Inhibition of Pim-1 kinase ameliorates dextran sodium sulfate-induced colitis in mice

The role of Pim-1 kinases in inflammatory signaling pathways

OBJECTIVE AND DESIGN

This observational study investigated the regulatory mechanism of Pim-1 in inflammatory signaling pathways.

MATERIALS

THP-1, RAW 264.7, BV2, and Jurkat human T cell lines were used.

TREATMENT

None.

METHODS

Lipopolysaccharide (LPS) was used to induce inflammation, followed by PIM1 knockdown. Western blot, immunoprecipitation, immunofluorescence, and RT-PCR assays were used to assess the effect of PIM1 knockdown on LPS-induced inflammation.

RESULTS

PIM1 knockdown in macrophage-like THP-1 cells suppressed LPS-induced upregulation of pro-inflammatory cytokines, inducible nitric oxide synthase, cyclooxygenase-2, phosphorylated Janus kinase, signal transducer and activator of transcription 3, extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and nuclear factor kappa B p65 (NF-κB p65). It also suppressed upregulation of inhibitor of NF-κB kinase α/β and enhanced the nuclear translocation of NF-κB p65. Moreover, it inhibited the upregulation of Nod-like receptor family pyrin domain-containing 3 (NLRP3) and cleavage of caspase-1 induced by co-treatment of LPS with adenosine triphosphate. Additionally, p-transforming growth factor-β-activated kinase 1 (TAK1) interacted with Pim-1. All three members of Pim kinases (Pim-1, Pim-2, and Pim-3) were required for LPS-mediated inflammation in macrophages; however, unlike Pim-1 and Pim-3, Pim-2 functioned as a negative regulator of T cell activity.

CONCLUSIONS

Pim-1 interacts with TAK1 in LPS-induced inflammatory responses and is involved in MAPK/NF-κB/NLRP3 signaling pathways. Additionally, considering the negative regulatory role of Pim-2 in T cells, further in-depth studies on their respective functions are needed.

PIM1 signaling in immunoinflammatory diseases: an emerging therapeutic target

PIM1, the proviral integration site for Moloney murine leukemia virus, is a member of the serine/threonine protein kinase family. It is involved in many biological events, such as cell survival, cell cycle progression, cell proliferation, and cell migration, and has been widely studied in malignant diseases. However, recent studies have shown that PIM1 plays a prominent role in immunoinflammatory diseases, including autoimmune uveitis, inflammatory bowel disease, asthma, and rheumatoid arthritis. PIM1 can function in inflammatory signal transduction by phosphorylating multiple inflammatory protein substrates and mediating macrophage activation and T lymphocyte cell specification, thus participating in the development of multiple immunoinflammatory diseases. Moreover, the inhibition of PIM1 has been demonstrated to ameliorate certain immunoinflammatory disorders. Based on these studies, we suggest PIM1 as a potential therapeutic target for immunoinflammatory diseases and a valid candidate for future research. Herein, for the first time, we provide a detailed review that focuses on the roles of PIM1 in the pathogenesis of immunoinflammatory diseases.

PIM1-HDAC2 axis modulates intestinal homeostasis through epigenetic modification

The mucosal barrier is crucial for intestinal homeostasis, and goblet cells are essential for maintaining the mucosal barrier integrity. The proviral integration site for Moloney murine leukemia virus-1 (PIM1) kinase regulates multiple cellular functions, but its role in intestinal homeostasis during colitis is unknown. Here, we demonstrate that PIM1 is prominently elevated in the colonic epithelia of both ulcerative colitis patients and murine models, in the presence of intestinal microbiota. Epithelial PIM1 leads to decreased goblet cells, thus impairing resistance to colitis and colitis-associated colorectal cancer (CAC) in mice. Mechanistically, PIM1 modulates goblet cell differentiation through the Wnt and Notch signaling pathways. Interestingly, PIM1 interacts with histone deacetylase 2 (HDAC2) and downregulates its level via phosphorylation, thereby altering the epigenetic profiles of Wnt signaling pathway genes. Collectively, these findings investigate the unknown function of the PIM1-HDAC2 axis in goblet cell differentiation and ulcerative colitis/CAC pathogenesis, which points to the potential for PIM1-targeted therapies of ulcerative colitis and CAC.

Endoplasmic reticulum stress is upregulated in inflammatory bowel disease and contributed TLR2 pathway-mediated inflammatory response

OBJECTIVE

Endoplasmic reticulum stress (ERS) and Toll-like receptor 2 (TLR2) signaling play an important role in inflammatory bowel disease (IBD); however, the link between TLR2 and ERS in IBD is unclear. This study investigated whether Thapsigargin (TG) -induced ER protein expression levels contributed to TLR2-mediated inflammatory response.

METHODS

The THP-1 cells were treated with TLR2 agonist (Pam3CSK4), ERS inducer Thapsigargin (TG) or inhibitor (TUDCA). The mRNA expressions of TLR1-TLR10 were detected by qPCR. The production and secretion of inflammatory factors were detected by PCR and ELISA. Immunohistochemistry was used to detect the expressions of GRP78 and TLR2 in the intestinal mucosa of patients with Crohn's disease (CD). The IBD mouse model was established by TNBS in the modeling group. ERS inhibitor (TUDCA) was used in the treatment group.

