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Hoevelmann J, Engel ME, Muller E, Hohlfeld A, Boehm M, Sliwa K, Viljoen CA. Global prevalence of mortality and LV recovery in women with PPCM – a systematic review and meta-analysis. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2508] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction
Peripartum cardiomyopathy (PPCM) remains a major contributor to maternal morbidity and mortality worldwide. The disease is associated with various complications mainly occurring early during its course. Reported adverse outcomes include decompensated heart failure, thromboembolic complications, arrhythmias and death.
Purpose
We aimed to systematically summarize the outcomes of women with PPCM across different geographical regions and to identify possible predictors of adverse outcomes.
Methods
For this systematic review and meta-analysis, we performed a comprehensive search of all articles published between January 2000 and June 2021 on PubMed/MEDLINE, Web of Science, Scopus and EBSCO Host, including Academic Search Premier, Africa-Wide Information, CINAHL. All cohort, case-control and cross-sectional studies, as well as control arms of randomized controlled trials (RCTs) reporting on the in-hospital complications and 6- and/or 12-month outcomes of PPCM were considered eligible.
Results
Forty-seven studies (4875 participants across 60 countries) met the eligibility criteria. Hemodynamic and echocardiographic parameters were similar across all continents. In-hospital mortality was reported as 1.9% [95% CI 0.5–4.0] across all regions. About 10% of patients received invasive ventilation, 21.5% inotropic and 3.1% received mechanical support, respectively. Left ventricular (LV) thrombus complicated 9.0% [95% CI 6.5–11.9] of patients and all-cause embolic events (i.e., stroke, arterial embolism, deep vein thrombosis, pulmonary embolus) occurred in 6.1% [95% CI 3.8–8.9]. Arrhythmias were seldomly reported. All-cause mortality was 8.0% [95% CI 5.5–10.8, I2=79,1%) at 6 months and 9.8% [95% CI 6.2–14.0], I2=80.48%) at 12 months respectively. Overall, 44.4% ([95% CI 36.2–52.8], I2=91.7%) of patients recovered their LV function within 6 months and 58.7% ([95% CI 48.1–68.9], I2=75.8%) within 12 months, respectively. The lowest rate of LV recovery was reported by studies conducted in the Middle East (13.6% [95% CI 9.5–18.1], 3 studies), whereas the highest rate of LV recovery was reported for patients from Europe (56.8% [95% CI 38.1–74.7], 6 studies, I2=93.3%). All-cause mortality was highest in Africa and Asia/Pacific. Europe and North America reported the highest prevalence of LV recovery. (Figure 1) Frequent prescription of beta-blockers, ACE-I/ARB and bromocriptine/cabergoline treatment was associated with significantly lower all-cause mortality and better LV recovery (Figure 2).
Conclusion
We identified significant global differences in prescribed treatment, prevalence of in-hospital complications and six- and 12-month outcomes. Frequent prescription of guideline-directed heart failure therapy was associated with better LV recovery and lower all-cause mortality. Timely initiation and up-titration of heart failure therapy should therefore be strongly encouraged to improve outcome in women with PPCM.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- J Hoevelmann
- Saarland University Hospital, Department of Cardiology , Homburg , Germany
| | - M E Engel
- University of Cape Town, Department of Medicine , Cape Town , South Africa
| | - E Muller
- University of Cape Town, Cape Heart Institute , Cape Town , South Africa
| | - A Hohlfeld
- South African Medical Research Council , Cape Town , South Africa
| | - M Boehm
- Saarland University Hospital, Department of Cardiology , Homburg , Germany
| | - K Sliwa
- University of Cape Town, Cape Heart Institute , Cape Town , South Africa
| | - C A Viljoen
- University of Cape Town, Division of Cardiology , Cape Town , South Africa
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Prendergast EA, Perkins S, Engel ME, Cupido B, Francis V, Joachim A, Al Kebsi M, Bode-Thomas F, Damasceno A, Abul Fadl A, El Sayed A, Gitura B, Kennedy N, Ibrahim A, Mucumbitsi J, Adeoye AM, Musuku J, Okello E, Olunuga T, Sheta S, Mayosi BM, Zühlke LJ. Participation in research improves overall patient management: insights from the Global Rheumatic Heart Disease registry (REMEDY). Cardiovasc J Afr 2018; 29:98-105. [PMID: 29570206 PMCID: PMC6008904 DOI: 10.5830/cvja-2017-054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 07/30/2017] [Accepted: 11/19/2017] [Indexed: 12/28/2022] Open
Abstract
