Progranulin Expression Levels Research Articles

PGRN exacerbates the progression of non-small cell lung cancer via PI3K/AKT/Bcl-2 antiapoptotic signaling

Progranulin (PGRN) is a growth factor that is involved in the progression of multiple tumors. However, the effects and molecular mechanisms by which PGRN induces lung cancer remain unclear. The expression level of PGRN was analyzed by conducting immunohistochemistry of the histological sections of lung tissues from non-small-cell lung carcinoma (NSCLC) patients. The proliferation, apoptosis, migration, and invasion of NSCLC cells were assessed by the MTT assay, Western blot, degree of wound healing, and Transwell assays. A nude mouse xenograft model was used to validate the role of PGRN in vivo. The expression level of PGRN was higher in male patients with lung adenocarcinoma than in those with lung squamous cell carcinoma; by contrast, no difference was observed in female patients. The overexpression of PGRN promoted the proliferation and anti-apoptosis of H520 (derived from lung squamous cell carcinoma) cells, whereas knockdown of PGRN inhibited the proliferation and anti-apoptosis of A549 (derived from lung adenocarcinoma) cells. Copanlisib (targeting PI3K) inhibited the increase in the expression of cell anti-apoptosis marker Bcl-2 induced by rhPGRN protein; the PI3K agonist 740 Y–P partially reversed the decrease in Bcl-2 expression induced by PGRN deficiency in both A549 and H520 cells. PGRN increased the expression of Ki-67, PCNA, and Bcl-2 in vivo. PGRN inhibited cell apoptosis depending on the PI3K/Akt/Bcl-2 signaling axis; PGRN positivity correlated with lung adenocarcinoma. PGRN is a potential biomarker for the treatment and diagnosis of NSCLC, especially in lung adenocarcinoma.

Secretory leukocyte protease inhibitor and progranulin as possible regulators of cervical remodeling in pregnancy

Secretory leukocyte protease inhibitor (SLPI) and progranulin (PGRN) are secretory proteins with an anti-inflammatory property. Their involvement in cervical remodeling in pregnant uterus is not yet elucidated. Thus, this study aimed to explore the significance of SLPI and PGRN in the maintenance of pregnancy by investigating the factors associated with their expression levels at the cervix. Concentrations of SLPI and PGRN proteins were measured in cervical mucus samples collected from asymptomatic pregnant women at 24–26 weeks of gestation (n = 166). The concentrations of those molecules were analyzed with clinical parameters related to risk for preterm delivery (PD). In pregnant mice, we evaluated the effect of lipopolysaccharide-induced inflammation and progesterone effect modulation on cervical mRNA expression of SLPI and PGRN. The cervical PGRN level was significantly lower in women with short cervix (<35 mm) and with a history of threatened PD. In women with short cervix, cervical SLPI concentrations were positively correlated with inflammatory cytokines, interleukin-6 (R2 = 0.75) and interleukin-8 (R2 = 0.71). In pregnant mice, cervical mRNA expressions of PGRN and SLPI were increased in response to progesterone supplementation and were suppressed by a progesterone antagonist, mifepristone. Lipopolysaccharide-induced inflammation caused remarkable upregulation in cervical SLPI mRNA level but not in PGRN. Progesterone and local inflammation are the factors controlling expression levels of PGRN and SLPI at the cervix. The observed relationship of PGRN and SLPI levels in the cervical mucus with PD-related clinical parameters supports that those anti-inflammatory molecules possibly play a significant role in appropriate regulation of cervical remodeling.

Progranulin promotes melanoma progression by inhibiting natural killer cell recruitment to the tumor microenvironment.

