Background: Uncoupling protein 1 (UCP1) is a proton uncoupler located across the mitochondrial membrane gener‑ ally involved in thermogenesis of brown adipose tissues. Although UCP1 is known to be strongly expressed in brown adipocytes, recent evidence suggest that white adipocytes can also express UCP1 under certain circumstances such as cold- or β-adrenergic receptor-stimulation, allowing them to acquire brown adipocyte-like features thereby becoming ’beige’ adipocytes. Results: In this study, we report that UCP1 can be expressed in adipose-tissue macrophages (ATM) lacking func‑ tional hypoxia-inducible factor-1 (HIF-1) and this does not require cold- nor β-adrenergic receptor activation. By using myeloid-specific Hif-1α knockout (KO) mice, we observed that these mice were protected from diet-induced obesity and exhibited an improved thermogenic tolerance upon cold challenge. ATM isolated from white adipose tissues (WAT) of these mice fed with high fat diet exhibited significantly higher M2-polarization, decreased gly‑ colysis, increased mitochondrial functions and acetyl-CoA levels, along with increased expression of Ucp1, peroxisome proliferator activated receptor-gamma co-activator-1a, and others involved in histone acetylation. Consistent with the increased Ucp1 gene expression, these ATM produced a significant amount of heat mediating lipolysis of cocultured adipocytes liberating free fatty acid. Treating ATM with acetate, a substrate for acetyl-CoA synthesis was able to boost the heat production in wild-type or Hif-1α-deficient but not UCP1-deficient macrophages, indicating that UCP1 was necessary for the heat production in macrophages. Lastly, we observed a significant inverse correlation between the number of UCP1-expressing ATM in WAT and the body mass index of human individuals. Conclusions UCP1-expressing ATM produce the heat to mediate lipolysis of adipocytes, indicating that this can be a novel strategy to treat and prevent diet-induced obesity.

Background: Uncoupling protein 1 (UCP1) is a proton uncoupler located across the mitochondrial membrane gener‑ ally involved in thermogenesis of brown adipose tissues. Although UCP1 is known to be strongly expressed in brown adipocytes, recent evidence suggest that white adipocytes can also express UCP1 under certain circumstances such as cold- or β-adrenergic receptor-stimulation, allowing them to acquire brown adipocyte-like features thereby becoming ’beige’ adipocytes. Results: In this study, we report that UCP1 can be expressed in adipose-tissue macrophages (ATM) lacking func‑ tional hypoxia-inducible factor-1 (HIF-1) and this does not require cold- nor β-adrenergic receptor activation. By using myeloid-specific Hif-1α knockout (KO) mice, we observed that these mice were protected from diet-induced obesity and exhibited an improved thermogenic tolerance upon cold challenge. ATM isolated from white adipose tissues (WAT) of these mice fed with high fat diet exhibited significantly higher M2-polarization, decreased gly‑ colysis, increased mitochondrial functions and acetyl-CoA levels, along with increased expression of Ucp1, peroxisome proliferator activated receptor-gamma co-activator-1a, and others involved in histone acetylation. Consistent with the increased Ucp1 gene expression, these ATM produced a significant amount of heat mediating lipolysis of cocultured adipocytes liberating free fatty acid. Treating ATM with acetate, a substrate for acetyl-CoA synthesis was able to boost the heat production in wild-type or Hif-1α-deficient but not UCP1-deficient macrophages, indicating that UCP1 was necessary for the heat production in macrophages. Lastly, we observed a significant inverse correlation between the number of UCP1-expressing ATM in WAT and the body mass index of human individuals. Conclusions UCP1-expressing ATM produce the heat to mediate lipolysis of adipocytes, indicating that this can be a novel strategy to treat and prevent diet-induced obesity.

