Effects of thyroid-stimulating hormone on adhesion molecules and pro-inflammatory cytokines secretion in human umbilical vein endothelial cells

Increased thyroid stimulating hormone (TSH) as a possible risk factor for atherosclerosis in subclinical hypothyroidism

Primary hypothyroidism (PHT) is associated with an increased risk for the development of atherosclerosis (AS) and other cardiovascular disorders. PHT induces atherosclerosis (AS) through the induction of endothelial dysfunction, and insulin resistance (IR). PHT promotes vasoconstriction and the development of hypertension. However, patients with subclinical PHT with normal thyroid hormones (THs) are also at risk for cardiovascular complications. In subclinical PHT, increasing thyroid stimulating hormone (TSH) levels could be one of the causative factors intricate in the progression of cardiovascular complications including AS. Nevertheless, the mechanistic role of PHT in AS has not been fully clarified in relation to increased TSH. Therefore, in this review, we discuss the association between increased TSH and AS, and how increased TSH may be involved in the pathogenesis of AS. In addition, we also discuss how L-thyroxine treatment affects the development of AS.

Thyroid hormone dysfunction in MOGAD and other demyelinating diseases

BACKGROUND

Thyroid hormones play a critical role in both neuronal and glial cell functions. Multiple sclerosis (MS) has increased co-occurrence with autoimmune thyroid diseases, and recent studies have suggested a potential link between neuromyelitis optica spectrum disorder (NMOSD) and thyroid hormones. However, no previous studies have examined the relationship between thyroid hormones and myelin oligodendrocyte glycoprotein-associated demyelination (MOGAD).

METHODS

We investigated the role of thyroid hormones in central nervous system (CNS) autoimmune demyelinating diseases in 26 MOGAD patients, 52 NMOSD patients, 167 patients with MS, and 16 patients with other noninflammatory neurological disorders. Thyroid hormone levels and clinical data (Expanded Disability Status Scale [EDSS]) were analyzed. Volumetric brain information was determined in brain magnetic resonance imaging (MRI) using the MDbrain platform.

RESULTS

MOGAD patients had significantly higher levels of free triiodothyronine (FT3) compared to NMOSD patients. No correlation was found between FT3 levels and disease severity or brain volume. Thyroid-stimulating hormone (TSH) levels did not differ significantly between the groups, but in NMOSD patients, higher TSH levels were associated with lower disability scores and increased brain volume. No significant differences in free thyroxine (FT4) levels were observed between the different groups, however, FT4 levels were significantly higher in relapsing versus monophasic MOGAD patients and increased FT4 levels were associated with a higher EDSS and lower brain volume in NMOSD patients.

CONCLUSION

Our findings highlight the potential involvement of thyroid hormones specifically in MOGAD patients and other demyelinating CNS disorders. Understanding the role of thyroid hormones in relapsing vs monophasic MOGAD patients and in comparison to other demyelinating disorder could lead to the development of therapeutic interventions. Further studies are needed to explore the precise mechanisms and potential interventions targeting the thyroid axis as a treatment strategy.

Atypical pituitary hormone-target tissue axis

A long-held belief is that pituitary hormones bind to their cognate receptors in classical target glands to actuate their manifold functions. However, a number of studies have shown that multiple types of pituitary hormone receptors are widely expressed in non-classical target organs. Each pituitary gland-derived hormone exhibits a wide range of nonconventional biological effects in these non-classical target organs. Herein, the extra biological functions of pituitary hormones, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, adrenocorticotrophic hormone, and prolactin when they act on non-classical organs were summarized, defined by the novel concept of an "atypical pituitary hormone-target tissue axis." This novel proposal explains the pathomechanisms of abnormal glucose and lipid metabolism, obesity, hypertension, fatty liver, and atherosclerosis while offering a more comprehensive and systematic insights into the coordinated regulation of environmental factors, genetic factors, and neuroendocrine hormones on human biological functions. The continued exploration of the physiology of the "atypical pituitary hormone-target tissue axis" could enable the identification of novel therapeutic targets for metabolic diseases.