Progranulin (PGRN) is a growth factor with significant biological effects in different types of cancer. However, its role in melanoma progression has not been explored. In this study, we first analyze clinical datasets and show that high PGRN expression levels are correlated with poor prognosis of melanoma patients. Further, we demonstrate in a transplanted murine melanoma model in which the endogenous Grn gene encoding PGRN has been deleted that tumor-derived, not host-derived PGRN, promotes melanoma growth and metastasis. Immunological analyses reveal an enhanced infiltration of natural killer cells, but not T lymphocytes, into PGRN-deficient tumors compared to the wild type control. Antibody-mediated depletion confirms the critical role of NK cells in controlling B16 tumor growth. RNA-seq analysis reveals that several chemokines including CCL5 are strongly upregulated in PGRN-deficient tumor. Silencing CCL5 expression in PGRN-deficient tumor reduces NK cell recruitment and restores tumor growth to the control level. Lastly, we show that PGRN inhibits Ccl5 gene expression at the transcriptional level. This study highlights a novel and critical role of PGRN in melanoma growth and metastasis and suggests that it may represent a potential therapeutic target.

Expression of Progranulin in a Mouse Model of Newborn Hypoxic-ischemic Brain Damage

Neonatal hypoxic ischemic encephalopathy (HIE) is one of the main reasons of death and disability in neonatal, for lack of blood and oxygen during the time of birth. Progranulin (PGRN) as a neurotrophic factor is extensively expressed in the brain can regulate neurite growth and promote neuronal survival. The mutations of PGRN gene may contribute to frontotemporal dementia (FTD). However, the role of PGRN in neonatal HIE remains unclear. We designed this study to investigate the changes of PGRN expression in the brain of newborn mice at different time points after hypoxic -ischemic brain damage (HIBD). Postnatal 7day (P7) mouse pups were induced HIBD model by the method of Rice with some improvement. TTC was used to detect the ischemic lesion volume. The localization of PGRN brain cells was detected by immunofluorescence. We also used Western blotting to measure the expression level of PGRN at different days (1, 3, 7 days) following HIBD. The results showed that we established the HIIBD model successfully. PGRN was primarily expressed in neurons and microglia, but rarely in astrocytes. In addition, PGRN expression in the brain of HIBD mice markedly increased at 1 day and 3 days and was restored at 7 days after HIBD. The results indicated that increased PGRN levels may be involved in the pathological mechanism and neural repair process of HIBD.

Progranulin overproduction due to constitutively activated c-Abl/PKC-δ/Fli1 pathway contributes to the resistance of dermal fibroblasts to the anti-fibrotic effect of tumor necrosis factor-α in localized scleroderma

BackgroundDermal fibroblasts derived from patients with systemic sclerosis (SSc) overproduce progranulin (PGRN), an endogenous antagonist of tumor necrosis factor (TNF) receptors, due to the deficiency of transcription factor Fli1. Fli1 expression is also decreased in dermal fibroblasts derived from patients with localized scleroderma (LSc). ObjectiveTo investigate the expression levels of PGRN and its contribution to the induction of pro-fibrotic phenotype in LSc dermal fibroblasts. MethodsPGRN expression levels were determined by immunohistochemistry and quantitative reverse transcription PCR in the skin of human subjects. The role of PGRN in fibroblast activation was examined with gene silencing technique. The involvement of c-Abl/protein kinase C (PKC)-δ/Fli1 pathway in the regulation of PGRN expression was investigated by immunoblotting. ResultsThe expression levels of PGRN and TNF-α were elevated in LSc skin lesions compared with healthy control skin. LSc dermal fibroblasts were less responsive to the anti-fibrotic effect of TNF-α than normal dermal fibroblasts. Importantly, gene silencing of PGRN reversed the response to TNF-α in LSc dermal fibroblasts. Similar to SSc dermal fibroblasts, the inhibition of c-Abl/PKC-δ/Fli1 pathway by gene silencing of ABL1 or PRKCD significantly suppressed PGRN expression in LSc dermal fibroblasts. ConclusionPGRN overproduction due to constitutively activated c-Abl/PKC-δ/Fli1 pathway may contribute to the resistance of LSc dermal fibroblasts to the anti-fibrotic effect of TNF-α, which may be involved in maintaining their pro-fibrotic phenotype under the pro-inflammatory condition, as is the case with SSc.

Progranulin protects lung epithelial cells from cigarette smoking-induced apoptosis.

Emphysema is characterized by irreversible destruction of alveolar walls with distal air space enlargement. Cigarette smoke (CS) is considered a major risk factor for emphysematous changes in COPD. Progranulin (PGRN), a glycoprotein induced by CS, has been reported to participate in apoptosis. However, the precise role of PGRN in emphysema is currently unknown. This study aimed to evaluate the role of PGRN in human alveolar epithelial cells (AECs) in response to CS. First, PGRN expression was assessed in a mouse model of CS-induced emphysema and in AECs after exposure to CS extract (CSE). Then, the effect of PGRN on CSE-mediated apoptosis was determined under PGRN silencing or overexpressing conditions. To investigate the functional mechanism of PGRN, endoplasmic reticulum (ER) stress markers and the mitogen-activated protein kinase (MAPK) pathway were also evaluated in the CSE-exposed cells. Finally, PGRN expression levels in sera and peripheral blood mononuclear cells (PBMCs) were measured and compared between patients with COPD and healthy subjects. Our results revealed that PGRN expression was elevated in CS-exposed mouse lungs and CSE-treated AECs. CSE-induced cellular apoptosis was significantly increased in PGRN-knockdown AECs and decreased in PGRN-overexpression cells. The activation of ER stress-associated molecules correlated with PGRN expression levels. Compared with healthy controls, COPD patients exhibited significantly lower PGRN serum levels and higher PBMC intracellular PGRN levels. PGRN in airway epithelial cells may regulate CS-induced AEC apoptosis and may be involved in the development of COPD.

Abstract 698: Progranulin targeting in urothelial cancer cells inhibits motility, tumor growth in vitro and in vivo and sensitizes cells to cisplatin

Abstract Introduction and Objective: Bladder cancer is a major public health problem and affects more than 74,000 Americans with more than 16,000 estimated deaths in 2015. The majority of deaths are due to metastatic spread, commonly to the lungs. Understanding the molecular mechanisms regulating bladder tumor cell invasion and progression toward metastases is essential for developing better therapies to treat bladder cancer patients. The growth factor progranulin has emerged in recent years as an important regulator of transformation in several cancer models. We have previously established a critical role for progranulin in bladder cancer as in fact progranulin acts as an autocrine growth factor and promote motility and invasion of invasive urothelial cancer cells. In addition, progranulin is upregulated in high grade bladder cancer tissues compared to normal tissue controls suggesting that progranulin might work as a novel biomarker with predictive value for bladder cancer progression. However, whether progranulin is important for anchorage-independent growth and in vivo tumor formation of urothelial cancer cells has not been previously established. Methods: Progranulin depletion was achieved by stably transfecting tumorigenic T24T, UMUC3 urothelial cancer cells with a plasmid expressing an anti-progranulin shRNA. Progranulin-depleted and control UMUC-3 and T24T cells were tested for motility, invasion and anchorage-independent growth by soft-agar assays. Tumor formation in vivo was assessed in various UMUC-3-derived cell lines by xenograft and orthotopic models. Sensitivity to cisplatin was assessed by cell survival curves. Progranulin expression levels in a bladder tissue microarray were analyzed by HIC. Results: Progranulin-depleted T24T and UMUC-3 cells were significantly inhibited in their ability to migrate, close a wound and invade through Matrigel compared to control cells in both serum-deprived and 1% serum media. In addition, progranulin targeting strongly reduced the ability of T24T and UMUC-3 cells to grow in anchorage-independency and form colonies in soft-agar. Significantly progranulin-depleted UMUC-3 cells were severely inhibited in tumor formation in vivo as assessed by both xenograft and orthotopic models in immunocompromised mice. Importantly, progranulin depletion sensitized UMUC-3 cells to cisplatin. Finally, progranulin levels correlated with tumor progression in bladder cancer tissues. Conclusions: Our data are translationally relevant as indicate that progranulin exerts an essential functional role in the regulation of bladder cancer progression. Thus, progranulin may constitute a novel target for therapeutic intervention in bladder tumors. In addition, progranulin may serve as novel biomarker for diagnosis and prognosis of bladder cancer. Citation Format: Simone Buraschi, Shi-Qiong Xu, Manuela Stefanello, Igor Moskalev, Alaide Morcavallo, Marco Genua, Ryuta Tanimoto, Thomas Neill, Stephen C. Peiper, Leonard G. Gomella, Antonino Belfiore, Peter C. Black, Renato V. Iozzo, Andrea Morrione. Progranulin targeting in urothelial cancer cells inhibits motility, tumor growth in vitro and in vivo and sensitizes cells to cisplatin. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 698.

