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Maxillary and dental development in the offspring of protein-restricted female rats
Bruno Calsa1, Tainá Jaqueline Bortolança2, Beatriz Calloni Masiero1
1Graduate Program of Biomedical Sciences, Herminio Ometto University Center, Araras, São Paulo, Brazil.
Insights
Maternal protein restriction during pregnancy and lactation impairs offspring's dental and maxillary development. Limiting protein only during gestation allows for normal development, but combined restriction leads to impaired tooth formation.
Area of Science:
- Developmental Biology
- Nutritional Science
- Oral Biology
Background:
- Nutritional deficits during critical developmental windows can negatively impact organ physiology.
- Maternal nutrition plays a crucial role in fetal development, including craniofacial structures.
Purpose of the Study:
- To investigate the effects of maternal protein restriction during pregnancy and lactation on dental and maxillary development in rat pups.
- To analyze the specific impacts of protein restriction timing (gestation, lactation, or both) on key developmental markers.
Main Methods:
- Female rats were assigned to four dietary groups: normal-protein (NP), low-protein during lactation (LP-L), low-protein during pregnancy and lactation (LP), and low-protein during pregnancy (LP-G).
- Maxillae from 15-day-old male pups were collected and analyzed for dental and bone development markers.
- Gene expression analysis (OPG, RANKL, Dspp) and assessments of dentin thickness, alveolar bone area, pulp vascularity, and mineralization were performed.
Main Results:
- All protein-restricted groups showed increased dentin thickness and reduced alveolar bone area.
- The LP group (protein restriction during gestation and lactation) exhibited significant negative effects: reduced osteoprotegerin (OPG), increased RANKL, delayed odontoblast maturation, decreased dental pulp vascularity, reduced alveolar bone, and impaired mineralization.
- The LP-L group showed less severe effects, with enhanced BMP-7, VEGF, and RANKL suggesting compensatory mechanisms for osteogenesis.
- The LP-G group displayed increased Dspp expression, indicating potential odontoblast maturation delays or recuperation.
Conclusions:
- Maternal protein restriction significantly impacts dental and maxillary development in offspring.
- Protein restriction solely during gestation permits normal development, whereas combined gestation-lactation restriction leads to impaired odontogenesis.
- Impaired odontogenesis due to maternal protein restriction may increase the susceptibility to dental anomalies.
Abstract:
Nutritional restriction during developmental periods impairs organ physiology. Female rats were subjected to protein restriction during pregnancy and lactation to analyze dental and maxillary development. Four exposure groups were considered: normal-protein diet during pregnancy and lactation (NP, 17% casein), low-protein diet during lactation (LP-L, 6% casein), low-protein diet during pregnancy and lactation (LP), and low-protein diet during pregnancy (LP-G). Maxillae from 15-day-old male pups were collected. All protein-restricted groups presented increased dentin thickness and reduced alveolar bone area. When protein restriction was applied during both gestation and lactation (LP), harmful effects were observed in the form of loss of protective OPG (osteoprotegerin) in tooth epithelium-mesenchyme, due to higher RANKL expression, delay in odontoblast maturation, less dental pulp vascularity, reduction in amount of alveolar bone, and less matrix mineralization. In the LP-L group, effects of protein restriction seemed less harmful, and despite less alveolar bone, the enhancement in BMP-7, VEGF, and RANKL seems a compensatory signal to maintain maxillary osteogenesis. In LP-G animals, Dspp expression was higher, suggesting a delay in odontoblast maturation or expression recuperation. In conclusion, maternal protein restriction affects dental and maxillary development. A low-protein diet only in gestation allows for normal development. A low-protein diet during gestation-lactation results in impaired odontogenesis that may increase susceptibility of dental anomalies.
