Wip1 Phosphatase Involved in Lipopolysaccharide-Induced Neuroinflammation

Clonal haematopoiesis - a novel entity that modifies pathological processes in elderly

Progress in the development of new sequencing techniques with wider accessibility and higher sensitivity of the protocol of deciphering genome particularities led to the discovery of a new phenomenon - clonal haematopoiesis. It is characterized by the presence in the bloodstream of elderly people a minor clonal population of cells with mutations in certain genes, but without any sign of disease related to the hematopoietic system. Here we will review this recent advancement in the field of clonal haematopoiesis and how it may affect the disease's development in old age.

The biological function and the regulatory roles of wild-type p53-induced phosphatase 1 in immune system

Wild-type p53-induced phosphatase 1 (WIP1) belongs to the protein phosphatase 2C (PP2C) family and is a mammalian serine/threonine specific protein phosphatase to dephosphorylate numerous signaling molecules. Mammalian WIP1 regulates a wide array of targeting molecules and plays key regulatory roles in many cell processes such as DNA damage and repair, cell proliferation, differentiation, apoptosis, and senescence. WIP1 promotes the formation and development of tumors as an oncogene and a negative regulator of p53. It is also involved in the regulation of aging, neurological diseases and immune diseases. Recent studies demonstrated the critical roles of WIP1 in the differentiation and function of immune cells including T cells, neutrophils and macrophages. In the present manuscript, we briefly summarized the expression patterns, biological function and the target molecules and signal pathways of WIP1 and mainly discussed the latest advances on the regulatory effects of WIP1 in the immune system. WIP1 may be a potential target molecule to treat cancers and immune diseases such as allergic asthma.

Wip1 knockout inhibits neurogenesis by affecting the Wnt/β-catenin signaling pathway in focal cerebral ischemia in mice

Neurogenesis correlates closely with the recovery of neural function after brain ischemia but the critical proteins and signaling pathways involved remain unclear. The phosphatase WIP1 has been shown to regulate neurogenesis in models of aging. However, it is not known if WIP1 affects neurogenesis and functional recovery after brain ischemia. To explore these questions, we performed permanent middle cerebral artery occlusion (MCAO) in mice and performed BrdU labeling, neurobehavioral testing, western blotting, and immunofluorescence staining. We found that ischemia induced WIP1 expression in the area bordering the injury. Compared to wild-type mice, the knockout of the Wip1 gene inhibited neurological functional recovery, reduced the expression of doublecortin, and inactivated the Wnt/β-Catenin signaling pathway in cerebral ischemia in mice. Pharmacological activation of the Wnt/β-Catenin signaling pathway compensated for the Wip1 knockout-induced deficit in neuroblast formation in animals with MCAO. These findings indicate that WIP1 is essential for neurogenesis after brain injury by activating the Wnt/β-Catenin signaling pathway.

Expression of wild-type p53-induced phosphatase 1 in diabetic epiretinal membranes

Objective

The aims of the present study were to investigate the expression and distribution of Wild-type p53-induced phosphatase 1 (Wip1) in diabetic patients with proliferative diabetic retinopathy (PDR) with epiretinal membranes (ERMs) meanwhile analyze the colocalization of Wip1 and nuclear factor kappa-B (NF-κB) p65 in ERMs.

Methods

ERMs samples were collected from patients with PDR (PDR group) or non-diabetic patients with idiopathic epiretinal membranes (iERMs) (control group) during pars plana vitrectomy. Real-Time PCR analysis was carried out to examine the mRNA expression of Wip1 in ERMs. Immunohistochemical analysis and Immunofluorescent analysis were performed to detect the protein expression of Wip1 in ERMs. Double immunofluorescent staining was performed to detect the colocalization of Wip1 and glial fibrillary acidic protein (GFAP) (retinal glial cells marker), also Wip1 and NF-κB.

Results

ERMs were obtained from 17 eyes of 17 patients with PDR (the PDR group) and 9 eyes of 9 nondiabetic patients (the control group) with iERMs. Our results showed high expression levels of Wip1 mRNAs in ERMs after PDR, but low in iERMs. In addition, both immunohistochemistry and immunofluorescence assay showed strong immunoreactivity for Wip1 in PDR ERMs. Furthermore, Wip1 and GFAP were coexpressed in PDR membranes. Finally, the expression of Wip1 was paralleled with NF-κB.

Conclusion

These data support the notion that Wip1 contributes to the formation of the ERMs in PDR membranes via NF-κB signaling.

