Background: Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups. Results: In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05). Conclusions Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.

Background: The role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) in adipose tissue remains poorly understood. This study investigates adipose tissue dysfunction in heterozygous APE1/Ref-1 deficiency (APE1/Ref-1+/-) mice, focusing on changes in adipocyte physiology, oxidative stress, adipokine regulation, and adipose tissue distribution. Methods: APE1/Ref-1 mRNA and protein levels in white adipose tissue (WAT) were measured in APE1/Ref-1+/- mice, compared to their wild-type (APE1/Ref-1+/+) controls. Oxidative stress was assessed by evaluating reactive oxygen species (ROS) levels. Histological and immunohistochemical analyses were conducted to observe adipocyte size and macrophage infiltration of WAT. Adipokine expression was measured, and micro-magnetic resonance imaging (MRI) was used to quantify abdominal fat volumes. Results: APE1/Ref-1+/- mice exhibited significant reductions in APE1/Ref-1 mRNA and protein levels in WAT and liver tissue. These mice also showed elevated ROS levels, suggesting a regulatory role for APE1/Ref-1 in oxidative stress in WAT and liver. Histological and immunohistochemical analyses revealed hypertrophic adipocytes and macrophage infiltration in WAT, while Oil Red O staining demonstrated enhanced ectopic fat deposition in the liver of APE1/Ref-1+/- mice. These mice also displayed altered adipokine expression, with decreased adiponectin and increased leptin levels in the WAT, along with corresponding alterations in plasma levels. Despite no significant changes in overall body weight, microMRI assessments demonstrated a significant increase in visceral and subcutaneous abdominal fat volumes in APE1/Ref-1+/- mice. Conclusion APE1/Ref-1 is crucial in adipokine regulation and mitigating oxidative stress. These findings suggest its involvement in adipose tissue dysfunction, highlighting its potential impact on abdominal fat distribution and its implications for obesity and oxidative stress-related conditions.

Background: Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups. Results: In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05). Conclusions Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.

Background: Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups. Results: In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05). Conclusions Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.

Background: The role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) in adipose tissue remains poorly understood. This study investigates adipose tissue dysfunction in heterozygous APE1/Ref-1 deficiency (APE1/Ref-1+/-) mice, focusing on changes in adipocyte physiology, oxidative stress, adipokine regulation, and adipose tissue distribution. Methods: APE1/Ref-1 mRNA and protein levels in white adipose tissue (WAT) were measured in APE1/Ref-1+/- mice, compared to their wild-type (APE1/Ref-1+/+) controls. Oxidative stress was assessed by evaluating reactive oxygen species (ROS) levels. Histological and immunohistochemical analyses were conducted to observe adipocyte size and macrophage infiltration of WAT. Adipokine expression was measured, and micro-magnetic resonance imaging (MRI) was used to quantify abdominal fat volumes. Results: APE1/Ref-1+/- mice exhibited significant reductions in APE1/Ref-1 mRNA and protein levels in WAT and liver tissue. These mice also showed elevated ROS levels, suggesting a regulatory role for APE1/Ref-1 in oxidative stress in WAT and liver. Histological and immunohistochemical analyses revealed hypertrophic adipocytes and macrophage infiltration in WAT, while Oil Red O staining demonstrated enhanced ectopic fat deposition in the liver of APE1/Ref-1+/- mice. These mice also displayed altered adipokine expression, with decreased adiponectin and increased leptin levels in the WAT, along with corresponding alterations in plasma levels. Despite no significant changes in overall body weight, microMRI assessments demonstrated a significant increase in visceral and subcutaneous abdominal fat volumes in APE1/Ref-1+/- mice. Conclusion APE1/Ref-1 is crucial in adipokine regulation and mitigating oxidative stress. These findings suggest its involvement in adipose tissue dysfunction, highlighting its potential impact on abdominal fat distribution and its implications for obesity and oxidative stress-related conditions.