The Tri-iodothyronine (T3) Level Is a Prognostic Factor for Patients With Advanced NSCLC: Receiving Immune Checkpoint Inhibitors and Is Associated With Liver Metastasis

BACKGROUND

Endocrine hormones influence tumor progression and the response to treatment. Despite the importance of immune checkpoint inhibitors (ICIs) as treatments for advanced non-small cell lung cancer (NSCLC), few studies have explored the effects of hormone levels in NSCLC patients on the effectiveness of ICI therapies. We thus investigated the effects of baseline blood markers in patients with advanced NSCLC on ICI treatments.

METHODS

Patients with advanced NSCLC who received programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors at Chungnam National University Hospital between December 2016 and November 2020 and who lacked any history of thyroid gland-related diseases were analyzed retrospectively. We collected clinical information and baseline laboratory data, including the levels of endocrine hormones, cytokines, complete blood counts (CBCs), and peripheral blood chemistry panels. We explored the relationships of hormone levels with clinical outcomes (overall survival [OS], progression-free survival [PFS], and best response), liver metastasis, and blood markers using the Kaplan-Meier method, Cox's proportional hazards regression, and logistic regression.

RESULTS

A total of 113 patients were enrolled. A shorter PFS was independently associated with liver metastasis, higher cortisol levels, and lower hemoglobin (Hb) levels; a shorter OS was associated with liver metastasis, lower tri-iodothyronine (T3) levels, higher lactate dehydrogenase (LDH) levels, and lower albumin levels. Patients with low T3 levels exhibited a shorter PFS and OS, and a poorer best response. Patients with low T3 levels tended to have higher disease progression rates, lower levels of adrenocorticotropic hormone (ACTH), C-peptide, albumin, Hb, and neutrophil-to-lymphocyte ratio, and higher levels of interleukin (IL)-6, white blood cells, platelets, compared with those with normal T3 levels. We found a significant association between a low T3 level and liver metastasis.

CONCLUSIONS

We found the baseline T3 level was associated with both prognosis and the response to ICIs in patients with advanced NSCLC, probably reflecting impaired liver function and systemic inflammation induced by the interaction of T3 with other biomarkers, such as IL-6, ACTH, cortisol, C-peptide, Hb, LDH, and albumin.

Correlation Between Hypothyroidism During Pregnancy and Glucose and Lipid Metabolism in Pregnant Women and Its Influence on Pregnancy Outcome and Fetal Growth and Development

Purpose:

To observe the correlation between hypothyroidism during pregnancy and glucose and lipid metabolism in pregnant women and its influence on a pregnancy outcome and fetal growth and development.

Methods

About 152 patients with hypothyroidism during pregnancy in our hospital from June 2017 to June 2020 were selected as the observation group and divided into the overt hypothyroidism (OH) group, the subclinical hypothyroidism (SCH) group, and the low T4 group. Another 60 pregnant women with normal antenatal examination and normal thyroid function were selected as the normal group. The glucose and lipid metabolism indexes of each group were compared. The pregnant women in the OH group and the SCH group were given levothyroxine intervention, and the pregnancy outcome and infant development of the two groups were compared.

Results

The fasting blood glucose and hemoglobin A1c, triglyceride and low-density lipoprotein of the OH group and the SCH group were higher than the low T4 group and the normal group, and the OH group was higher than the SCH group (p < 0.05). The incidence of premature delivery and premature rupture of membranes at term (PROM at term) in the hypothyroidism non-control group was higher than the hypothyroidism control group (p < 0.05). The mental development index and the psychomotor development index in the hypothyroidism non-control group were lower than the hypothyroidism control group (p < 0.05).

Conclusion

Pregnant women with hypothyroidism during pregnancy are more prone to glucose and lipid metabolism disorder, which increases the risk of premature delivery and PROM at term, and has certain influence on the intellectual development and psychomotor development of infants.