Wip1 regulates blood-brain barrier function and neuro-inflammation induced by lipopolysaccharide via the sonic hedgehog signaling signaling pathway

The blood brain barrier (BBB) is a diffusion barrier that maintains the brain environment. Wip1 is a nuclear phosphatase induced by many factors and involved in various stresses, tumorigenesis, organismal aging, and neurogenesis. Wip1's role in BBB integrity has not been thoroughly investigated. The purpose of the present study was to investigate the effect and mechanism of Wip1 on lipopolysaccharide (LPS)-induced BBB dysfunction and inflammation in an in vitro BBB model. The in vitro BBB model was established by co-culturing human brain-microvascular endothelial cells and human astrocytes and then exposing them to 1μg/ml LPS for 6, 12, 18, 24, and 48h. Wip1 expression was significantly elevated by LPS treatment. Knockdown of Wip1 aggravated the increased permeability and decreased transepithelial electrical resistance, protein expression of ZO-1, and occludin induced by LPS. Wip1 silencing augmented the elevated inflammatory cytokines TNF-α, IL-1β, IL-12, and IL-6 of the BBB induced by LPS, whereas overexpression of Wip1 showed a contrary effect. Sonic hedgehog signaling (SHH) was activated by Wip1 overexpression and inhibited by Wip1 silencing. Additionally, activating or inhibiting the SHH pathway by purmorphamine or cyclopamine, respectively, abolished the Wip1-induced changes in transepithelial electrical resistance and permeability and inflammatory responses in the LPS-injured BBB model. Our results demonstrate that Wip1 may protect the BBB against LPS-induced integrity disruption and inflammatory response through the SHH signaling pathway.

Memory Training Program Decreases the Circulating Level of Cortisol and Pro-inflammatory Cytokines in Healthy Older Adults

Aging cognitive decline has been associated to impairment of the Hypothalamus Pituitary Adrenals (HPA) axis activity and a higher level of the systemic inflammation. However, little is known about the molecules driving this process at peripheral level. In addition, the cognitive function is to some extent modifiable with Memory Training (MT) programs, even among older adults and beyond. The study aims to evaluate whether MT could contribute to ameliorate cognitive performance and modulate the HPA axis activity as well the low level inflammation in the aging phenotype. Whether the phosphatase WIP-1, a negative regulator for inflammation, is involved in this process was also investigated. We recruited 31 young adults (19-28, years of age) and 62 older adults aged over 60. Thirty-two older adults were submitted to 6-months of MT program (EG), and 28 older adults were no treated and used as Control Group (CG). Global cognitive functioning (MMSE score), verbal and visual memory, and attention were assessed at baseline (T0) and after 6-months (T1). At the same time, plasmatic level of Cortisol (C), IL-1β, IL-18, IL-6, and the expression of WIP-1 mRNA and protein in ex vivo Peripheral Blood Mononuclear Cells were analyzed in young adults at T0, as well in older adults at T0 and T1. Together, the results suggest that MT improves the global cognitive functionality, verbal and visual memory, as well as the level of attention. At the same time we observed a decrease of the plasmatic level of C, of the cytokines, and an increase of the expression of mRNA and protein of WIP-1. The analysis of correlations highlighted that the level of the mRNA of WIP-1 was positively associated to the MMSE score, and negatively to the C and cytokine levels. In conclusion, we purpose the MT as tool that could help support successful aging through the improving of memory, attention and global cognitive function performance. Furthermore, this approach could participate to maintain lower the peripheral levels of the C and pro-inflammatory cytokines. The WIP-1 as a potential new target of the pathophysiology of aging is theorized.

WIP1 Phosphatase Plays a Critical Neuroprotective Role in Brain Injury Induced by High-Altitude Hypoxic Inflammation

The hypobaric hypoxic environment in high-altitude areas often aggravates the severity of inflammation and induces brain injury as a consequence. However, the critical genes regulating this process remain largely unknown. The phosphatase wild-type p53-induced phosphatase 1 (WIP1) plays important roles in various physiological and pathological processes, including the regulation of inflammation in normoxia, but its functions in hypoxic inflammation-induced brain injury remain unclear. Here, we established a mouse model of this type of injury and found that WIP1 deficiency augmented the release of inflammatory cytokines in the peripheral circulation and brain tissue, increased the numbers of activated microglia/macrophages in the brain, aggravated cerebral histological lesions, and exacerbated the impairment of motor and cognitive abilities. Collectively, these results provide the first in vivo evidence that WIP1 is a critical neuroprotector against hypoxic inflammation-induced brain injury.

Phosphatase Wip1 in Immunity: An Overview and Update

Wild-type p53-induced phosphatase 1 (Wip1) is a newly identified serine/threonine phosphatase, which belongs to the PP2C family. Due to its involvement in stress-induced networks and overexpression in human tumors, primary studies have mainly focused on the role of Wip1 in tumorigenesis. It now has also been implicated in regulating several other physiological processes such as organism aging and neurogenesis. Recent evidence highlights a new role of Wip1 in controlling immune response through regulating immune cell development and function, as well as through the interplay with inflammatory signaling pathways such NF-κB and p38 mitogen-activated protein kinase. In this short review, we will give an overview of Wip1 in immunity to better understand this important phosphatase.