Pancreatitis associated protein I (PAP-I) alters adhesion and motility of human melanocytes and melanoma cells

A novel peptide derived from human pancreatitis-associated protein inhibits inflammation in vivo and in vitro and blocks NF-kappa B signaling pathway

Background

Pancreatitis-associated protein (PAP) is a pancreatic secretory protein belongs to the group VII of C-type lectin family. Emerging evidence suggests that PAP plays a protective effect in inflammatory diseases. In the present study, we newly identified a 16-amino-acid peptide (named PAPep) derived from C-type lectin-like domain (CTLD) of human PAP with potent anti-inflammatory activity using both in vivo and in vitro assays.

Methodology/Principal Findings

We assessed the anti-inflammatory effect of PAPep on endotoxin-induced uveitis (EIU) in rats and demonstrated that intravitreal pretreatment of PAPep concentration-dependently attenuated clinical manifestation of EIU rats, reduced protein leakage and cell infiltration into the aqueous humor (AqH), suppressed tumor necrosis factor (TNF)-α, interleukin (IL)-6, intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein (MCP)-1 production in ocular tissues, and improved histopathologic manifestation of EIU. Furthermore, PAPep suppressed the LPS-induced mRNA expression of TNF-α and IL-6 in RAW 264.7 cells, inhibited protein expression of ICAM-1 in TNF-α-stimulated human umbilical vein endothelial cells (HUVECs) as well as U937 cells adhesion to HUVECs. Western blot analysis in ocular tissues and different cell lines revealed that the possible mechanism for this anti-inflammatory effect of PAPep may depend on its ability to inhibit the activation of NF-kB signaling pathway.

Conclusions/Significance

Our studies provide the first evidence that the sequence of PAPep is within the critically active region for the anti-inflammatory function of PAP and the peptide may be a promising candidate for the management of ocular inflammatory diseases.

PAP1 signaling involves MAPK signal transduction

Pancreatitis-associated protein 1 (PAP1) belongs to the Reg family of secretory proteins. Several important biological roles have been attributed to PAP1 but the signaling pathways activated by this protein remain only partially understood. Here, we describe the intracellular pathways triggered by PAP1 in a pancreatic acinar cell line. Taking advantage of the fact that PAP1 induces its own transcription, we performed ChIP assays to analyze the recruitment of transcriptional factors on its promoter. Our results show that PAP1 increased the transactivation activity of pap1 and the binding on its promoter of the nuclear factors C/EBPbeta, P-CREB, P-ELK1, EGR1, STAT3, and ETS2, which are downstream targets of MAPK signaling. p44/42, p38, and JNK MAPKs activity increased after PAP1 treatment. In addition, pharmacological inhibition of these kinases markedly inhibited the induction of pap1 mRNA. Taken together, these results indicated that the mechanism of PAP1 action involves the activation of the MAPK superfamily.

Expression of Reg/PAP family members during motor nerve regeneration in rat

In this study, we examined the expression of mRNAs for Regenerating gene (Reg)/pancreatitis-associated protein (PAP) family members following hypoglossal nerve injury in rats. In addition to four rat family members (RegI, Reg-2/PAP I, PAP II, and PAP III) that had been identified, we newly cloned and sequenced a type-IV Reg gene in rats. Among these five family members, the expression of Reg-2/PAP I mRNA was predominantly enhanced in injured motor neurons after axotomy. Furthermore, a marked induction of PAP III mRNA was observed in the distal part of the injured nerve. A polyclonal antibody was raised against PAP III, and a Western blotting analysis using this antibody confirmed an increased level of PAP III protein in the injured nerve. These results suggest that Reg family members would be new mediators among injured neurons and glial cells, and may play pivotal roles during nerve regeneration.

The multifunctional family of secreted proteins containing a C-type lectin-like domain linked to a short N-terminal peptide

PSP/Lithostathine/PTP/regI, PAP/p23/HIP, reg1L, regIV and "similar to PAP" are the members of a multifunctional family of secreted proteins containing a C-type lectin-like domain linked to a short N-terminal peptide. The expression of this group of proteins is controlled by complex mechanisms, some members being constitutively expressed in certain tissues while, in others, they require activation by several factors. These members have several apparently unrelated biological effects, depending on the member studied and the target cell. These proteins may act as mitogenic, antiapoptotic or anti-inflammatory factors, can regulate cellular adhesion, promote bacterial aggregation, inhibit CaCO3 crystal growth or increase resistance to antitumoral agents. The presence of specific receptors for these proteins is suggested because biological effects were observed after the addition of purified protein to culture media or after systemic administration to animals, whereas other biological effects could be explained by their biochemical capacity to form homo or heteromers or to form insoluble fibrils at physiological pH.