Possible effects of Treponema pallidum infection on human vascular endothelial cells

Pathogens can affect host cells in various ways, and the same effect can be found in the Treponema pallidum acting on the endothelium of host vessels, and the mechanism is often complex and multiple. Based on the existing T. pallidum of a cognitive framework, the first concerns involving T. pallidum or the bacteria protein directly acted on vascular endothelial cells of the host, the second concerns mainly involved in the process of T. pallidum infection in vivo blood lipid change, secretion of cytokines and the interactions between immune cells indirectly. Through both direct and indirect influence, this study explores the role of host by T. pallidum infect in the process of the vascular endothelium.

Subclinical Hypothyroidism in Patients with Diabetic Retinopathy: Role of Vascular Endothelial Growth Factor

BACKGROUND

Considering the vital role of vascular endothelial growth factor (VEGF) in the development of diabetic retinopathy (DR) in one hand and the frequent association between subclinical hypothyroidism (SCH) and DR on the other hand.

OBJECTIVE

The present study was proposed to explore the possible role of VEGF in the relation between SCH and DR, thus we investigated the relation between SCH and VEGF levels in patients with DR.

METHODS

Two hundred patients with DR were recruited in this study [100 patients with proliferative diabetic retinopathy (PDR) and 100 patients with non-proliferative diabetic retinopathy (NPDR)]. Patients with DR were divided into 2 groups according to thyroid function: patients with SCH or those with euthyroidism. Patients were subjected to careful history taking, and underwent clinical and ophthalmological examination. Fasting blood glucose, glycosylated hemoglobin, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), TSH, FT4, FT3, VEGF and thyroid volume were assessed Results: Among all the studied patients, 21.5% (43/200) had SCH. DR patients with SCH had higher age, diabetes duration, HbA1c, HOMA-IR and VEGF than those with euthyroidism. The frequency of PDR in patients with SCH was 72.1% (31/43) and 43.9% (69/157) in those with euthyroidism, whereas the frequency of NPDR in patients with SCH was 27.9 (12/43) and 56.1% (88/157) in those with euthyroidism (P < 0.003). In multivariate analysis, PDR, HOMA-IR and VEGF levels were the significant predictor variables of SCH.

CONCLUSIONS

Increased VEGF levels may be implicated in the relationship between SCH and DR.

The role of thyroid-stimulating hormone and thyroglobulin antibody in abnormally invasive placenta

PURPOSE

Thyroid hormones and antibodies are known to participate in angiogenesis and invasion and also thyroid hormone receptors are expressed in the placenta. We aimed to evaluate the relationship of serum levels of thyroid-stimulating hormone (TSH), thyroid hormones (TH), and anti-thyroid antibodies with abnormally invasive placenta (AIP). We also aimed to investigate whether they are related with cesarean hysterectomy and massive blood transfusion need in AIP cases.

METHODS

A total of 88 pregnant patients were enrolled in this prospective case-control study (30 with AIP, 28 with non-adherent placenta previa totalis (PPT) and 30 controls). Serum TSH, thyroid hormone [T3 (triiodothyronine) and T4 (thyroxine)] and thyroid antibodies against thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) levels were studied in maternal serum at initial admission to our Perinatology Unit (at early third trimester). The factors associated with increased risk of AIP, cesarean hysterectomy, massive blood transfusion, and adverse perinatal outcomes were evaluated with multiple logistic regression analysis. Adjusted odds ratios and 95% confidence intervals were also calculated.

RESULTS

Serum TSH and TgAb levels were significantly lower in the AIP group than both PPT and control groups (p = .01, p < .001 and p < .001, p < .001 respectively). Decreased serum levels of TSH (<2.16 mIU/L) and TgAb (<2.70 mIU/L) levels and high previous cesarean section rates were found to be independently associated with AIP in pregnant women with PPT (OR: 0.4, 95% CI: 0.1-0.9; p = .04, OR: 0.7, 95%CI: 0.4-1.3, p = .02 and OR: 0.1, 95% CI: 0.1-0.5, p = .01). Decreased serum TSH and TgAb levels were found to be independently associated with an increased rate of cesarean hysterectomy and massive blood transfusion in AIP cases (OR: 3.7, 95% CI: 1.4-9.8; p = .01, OR: 1.8, 95% CI: 1.1-3.1; p = .03 and OR: 2.6, 95% CI: 1.0-6.5; p = .05, OR: 2.2, 95% CI: 1.1-4.1 p = .02). Decreased TSH and TgAb serum levels were also found to be independently associated with adverse perinatal outcomes in AIP cases (OR: 3.4, 95% CI: 1.3-11.0; p = .01 and OR: 1.978, 95% CI: 2-3.6; p = .03).