Background: The role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) in adipose tissue remains poorly understood. This study investigates adipose tissue dysfunction in heterozygous APE1/Ref-1 deficiency (APE1/Ref-1+/-) mice, focusing on changes in adipocyte physiology, oxidative stress, adipokine regulation, and adipose tissue distribution. Methods: APE1/Ref-1 mRNA and protein levels in white adipose tissue (WAT) were measured in APE1/Ref-1+/- mice, compared to their wild-type (APE1/Ref-1+/+) controls. Oxidative stress was assessed by evaluating reactive oxygen species (ROS) levels. Histological and immunohistochemical analyses were conducted to observe adipocyte size and macrophage infiltration of WAT. Adipokine expression was measured, and micro-magnetic resonance imaging (MRI) was used to quantify abdominal fat volumes. Results: APE1/Ref-1+/- mice exhibited significant reductions in APE1/Ref-1 mRNA and protein levels in WAT and liver tissue. These mice also showed elevated ROS levels, suggesting a regulatory role for APE1/Ref-1 in oxidative stress in WAT and liver. Histological and immunohistochemical analyses revealed hypertrophic adipocytes and macrophage infiltration in WAT, while Oil Red O staining demonstrated enhanced ectopic fat deposition in the liver of APE1/Ref-1+/- mice. These mice also displayed altered adipokine expression, with decreased adiponectin and increased leptin levels in the WAT, along with corresponding alterations in plasma levels. Despite no significant changes in overall body weight, microMRI assessments demonstrated a significant increase in visceral and subcutaneous abdominal fat volumes in APE1/Ref-1+/- mice. Conclusion APE1/Ref-1 is crucial in adipokine regulation and mitigating oxidative stress. These findings suggest its involvement in adipose tissue dysfunction, highlighting its potential impact on abdominal fat distribution and its implications for obesity and oxidative stress-related conditions.

Background: Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups. Results: In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05). Conclusions Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.

Background: The role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) in adipose tissue remains poorly understood. This study investigates adipose tissue dysfunction in heterozygous APE1/Ref-1 deficiency (APE1/Ref-1+/-) mice, focusing on changes in adipocyte physiology, oxidative stress, adipokine regulation, and adipose tissue distribution. Methods: APE1/Ref-1 mRNA and protein levels in white adipose tissue (WAT) were measured in APE1/Ref-1+/- mice, compared to their wild-type (APE1/Ref-1+/+) controls. Oxidative stress was assessed by evaluating reactive oxygen species (ROS) levels. Histological and immunohistochemical analyses were conducted to observe adipocyte size and macrophage infiltration of WAT. Adipokine expression was measured, and micro-magnetic resonance imaging (MRI) was used to quantify abdominal fat volumes. Results: APE1/Ref-1+/- mice exhibited significant reductions in APE1/Ref-1 mRNA and protein levels in WAT and liver tissue. These mice also showed elevated ROS levels, suggesting a regulatory role for APE1/Ref-1 in oxidative stress in WAT and liver. Histological and immunohistochemical analyses revealed hypertrophic adipocytes and macrophage infiltration in WAT, while Oil Red O staining demonstrated enhanced ectopic fat deposition in the liver of APE1/Ref-1+/- mice. These mice also displayed altered adipokine expression, with decreased adiponectin and increased leptin levels in the WAT, along with corresponding alterations in plasma levels. Despite no significant changes in overall body weight, microMRI assessments demonstrated a significant increase in visceral and subcutaneous abdominal fat volumes in APE1/Ref-1+/- mice. Conclusion APE1/Ref-1 is crucial in adipokine regulation and mitigating oxidative stress. These findings suggest its involvement in adipose tissue dysfunction, highlighting its potential impact on abdominal fat distribution and its implications for obesity and oxidative stress-related conditions.

Background: Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups. Results: In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05). Conclusions Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multipotent protein that plays essential roles in cellular responses to oxidative stress. Methods: To examine the role of APE1/Ref-1 in ischemia-reperfusion (I/R) injuries and hydrogen peroxide (H2O2)-induced renal tubular apoptosis, we studied male C57BL6 mice and human proximal tubular epithelial (HK-2) cells treated with H2O2 at different concentrations. The colocalization of APE1/Ref-1 in the proximal tubule, distal tubule, thick ascending limb, and collecting duct was observed with confocal microscopy. The overexpression of APE1/Ref-1 with knockdown cell lines using an APE1/Ref-1–specific DNA or small interfering RNA (siRNA) was used for the apoptosis assay. The promotor activity of nuclear factor kappa B (NF-κB) was assessed and electrophoretic mobility shift assay was conducted. Results: APE1/Ref-1 was predominantly localized to the renal tubule nucleus. In renal I/R injuries, the levels of APE1/Ref-1 protein were increased compared with those in kidneys subjected to sham operations. The overexpression of APE1/Ref-1 in HK-2 cells enhanced the Bax/Bcl-2 ratio as a marker of apoptosis. Conversely, the suppression of APE1/Ref-1 expression by siRNA in 1-mM H2O2-treated HK-2 cells decreased the Bax/Bcl-2 ratio, the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and NF-κB. In HK-2 cells, the promoter activity of NF-κB increased following H2O2 exposure, and this effect was further enhanced by APE1/Ref-1 transfection. Conclusion: The inhibition of APE1/Ref-1 with siRNA attenuated H2O2-induced apoptosis through the modulation of mitogen-activated protein kinase pathways mediated by ERK, JNK, and p38 and the nuclear activation of NF-κB and proapoptotic factors.