RESULTS

The expression of TLRs was detected via polymerase chain reaction (PCR) in THP-1 cells treated by ERS agonist Thapsigargin (TG). According to the findings, TG could promote TLR2 and TLR5 expression. Subsequently, in TLR2 agonist Pam3CSK4 induced THP-1 cells, TG could lead to increased expression of the inflammatory factors such as TNF-α, IL-1β and IL-8, and ERS inhibitor (TUDCA) could block this effect. However, Pam3CSK4 did not significantly impact the GRP78 and CHOP expression. Based upon the immunohistochemical results, TLR2 and GRP78 expression were significantly increased in the intestinal mucosa of patients with Crohn's disease (CD). For in vivo experiments, TUDCA displayed the ability to inhibit intestinal mucosal inflammation and reduce GRP78 and TLR2 proteins.

CONCLUSIONS

ERS and TLR2 is upregulated in inflammatory bowel disease, ERS may promote TLR2 pathway-mediated inflammatory response. Moreover, ERS and TLR2 signaling could be novel therapeutic targets for IBD.

Mesenchymal stem cells attenuate systemic lupus erythematosus by inhibiting NLRP3 inflammasome activation through Pim-1 kinase

The inflammatory response runs through the whole pathogenesis of systemic lupus erythematosus (SLE). Mesenchymal stem cells (MSC) have exhibited a positive therapeutic effect on SLE. This study aimed to ascertain the pathogenic role of inflammasome activation in SLE and whether MSC alleviate SLE by suppressing it. The results showed that the nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasome was activated in macrophages from MRL/lpr mice and patients with SLE, correlating with disease activity. After MSC transplantation, the disease severity in MRL/lpr mice was alleviated, and NLRP3 inflammasome activation was inhibited with decreased levels of NLRP3 and caspase-1 in macrophages. Furthermore, lower serum levels of interleukin (IL)-1β and IL-18 were observed in patients with SLE who underwent MSC transplantation. In vitro and in vivo studies indicated that MSC suppressed NLRP3 inflammasome activation by inhibiting Pim-1 expression. The findings provide an updated view of inflammasome signaling in SLE. Additionally, MSC ameliorated SLE by inhibiting NLRP3 inflammasome activation, implying a possible molecular mechanism for the clinical application of MSC and a potential therapeutic target in patients with SLE.

Three Distinct Transcriptional Profiles of Monocytes Associate with Disease Activity in Scleroderma Patients

OBJECTIVE

Patients with diffuse cutaneous systemic sclerosis (dcSSc) display a complex clinical phenotype. Transcriptional profiling of whole blood or tissue from patients are affected by changes in cellular composition that drive gene expression and an inability to detect minority cell populations. We undertook this study to focus on the 2 main subtypes of circulating monocytes, classical monocytes (CMs) and nonclassical monocytes (NCMs) as a biomarker of SSc disease severity.

METHODS

SSc patients were recruited from the Prospective Registry for Early Systemic Sclerosis. Clinical data were collected, as well as peripheral blood for isolation of CMs and NCMs. Age-, sex-, and race-matched healthy volunteers were recruited as controls. Bulk macrophages were isolated from the skin in a separate cohort. All samples were assayed by RNA sequencing (RNA-seq).

RESULTS

We used an unbiased approach to cluster patients into 3 groups (groups A-C) based on the transcriptional signatures of CMs relative to controls. Each group maintained their characteristic transcriptional signature in NCMs. Genes up-regulated in group C demonstrated the highest expression compared to the other groups in SSc skin macrophages, relative to controls. Patients from groups B and C exhibited worse lung function than group A, although there was no difference in SSc skin disease at baseline, relative to controls. We validated our approach by applying our group classifications to published bulk monocyte RNA-seq data from SSc patients, and we found that patients without skin disease were most likely to be classified as group A.

CONCLUSION

We are the first to show that transcriptional signatures of CMs and NCMs can be used to unbiasedly stratify SSc patients and correlate with disease activity outcome measures.

Targeting PIM Kinases to Improve the Efficacy of Immunotherapy

The Proviral Integration site for Moloney murine leukemia virus (PIM) kinases is a family of serine/threonine kinases that regulates numerous signaling networks that promote cell growth, proliferation, and survival. PIM kinases are commonly upregulated in both solid tumors and hematological malignancies. Recent studies have demonstrated that PIM facilitates immune evasion in cancer by promoting an immunosuppressive tumor microenvironment that suppresses the innate anti-tumor response. The role of PIM in immune evasion has sparked interest in examining the effect of PIM inhibition in combination with immunotherapy. This review focuses on the role of PIM kinases in regulating immune cell populations, how PIM modulates the immune tumor microenvironment to promote immune evasion, and how PIM inhibitors may be used to enhance the efficacy of immunotherapy.

