliation(s)
- Tyren M Dodgen
- Department of Pharmacology, University of Pretoria, Pretoria, South Africa
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21
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Vanrensburg C, Durandt C, Garlinski P, Osullivan J. Evaluation of the antineoplastic activities of the riminophenazine agents clofazimine and b669 in tumor-bearing rats and mice. Int J Oncol 2012; 3:1011-3. [PMID: 21573467 DOI: 10.3892/ijo.3.5.1011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The riminophenazine agents clofazimine and its analogue B669 displayed anti-tumor activity at 30 mg/kg/day in benzo[a]pyrene (BP) induced sarcomas of mice as well as dimethylbenz-anthracene (DMBA)-induced rat mammary tumors. No hematological toxicity of these drugs at doses up to 60 mg/kg/day for one month was observed. This is the first study to document in vivo anti-neoplastic activities of clofazimine and B669.
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Affiliation(s)
- C Vanrensburg
- NATL UNIV IRELAND UNIV COLL DUBLIN,DEPT CHEM,DUBLIN 4,IRELAND
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22
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Cockeran R, Durandt C, Feldman C, Mitchell TJ, Anderson R. Pneumolysin activates the synthesis and release of interleukin-8 by human neutrophils in vitro. J Infect Dis 2002; 186:562-5. [PMID: 12195386 DOI: 10.1086/341563] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2002] [Revised: 04/23/2002] [Indexed: 11/03/2022] Open
Abstract
The effects that the Streptococcus pneumoniae-derived, proinflammatory toxin, pneumolysin (8.37 and 41.75 ng/mL), has on the production of interleukin (IL)-8 and tumor-necrosis factor (TNF)-alpha by human neutrophils have been investigated in vitro. Total and extracellular IL-8 and TNF-alpha were assayed by enzyme-linked immunosorbent assay, and flow cytometry and colorimetric procedures were used to detect intracellular cytokine and cytokine messenger RNA, respectively. Treatment of neutrophils with pneumolysin either alone or in combination with the chemotactic tripeptide, N-formyl-l-methionyl-l-leucyl-l-phenylalanine (1 microM), resulted in a time-dependent (maximal at 6 h) increase in synthesis and release of IL-8 but not of TNF-alpha, which was associated with increased expression of IL-8 messenger RNA transcripts and was abrogated by either cycloheximide (10 microg/mL) or depletion of Ca(2+) from the cell-suspending medium. These interactions between the toxin and neutrophils may contribute to the exaggerated pulmonary inflammatory responses caused by pneumolysin-producing strains of the pneumococcus.
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Affiliation(s)
- Riana Cockeran
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Institute of Pathology, University of Pretoria, South Africa.
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Durandt C, van Rensburg CE. Effects of tetramethylpiperidine (TMP)-substituted phenazines on membrane stability and P-glycoprotein function. Int J Oncol 2001; 19:579-83. [PMID: 11494039 DOI: 10.3892/ijo.19.3.579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The lipophilicity and membrane-destabilizing activities of clofazimine and three tetramethyl-piperidine (TMP)-substituted phenazines were compared with the anti-tumor and multiple drug resistance (MDR) neutralizing potential of these agents using a P-glycoprotein (P-gp)-expressing small cell lung cancer cell line (H69/LX4). Partition coefficients were measured as an index of lipophilicity, while membrane-destabilizing potential was measured using a conventional hemolytic assay. The membrane-destabilizing potential of the TMP-substituted phenazines was found to correlate positively with the degree of lipophilicity, as well as with MDR reversal activity. The presence of a TMP group, as well as chlorine atoms on the phenyl and anilino rings of these agents contributed to the enhancement of anti-tumor activity by potentiating membrane-destabilizing activity. TMP-substituted phenazines may be useful in the design of novel anti-cancer and MDR reversal agents.
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Affiliation(s)
- C Durandt
- Medical Research Council Unit for Inflammation and Immunity, Department of Immunology, Institute for Pathology, Faculty of Medicine, University of Pretoria, Pretoria 0001, Republic of South Africa
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