Guixian Tang1,2, Pan Chen1,2, Guanmao Chen1,2, Shuming Zhong3, JiaYing Gong2,4, Hui Zhong5, Tao Ye6, Feng Chen1,2, Jurong Wang1,2, Zhenye Luo1,2, Zhangzhang Qi1,2, Yanbin Jia3, Ying Wang1,2, Li Huang1,2. 1. Medical Imaging Center, First Affiliated Hospital of Jinan University, Guangzhou510630, China. 2. Institute of Molecular and Functional Imaging, Jinan University, Guangzhou510630, China. 3. Department of Psychiatry, First Affiliated Hospital of Jinan University, Guangzhou510630, China. 4. Department of Radiology, Six Affiliated Hospital of Sun Yat-sen University, Guangzhou510655, China. 5. Biomedical Translational Research Institute, Jinan University, Guangzhou510630, China. 6. Clinical Laboratory Center, First Affiliated Hospital of Jinan University, Guangzhou510630, China.
Abstract
BACKGROUND: Inflammation might play a role in bipolar disorder (BD), but it remains unclear the relationship between inflammation and brain structural and functional abnormalities in patients with BD. In this study, we focused on the alterations of functional connectivity (FC), peripheral pro-inflammatory cytokines and their correlations to investigate the role of inflammation in FC in BD depression. METHODS: In this study, 42 unmedicated patients with BD II depression and 62 healthy controls (HCs) were enrolled. Resting-state-functional magnetic resonance imaging was performed in all participants and independent component analysis was used. Serum levels of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) were measured in all participants. Correlation between FC values and IL-6 and IL-8 levels in BD was calculated. RESULTS: Compared with the HCs, BD II patients showed decreased FC in the left orbitofrontal cortex (OFC) implicating the limbic network and the right precentral gyrus implicating the somatomotor network. BD II showed increased IL-6 (p = 0.039), IL-8 (p = 0.002) levels. Moreover, abnormal FC in the right precentral gyrus were inversely correlated with the IL-8 (r = -0.458, p = 0.004) levels in BD II. No significant correlation was found between FC in the left OFC and cytokines levels. CONCLUSIONS: Our findings that serum IL-8 levels are associated with impaired FC in the right precentral gyrus in BD II patients suggest that inflammation might play a crucial role in brain functional abnormalities in BD.
BACKGROUND:Inflammation might play a role in bipolar disorder (BD), but it remains unclear the relationship between inflammation and brain structural and functional abnormalities in patients with BD. In this study, we focused on the alterations of functional connectivity (FC), peripheral pro-inflammatory cytokines and their correlations to investigate the role of inflammation in FC in BD depression. METHODS: In this study, 42 unmedicated patients with BD II depression and 62 healthy controls (HCs) were enrolled. Resting-state-functional magnetic resonance imaging was performed in all participants and independent component analysis was used. Serum levels of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) were measured in all participants. Correlation between FC values and IL-6 and IL-8 levels in BD was calculated. RESULTS: Compared with the HCs, BD II patients showed decreased FC in the left orbitofrontal cortex (OFC) implicating the limbic network and the right precentral gyrus implicating the somatomotor network. BD II showed increased IL-6 (p = 0.039), IL-8 (p = 0.002) levels. Moreover, abnormal FC in the right precentral gyrus were inversely correlated with the IL-8 (r = -0.458, p = 0.004) levels in BD II. No significant correlation was found between FC in the left OFC and cytokines levels. CONCLUSIONS: Our findings that serum IL-8 levels are associated with impaired FC in the right precentral gyrus in BD II patients suggest that inflammation might play a crucial role in brain functional abnormalities in BD.