Background: Uncoupling protein 1 (UCP1) is a proton uncoupler located across the mitochondrial membrane gener‑ ally involved in thermogenesis of brown adipose tissues. Although UCP1 is known to be strongly expressed in brown adipocytes, recent evidence suggest that white adipocytes can also express UCP1 under certain circumstances such as cold- or β-adrenergic receptor-stimulation, allowing them to acquire brown adipocyte-like features thereby becoming ’beige’ adipocytes. Results: In this study, we report that UCP1 can be expressed in adipose-tissue macrophages (ATM) lacking func‑ tional hypoxia-inducible factor-1 (HIF-1) and this does not require cold- nor β-adrenergic receptor activation. By using myeloid-specific Hif-1α knockout (KO) mice, we observed that these mice were protected from diet-induced obesity and exhibited an improved thermogenic tolerance upon cold challenge. ATM isolated from white adipose tissues (WAT) of these mice fed with high fat diet exhibited significantly higher M2-polarization, decreased gly‑ colysis, increased mitochondrial functions and acetyl-CoA levels, along with increased expression of Ucp1, peroxisome proliferator activated receptor-gamma co-activator-1a, and others involved in histone acetylation. Consistent with the increased Ucp1 gene expression, these ATM produced a significant amount of heat mediating lipolysis of cocultured adipocytes liberating free fatty acid. Treating ATM with acetate, a substrate for acetyl-CoA synthesis was able to boost the heat production in wild-type or Hif-1α-deficient but not UCP1-deficient macrophages, indicating that UCP1 was necessary for the heat production in macrophages. Lastly, we observed a significant inverse correlation between the number of UCP1-expressing ATM in WAT and the body mass index of human individuals. Conclusions UCP1-expressing ATM produce the heat to mediate lipolysis of adipocytes, indicating that this can be a novel strategy to treat and prevent diet-induced obesity.

Purpose: To analyze changes in refractive error among elementary school children under the age of 13 who visited an outpatient clinic for eye examinations before and after the onset of the COVID-19 pandemic. Methods: A retrospective analysis of medical records was conducted to calculate the spherical equivalent refractive error of the right eye for 3,854 children aged 6 to 12 who attended our ophthalmology department from 2016 to 2023. We analyzed the average refractive error and myopia prevalence by year and subsequently performed a subgroup analysis by dividing the children into two age groups: 6-9 years old and 10-12 years old. To provide insight into long-term trends, data from 4,351 subjects aged 6-12 years from the 4th, 5th (2008-2012), and 7th (2016) Korea National Health and Nutrition Examination Surveys were also analyzed for reference. Results: The mean refractive error for subjects visiting our clinic throughout the study period was -1.51 ± 2.12 D. A trend of increasing myopic values in refractive error was observed from 2017 to 2021, with a more substantial change noted in 2020 compared to other years, though not reaching statistical significance. In the subgroup analysis, the change in refractive error for the 6-9-year-old group was more pronounced in 2020 but did not reach statistical significance, and no specific trend was identified in the 10-12-year-old group. Myopia prevalence exhibited a consistent increase since 2019 in the 6-9 age group, with a higher proportion of moderate myopia in 2020 compared to previous years. Conversely, no distinct trend was observed in the 10-12-year-old group. Conclusions Although statistical significance was not reached, it appears that the increase in indoor activities due to COVID-19 had an impact on the changes in refractive values for elementary school children, especially in the lower grades of elementary school in 2020.

Background: Uncoupling protein 1 (UCP1) is a proton uncoupler located across the mitochondrial membrane gener‑ ally involved in thermogenesis of brown adipose tissues. Although UCP1 is known to be strongly expressed in brown adipocytes, recent evidence suggest that white adipocytes can also express UCP1 under certain circumstances such as cold- or β-adrenergic receptor-stimulation, allowing them to acquire brown adipocyte-like features thereby becoming ’beige’ adipocytes. Results: In this study, we report that UCP1 can be expressed in adipose-tissue macrophages (ATM) lacking func‑ tional hypoxia-inducible factor-1 (HIF-1) and this does not require cold- nor β-adrenergic receptor activation. By using myeloid-specific Hif-1α knockout (KO) mice, we observed that these mice were protected from diet-induced obesity and exhibited an improved thermogenic tolerance upon cold challenge. ATM isolated from white adipose tissues (WAT) of these mice fed with high fat diet exhibited significantly higher M2-polarization, decreased gly‑ colysis, increased mitochondrial functions and acetyl-CoA levels, along with increased expression of Ucp1, peroxisome proliferator activated receptor-gamma co-activator-1a, and others involved in histone acetylation. Consistent with the increased Ucp1 gene expression, these ATM produced a significant amount of heat mediating lipolysis of cocultured adipocytes liberating free fatty acid. Treating ATM with acetate, a substrate for acetyl-CoA synthesis was able to boost the heat production in wild-type or Hif-1α-deficient but not UCP1-deficient macrophages, indicating that UCP1 was necessary for the heat production in macrophages. Lastly, we observed a significant inverse correlation between the number of UCP1-expressing ATM in WAT and the body mass index of human individuals. Conclusions UCP1-expressing ATM produce the heat to mediate lipolysis of adipocytes, indicating that this can be a novel strategy to treat and prevent diet-induced obesity.