Hepatic Estrogen Sulfotransferase Distantly Sensitizes Mice to Hemorrhagic Shock-Induced Acute Lung Injury

Estrogen sulfotransferase and sulfatase in steroid homeostasis, metabolic disease, and cancer

Sulfation and desulfation of steroids are opposing processes that regulate the activation, metabolism, excretion, and storage of steroids, which account for steroid homeostasis. Steroid sulfation and desulfation are catalyzed by cytosolic sulfotransferase and steroid sulfatase, respectively. By modifying and regulating steroids, cytosolic sulfotransferase (SULT) and steroid sulfatase (STS) are also involved in the pathophysiology of steroid-related diseases, such as hormonal dysregulation, metabolic disease, and cancer. The estrogen sulfotransferase (EST, or SULT1E1) is a typical member of the steroid SULTs. This review is aimed to summarize the roles of SULT1E1 and STS in steroid homeostasis and steroid-related diseases.

Estradiol attenuates LPS-induced acute lung injury via induction of aquaporins AQP1 and AQP5

Background

Acute lung injury (ALI) is associated with increased inflammation and oxidative stress. Estradiol is produced by the ovaries and is the most active hormone of estrogen. Our aim was to investigate whether estradiol contributes to protect against lipopolysaccharide (LPS)-induced ALI via induction of aquaporins AQP1 and AQP5 and the underlying mechanisms. Methods and results For induction of ALI, LPS was applied once by intraperitoneal injection in SD rats 14 days after oophorectomy. To assess the therapeutic effects of estradiol on LPS-induced ALI, estradiol was subcutaneously injected for 1 h prior to LPS challenge. Estradiol can significantly attenuate the lung edema reflected by decreasing wet-to-dry weight ratio and permeability of lung and total protein concentration of bronchial lavage fluid (BALF). Results of histological detection showed that estradiol attenuated the lung injury reflected by reducing edema, congestion, and thickening pulmonary septal of lung tissues. In addition, estradiol attenuated TNF-α, IL-1β, and IL-6 and oxidative stress in lung tissues. Estradiol was more effective than estradiol associated with ERα antagonist or ERβ antagonist in protecting against LPS-induced ALI in rats. Mechanistically, we investigate whether estradiol regulates the expression of AQP1 and AQP5 in lung tissues. Of interest, estradiol upregulates AQP1 and AQP5 mRNA and protein expression. Taken together, these results demonstrate that estradiol can increase the expression of AQP1 and AQP5, which plays a critical role in ameliorating oxidative stress and downregulating inflammatory responses induced by LPS.Conclusion Therefore, these findings strongly suggest that AQP1 and AQP5 mediate the anti-inflammatory and antioxidant effects of estradiol.

Inhibition of Estrogen Sulfotransferase (SULT1E1/EST) Ameliorates Ischemic Acute Kidney Injury in Mice

BACKGROUND

Studies have suggested that estrogens may protect mice from AKI. Estrogen sulfotransferase (SULT1E1, or EST) plays an important role in estrogen homeostasis by sulfonating and deactivating estrogens, but studies on the role of SULT1E1 in AKI are lacking.

METHODS

We used the renal ischemia-reperfusion model to investigate the role of SULT1E1 in AKI. We subjected wild-type mice, Sult1e1 knockout mice, and Sult1e1 knockout mice with liver-specific reconstitution of SULT1E1 expression to bilateral renal ischemia-reperfusion or sham surgery, either in the absence or presence of gonadectomy. We assessed relevant biochemical, histologic, and gene expression markers of kidney injury. We also used wild-type mice treated with the SULT1E1 inhibitor triclosan to determine the effect of pharmacologic inhibition of SULT1E1 on AKI.

RESULTS

AKI induced the expression of Sult1e1 in a tissue-specific and sex-specific manner. It induced expression of Sult1e1 in the liver in both male and female mice, but Sult1e1 induction in the kidney occurred only in male mice. Genetic knockout or pharmacologic inhibition of Sult1e1 protected mice of both sexes from AKI, independent of the presence of sex hormones. Instead, a gene profiling analysis indicated that the renoprotective effect was associated with increased vitamin D receptor signaling. Liver-specific transgenic reconstitution of SULT1E1 in Sult1e1 knockout mice abolished the protection in male mice but not in female mice, indicating that Sult1e1's effect on AKI was also tissue-specific and sex-specific.

CONCLUSIONS

SULT1E1 appears to have a novel function in the pathogenesis of AKI. Our findings suggest that inhibitors of SULT1E1 might have therapeutic utility in the clinical management of AKI.

Hepatic Estrogen Sulfotransferase Distantly Sensitizes Mice to Hemorrhagic Shock-Induced Acute Lung Injury

Hemorrhagic shock (HS) is a potential life-threatening condition that may lead to injury to multiple organs, including the lung. The estrogen sulfotransferase (EST, or SULT1E1) is a conjugating enzyme that sulfonates and deactivates estrogens. In this report, we showed that the expression of Est was markedly induced in the liver but not in the lung of female mice subject to HS and resuscitation. Genetic ablation or pharmacological inhibition of Est effectively protected female mice from HS-induced acute lung injury (ALI), including interstitial edema, neutrophil mobilization and infiltration, and inflammation. The pulmonoprotective effect of Est ablation or inhibition was sex-specific, because the HS-induced ALI was not affected in male Est-/- mice. Mechanistically, the pulmonoprotective phenotype in female Est-/- mice was accompanied by increased lung and circulating levels of estrogens, attenuated pulmonary inflammation, and inhibition of neutrophil mobilization from the bone marrow and neutrophil infiltration to the lung, whereas the pulmonoprotective effect was abolished upon ovariectomy, suggesting that the protection was estrogen dependent. The pulmonoprotective effect of Est ablation was also tissue specific, as loss of Est had little effect on HS-induced liver injury. Moreover, transgenic reconstitution of human EST in the liver of global Est-/- mice abolished the pulmonoprotective effect, suggesting that it is the EST in the liver that sensitizes mice to HS-induced ALI. Taken together, our results revealed a sex- and tissue-specific role of EST in HS-induced ALI. Pharmacological inhibition of EST may represent an effective approach to manage HS-induced ALI.