The serine/threonine phosphatase 2A (PP2A) has been implicated in the pathogenesis of Alzheimer's disease (AD) due to its important role in regulating dephosphorylation of the microtubule-associated protein tau and mitogen-activated protein (MAP) kinase. In the present study, we show that PP2A was responsible for dephosphorylation of the extracellular signal-regulated kinase 1/2 (Erk1/2) following its activation by BK stimulation. Abnormal gene and protein expressions of PP2A, as well as its activity, were found to contribute to the abnormally prolonged Erk1/2 phosphorylation in the AD fibroblasts. Inhibition of PP2A with okadiac acid produced enhanced and more lasting Erk1/2 phosphorylation after BK stimulation, whereas FK506, an inhibitor of PP2B and FK-binding protein, inhibited the BK-stimulated Erk1/2 phosphorylation. Furthermore, while the phosphorylated Erk1/2 was concentrated in the nucleus of AC cells, it was mainly distributed in the extranuclear compartments of AD cells. These results suggest that the delayed dephosphorylation of Erk1/2 in AD cells following its BK-stimulated activation may be due to deficits of PP2A activity and impaired nuclear translocation of phosphorylated Erk1/2.
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http://dx.doi.org/10.1016/s0969-9961(03)00124-4 | DOI Listing |
Arch Dermatol Res
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Department of Genetics & Biotechnology, Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Youngin, 17104, Republic of Korea.
Abnormal melanin synthesis within melanocytes can result in pigmentary skin disorders. Although pigmentation alterations associated with inflammation are frequently observed, the precise reason for this clinical observation is still unknown. More specifically, although many cytokines are known to be critical for inflammatory skin processes, it is unclear how they affect epidermal melanocyte function.
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Zhejiang Provincial Key Laboratory of Pancreatic Disease, Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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January 2025
Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; Institute of Biosciences, University Research Center Ioannina, University of Ioannina, Ioannina, Greece. Electronic address:
PTEN, a tumor suppressor phosphatase, regulates cellular functions by antagonizing the growth promoting PI3K/Akt/mTOR pathway through the dephosphorylation of the second messenger PIP. Many preclinical cellular and animal studies have used PTEN inhibitors to highlight specific disease contexts where acute activation of PI3K/Akt/mTOR pathway might offer therapeutic advantages. In the present study we have re-evaluated first-generation PTEN inhibitors, including established bisperoxo-vanadium complexes (bpVs).
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January 2025
College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China; Anhui Province Key Laboratory of Local Livestock and Poultry Genetic Resource Conservation and Bio-breeding, Anhui Agricultural University, 130 Changjiang West Rd., Hefei 230036, PR China.
Skeletal muscle satellite cells (SMSCs) are critical for postnatal skeletal muscle growth and regeneration. Adiponectin plays a pivotal role in regulating muscle glucose uptake and fatty acid metabolism. However, its function in the proliferation and differentiation of chicken SMSCs remains poorly understood.
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Department of Pharmacology & Toxicology, Faculty of Pharmacy, Al-Azhar University, Assiut, Egypt.
5-Fluorouracil (5-FU) is a DNA analog used in chemotherapy to treat various tumors. However, the clinical use of 5-FU is limited due to its severe adverse effects, particularly its nephrotoxicity. Morin (MRN) is a flavanol found in many different plants, including those in the Moraceae family, and has anti-inflammatory and antioxidant bioactivities.
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