MP61-13 PROGRANULIN TARGETING IN UROTHELIAL CANCER CELLS INHIBITS MOTILITY, ANCHORAGE-INDEPENDENT GROWTH, TUMOR FORMATION IN VIVO AND SENSITIZES CELLS TO CISPLATIN

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology II1 Apr 2016MP61-13 PROGRANULIN TARGETING IN UROTHELIAL CANCER CELLS INHIBITS MOTILITY, ANCHORAGE-INDEPENDENT GROWTH, TUMOR FORMATION IN VIVO AND SENSITIZES CELLS TO CISPLATIN Simone Buraschi, Shi-Qiong Xu, Manuela Stefanello, Igor Moskalev, Alaide Morcavallo, Marco Genua, Ryuta Tanimoto, Thomas Neill, Stephen C Peiper, Leonard G Gomella, Peter C Black, Antonino Belfiore, Renato V Iozzo, and Andrea Morrione Simone BuraschiSimone Buraschi More articles by this author , Shi-Qiong XuShi-Qiong Xu More articles by this author , Manuela StefanelloManuela Stefanello More articles by this author , Igor MoskalevIgor Moskalev More articles by this author , Alaide MorcavalloAlaide Morcavallo More articles by this author , Marco GenuaMarco Genua More articles by this author , Ryuta TanimotoRyuta Tanimoto More articles by this author , Thomas NeillThomas Neill More articles by this author , Stephen C PeiperStephen C Peiper More articles by this author , Leonard G GomellaLeonard G Gomella More articles by this author , Peter C BlackPeter C Black More articles by this author , Antonino BelfioreAntonino Belfiore More articles by this author , Renato V IozzoRenato V Iozzo More articles by this author , and Andrea MorrioneAndrea Morrione More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.887AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Bladder cancer is a major public health problem and affects more than 74,000 Americans with more than 16,000 estimated deaths in 2015. The majority of deaths are due to metastatic spread, commonly to the lungs. Understanding the molecular mechanisms regulating bladder tumor cell invasion and progression toward metastases is essential for developing better therapies to treat bladder cancer patients. The growth factor progranulin has emerged in recent years as an important regulator of transformation in several cancer models. We have previously established a critical role for progranulin in bladder cancer as in fact progranulin acts as an autocrine growth factor and promote motility and invasion of invasive urothelial cancer cells. In addition, progranulin is upregulated in high grade bladder cancer tissues compared to normal tissue controls suggesting that progranulin might work as a novel biomarker with predictive value for bladder cancer progression. However, whether progranulin is important for anchorage-independent growth and in vivo tumor formation of urothelial cancer cells has not been previously established. METHODS Progranulin depletion was achieved by stably transfecting tumorigenic T24T, UMUC3 urothelial cancer cells with a plasmid expressing an anti-progranulin shRNA. Progranulin-depleted and control UMUC-3 and T24T cells were tested for motility, invasion and anchorage-independent growth by soft-agar assays. Tumor formation in vivo was assessed in various UMUC-3-derived cell lines by xenograft and orthotopic models. Sensitivity to cisplatin was assessed by cell survival curves. Progranulin expression levels in a bladder tissue microarray were analyzed by HIC. RESULTS Progranulin-depleted T24T and UMUC-3 cells were significantly inhibited in their ability to migrate, close a wound and invade through Matrigel compared to control cells in both serum-deprived and 1% serum media. In addition, progranulin targeting strongly reduced the ability of T24T and UMUC-3 cells to grow in anchorage-independency and form colonies in soft-agar. Significantly progranulin-depleted UMUC-3 cells were severely inhibited in tumor formation in vivo as assessed by both xenograft and orthotopic models in immunocompromised mice. Importantly, progranulin depletion sensitized UMUC-3 cells to cisplatin. Finally, progranulin levels correlated with tumor progression in bladder cancer tissues. CONCLUSIONS Our data are translationally relevant as indicate that progranulin exerts an essential functional role in the regulation of bladder cancer progression. Thus, progranulin may constitute a novel target for therapeutic intervention in bladder tumors. In addition, progranulin may serve as novel biomarker for diagnosis and prognosis of bladder cancer. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e808 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Simone Buraschi More articles by this author Shi-Qiong Xu More articles by this author Manuela Stefanello More articles by this author Igor Moskalev More articles by this author Alaide Morcavallo More articles by this author Marco Genua More articles by this author Ryuta Tanimoto More articles by this author Thomas Neill More articles by this author Stephen C Peiper More articles by this author Leonard G Gomella More articles by this author Peter C Black More articles by this author Antonino Belfiore More articles by this author Renato V Iozzo More articles by this author Andrea Morrione More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

PGRN promotes migration and invasion of epithelial ovarian cancer cells through an epithelial mesenchymal transition program and the activation of cancer associated fibroblasts

In this paper, we aimed to explore whether progranulin (PGRN) could induce epithelial ovarian cancer cells to undergo an epithelial mesenchymal transition (EMT) program directly and through its activation of cancer associated fibroblasts (CAFs) indirectly. Immunohistochemistry(IHC) staining of tissue samples of 78 cases of epithelial ovarian cancer (EOC) patients found that PGRN expression levels were negatively correlated with E-cadherin levels (r=−0.289, P=0.013) and positively correlated with Slug levels (r=0.332, P=0.003); Cell experiments showed that PGRN overexpression could increase the migratory and invasive abilities of A2780 cells significantly. Moreover, high doses (62ng/ml) of recombinant PGRN could induce 14.7 fold high expression of smooth muscle actin α (α-SMA) in human normal fibroblasts. In addition, patients with both high levels of PGRN and α-SMA in their tissue samples had the worst disease free survival (DFS) and overall survival (OS) than those with low levels of PGRN or α-SMA. All the results suggest that PGRN could promote invasiveness of EOC cells through an EMT program directly and through activation of CAFs indirectly. This may provide a new effective therapy target for EOC.

Progranulin Overproduction Due to Fli-1 Deficiency Contributes to the Resistance of Dermal Fibroblasts to Tumor Necrosis Factor in Systemic Sclerosis.