Background Rheumatic heart disease (RHD) is a major public health problem in low– and middle–income countries (LMICs), with a paucity of high–quality trial data to improve patient outcomes. Investigators felt that involvement in a recent large, observational RHD study impacted positively on their practice, but this was poorly defined. Aim The purpose of this study was to document the experience of investigators and research team members from LMICs who participated in a prospective, multi–centre study, the global Rheumatic Heart Disease Registry (REMEDY), conducted in 25 centres in 14 countries from 2010 to 2012. Methods We conducted an online survey of site personnel to identify and quantify their experiences. Telephone interviews were conducted with a subset of respondents to gather additional qualitative data. We asked about their experiences, positive and negative, and about any changes in RHD management practices resulting from their participation in REMEDY as a registry site. Results The majority of respondents in both the survey and telephone interviews indicated that participation as a registry site improved their management of RHD patients. Administrative changes included increased attention to follow–up appointments and details in patient records. Clinical changes included increased use of penicillin prophylaxis, and more frequent INR monitoring and contraceptive counselling. Conclusions Our study demonstrates that participation in clinical research on RHD can have a positive impact on patient management. Furthermore, REMEDY has led to increased patient awareness and improved healthcare workers’ knowledge and efficiency in caring for RHD patients.
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Affiliation(s)
- E A Prendergast
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - S Perkins
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - M E Engel
- Department of Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - B Cupido
- Division of Cardiology, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - V Francis
- Department of Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - A Joachim
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - M Al Kebsi
- Faculty of Medicine and Surgery, University of Sana'a, Al-Thawrah, Cardiac Centre, Sana'a, Yemen
| | - F Bode-Thomas
- Departments of Paediatrics, University of Jos and Jos University Teaching Hospital, Jos, Nigeria
| | - A Damasceno
- Department of Medicine, Eduardo Mondlane University, Maputo, Mozambique
| | - A Abul Fadl
- Faculty of Medicine, Benha University, Cairo, Egypt
| | - A El Sayed
- Cardiothoracic Surgery Department, Al Shaab Teaching Hospital and Faculty of Medicine, Alzaiem Alazhari University, Khartoum, Sudan
| | - B Gitura
- Cardiology Unit, Department of Medicine, Kenyatta National Teaching and Referral Hospital, Nairobi, Kenya
| | - N Kennedy
- Department of Paediatrics and Child Health, College of Medicine, University of Malawi, Blantyre, Malawi; Centre for Medical Education, Queen's University, Belfast; Royal Belfast Hospital for Sick Children, Belfast, Ireland
| | - A Ibrahim
- Cardiothoracic Surgery Department, Al Shaab Teaching Hospital and Faculty of Medicine, Alzaiem Alazhari University, Khartoum, Sudan
| | - J Mucumbitsi
- Paediatric Cardiology Unit, Department of Paediatrics, King Faisal Hospital, Kigali, Rwanda
| | - A M Adeoye
- Division of Cardiology, Department of Medicine, University College Hospital, Ibadan, Nigeria
| | - J Musuku
- University Teaching Hospital, Department of Paediatrics and Child Health, University of Zambia, Lusaka, Zambia
| | - E Okello
- Uganda Heart Institute, Kampala, Uganda
| | - T Olunuga
- Department of Medicine, Federal Medical Centre, Abeokuta, Nigeria
| | - S Sheta
- Department of Paediatrics, Division of Paediatric Cardiology, Faculty of Medicine, Cairo University Children's Hospital, Cairo, Egypt
| | - B M Mayosi
- Department of Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Division of Cardiology, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Dean of Faculty of Health Sciences, University of Cape Town, South Africa
| | - L J Zühlke
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Department of Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Division of Cardiology, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
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Abstract
SETTING Cape Town, South Africa. OBJECTIVE To evaluate the current system of tuberculosis surveillance in the Cape Metro region. DESIGN This evaluation was based on the 'Updated Guidelines for Evaluating Public Health Surveillance Systems' of the Centers for Disease Control and Prevention, modified to render the framework applicable to the context of tuberculosis (TB) surveillance. The evaluation incorporated qualitative exploration of perceptions and experiences of system users. RESULTS System users were very accepting of the system and were committed to seeing it achieve its purpose within public health. Some individuals expressed concerns about the rigidity of the Electronic TB Register software and its analysis capabilities. Dissemination of TB data and evidence-based action within the Cape Metro region are strong attributes of Cape Town's TB surveillance system. At the time of the evaluation, integration of TB and human immunodeficiency virus (HIV) data was weak, as was multidrug-resistant TB (MDR-TB) surveillance; the South African Tuberculosis Control Programme is developing initiatives to improve these areas. CONCLUSIONS Cape Metro's TB surveillance is strong, although it would be strengthened by increasing availability of data reflecting TB-HIV co-infection and MDR-TB. Systems operations could be improved by increasing software flexibility, and increased integration of electronic data across health regions would enhance the capacity and assessment of control efforts.