CONCLUSION

Decreased serum TSH and TgAb levels, and previous history of cesarean section were all found to be significantly associated with AIP in cases with PPT. We suggest that maternal serum TSH and TgAb levels can provide additional contribution to obstetric Doppler ultrasound in the diagnosis of AIP and thus can reduce the risks of unplanned cesarean hysterectomy in cases with PPT.

FABP4 levels in hypothyroidism and its relationship with subclinical atherosclerosis

Background/aim

The aim of this study is to evaluate the relationship between serum fatty acid binding protein 4 (FABP4) levels and carotid intima media thickness (CIMT) in patients with hypothyroidism.

Materials and methods

Forty subclinical hypothyroidism patients, 40 overt hypothyroidism patients, and 40 healthy controls were enrolled in the study. Blood pressure, body mass index, CIMT, fasting blood sugar, creatine, alanine aminotransferase, lipid parameters, insulin, free thyroxine, triiodothyronine, thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), high-sensitivity C-reactive protein (Hs-CRP), and FABP4 levels of all participants were measured.

Results

Serum FABP4 levels were significantly higher in patients with subclinical and overt hypothyroidism than healthy controls (HCs) (P = 0.044 and P = 0.014, respectively). There was no significant difference in terms of FABP4 levels between patients with subclinical and overt hypothyroidism (P = 0.641). Serum TSH levels and serum FABP4 levels were positively correlated (r = 0.201, P = 0.039). CIMT was found to be higher in patients with subclinical and overt hypothyroidism than in HCs (P = 0.042 and P < 0.001, respectively). No correlation was found between CIMT and FABP4 levels (r = 0.038, P = 0.702). There was a positive correlation between CIMT and TSH, anti-TPO, anti-TG, triglycerides (TG), and total cholesterol levels. It was found that high TG levels were an independent factor that increased CIMT (r = 0.382, r2 = 0.146).

Conclusion

In patients with subclinical and overt hypothyroidism, the level of FABP4 increases and this increase is correlated with the increase in TSH level. It is thought that FABP4 does not play a role in atherosclerosis development in patients with hypothyroidism without metabolic disorder.

Correlation analysis of serum thyroid stimulating hormone with acute cerebrovascular disease

Background

Acute cerebrovascular disease (ACVD) could cause abnormal metabolism of thyroid hormones (TH), mostly represented as a euthyroid sick syndrome or low T3 syndrome. However, the changes in serum thyroid-stimulating hormone (TSH) are controversial. The aim of this study is to investigate the clinical significance of TSH alteration in patients with ACVD.

Method

Patients with ACVD admitted in our hospitals between January 2013 and September 2017 were enrolled in this study (n = 245, including 176 cerebral infarctions and 69 cerebral hemorrhages). Their thyroid hormones were measured and compared with healthy individuals (n = 75). The correlation of TSH with severity and prognosis of ACVD were analyzed by receiver operating characteristic curve.

Results

Serum TSH in ACVD group was higher than the control group (1.64 ± 1.08 vs. 1.26 ± 0.36 μIU/mL, P < 0.05). The TSH levels in intermediate and severe patients with ACVD were higher than in mild patients (1.72 ± 1.18 vs. 2.71 ± 0.93 vs. 1.02 ± 0.47 μIU/mL, P < 0.05). Receiver Operating Characteristic curve (ROC) of TSH in determining the severity of patients were 0.863 (Area under the curve, AUC), 1.496 μIU/L (optimal threshold), 76.5% (sensitivity) and 87.3% (specificity). TSH levels in improved and unchanged groups were significantly higher than the primarily healing group (2.27 ± 1.11 vs. 2.88 ± 1.07 vs. 0.86 ± 0.46 μIU/mL, P < 0.05). ROC of TSH in determining the prognosis of patients was 0.910 (AUC), 1.681 mIU/L (optimal threshold), 79.8% (sensitivity) and 90.5% (specificity) correspondingly.