Melanocytic colonization of a meningothelial meningioma: histopathological and ultrastructural findings with immunohistochemical and genetic correlation: case report

OBJECTIVE AND IMPORTANCE

Melanocytic colonization of nonpigmented extracranial tumors has been reported in adenocarcinomas, squamous cell carcinomas, skin appendage tumors, and dermatofibrosarcoma protuberans. To our knowledge, melanocytic colonization of a meningioma has not previously been described.

CLINICAL PRESENTATION

We report an unusual case of a 70-year-old African-American woman who presented with a large frontoparietal meningioma that extended through the calvarium.

INTERVENTION

Craniotomy with gross total resection of the tumor was performed. Histochemistry, immunocytochemistry, ultrastructural analysis, and molecular genetic study via fluorescence in situ hybridization confirmed melanocytic colonization of a meningothelial meningioma.

CONCLUSION

With the inclusion of meningothelial meningioma, the spectrum of tumors affected by melanocytic colonization continues to expand.

The pancreatitis-associated protein induces lung inflammation in the rat through activation of TNFalpha expression in hepatocytes

The pancreatitis-associated protein (PAP) is a pancreatic stress protein overexpressed during acute pancreatitis, a disease often accompanied by lung inflammation. We investigated whether PAP was involved in the occurrence of this remote complication of pancreatitis and whether the liver might be implicated in the process. PAP was injected into the vena cava of rats (40 or 400 micro g/kg body weight). For comparison, pancreatitis was induced in rats by intraductal administration of sodium taurocholate. Three hours later, parameters of inflammation and mRNA concentrations of TNFalpha, P-selectin, heat shock protein (HSP)-70, and extracellular superoxide dismutase (EC-SOD) were monitored in lung and liver. Significant increases in P-selectin expression, neutrophil infiltration, and oxidative stress revealed that PAP treatment induced lung inflammation in rats and exacerbated inflammation in animals with pancreatitis. Plasma TNFalpha level was increased and TNFalpha mRNA was strongly overexpressed in liver, with concomitant activation of NF-kappaB; in situ hybridization revealed that TNFalpha overexpression was mainly located to hepatocytes. Lung inflammation induced by PAP could be prevented by injection of anti-TNFalpha antibodies. It was concluded that, during pancreatitis, PAP released by the pancreas could mediate lung inflammation through induction of hepatic TNFalpha expression and subsequent increase in circulating TNFalpha.

Genomic analysis of alachlor-induced oncogenesis in rat olfactory mucosa

Alachlor induces olfactory mucosal tumors in rats in a highly ordered temporal process. We used GeneChip analysis to test the hypothesis that histological progression and oncogenic transformation are accompanied by gene expression changes that might yield clues as to the molecular pathogenesis of tumor formation. Acute alachlor exposure caused upregulation of matrix metalloproteinases (MMP)-2 and -9, tissue inhibitor of metalloproteinase-1, carboxypeptidase Z, and other genes related to extracellular matrix homeostasis. Heme oxygenase was upregulated acutely and maintained elevated expression. Expression of ebnerin, related to the putative human tumor suppressor gene DMBT1, progressively increased in alachlor-treated olfactory mucosa. Progression from adenomas to adenocarcinoma was correlated with upregulation of genes in the wnt signaling pathway. Activated wnt signaling was confirmed by immunohistochemical localization of beta-catenin to nuclei of adenocarcinomas, but not earlier lesions. These observations suggest that initiation and progression of alachlor-induced olfactory mucosal tumors is associated with alterations in extracellular matrix components, induction of oxidative stress, upregulation of ebnerin, and final transformation to a malignant state by wnt pathway activation.

Identification by cDNA microarray technology of genes modulated by artificial ultraviolet radiation in normal human melanocytes: relation to melanocarcinogenesis

Target genes of ultraviolet stress response in cutaneous melanocytes, potentially associated with solar-induced melanocarcinogenesis, were characterized by cDNA microarray technology. In cultured normal human melanocytes, 198 genes out of approximately 9000 arrayed were found modulated > or = 1.9 times following artificial ultraviolet minus sign mainly ultraviolet-B minus sign irradiation (100 mJ per cm(2)). Among them, 159 corresponded to known sequences, the encoded proteins being mostly involved in DNA or RNA binding/synthesis/modification, or ribosomal proteins. The others were transcription factors, receptors, tumor suppressors, and (proto)oncogenes. Members of these families have already been linked to melanoma. In addition, some of the modulated genes were borne by chromosomes harboring candidate melanoma loci. Comparisons with genes modified in melanoma samples reported in previous studies with similar microarray platform showed that 59% of the known genes sensitive to ultraviolet were modulated in the same way. Furthermore, 39 expressed sequence tags were modulated, and preliminary experiments showed that two expressed sequence tags displayed differential expressions both in melanoma cell lines and in melanoma tumors. These results provide a basis for further studies on the role of modulated genes in ultraviolet-induced melanoma. Because some of these genes are potential markers of the disease, they might help for developing new molecular-based strategies for risk prediction in patients.