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Affiliation(s)
- C L Heidebrecht
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
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Dave JA, Engel ME, Freercks R, Peter J, May W, Badri M, Van Niekerk L, Levitt NS. Abnormal glucose metabolism in non-diabetic patients presenting with an acute stroke: prospective study and systematic review. QJM 2010; 103:495-503. [PMID: 20430755 DOI: 10.1093/qjmed/hcq062] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Non-diabetic patients presenting with an acute stroke often have hyperglycaemia. In most populations it is unknown whether the hyperglycaemia is transient and due to the acute stress response or whether it represents undiagnosed abnormal glucose metabolism. AIM To evaluate the prevalence and predictors of persistent hyperglycaemia in non-diabetic patients with an acute stroke. DESIGN Prospective observational study. METHODS Non-diabetic patients over 40 years old with an acute stroke were enrolled over a 2-year period. On admission patients were evaluated with an HbA(1c) and a 75 g oral glucose tolerance test (OGTT). The OGTT was repeated 3 months later. A meta-analysis was performed to interpret our results in the context of published data. RESULTS One hundred and seven patients were analysed. On admission 26 (24%) patients had diabetes, 39 (37%) had impaired glucose tolerance and 42 (39%) had normal glucose tolerance. Forty-four (68%) patients with hyperglycaemia on admission were re-investigated at least 3 months after discharge. Of these, 6 (14%) had diabetes, 12 (27%) had impaired glucose tolerance and 26 (59%) had normal glucose tolerance. A 2-h post-load glucose value >or=10 mmol/l predicted persistent hyperglycaemia with 72.2% sensitivity, 65.4% specificity and a positive predictive value and negative predictive value of 59.1 and 77.3%, respectively. A meta-analysis of prevalence data of impaired glucose metabolism in non-diabetic individuals 3 months after having had an acute stroke revealed a combined prevalence of 58% (95% confidence interval 25.4-90.5%). CONCLUSION In this study hyperglycaemia in the setting of an acute stroke was transient in the majority of patients.
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Affiliation(s)
- J A Dave
- Division of Diabetic Medicine and Endocrinology, Department of Medicine, J-floor, Old Main Building, Groote Schuur Hospital, Anzio Road, Observatory, 7925 Cape Town, South Africa.
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Abstract
BACKGROUND Corticosteroids used in addition to antituberculous therapy have been reported to benefit people with tuberculous pleurisy. However, research findings are inconsistent, raising doubt as to whether such treatment is worthwhile. Concern also exists regarding the potential adverse effects of corticosteroids, especially in HIV-positive people. OBJECTIVES To evaluate the effects of adding corticosteroids to drug regimens for tuberculous pleural effusion. SEARCH STRATEGY In May 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 2), MEDLINE, EMBASE, LILACS, Current Controlled Trials, and reference lists of articles. SELECTION CRITERIA Randomized and quasi-randomized controlled trials comparing any corticosteroid with no treatment, placebo, or other active treatment (both groups should receive the same antituberculous drug regimen) in people diagnosed with tuberculous pleurisy. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial methodological quality and extracted data. Data were analysed using relative risks (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI). The fixed-effect model was applied in the absence of statistically significant heterogeneity. MAIN RESULTS Six trials with 633 participants met the inclusion criteria; one trial included only HIV-positive people. Compared to control, corticosteroid use was associated with less residual pleural fluid at four weeks (RR 0.76, 95% CI 0.62 to 0.94; 394 participants, 3 trials) and reduced pleural thickening (RR 0.69, 95% CI 0.51 to 0.94; 309 participants, 4 trials). We found no evidence of an effect of corticosteroids on death from any cause (194 participants, 1 trial), respiratory function (191 participants, 2 trials), residual pleural fluid at eight weeks (399 participants, 4 trials), or pleural adhesions (123 participants, 2 trials). Although discontinuation of treatment due to adverse events was more frequent in participants receiving corticosteroids than placebo (RR 2.80, 95% CI 1.12 to 6.98; 586 participants, 6 trials), the effects were generally mild. The risk of Kaposi sarcoma may be increased in HIV-positive people receiving corticosteroids (RR 13.00, 95% CI 0.74 to 227.63; 194 participants, 1 trial). AUTHORS' CONCLUSIONS There are insufficient data to support evidence-based recommendations regarding the use of adjunctive corticosteroids in people with tuberculous pleurisy. Randomized controlled trials that are sufficiently powered to evaluate the effects of corticosteroids on both morbidity and mortality are needed. The effects of corticosteroids on HIV-related complications, such as Kaposi sarcoma, should be assessed in people co-infected with HIV.
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Affiliation(s)
- M E Engel
- Faculty of Health Sciences, University of Cape Town, Department of Medicine, J47 Old Main Building, Groote Schuur Hospital, Observatory, South Africa, 7925.
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Sobol Z, Engel ME, Rubitski E, Ku WW, Aubrecht J, Schiestl RH. Genotoxicity profiles of common alkyl halides and esters with alkylating activity. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 2007; 633:80-94. [PMID: 17644026 DOI: 10.1016/j.mrgentox.2007.05.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 04/25/2007] [Accepted: 05/04/2007] [Indexed: 11/15/2022]
Abstract
Drug synthesis and/or formulation can generate genotoxic impurities. For instance, strong acid/alcohol interactions during the process of drug salt formation produce alkylating agents such as alkyl halides and alkyl esters of alkyl sulfonic acids. The genotoxicity of a few classic alkylating agents such as methyl and ethyl methanesulfonate have been previously well characterized, whereas the majority of compounds from this class have only been tested in the Salmonella reversion assay. Therefore, the goal of this study was to investigate clastogenicity and DEL recombination profiles of 22 halogenated alkanes and alkylesters of sulfuric and alkane-, aryl-sulfonic acids using a battery of cellular and molecular assays. The in-vitro micronucleus assay in CHO cells was used to measure clastogenicity and the deletion recombination (DEL) assay in S. cerevisiae provided a measure of DNA deletions. We also examined the compounds' reactivity towards 4-(p-nitrobenzyl)pyridine (NBP), a surrogate molecule for biological ring nitrogens. Methylating agents were most potent in all three assays and the alkyl chlorides evaluated in our study were negative in all three assays. Also, a strong correlation was found between the MN, DEL and NBP assays. In summary, this study contributes to a better understanding of the genotoxic properties of common alkyl halides and alkyl esters with alkylating activity and might provide guidance for managing risk of genotoxic process-related impurities of drug substances and products.
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Affiliation(s)
- Z Sobol
- Department of Pathology, Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
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Engel ME, Hickstein DD, Bauer TR, Calder C, Manes B, Frangoul H. Matched unrelated bone marrow transplantation with reduced-intensity conditioning for leukocyte adhesion deficiency. Bone Marrow Transplant 2006; 37:717-8. [PMID: 16489359 DOI: 10.1038/sj.bmt.1705301] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bhowmick NA, Ghiassi M, Bakin A, Aakre M, Lundquist CA, Engel ME, Arteaga CL, Moses HL. Transforming growth factor-beta1 mediates epithelial to mesenchymal transdifferentiation through a RhoA-dependent mechanism. Mol Biol Cell 2001; 12:27-36. [PMID: 11160820 PMCID: PMC30565 DOI: 10.1091/mbc.12.1.27] [Citation(s) in RCA: 801] [Impact Index Per Article: 34.8] [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: 06/29/2000] [Revised: 09/06/2000] [Accepted: 11/07/2000] [Indexed: 12/21/2022] Open
Abstract
Transforming growth factor-beta1 (TGF-beta) can be tumor suppressive, but it can also enhance tumor progression by stimulating the complex process of epithelial-to-mesenchymal transdifferentiaion (EMT). The signaling pathway(s) that regulate EMT in response to TGF-beta are not well understood. We demonstrate the acquisition of a fibroblastoid morphology, increased N-cadherin expression, loss of junctional E-cadherin localization, and increased cellular motility as markers for TGF-beta-induced EMT. The expression of a dominant-negative Smad3 or the expression of Smad7 to levels that block growth inhibition and transcriptional responses to TGF-beta do not inhibit mesenchymal differentiation of mammary epithelial cells. In contrast, we show that TGF-beta rapidly activates RhoA in epithelial cells, and that blocking RhoA or its downstream target p160(ROCK), by the expression of dominant-negative mutants, inhibited TGF-beta-mediated EMT. The data suggest that TGF-beta rapidly activates RhoA-dependent signaling pathways to induce stress fiber formation and mesenchymal characteristics.
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Affiliation(s)
- N A Bhowmick
- Vanderbilt-Ingram Cancer Center, Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Abstract
SMAD and JNK cascades are essential components of the transforming growth factor-beta (TGF-beta) signaling machinery and are implicated in common transcriptional responses. However, the relationship of these pathways to one another downstream of the TGF-beta receptor complex is unknown. We show that JNK is rapidly activated by TGF-beta in a SMAD-independent manner and phosphorylates Smad3 outside its -SSXS motif. Smad3 phosphorylation by JNK facilitates both its activation by the TGF-beta receptor complex and its nuclear accumulation. JNK regulates SMAD- and TGF-beta-mediated transcriptional responses, yet JNK activators only partially stimulate transcriptional responses characteristic of TGF-beta without coincident SMAD pathway activation. These results suggest an interdependent relationship between the JNK and SMAD pathways in TGF-beta-mediated transcription.
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Affiliation(s)
- M E Engel
- Department of Cell Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37232-6838, USA
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Engel ME, Datta PK, Moses HL. Signal transduction by transforming growth factor-beta: a cooperative paradigm with extensive negative regulation. J Cell Biochem Suppl 1999; 30-31:111-22. [PMID: 9893262] [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] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Transforming growth factor-beta (TGF-beta) represents an evolutionarily conserved family of secreted factors that mobilize a complex signaling network to control cell fate by regulating proliferation, differentiation, motility, adhesion, and apoptosis. TGF-beta promotes the assembly of a cell surface receptor complex composed of type I (T beta RI) and type II (T beta RII) receptor serine/threonine kinases. In response to TGF-beta binding, T beta RII recruits and activates T beta RI through phosphorylation of the regulatory GS-domain. Activated T beta RI then initiates cytoplasmic signaling pathways to produce cellular responses. SMAD proteins together constitute a unique signaling pathway with key roles in signal transduction by TGF-beta and related factors. Pathway-restricted SMADs are phosphorylated and activated by type I receptors in response to stimulation by ligand. Once activated, pathway-restricted SMADs oligomerize with the common-mediator Smad4 and subsequently translocate to the nucleus. Genetic analysis in Drosophila melanogaster and Caenorhabditis elegans, as well as T beta RII and SMAD mutations in human tumors, emphasizes their importance in TGF-beta signaling. Mount ng evidence indicates that SMADs cooperate with ubiquitous cytoplasmic signaling cascades and nuclear factors to produce the full spectrum of TGF-beta responses. Operating independently, these ubiquitous elements may influence the nature of cellular responses to TGF-beta. Additionally, a variety of regulatory schemes contribute temporal and/or spatial restriction to TGF-beta responses. This report reviews our current understanding of TGF-beta signal transduction and considers the importance of a cooperative signaling paradigm to TGF-beta-mediated biological responses.
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Affiliation(s)
- M E Engel
- Department of Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-6838, USA
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Abstract
Transforming growth factor beta (TGF-beta) is the prototype for an evolutionarily conserved superfamily of secreted factors implicated in diverse biological phenomena. The pleiotropic responses to TGF-beta are initiated by a heteromeric receptor complex that binds and phosphorylates downstream effectors. Among these, the Smads have been extensively studied. However, less attention has been directed toward alternative downstream effectors and their participation in TGF-beta signal transduction. We show that TGF-beta promotes accumulation of the labile monomeric GTPase RhoB by antagonizing its normal proteolytic destruction, presumably via the 26 S proteasome. RhoB accumulates in its isoprenylated form. Transient overexpression of wild type RhoB but not its dominant negative mutant RhoB-N19 antagonizes TGF-beta-mediated transcriptional activation. These results suggest a novel mechanism of regulation by TGF-beta and implicate RhoB as a negative regulator of TGF-beta signal transduction.
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Affiliation(s)
- M E Engel
- Department of Cell Biology and the Vanderbilt Cancer Center, Vanderbilt University, Nashville, Tennessee 37232-6838, USA
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Engel ME, Mouton SC, Emms M. Paediatric rhabdomyosarcoma: MyoD1 demonstration in routinely processed tissue sections using wet heat pretreatment (pressure cooking) for antigen retrieval. J Clin Pathol 1997; 50:37-9. [PMID: 9059354 PMCID: PMC499710 DOI: 10.1136/jcp.50.1.37] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [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: 02/03/2023]
Abstract
AIMS To investigate wet heat pretreatment (pressure cooking) as a means of antigen retrieval for demonstration of MyoD1 in paraffin wax embedded tissue. METHODS Routinely processed tissue sections of transmission electron microscope confirmed cases of rhabdomyosarcoma were stained immunohistochemically with the MyoD1 antibody. Antigen retrieval was achieved by wet heat pretreatment of the tissue sections. RESULTS MyoD1 was stained successfully in all seven cases. The protein was localised to nuclei and cytoplasm depending on the type of tumour cell. CONCLUSIONS Wet heat pretreatment for antigen retrieval from routinely processed tissue sections permits excellent subsequent immunostaining for MyoD1 in rhabdomyoblasts.
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Affiliation(s)
- M E Engel
- Department of Pathology, Red Cross Children's Hospital, Rondebosch, South Africa
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Kawabata M, Imamura T, Miyazono K, Engel ME, Moses HL. Interaction of the transforming growth factor-beta type I receptor with farnesyl-protein transferase-alpha. J Biol Chem 1995; 270:29628-31. [PMID: 8530343 DOI: 10.1074/jbc.270.50.29628] [Citation(s) in RCA: 59] [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] [Indexed: 01/31/2023] Open
Abstract
Transforming growth factor-beta 1 (TGF-beta 1) is the prototype of a large family of molecules that regulate a variety of biological processes. The type I (T beta R-I) and type II (T beta R-II) receptors for TGF-beta 1 are transmembrane serine/threonine kinases, forming a heteromeric signaling complex. Recent studies have shown that T beta R-II is a constitutively active kinase and phosphorylates T beta R-I upon ligand binding, suggesting that T beta R-I is the effector subunit of the receptor complex, which transduces signals to intracellular targets. This model has been further confirmed by the identification of constitutively active T beta R-I that mediates TGF-beta 1-specific cellular responses in the absence of ligand and T beta R-II. To investigate signaling by TGF-beta 1, we have sought to isolate proteins that interact with the cytoplasmic region of T beta R-I. One of the proteins identified was the alpha subunit of farnesyl-protein transferase (FT alpha) that modifies a series of peptides including Ras. T beta R-I specifically interacts with FT alpha in the yeast two-hybrid system. Glutathione S-transferase-T beta R-I fusion proteins bind FT alpha translated in vitro. T beta R-I also phosphorylates FT alpha. We further show that the constitutively active T beta R-I interacted with FT alpha very strongly whereas an inactive form of T beta R-I did not. These results suggest that FT alpha may be one of the substrates of the activated T beta R-I kinase.
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Affiliation(s)
- M Kawabata
- Vanderbilt Cancer Center, Nashville, Tennessee 37232-6838, USA
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