Background: Tumor necrosis factor (TNF)-α can upregulate the expression of plasminogen activator inhibitor (PAI)-1, an inhibitor of fibrinolysis. Adiponectin (Adp) antagonizes TNF-α by negatively regulating its expression in various tissues. In the present study, the ability of Adp to suppress TNF-α-induced PAI-1 upregulation and the underlying mechanisms were evaluated. Methods: Human umbilical vein endothelial cells (HUVECs) were treated with TNF-α in the presence or absence of Adp, and PAI-1 mRNA and antigen expression, activated signaling pathways, and molecular mechanisms were analyzed by qRT-PCR and ELISA. Results: Adp decreased the TNF-α-induced upregulation of PAI-1 mRNA and protein expression and suppressed TNF-α-induced cAMP-PKA-AMPK inactivation. Adp also suppressed the TNF-α-induced NF-kB binding capability on the PAI-1 promoter. Moreover, these Adp-induced effects were further enhanced or prevented by treatment with the cAMP inhibitor Rp-cAMPs or activator forskolin, respectively. Conclusions: Our data suggest that Adp abrogates TNF-α-activated PAI-1 expression by activating cAMP-PKA-AMPK signaling to suppress NF-kB binding to the PAI-1 promoter in HUVECs. Given the antifibrotic effect of PAI-1 abrogation, Adp may be utilized as a novel agent in the treatment of fibrotic diseases.
Rationale:
The differential diagnosis of conditions manifesting as bone and joint pain is complex. Although many individuals with acute leukemia experience bone pain, lumbosacral pain as an early feature of acute lymphoblastic leukemia (ALL) is rare.
Patient concerns:
Here we report a case of an adult who presented with a 7-month history of persistent lumbosacral pain which had become more severe during the previous month.
Diagnoses:
Prior to referral, his full blood count revealed no abnormalities, and a computerized tomography scan revealed mild bone hyperplasia of his lumbar vertebrae, with disc herniations of L3–S1. His blood biochemistry and urinary test results had been normal. After referral to our clinic, tests of the morphology, immunology, cytogenetics, and molecular biology of his bone marrow led to a diagnosis of MLL-AF4 fusion positive B-cell ALL.
Interventions:
Prior to his referral, he had been treated with painkillers by local doctors. The painkillers initially provided pain relief, but their effect wore off over time. After diagnosis, he was started on an adult ALL chemotherapy protocol.
Outcomes:
His symptoms resolved within a week of starting chemotherapy. At his most recent assessment, 10 months after diagnosis, he was on maintenance chemotherapy and in remission.
Lessons:
This case illustrates that prolonged lumbosacral pain may be a symptom of a life-threatening condition, rather than only attributable to chronic inflammation or disk herniations. Therefore, clinicians need to pay attention to subtle differences in the clinical presentation of patients with lumbosacral pain.
Immunothrombosis is a mechanism of defense of the organism against pathogenic microorganisms that increases their recognition, limitation, and clearance and is part of the innate immune defense. Physiological immunothrombosis is beneficial to the body against the invasion of pathogenic microorganisms, but when immunothrombosis is out of control, it is easy to cause thrombotic diseases, thus, causing unpredictable consequences to the body. Neutrophils play a pivotal role in this process. Understanding the mechanism of neutrophils in immune thrombosis and out-of-control is particularly important for the treatment of related thrombotic diseases. In this review, we studied the role of neutrophils in immune thrombosis and each link out of control (including endothelial cell dysfunction; activation of platelets; activation of coagulation factor; inhibition of the anticoagulation system; and inhibition of the fibrinolysis system).
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