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Chang EI, Rozance PJ, Wesolowski SR, Nguyen LM, Shaw SC, Sclafani RA, Bjorkman KK, Peter AK, Hay WW, Brown LD. Rates of myogenesis and myofiber numbers are reduced in late gestation IUGR fetal sheep. J Endocrinol 2019; 244:339-352. [PMID: 31751294 PMCID: PMC7192794 DOI: 10.1530/joe-19-0273] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/12/2019] [Indexed: 12/14/2022]
Abstract
Intrauterine growth-restricted (IUGR) fetuses are born with reduced skeletal muscle mass. We hypothesized that reduced rates of myogenesis would contribute to fewer and smaller myofibers in IUGR fetal hindlimb muscle compared to the normally growing fetus. We tested this hypothesis in IUGR fetal sheep with progressive placental insufficiency produced by exposing pregnant ewes to elevated ambient temperatures from 38 to 116 days gestation (dGA; term = 147 dGA). Surgically catheterized control (CON, n = 8) and IUGR (n = 13) fetal sheep were injected with intravenous 5-bromo-2′-deoxyuridine (BrdU) prior to muscle collection (134 dGA). Rates of myogenesis, defined as the combined processes of myoblast proliferation, differentiation, and fusion into myofibers, were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. Total myofiber number was determined for the entire cross-section of the FDS muscle. In IUGR fetuses, the number of BrdU+ myonuclei per myofiber cross-section was lower in BF, TA, and FDS (P < 0.05), total myonuclear number per myofiber cross-section was lower in BF and FDS (P < 0.05), and total myofiber number was lower in FDS (P < 0.005) compared to CON. mRNA expression levels of cyclins, cyclin-dependent protein kinases, and myogenic regulatory factors were lower (P < 0.05), and inhibitors of the cell cycle were higher (P < 0.05) in IUGR BF compared to CON. Markers of apoptosis were not different in IUGR BF muscle. These results show that in IUGR fetuses, reduced rates of myogenesis produce fewer numbers of myonuclei, which may limit hypertrophic myofiber growth. Fewer myofibers of smaller size contribute to smaller muscle mass in the IUGR fetus.
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Affiliation(s)
- Eileen I. Chang
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Paul J. Rozance
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Stephanie R. Wesolowski
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Leanna M. Nguyen
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Steven C. Shaw
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Robert A. Sclafani
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kristen K. Bjorkman
- Department of Molecular, Cellular and Developmental Biology and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Angela K. Peter
- Department of Molecular, Cellular and Developmental Biology and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - William W. Hay
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
| | - Laura D. Brown
- Department of Pediatrics, University of Colorado School of Medicine, Perinatal Research Center, Aurora, Colorado, USA
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Micke G, Sullivan T, Soares Magalhaes R, Rolls P, Norman S, Perry V. Heifer nutrition during early- and mid-pregnancy alters fetal growth trajectory and birth weight. Anim Reprod Sci 2010; 117:1-10. [DOI: 10.1016/j.anireprosci.2009.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 03/09/2009] [Accepted: 03/25/2009] [Indexed: 10/21/2022]
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Lumbers ER, Kim MY, Burrell JH, Kumarasamy V, Boyce AC, Gibson KJ, Gatford KL, Owens JA. Effects of intrafetal IGF-I on growth of cardiac myocytes in late-gestation fetal sheep. Am J Physiol Endocrinol Metab 2009; 296:E513-9. [PMID: 19126787 DOI: 10.1152/ajpendo.90497.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intrafetal insulin-like growth factor (IGF)-I promotes cardiac hypertrophy in the late-gestation fetal sheep; whether these effects are sustained is unknown. IGF-I was infused for 4 days at 80 microg/h from 121 to 125 days of gestation, and its effects at 128 days, 3 days after the infusion stopped, were determined by comparison with untreated fetal sheep. After IGF-I treatment, fetal weights were similar to those in control fetuses but kidney weights were bigger (P < 0.05), as were spleen weights of male fetuses (P < 0.05). Cardiac myocytes were larger in female than male fetal sheep (P < 0.001). IGF-I increased male (P < 0.001) but not female myocyte volumes. IGF-I did not alter the proportions of uni- or binucleated right or left ventricular myocytes. Female fetal sheep had a greater proportion of binucleated cardiac myocytes than males (P < 0.05). IGF-I-treated fetuses had a slightly greater proportion of right ventricular nuclei in cell cycle phase G(2)/M and a reduced proportion of G(0)/G(1) phase nuclei (P < 0.1). Therefore, evidence for IGF-I-stimulated cardiac cell hyperplasia in fetal sheep in late gestation was limited. In conclusion, the greater sizes and larger proportion of binucleated cardiac myocytes in female fetal sheep suggest that myocyte maturation may occur earlier in females than in males. This may explain in part the male sex-specific responsiveness of cardiac hypertrophy to IGF-I in late gestation. If IGF-I-stimulated cardiomyocyte growth is accompanied by maturation of contractile function, IGF-I may be a potential therapeutic agent for maintaining cardiac output in preterm males.