Conclusion

Since elevated TSH in ACVD patients affects the outcome of thyroid function evaluation, it is preferable to re-check after the acute period. A correlation between a high TSH level and the severity and prognosis of ACVD was detected, but the mechanism of this correlation needs to be further studied.

2,4,6-Tribromophenol Exposure Decreases P-Glycoprotein Transport at the Blood-Brain Barrier

2,4,6-Tribromophenol (TBP, CAS No. 118-79-6) is a brominated chemical used in the production of flame-retardant epoxy resins and as a wood preservative. In marine environments, TBP is incorporated into shellfish and consumed by predatory fish. Food processing and water treatment facilities produce TBP as a byproduct. 2,4,6-Tribromophenol has been detected in human blood and breast milk. Biologically, TBP interferes with estrogen and thyroid hormone signaling, which regulate important transporters of the blood-brain barrier (BBB). The BBB is a selectively permeable barrier characterized by brain microvessels which are composed of endothelial cells mortared by tight-junction proteins. ATP-binding cassette (ABC) efflux transporters on the luminal membrane facilitate the removal of unwanted endobiotics and xenobiotics from the brain. In this study, we examined the in vivo and ex vivo effects of TBP on two important transporters of the BBB: P-glycoprotein (P-gp, ABCB1) and Multidrug Resistance-associated Protein 2 (MRP2, ABCC2), using male and female rats and mice. 2,4,6-Tribromophenol exposure ex vivo resulted in a time- (1-3 h) and dose- (1-100 nM) dependent decrease in P-gp transport activity. MRP2 transport activity was unchanged under identical conditions. Immunofluorescence and western blotting measured decreases in P-gp expression after TBP treatment. ATPase assays indicate that TBP is not a substrate and does not directly interact with P-gp. In vivo dosing with TBP (0.4 µmol/kg) produced decreases in P-gp transport. Co-treatment with selective protein kinase C (PKC) inhibitors prevented the TBP-mediated decreases in P-gp transport activity.

Effects of thyroxine on adhesion molecules and proinflammatory cytokines secretion on human umbilical vein endothelial cells

Thyroid dysfunction is associated with elevated cardiovascular risk factors and atherosclerosis. It could be suggested that, hyperthyroidism is related to a higher prevalence of arterial abnormalities. Therefore, evaluating the endothelial dysfunction (ED) related biomarkers seem to be an important issue. It is not clear whether endothelial cells are biologically responsive to thyroid hormones (THs) or how THs induces the production of endothelial cells (EC)-derived proinflammatory mediators. Hence, in this study the effects of thyroxine (T₄) on ED and inflammatory related mediators were evaluated. Human umbilical vein endothelial cells was used as endothelial cell model which was treated with concentrations of 50, 100, 200 nmol/L of T₄ in various exposure times. In the following, gene and protein expression levels of EC-related markers including intercellular adhesion molecule-1 (ICAM-1), vascular endothelial growth factor (VEGF), and E-selectin were determined using real time polymerase chain reaction (RT-PCR) and western blotting methods. Also, interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) protein levels as proinflammatory cytokines were determined by enzyme linked immunosorbent assay (ELISA) method. Gene and protein expression analysis revealed that T₄ treatments up regulated the levels of VEGF, ICAM-1, and E-selectin as ED markers. In addition, T₄-treated cells had higher significant levels of IL-6 and TNF-α versus untreated cells in different incubation times. This study proposed the atherosclerotic effects of thyroid hormone. Based on our findings, T4 had strong effects on the gene and protein expression levels of pro-inflammatory, angiogenesis, and ED major mediators associated with atherosclerosis development.