Ultrastructural and immunohistochemical study of the influence of fluoride excess on the development of rat incisor tooth buds

Hassunuma, Renato Massaharu; Filho, Edson Virgílio Zen; Ceolin, Danielle Santi; Cestari, Tânia Mary; Taga, Rumio; Assis, Gérson Francisco de

doi:10.1590/s1678-77572007000400010

Cited by 7 publications

(2 citation statements)

References 21 publications

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“…During pregnancy and lactation, although the transfer of fluoride from mother to fetus is regulated by the placenta and the transfer of plasma to breast milk is inhibited (76), fluoride concentrations in breast milk and amniotic fluid increase significantly after the intake of fluorinated foods (77)(78)(79)(80)(81). Excessive fluoride exposure results in increased organic material in the secretory stage of enamel formation.…”

Section: Fluorosis and Maternal Brick Tea Consumptionmentioning

confidence: 99%

Brick tea consumption and its relationship with fluorosis in Tibetan areas

et al. 2022

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Brick tea-type fluorosis (BTF) due to a high intake of brick tea is possible in Tibetan populations, and dental fluorosis (DF) and skeletal fluorosis (SF) are its primary manifestations. To determine the prevalence of DF and SF and their relationships with brick tea intake in Tibetan populations, a literature review was conducted for studies published between 1994 and 2021. The available evidence revealed that brick tea may be produced from older stems and leaves of the tea plant and that the fluoride content of brick tea exceeds the national standard. The harsh environment of the plateau has led to limited food sources for the local Tibetan people who form the habit of drinking tea leaves as a satiation solution to digest greasy food and replenish vitamins, and regular consumption of brick tea leads to excessive exposure of Tibetan residents to fluoride. Studies in Tibet showed that the prevalence of DF in children was 14.06–75.93% in different districts, and the overall pooled prevalence of DF was 26.08%. The prevalence of SF in adults was 19.90–74.77% in different Tibetan districts, and the overall pooled prevalence of SF was 33.84%. The analysis of risk factors showed that the prevalence of BTF may be related to high-altitude and different working and living conditions, and BTF in children may be associated with fluoride intake during mothers’ pregnancy and lactation. With the development of bioinformatics research, gene polymorphisms were suspected to be related to susceptibility to fluorosis in Tibetan populations. The study of BTF in Tibetan people needs to be further investigated and standardized, and additional studies evaluating the pathogenesis and preventive measures of BTF are warranted.

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Section: Fluorosis and Maternal Brick Tea Consumptionmentioning

confidence: 99%

Brick tea consumption and its relationship with fluorosis in Tibetan areas

et al. 2022

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“…Early indications that excess fluoride may trigger an ER stress–like response in ameloblasts were provided by histological reports suggesting that fluoride disturbs ameloblast intracellular protein trafficking (Matsuo et al, 1996 ), including the retention of ER cargo and the appearance of a dilated ER (Hassunuma et al, 2007 ). These observations are consistent with ameloblasts suffering ER stress but the up-regulation of UPR components provides unequivocal evidence that the UPR is associated with the ameloblast response to fluoride.…”

Section: The Role Of the Upr In The Pathobiology Of Fluorosismentioning

confidence: 99%

The Unfolded Protein Response in Amelogenesis and Enamel Pathologies

et al. 2017

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During the secretory phase of their life-cycle, ameloblasts are highly specialized secretory cells whose role is to elaborate an extracellular matrix that ultimately confers both form and function to dental enamel, the most highly mineralized of all mammalian tissues. In common with many other “professional” secretory cells, ameloblasts employ the unfolded protein response (UPR) to help them cope with the large secretory cargo of extracellular matrix proteins transiting their ER (endoplasmic reticulum)/Golgi complex and so minimize ER stress. However, the UPR is a double-edged sword, and, in cases where ER stress is severe and prolonged, the UPR switches from pro-survival to pro-apoptotic mode. The purpose of this review is to consider the role of the ameloblast UPR in the biology and pathology of amelogenesis; specifically in respect of amelogenesis imperfecta (AI) and fluorosis. Some forms of AI appear to correspond to classic proteopathies, where pathological intra-cellular accumulations of protein tip the UPR toward apoptosis. Fluorosis also involves the UPR and, while not of itself a classic proteopathic disease, shares some common elements through the involvement of the UPR. The possibility of therapeutic intervention by pharmacological modulation of the UPR in AI and fluorosis is also discussed.

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The influence of chronic fluorosis on mitochondrial dynamics morphology and distribution in cortical neurons of the rat brain

et al. 2012

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The present study was designed to evaluate the effects of chronic fluorosis on the dynamics (including fusion and fission proteins), fragmentation, and distribution of mitochondria in the cortical neurons of the rat brain in an attempt to elucidate molecular mechanisms underlying the brain damage associated with excess accumulation of fluoride. Sixty Sprague-Dawley rats were divided randomly into three groups of 20 each, that is, the untreated control group (drinking water naturally containing <0.5 mg fluoride/l, NaF), the low-fluoride group (whose drinking water was supplemented with 10 mg fluoride/l) and the high-fluoride group (50 mg fluoride/l). After 6 months of exposure, the expression of mitofusin-1 (Mfn1), fission-1 (Fis1), and dynamin-related protein-1 (Drp1) at both the protein and mRNA levels were detected by Western blotting, immunohistochemistry, and real-time PCR, respectively. Moreover, mitochondrial morphology and distribution in neurons were observed by transmission electron or fluorescence microscopy. In the cortices of the brains of rats with chronic fluorosis, the level of Mfn1 protein was clearly reduced, whereas the levels of Fis1 and Drp1 were elevated. The alternations of expression of the mRNAs encoding all three of these proteins were almost the same as the corresponding changes at the protein levels. The mitochondria were fragmented and the redistributed away from the axons of the cortical neurons. These findings indicate that chronic fluorosis induces abnormal mitochondrial dynamics, which might in turn result in a high level of oxidative stress.

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Ultrastructural and immunohistochemical study of the influence of fluoride excess on the development of rat incisor tooth buds

Cited by 7 publications

References 21 publications

Brick tea consumption and its relationship with fluorosis in Tibetan areas

Brick tea consumption and its relationship with fluorosis in Tibetan areas

The Unfolded Protein Response in Amelogenesis and Enamel Pathologies

The influence of chronic fluorosis on mitochondrial dynamics morphology and distribution in cortical neurons of the rat brain

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