Inhibition of CEBPB Attenuates Lupus Nephritis via Regulating Pim-1 Signaling

Systemic lupus erythematosus (SLE) is an autoimmune disease leading to inflammatory damage in multiple target organs, and lupus nephritis (LN) is one of the most life-threatening organ manifestations. CCAAT/enhancer-binding protein β (CEBPB) regulates the NLRP3 inflammasome and is involved in the pathogenesis of SLE. However, the role and mechanism of CEBPB in LN remains unclear. MRL/lpr mice and lipopolysaccharides (LPS) combined with adenosine triphosphate- (ATP-) treated glomerular podocytes were used as models of LN in vivo and in vitro, respectively. In vivo, we investigated the expressions of CEBPB during the development of MRL/lpr mice. Then we assessed the effect of CEBPB inhibition on renal structure and function through injecting shCEBPB lentivirus into MRL/lpr mice. In vitro, glomerular podocytes were treated with Pim-1-OE and siCEBPB to explore the relation between CEBPB and Pim-1. The progression of LN in mice was associated with the increased level of CEBPB, and the inhibition of CEBPB ameliorated renal structure impairments and improved renal function damage associated with LN. Knockdown of CEBPB could suppress the activation of NLRP3 inflammasome and the secretion of IL-1β and IL-6. Furthermore, the knockdown of CEBPB could inhibit NLRP3 inflammasome activation and pyroptosis via binding to Pim-1 promoter to downregulate its expression, and the overexpression of Pim-1 reversed the effects of CEBPB deficiency. The regulation of CEBPB on Pim-1 facilitated pyroptosis by activating NLRP3 inflammasome, thereby promoting the development of LN.

Targeting Lineage-Specific Transcription Factors and Cytokines of the Th17/Treg Axis by Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]pyridazinone Attenuates TNBS-Induced Experimental Colitis

The pharmacotherapy of inflammatory bowel disease (IBD) is still not fully effective and safe. Attempts to search for new IBD drugs remain an incessant research aim. One of the novel approaches is targeting the developmental pathway molecules and effector cytokines of Th17/Treg axis. This study aimed to elucidate the impact of new pyrrolo[3,4-d]pyridazinone derivatives, compounds 7b, 10b, or 13b, on the course of experimental colitis in rats and to assess whether these new compounds may influence Th17/Treg axis. Rats were pretreated with studied compounds intragastrically before intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid used for colitis induction. Body weight loss, disease activity index, colon index, and colon tissue damage were analyzed to evaluate the severity of colitis. The colonic levels of RORγt, STAT3, CCR6, Foxp3, IL-6, IL-10, IL-17, TNF-α, IL-23, and PGE₂ were assessed. Pretreatment with compounds 7b and 13b alleviated the severity of colitis and concomitantly counteracted the increased levels of RORγt, STAT3, CCR6, IL-6, IL-17, IL-23, TNF-α, and PGE₂. The beneficial effect of compounds 7b and 13b may be due to the decrease in the levels of Th17-specific transcription factors and cytokines. The studied compounds might therefore constitute a promising therapeutic strategy in Th17/Treg imbalance-driven inflammatory conditions such as IBD.

The Role of NLRP3 Inflammasome in Lupus Nephritis

Lupus nephritis (LN) is the most frequent and severe of systemic lupus erythematosus (SLE) clinical manifestations and contributes to the increase of morbidity and mortality of patients due to chronic kidney disease. The NLRP3 (NLR pyrin domain containing 3) is a member of the NLR (NOD-like receptors), and its activation results in the production of pro-inflammatory cytokines, which can contribute to the pathogenesis of LN. In this review manuscript, we approach the relation between the NLRP3 inflammasome, SLE, and LN, highlighting the influence of genetic susceptibility of NLRP3 polymorphisms in the disease; the main functional studies using cellular and animal models of NLRP3 activation; and finally, some mechanisms of NLRP3 inhibition for the development of possible therapeutic drugs for LN.

Targeting PIM Kinases to Overcome Therapeutic Resistance in Cancer

Cancer progression and the onset of therapeutic resistance are often the results of uncontrolled activation of survival kinases. The proviral integration for the Moloney murine leukemia virus (PIM) kinases are oncogenic serine/threonine kinases that regulate tumorigenesis by phosphorylating a wide range of substrates that control cellular metabolism, proliferation, and survival. Because of their broad impact on cellular processes that facilitate progression and metastasis in many cancer types, it has become clear that the activation of PIM kinases is a significant driver of resistance to various types of anticancer therapies. As a result, efforts to target PIM kinases for anticancer therapy have intensified in recent years. Clinical and preclinical studies indicate that pharmacologic inhibition of PIM has the potential to significantly improve the efficacy of standard and targeted therapies. This review focuses on the signaling pathways through which PIM kinases promote cancer progression and resistance to therapy, as well as highlights biological contexts and promising strategies to exploit PIM as a therapeutic target in cancer.

Discovery of SARxxxx92, a pan-PIM kinase inhibitor, efficacious in a KG1 tumor model

N-substituted azaindoles were discovered as potent pan-PIM inhibitors. