Bipolar limbic expression of auto-immune thyroid targets: thyroglobulin and thyroid-stimulating hormone receptor

Prevalence and Factors Associated with Subclinical Hypothyroidism in Major Depressive Disorder Patients with Dyslipidemia

Background

Major depressive disorder (MDD) is a common psychiatric disorder with a high prevalence of comorbidity with subclinical hypothyroidism. The aim of this study was to investigate the prevalence and factors influencing the comorbidity of subclinical hypothyroidism in patients with dyslipidemic MDD who were hospitalized for the first time in a Chinese population.

Methods

The study incorporated 708 first-time hospitalized MDD patients, all with dyslipidemia. Data collection encompassed socio-demographic information, blood pressure, fasting blood glucose (FBG), lipid, and thyroid hormone levels. Participants were evaluated using the Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and Positive Symptom Subscale (PSS).

Results

The prevalence of subclinical hypothyroidism in dyslipidemic MDD patients with the first hospitalization was 39.97%. The course of the disease, age at onset, HAMA score, and low-density lipoprotein cholesterol (LDL-C) were risk factors for subclinical hypothyroidism in dyslipidemic MDD patients. The course of disease, age at onset, HAMA score, HAMD score, FBG, and systolic blood pressure (SBP) levels were observed to influence serum Thyroid Stimulating Hormone (TSH) levels.

Conclusion

MDD patients with dyslipidemia have a high prevalence of subclinical hypothyroidism, and the outcome is associated with anxiety, fasting glucose, and lipids. This study provides a potential biomarker for the identification of co-morbid subclinical hypothyroidism in MDD patients with dyslipidaemia.

Association between subclinical hypothyroidism and psychotic features in Chinese young adults with first-episode and untreated major depressive disorder

BACKGROUND

Thyroid dysfunction is often reported in patients with major depressive disorder (MDD) and may be associated with depression severity and psychotic symptoms. We included young adults with first-episode and untreated MDD to avoid the effect of age and disease duration on thyroid dysfunction and psychotic symptoms.

METHODS

481 young patients with MDD (aged 18-24 years) were recruited. The Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Positive and Negative Syndrome Scale (PANSS) positive subscale and Global Impression of Severity Scale (CGIS) were used to assess depression, anxiety, psychotic symptoms and disease severity, respectively.

RESULTS

The prevalence rate of subclinical hypothyroidism (SCH) and thyroid antibody positivity was 56.76 % (273/481) and 26.61 % (128/481) in young MDD, respectively. A higher proportion of MDD patients with SCH displayed psychotic features (14.3 % vs. 5.3 %, OR = 2.985, p = 0.001). TSH was a risk factor for psychotic symptoms in MDD patient with SCH (B = 0.136, p = 0.017, OR = 1.384), with an AUC of 0.709, indicating acceptable discrimination. Multivariate regression analysis also showed that TSH was also independently associated with PANSS positive score (B = 0.339, t = 2.019, p = 0.045).

LIMITATION

This cross-sectional study design did not demonstrate a causal relationship. Relying solely on the PANSS positive subscale as psychotic symptoms may cause bias.

CONCLUSIONS

Our findings suggest that SCH is common in young patients with first-episode and untreated MDD. MDD patients with higher TSH levels may suffer from more psychotic symptoms. Regular screening of serum thyroid hormones is necessary in patients with MDD.

Association between thyroid autoimmunity and antidepressant treatment-emergent mania in pediatric mood disorders

Risk factors associated with antidepressant treatment-emergent mania(ATEM) are poorly characterized in child and adolescent populations. To identify better biomarkers, we aimed to explore whether thyroid autoimmunity is associated with ATEM in pediatric mood disorders. We enrolled two groups of pediatric mood disorders, those with ATEM+ (n = 29) and those with ATEM- controls (n = 31). All diagnoses were made according to structured interviews by the clinicians. Autoimmune thyroiditis (anti-thyroid peroxidase antibodies [TPO-abs] and thyroid function (thyroid-stimulating hormone [TSH] and free thyroxin [FT4]) were assessed. Logistic regression was used to explore the relationship between TPO-abs seroprevalence and ATEM+ while controlling for covariates. Group comparisons showed that the patient with ATEM+ had significantly higher seroprevalence and titer of TPO-abs compared to ATEM- controls. In logistic regression analysis adjusting for age, gender, Tanner stage, body mass index, antipsychotic treatments, smoking status and family history of thyroid disorder, the seroprevalence of TPO-abs (>60 U/mL) was significantly associated with ATEM+ (OR = 3.67, 95% confidence interval [CI] = 1.2-11.1, p = 0.022). Our findings demonstrated that seroprevalence and titer of TPO-abs in pediatric mood disorders are associated with ATEM+ status. TPO-abs could potentially serve as a biomarker when assessing the risk of ATEM in the child and adolescent population.

