Obesity contributes to the development of type 2 diabetes, but the underlying mechanisms are poorly understood. Using cell culture and mouse models, we show that obesity causes endoplasmic reticulum (ER) stress. This stress in turn leads to suppression of insulin receptor signaling through hyperactivation of c-Jun N-terminal kinase (JNK) and subsequent serine phosphorylation of insulin receptor substrate-1 (IRS-1). Mice deficient in X-box-binding protein-1 (XBP-1), a transcription factor that modulates the ER stress response, develop insulin resistance. These findings demonstrate that ER stress is a central feature of peripheral insulin resistance and type 2 diabetes at the molecular, cellular, and organismal levels. Pharmacologic manipulation of this pathway may offer novel opportunities for treating these common diseases.

Endoplasmic reticulum (ER) stress is a key link between obesity, insulin resistance, and type 2 diabetes. Here, we provide evidence that this mechanistic link can be exploited for therapeutic purposes with orally active chemical chaperones. 4-Phenyl butyric acid and taurine-conjugated ursodeoxycholic acid alleviated ER stress in cells and whole animals. Treatment of obese and diabetic mice with these compounds resulted in normalization of hyperglycemia, restoration of systemic insulin sensitivity, resolution of fatty liver disease, and enhancement of insulin action in liver, muscle, and adipose tissues. Our results demonstrate that chemical chaperones enhance the adaptive capacity of the ER and act as potent antidiabetic modalities with potential application in the treatment of type 2 diabetes.

Mammalian target of rapamycin, mTOR, is a major sensor of nutrient and energy availability in the cell and regulates a variety of cellular processes, including growth, proliferation, and metabolism. Loss of the tuberous sclerosis complex genes (TSC1 or TSC2) leads to constitutive activation of mTOR and downstream signaling elements, resulting in the development of tumors, neurological disorders, and at the cellular level, severe insulin/IGF-1 resistance. Here, we show that loss of TSC1 or TSC2 in cell lines and mouse or human tumors causes endoplasmic reticulum (ER) stress and activates the unfolded protein response (UPR). The resulting ER stress plays a significant role in the mTOR-mediated negative-feedback inhibition of insulin action and increases the vulnerability to apoptosis. These results demonstrate ER stress as a critical component of the pathologies associated with dysregulated mTOR activity and offer the possibility to exploit this mechanism for new therapeutic opportunities.

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Although masses of high density at mammography, circumscribed border associated with posterior acoustic enhancement and internal cystic areas at sonography should suggest the diagnosis of phyllodes tumors rather than large sized fibroadenomas, there was a substantial overlap in the mammographic and sonographic characteristics of these two tumors. Therefore, an excisional biopsy would be necessary for equivocal masses.

The aim of this study was to describe the mammographic and sonographic findings of idiopathic granulomatous mastitis which is a rare inflammatory disease of the breast of unknown etiology. The clinical, radiologic, and pathologic features of 12 cases with idiopathic granulomatous mastitis were retrospectively reviewed. Mammography was performed in all cases, 8 of which showed a focal asymmetric density, 3 had a mass with irregular margins, and 1 had no abnormality. Sonography was performed in 10 cases, and a focal area with inhomogeneous and hypoechoic pattern was depicted in 6 cases, 4 of which were associated with internal tubular hypoechoic structures. One case revealed a hypoechoic mass consistent with malignancy. In 1 case sonography showed an edematous pattern involving nearly the entire breast. Two patients had normal sonograms. If a focal asymmetric density is seen in mammography and inhomogeneous hypoechogenity with internal hypoechoic tubular structures accompany ultrasonographically, these findings should suggest the possibility of idiopathic granulomatous mastitis; however, very often idiopathic granulomatous mastitis mimics a breast carcinoma clinically and the final diagnosis should be reached histopathologically due to high false-positive and false-negative mammographic appearances.

Objective: Ankaferd ® Blood Stopper (ABS) is an herbal extract that has historically been used as a hemostatic agent in traditional Turkish medicine. ABS is comprised of a standardized herbal mixture of T. vulgaris, G. glabra, V. vinifera, A. officinarum, and U. dioica. ABS's basic mechanism of action is the formation of an encapsulated protein web, which represents the focal point for vital erythrocyte masses. The hemostatic effects of ABS have been observed in vitro and in vivo. ABS was registered as a hemostatic agent for external hemorrhages and dental bleeding following phase I randomized, double-blind crossover placebo-controlled clinical research, and safety and efficacy reports. In terms of the potential use of ABS, transcription factors may be novel factors that play a role in the hemostatic and other pleiotropic effects of ABS. Materials and Methods: Hence, the present study aimed to investigate the effects of ABS on endothelium, and possible transcription factor changes in HUVEC (human umbilical vein endothelial cells) and the erythrocyte membrane profile. ABS (5 μL and 50 μL) was administered to HUVEC (in 75 cm 2 ; ~75% fullness) for 5 min and 15 min. Results: ABS caused significant increases in the level of activation of the following transcription factors; AP2, AR, CRE/ATF1, CREB, E2F1-5, E2F6, EGR, GATA, HNF-1, ISRE, Myc-Max, NF-1, NFkB, p53, PPAR, SMAD 2/3, SP1, TRE/AP1, and YY1. Following erythrocyte membrane isolation, protein complexes were undissolved, but denatured. The protein complex formed was resistant to heat and detergent. Trypsin and sonication were used in order to break this complex; the complex dissolved and erythrocyte membrane proteins were released in SDS-PAGE. Conclusion: ABS established a very fast and solid protein web, and increased the level of transcription factor activation. Therefore the cellular effects of ABS could be related to different intracellular biological pathways. (Turk J Hematol 2011; 28: 276-85)

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