Brain diseases and tumorigenesis: The good and bad cops of pentraxin3

β-Galactosylceramidase Deficiency Causes Upregulation of Long Pentraxin-3 in the Central Nervous System of Krabbe Patients and Twitcher Mice

Globoid cell leukodystrophy (GLD), or Krabbe disease, is a neurodegenerative sphingolipidosis caused by genetic deficiency of lysosomal β-galactosylceramidase (GALC), characterized by neuroinflammation and demyelination of the central (CNS) and peripheral nervous system. The acute phase protein long pentraxin-3 (PTX3) is a soluble pattern recognition receptor and a regulator of innate immunity. Growing evidence points to the involvement of PTX3 in neurodegeneration. However, the expression and role of PTX3 in the neurodegenerative/neuroinflammatory processes that characterize GLD remain unexplored. Here, immunohistochemical analysis of brain samples from Krabbe patients showed that macrophages and globoid cells are intensely immunoreactive for PTX3. Accordingly, Ptx3 expression increases throughout the course of the disease in the cerebrum, cerebellum, and spinal cord of GALC-deficient twitcher (Galc^twi/twi) mice, an authentic animal model of GLD. This was paralleled by the upregulation of proinflammatory genes and M1-polarized macrophage/microglia markers and of the levels of PTX3 protein in CNS and plasma of twitcher animals. Crossing of Galc^twi/twi mice with transgenic PTX3 overexpressing animals (hPTX3 mice) demonstrated that constitutive PTX3 overexpression reduced the severity of clinical signs and the upregulation of proinflammatory genes in the spinal cord of P35 hPTX3/Galc^twi/twi mice when compared to Galc^twi/twi littermates, leading to a limited increase of their life span. However, this occurred in the absence of a significant impact on the histopathological findings and on the accumulation of the neurotoxic metabolite psychosine when evaluated at this late time point of the disease. In conclusion, our results provide the first evidence that PTX3 is produced in the CNS of GALC-deficient Krabbe patients and twitcher mice. PTX3 may exert a protective role by reducing the neuroinflammatory response that occurs in the spinal cord of GALC-deficient animals.

Tumor Necrosis Factor Alpha-Induced Proteins in Malignant Tumors: Progress and Prospects

Tumor necrosis factor (TNF) is the first cytokine used in tumor biotherapy, but TNF-related drugs are limited by the lack of specific targets. Tumor necrosis factor alpha-induced proteins (TNFAIPs), derived from TNF, is a protein family and participates in proliferation, invasion and metastasis of tumor cells. In order to better understand biological functions and potential roles of TNFAIPs in malignant tumors, this paper in the form of “Gene–Protein–Tumor correlation” summarizes the biological characteristics, physiological functions and mechanisms of TNFAIPs by searching National Center of Biotechnology Information, GeneCards, UniProt and STRING databases. The relationship between TNFAIPs and malignant tumors is analyzed, and protein–protein interaction diagram in members of TNFAIPs is drawn based on TNF for the first time. We find that TNF as a key factor is related to TNFAIP1, TNFAIP3, TNFAIP5, TNFAIP6, TNFAIP8 and TNFAIP9, which can be directly involved in activating TNFAIP1, TNFAIP5, TNFAIP8 and TNFAIP9. We confirm that the mechanism of TNFAIP1, TNFAIP2 and TNFAIP3 inducing tumors may be related to NF-κB signaling pathway, but the mechanism of tumor induction by other members of TNFAIPs is not clear. In the future, translational studies are needed to explore the mechanisms of TNF-TNFAIPs-tumors.

Pentraxin 3 contributes to neurogenesis after traumatic brain injury in mice

Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation. It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes, and potentially has multiple protective effects in stroke; however, its role in the adult brain after traumatic brain injury is unknown. In the present study, a moderate model of traumatic brain injury in mice was established using controlled cortical impact. The models were intraventricularly injected with recombinant pentraxin 3 (the recombinant pentraxin 3 group) or an equal volume of vehicle (the control group). The sham-operated mice underwent craniotomy, but did not undergo the controlled cortical impact. The potential neuroprotective and neuroregenerative roles of pentraxin 3 were investigated on days 14 and 21 after traumatic brain injury. Western blot assay showed that the expression of endogenous pentraxin 3 was increased after traumatic brain injury in mice. Furthermore, the neurological severity test and wire grip test revealed that recombinant pentraxin 3 treatment reduced the neurological severity score and increased the wire grip score, suggesting an improved recovery of sensory-motor functions. The Morris water maze results demonstrated that recombinant pentraxin 3 treatment reduced the latency to the platform, increased the time spent in the correct quadrant, and increased the number of times traveled across the platform, thus suggesting an improved recovery of cognitive function. In addition, to investigate the effects of pentraxin 3 on astrocytes, specific markers of A2 astrocytes were detected in primary astrocyte cultures in vitro using western blot assay. The results demonstrated that pentraxin 3 administration activates A2 astrocytes. To explore the protective mechanisms of pentraxin 3, immunofluorescence staining was used. Intraventricular injection of recombinant pentraxin 3 increased neuronal maintenance in the peri-injured cortex and ipsilateral hippocampus, increased the number of doublecortin-positive neural progenitor cells in the subventricular and subgranular zones, and increased the number of bromodeoxyuridine (proliferation) and neuronal nuclear antigen (mature neuron) double-labeled cells in the hippocampus and peri-injured cortex. Pentraxin 3 administration also increased the number of neurospheres and the number of bromodeoxyuridine and doublecortin double-labeled cells in neurospheres, and enhanced the proliferation of neural progenitor cells in primary neural progenitor cell cultures in vitro. In conclusion, recombinant pentraxin 3 administration activated A2 astrocytes, and consequently improved the recovery of neural function by increasing neuronal survival and enhancing neurogenesis. All experiments were approved by the Animal Ethics Committee of the First Affiliated Hospital of Chongqing Medical University, China on March 1, 2016.

ccf-mtDNA as a Potential Link Between the Brain and Immune System in Neuro-Immunological Disorders

Fragments of mitochondrial DNA (mtDNA) are released outside the cell and they appear to persist in extracellular fluids as circulating, cell-free, mtDNA (ccf-mtDNA). When compared to nuclear DNA, such a double stranded mtDNA is more resistant to nuclease degradation. In fact, it is stable extracellularly where it can be detected in both plasma and cerebrospinal fluid (CSF), here acting as a potential biomarker in various disorders. In neurological diseases (Alzheimer's disease, Parkinson's disease and end-stage progressive Multiple Sclerosis), a decreased amount of CSF ccf-mtDNA is related with progressive cell dysfunction. This suggests an alteration in neuronal mtDNA levels (mtDNA replication, degradation and depletion) in vulnerable brain regions at early stages of neurodegeneration leading to reduced mtDNA release, which takes place before actual cell death occurs. On the other hand, elevated CSF ccf-mtDNA levels are reported in acute phases of relapsing-remitting Multiple Sclerosis (RRMS). This occurs during acute inflammation, which anticipates the neurodegenerative process. Thus, an increase in inflammatory cells in the affected regions is expected to add on mtDNA release into the CSF. In addition, similarly to bacterial DNA, the non-methylated CpG sites of mtDNA, which activate innate immunity and inflammation, are likely to participate in the molecular mechanisms of disease. Thus, ccf-mtDNA may represent a powerful biomarker for disease screening and prognosis at early stage, although its biological role may extend to generating the neurobiology of disease. The present manuscript discusses recent experimental findings in relationship with clinical evidence comparing neuro-immunological features of neurodegenerative disorders with frankly neuro-infectious diseases.

Cell Clearing Systems Bridging Neuro-Immunity and Synaptic Plasticity

In recent years, functional interconnections emerged between synaptic transmission, inflammatory/immune mediators, and central nervous system (CNS) (patho)-physiology. Such interconnections rose up to a level that involves synaptic plasticity, both concerning its molecular mechanisms and the clinical outcomes related to its behavioral abnormalities. Within this context, synaptic plasticity, apart from being modulated by classic CNS molecules, is strongly affected by the immune system, and vice versa. This is not surprising, given the common molecular pathways that operate at the cross-road between the CNS and immune system. When searching for a common pathway bridging neuro-immune and synaptic dysregulations, the two major cell-clearing cell clearing systems, namely the ubiquitin proteasome system (UPS) and autophagy, take center stage. In fact, just like is happening for the turnover of key proteins involved in neurotransmitter release, antigen processing within both peripheral and CNS-resident antigen presenting cells is carried out by UPS and autophagy. Recent evidence unravelling the functional cross-talk between the cell-clearing pathways challenged the traditional concept of autophagy and UPS as independent systems. In fact, autophagy and UPS are simultaneously affected in a variety of CNS disorders where synaptic and inflammatory/immune alterations concur. In this review, we discuss the role of autophagy and UPS in bridging synaptic plasticity with neuro-immunity, while posing a special emphasis on their interactions, which may be key to defining the role of immunity in synaptic plasticity in health and disease.

Increased serum pentraxin-3 level predicts poor prognosis in patients with colorectal cancer after curative surgery, a cohort study

Pentraxin-3 (PTX3) is a glycoprotein involved in inflammation and immune regulation of cancer. The aim of this study was to evaluate the serum PTX3 level in patients with colorectal cancer (CRC) and analyze its prognostic significance.A total of 263 consecutive patients underwent radical resection for primary CRC and 126 healthy controls were enrolled in this study. Serum PTX3 level was measured within the day before surgery though enzyme-linked immunosorbent assays, comparing with the level of healthy control. Baseline demographic and clinical characteristics were recorded. The association between serum PTX3 level and survival outcome was analyzed by the Kaplan-Meier with Log-Rank test and Cox regression methods.Mean serum PTX3 level in CRC patients was higher than that of healthy control (13.8 ± 3.2ng/mL versus 3.3 ± 1.2ng/mL, P < .001). Finally, 55 (20.9%) patients out of all 263 patients studied had died during following-up period. All patients were divided into 2 groups using the optimal cutoff value (12.6 ng/mL) of PTX3 level using a sensitivity of 68.0% and a specificity of 71.7% as optimal conditions from receiver operating curve analysis. Patients with a PTX3≥12.6ng/mL had poorer 5 years overall survival rate (76.6% versus 67.8%, P = .025) patients with a PTX3 < 12.6ng/mL in univariate analysis and serum PTX3 level also been confirmed as an independent predictor for survival for CRC in multivariate analysis (Hazard ratio, 1.468; 95% [confidence interval] CI, 1.081-1.976; P < .001).Serum PTX3 level can serve as an independent prognostic biomarker for CRC patients after curative resection.

Effects of 6 months of resveratrol versus placebo on pentraxin 3 in patients with type 2 diabetes mellitus: a double-blind randomized controlled trial

AIMS

The anti-inflammatory effects of the polyphenol resveratrol in patients with type 2 diabetes mellitus (T2DM) are controversial. Its role on pentraxin 3 (PTX3) concentrations, a human acute phase protein, has never been evaluated. Our aim was to determine whether a two-dosage resveratrol supplementation (500 and 40 mg/day) has an impact on PTX3 values in T2DM patients from a double-blind randomized placebo-controlled trial. Variations in total antioxidant status (TAS) were evaluated too.

METHODS

A total of 192 T2DM patients were randomized to receive resveratrol 500 mg/day (Resv 500 arm), resveratrol 40 mg/day (Resv 40 arm) or placebo for 6 months. At baseline and at the trial end, PTX3 and TAS values were determined.

RESULTS

A dose-dependent increase in PTX3 concentrations of 4.7% (Resv 40 arm) and 26.3% (Resv 500 arm), and 8.0% reduction after placebo were found. Adjusted mean differences of change versus placebo were 0.16 (95% CI 0.01-0.32) and 0.25 (0.09-0.42) in the Resv 40 and Resv 500 arms, respectively. At subgroup analyses, lower diabetes duration, aspirin, alcohol use, younger age, female gender, smoking (Resv 500 arm) and female gender and aspirin use (Resv 40 arm) were associated with higher PTX3 increments. A dose-dependent increment in TAS values in the resveratrol arms (1.4 and 6.4% for Resv 40 and Resv 500, respectively), and a reduction in placebo arm (-8.9%) were observed. Adjusted mean differences of change were 28.5 (95% CI 10.1-46.8) and 44.8 (25.4-64.1) in the Resv 40 and Resv 500 arms, respectively.

CONCLUSION

Resveratrol supplementation increased PTX3 and TAS levels in a dose-dependent manner in T2DM patients. At present, potential clinical implications of these results remain unclear. CLINICALTRIALS.

GOV IDENTIFIER

NCT02244879.

The inflammatory protein Pentraxin 3 in cardiovascular disease

The acute phase protein Pentraxin 3 (PTX3) plays a non-redundant role as a soluble pattern recognition receptor for selected pathogens and it represents a rapid biomarker for primary local activation of innate immunity and inflammation. Recent evidence indicates that PTX3 exerts an important role in modulating the cardiovascular system in humans and experimental models. In particular, there are conflicting points concerning the effects of PTX3 in cardiovascular diseases (CVD) since several observations indicate a cardiovascular protective effect of PTX3 while others speculate that the increased plasma levels of PTX3 in subjects with CVD correlate with disease severity and with poor prognosis in elderly patients.

In the present review, we discuss the multifaceted effects of PTX3 on the cardiovascular system focusing on its involvement in atherosclerosis, endothelial function, hypertension, myocardial infarction and angiogenesis. This may help to explain how the specific modulation of PTX3 such as the use of different dosing, time, and target organs could help to contain different vascular diseases. These opposite actions of PTX3 will be emphasized concerning the modulation of cardiovascular system where potential therapeutic implications of PTX3 in humans are discussed.

Emerging roles of the acute phase protein pentraxin-3 during central nervous system disorders

Pentraxin-3 (PTX3) is an acute phase protein (APP) and a member of the long pentraxin family that is recognised for its role in peripheral immunity and vascular inflammation in response to injury, infection and diseases such as atherosclerosis, cancer and respiratory disease. Systemic levels of PTX3 are highly elevated in these conditions, and PTX3 is now recognised as a new biomarker of disease risk and progression. There is extensive evidence demonstrating that central nervous system (CNS) disorders are primarily characterised by central activation of innate immunity, as well as activation of a potent peripheral acute phase response (APR) that influences central inflammation and contributes to poor outcome. PTX3 has been recently recognised to play important roles in CNS disorders, having both detrimental and neuroprotective effects. The present review aims to give an up-to-date account of the emerging roles of PTX3 in CNS disorders, and to provide a critical comparison between peripheral and central actions of PTX3 in inflammatory diseases.