Progranulin is a growth factor that is active in wound repair and is an antagonist of tumor necrosis factor (TNF) receptors, regulating fibroblast activation, angiogenesis, and inflammation. Because long-standing activation of gene programs related to wound healing is a hallmark of systemic sclerosis (SSc), we sought to investigate the role of progranulin in SSc. Progranulin expression levels in human and murine skin samples were determined by immunohistochemical analysis and quantitative reverse transcription-polymerase chain reaction. The role of progranulin in fibroblast activation was examined using a gene-silencing technique. Progranulin levels in serum obtained from 60 patients with SSc and 16 healthy control subjects were determined by enzyme-linked immunosorbent assay. Progranulin expression was increased in SSc dermal fibroblasts compared with normal dermal fibroblasts, both in vivo and in vitro. Transcription factor Fli-1, a deficiency of which is involved in the activation of SSc dermal fibroblasts, served as a potent repressor of the progranulin gene, and Fli-1(+/-) mice and bleomycin-treated wild-type mice exhibited up-regulated expression of progranulin in dermal fibroblasts. SSc dermal fibroblasts were resistant to the antifibrotic effect of TNF, but this resistance was reversed by gene silencing of progranulin. Serum progranulin levels were elevated in patients with early diffuse cutaneous SSc (dcSSc), especially in those with inflammatory skin symptoms, and were positively correlated with the C-reactive protein level. Progranulin overproduction due to Fli-1 deficiency may contribute to the constitutive activation of SSc dermal fibroblasts by antagonizing the antifibrotic effect of TNF. Progranulin may also be involved in the inflammatory process associated with progressive skin sclerosis in early dcSSc.

Effect of progranulin (PGRN) on the proliferation and senescence of cervical cancer cells.

We investigated the effect of progranulin (PGRN) expression on the proliferation and senescence of cervical cancer cells. PGRN small interfering RNA (siRNA) was introduced into the SiHa and HeLa cell lines of human cervical carcinoma using liposome-mediated transfection. The expression levels of PGRN in each cell line after transfection of PGRN siRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). Senescence in the cell lines was detected using the β-galactosidase-staining test, and proliferation was detected by clone formation. The RT-PCR assay showed that the expression of PGRN in all of the cell lines transfected with PGRN siRNA markedly decreased. In the clone-forming test, compared with the control group, the colony-forming ability in all cell lines decreased significantly after transfection with PGRN siRNA. The β-galactosidase-staining experiments showed that the phenomenon of cell aging in the PGRN interference group was more obvious than in the control group. After the cervical cancer cells had been transfected with PGRN siRNA, cell senescence was accelerated and clone-forming ability was markedly reduced. This suggests that PGRN can promote the proliferation of the cervical cancer cell line; proliferation of cervical cancer cells is achieved by inhibiting their senescence.

Possible involvement of the cerebellum in motor-function impairment in progranulin-deficient mice.

Progranulin (PGRN) is a multifunctional growth factor involved in many physiological and pathological processes in the brain such as sexual differentiation, neurogenesis, neuroinflammation, and neurodegeneration. Previously, we showed that PGRN was expressed broadly in the brain and the Purkinje cells in the cerebellum were one of the regions with the highest expression level of PGRN. Thus, in the present study, we investigated the possible roles of PGRN in the cerebellum by comparing wild-type (WT) and PGRN-deficient (KO) mice with immunohistochemical staining for calbindin, a marker of Purkinje cells. The results showed that the density of Purkinje cell dendrites in the molecular layer of the cerebellum was significantly higher in KO mice than in WT mice, although the number of cell bodies was comparable between the genotypes. Subsequently, as the cerebellum is the center of the motor function, we performed a rotarod test and found that KO mice remained on the rotating rod for significantly shorter periods than WT mice. However, KO and WT mice did not differ significantly with respect to the diameter of myofibers in a skeletal muscle. These results suggest that PGRN is involved in the development and/or maturation of neuronal networks comprising Purkinje cells in the cerebellum, which may be a prerequisite to normal motor function.

Elevated expression of secreted autocrine growth factor progranulin increases cervical cancer growth.

Little is known about the role of progranulin (PGRN) in cervical cancer, which is an autocrine growth factor. We used immunohistochemistry, western blot, and ELISA to determine the expression levels of PGRN in cervical cancer and cervical cancer cell lines. Immortalized normal cervical cell line H8 with lower PGRN expression was treated with recombinant human PGRN (rhPGRN) and forced expression of PGRN by transfection and cell proliferation were determined. PGRN knockdown by siRNA was also performed in HeLa cells with high PGRN expression and cell proliferation was also determined. Furthermore, H8 cell xenograft mouse model was employed to determine if PGRN treatment could increase tumorigenesis of H8 cell xenograft. Our results showed that PGRN expression was significantly increased in cervical cancer tissue and high expression of PGRN is closely correlated with the degree of malignancy in cervical cancer cell lines. Increased PGRN expression or rhPGRN treatment increased the proliferation of H8 cells. Consistently, PGRN knockdown in HeLa cells by siRNA transfection reduced proliferation of HeLa cells. In H8 cell xenograft model, both intraperitoneal and intratumoral rhPGRN treatments increased tumorigenic capacity of H8 cell line. Our results suggested that PGRN could be used as both a diagnostic biomarker and therapeutic target.

TMEM106B expression is reduced in Alzheimer’s disease brains

IntroductionTMEM106B is a transmembrane glycoprotein of unknown function located within endosome/lysosome compartments expressed ubiquitously in various cell types. Previously, the genome-wide association study (GWAS) identified a significant association of TMEM106B single nucleotide polymorphisms (SNPs) with development of frontotemporal lobar degeneration with ubiquitinated TAR DNA-binding protein-43 (TDP-43)-positive inclusions (FTLD-TDP), particularly in the patients exhibiting the progranulin (PGRN) gene (GRN) mutations. Recent studies indicate that TMEM106B plays a pathological role in various neurodegenerative diseases, including Alzheimer’s disease (AD). However, at present, the precise levels of TMEM106B expression in AD brains remain unknown.MethodsBy quantitative reverse transcription (RT)-PCR (qPCR), western blot and immunohistochemistry, we studied TMEM106B and PGRN expression levels in a series of AD and control brains, including amyotrophic lateral sclerosis, Parkinson’s disease, multiple system atrophy and non-neurological cases.ResultsIn AD brains, TMEM106B mRNA and protein levels were significantly reduced, whereas PGRN mRNA levels were elevated, compared with the levels in non-AD brains. In all brains, TMEM106B was expressed in the majority of cortical neurons, hippocampal neurons, and some populations of oligodendrocytes, reactive astrocytes and microglia with the location in the cytoplasm. In AD brains, surviving neurons expressed intense TMEM106B immunoreactivity, while senile plaques, neurofibrillary tangles and the perivascular neuropil, almost devoid of TMEM106B, intensely expressed PGRN.ConclusionsWe found an inverse relationship between TMEM106B (downregulation) and PGRN (upregulation) expression levels in AD brains, suggesting a key role of TMEM106B in the pathological processes of AD.

Deletion of progranulin exacerbates atherosclerosis in ApoE knockout mice

Progranulin (PGRN) is a multifunctional protein known to be involved in inflammation. However, the relation between PGRN and atherosclerosis remains elusive. The aim of this study was to define the role of PGRN in the development of atherosclerosis. First, we checked the expression levels of PGRN in human atherosclerotic plaques. Immunohistochemical analysis showed that PGRN is strongly expressed in foam cells of atherosclerotic plaques. We also found that PGRN is expressed more abundantly in macrophages than in the smooth muscle cells of atherosclerotic lesions in ApoE(-/-) mice fed a high-fat diet for 12 weeks. Next, PGRN(-/-)ApoE(-/-) mice were generated to investigate the effect of PGRN on the development of atherosclerosis. PGRN(-/-)ApoE(-/-) mice exhibited severe atherosclerotic lesions compared with PGRN(+/+)ApoE(-/-) mice, despite their anti-atherogenic lipid profile. These results are partly due to enhanced expression of inflammatory cytokines, adhesion molecules, and decreased expression of endothelial nitric oxide synthase. In addition, lack of PGRN leads to accumulate excessive cholesterol in the macrophages and alter HDL-associated proteins. PGRN seems to be involved in the pathogenesis of atherosclerosis, possibly by various anti-atherogenic effects, including modulation of local and/or systemic inflammation.

Abstract WP264: The Growth Factor Progranulin Suppresses Inflammatory Reactions and Attenuates Neuronal Injury Induced by Cerebral Ischemia-Reperfusion in Mice.

Objective —The growth factor progranulin (PGRN) is a widely expressed protein with various biological functions, and it is known to have an anti-inflammatory effect. The aim of this study was to investigate the possible ameliorative effects of PGRN against cerebral ischemia-reperfusion (I/R) injury. Methods —In vivo ischemic stroke was induced in 4-week-old male ddY mice by 2 h of middle cerebral artery occlusion (MCAO) followed by 22 h of reperfusion. The following 4 experimental protocols were devised: (1) to determine the expression level of PGRN in the I/R brain (n = 4 per group); (2) to establish the dose-response effects of intracerebroventricularly administered recombinant PGRN (r-PGRN; 0.1 to 1.0 ng) on cerebral I/R injury (n = 6 to 8 per group); (3) to establish the therapeutic time window of r-PGRN treatment (n = 8 to 9 per group); and (4) to investigate the effects of r-PGRN treatment on the expression of inflammatory cytokines in the I/R brain (n = 5 per group). Results —We found that the expression level of PGRN was significantly reduced in the I/R brain (P &lt; 0.01, vs. Sham; t test). The administration of 1.0 ng of r-PGRN at 2 h after MCAO resulted in a reduction in the infarct volume and brain swelling at 24 h after MCAO (P &lt; 0.01, vs. Vehicle, in each; Dunnett test), and this led to an improvement in neurological scores (P &lt; 0.05; Wilcoxon signed-rank test). Delayed administration of r-PGRN at 6 h after MCAO did not reduce the infarct volume, but significantly reduced brain swelling (P &lt; 0.05; t test). We also confirmed that r-PGRN administration significantly reduced the phosphorylation of NF-κB and expression of MMP-9 in the I/R brain (P &lt; 0.05, vs. Vehicle, in each; t test). Conclusion —r-PGRN treatment exerts ameliorative effects on experimental ischemic stroke, and these effects are due to the prevention of harmful inflammatory reactions following cerebral I/R. This study suggests the feasibility of r-PGRN administration as a novel therapeutic strategy for treatment in the acute phase of ischemic stroke.

Involvement of Progranulin in Hypothalamic Glucose Sensing and Feeding Regulation

Progranulin (PGRN) is a secreted glycoprotein with multiple biological functions, including modulation of wound healing and inflammation. Hypothalamic PGRN has been implicated in the development of sexual dimorphism. In the present study, a potential role for PGRN in the hypothalamic regulation of appetite and body weight was investigated. In adult rodents, PGRN was highly expressed in periventricular tanycytes and in hypothalamic neurons, which are known to contain glucose-sensing machinery. Hypothalamic PGRN expression levels were decreased under low-energy conditions (starvation and 2-deoxy-D-glucose administration) but increased under high-energy condition (postprandially). Intracerebrovetricular administration of PGRN significantly suppressed nocturnal feeding as well as hyperphagia induced by 2-deoxyglucose, neuropeptide Y, and Agouti-related peptide. Moreover, the inhibition of hypothalamic PGRN expression or action increased food intake and promoted weight gain, suggesting that endogenous PGRN functions as an appetite suppressor in the hypothalamus. Investigation of the mechanism of action revealed that PGRN diminished orexigenic neuropeptide Y and Agouti-related peptide production but stimulated anorexigenic proopiomelanocortin production, at least in part through the regulation of hypothalamic AMP-activated protein kinase. Notably, PGRN was also expressed in hypothalamic microglia. In diet-induced obese mice, microglial PGRN expression was increased, and the anorectic response to PGRN was blunted. These findings highlight a physiological role for PGRN in hypothalamic glucose-sensing and appetite regulation. Alterations in hypothalamic PGRN production or action may be linked to appetite dysregulation in obesity.