Cellular and molecular distribution of thyroid-specific proteins, thyroid-stimulating hormone receptor (TSH-R) and thyroglobulin (TG) in the central nervous system

The widespread extra-thyroidal localisation of thyroid-specific proteins, thyroid-stimulating hormone receptor (TSH-R) and thyroglobulin (TG), has been well documented. However, more recent years has seen the focus of this research area shift to the distribution of these thyroid-specific proteins, in the central nervous system (CNS). This is largely attributed to the well-known associations between thyroid auto-immunity and neuro-psychiatric disorders. Although these associations have not yet been well defined, there are several studies that demonstrate the presence of TSH-R and TG proteins in CNS regions and its cellular structures. In addition, there is an emerging body of evidence to describe the potential functional roles of these thyroid proteins in various regions of the CNS. In this review, the neural distribution of TSH-R and TG as well as their possible physiological implications in various regions of human and non-human brain is discussed.

Expression of functional thyroid-stimulating hormone receptor in microglia

OBJECTIVE

The purpose of the present study was to clarify the expression of thyroid-stimulating hormone receptor (TSHR) in microglial cells, and to explore its function.

MATERIALS AND METHODS

Expression of TSHR in microglia was determined by Western blot, immunocytofluorescence and double immunohistofluorescence. Cyclic adenosine 3',5'-monophosphate (cAMP) production was measured after thyrotropin receptor stimulating antibody (TSAb) treatment.

RESULTS

Results showed that TSHR protein was expressed and mainly located in the mouse microglia membrane. Moreover, TSAb stimulated cAMP production in mouse microglia (p<0.05).

CONCLUSIONS

This study demonstrated the presence of TSHR in microglial cells. Brain TSHR was able to respond specifically to TSAb stimulation, suggesting that TSHR expression is functional. As microglia are innate immune cells that maintain environmental stability in the central nervous system and play a key role in many neuroimmune diseases, expression of functional TSHR in microglia has important pathophysiological implications.

Effects of the LHPP gene polymorphism on the functional and structural changes of gray matter in major depressive disorder

Background

A single-nucleotide polymorphism (SNP) of the LHPP gene (rs35936514) has been reported to be associated with major depressive disorder (MDD) in genome-wide association studies. However, the systems-level neural effects of rs35936514 that mediate the association are unknown. We hypothesized that variations in rs35936514 would be associated with structural and functional changes in gray matter (GM) at rest in MDD patients.

Methods

A total of 50 MDD patients and 113 healthy controls (HCs) were studied. Functional connectivity (FC) was analyzed by defining the bilateral hippocampus as the seed region. Voxel-based morphometry (VBM) was performed to assess the patterns of GM volume. The subjects were further divided into two groups: a CC homozygous group (CC; 24 MDD and 56 HC) and a risk T-allele carrier group (CT/TT genotypes; 26 MDD and 57 HC). A 2×2 analysis of variance (ANOVA: diagnosis × genotype) was used to determine the interaction effects and main effect (P<0.05).

Results

Significant diagnosis × genotype interaction effects on brain morphology and FC were noted. Compared to other subgroups, the MDD patients with the T allele showed an increased hippocampal FC in the bilateral calcarine cortex and cuneus and a decreased hippocampal FC in the right dorsolateral prefrontal cortex (DLPFC), bilateral anterior cingulate cortex (ACC), and medial prefrontal cortex (MPFC), in addition to reduced GM volume in the right DLPFC, bilateral temporal cortex, and posterior cingulate cortex (PCC).

Conclusions

LHPP gene polymorphisms may affect functional and structural changes in the GM at rest and may play an important role in the pathophysiological mechanisms of MDD.