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Affiliation(s)
- Eugenie R Lumbers
- Department of Physiology, University of New South Wales, Sydney, Australia.
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Gerdts V, Tsang C, Griebel PJ, Babiuk LA. DNA vaccination in utero: a new approach to induce protective immunity in the newborn. Vaccine 2004; 22:1717-27. [PMID: 15068855 DOI: 10.1016/j.vaccine.2003.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Infectious diseases are the primary cause of neonatal morbidity and mortality in people, resulting in millions of deaths every year. Infection of the newborn with some of the pathogens involved, such as herpes simplex virus (HSV), human immunodeficiency virus (HIV), hepatitis B virus (HBV), human cytomegalovirus (HCMV) or group B Streptococcus sp. (GBS), usually occurs at the end of pregnancy, during birth or by breast feeding. Therefore, active immunization of the fetus might represent an effective approach to reduce the high risk of neonatal diseases. We recently showed that DNA immunization in utero within the third trimester of gestation induced strong humoral and cell-mediated immune responses in immunized fetal lambs. Here, we demonstrate that fetal immunization was safe and did not affect fetal gestation, neonatal viability, or significantly alter blood leukocyte populations. In utero immunization resulted in the induction of protective mucosal immunity and immune memory in the newborn lamb. Furthermore, there was no evidence that in utero DNA immunization induced immune tolerance. Our results also indicate that the uptake and expression of the plasmid DNA already occurred within the epithelium of the oral cavity. This correlates with our previous findings that local immune responses were found exclusively in the retropharyngeal lymph nodes draining the oral cavity.
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Affiliation(s)
- Volker Gerdts
- Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Sask., Canada S7N 5E3.
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Gerdts V, Snider M, Brownlie R, Babiuk LA, Griebel PJ. Oral DNA vaccination in utero induces mucosal immunity and immune memory in the neonate. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:1877-85. [PMID: 11823522 DOI: 10.4049/jimmunol.168.4.1877] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Infectious diseases are responsible for a significant number of deaths during the first weeks of life. Some of the salient pathogens include HSV, HIV, hepatitis B virus, group B streptococcus, Haemophilus sp., and Chlamydia sp. The vertical transmission of many of these pathogens significantly increases the risk of neonatal infection. We recently reported that oral DNA immunization in utero induced high serum Ab titers and cell-mediated immunity in fetal lambs. In this study, we demonstrate immune memory and mucosal immunity in newborn lambs following oral DNA immunization of the fetus. A single oral exposure in utero to plasmid DNA encoding a truncated form of glycoprotein D of bovine herpesvirus-1 induced detectable immune responses in 80% (12 of 15) of newborn lambs. There was no evidence for the induction of immune tolerance in nonresponding lambs. Responding lambs displayed both systemic and mucosal immune responses and reduced virus shedding following intranasal challenge. Furthermore, strong anamnestic responses were evident for at least 3 mo after birth. The efficacy of in utero oral DNA immunization was further demonstrated with the hepatitis B surface Ag, and protective serum Ab titers occurred in 75% of immunized lambs. Thus, the present investigation confirms that oral DNA immunization in utero can induce both mucosal and systemic immune responses in the neonate and that this immunity has the potential to prevent vertical disease transmission.
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MESH Headings
- Administration, Oral
- Animals
- Animals, Newborn
- Antibodies, Viral/biosynthesis
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- DNA, Viral/genetics
- Fetus
- Hepatitis B Surface Antigens/genetics
- Hepatitis B Surface Antigens/immunology
- Herpesviridae Infections/immunology
- Herpesviridae Infections/prevention & control
- Herpesvirus 1, Bovine/immunology
- Herpesvirus 1, Bovine/pathogenicity
- Immunity, Mucosal
- Immunologic Memory
- Kinetics
- Sheep
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/adverse effects
- Vaccines, DNA/immunology
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/adverse effects
- Vaccines, Inactivated/immunology
- Viral Proteins/genetics
- Viral Proteins/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/adverse effects
- Viral Vaccines/immunology
- Virus Shedding
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Affiliation(s)
- Volker Gerdts
- Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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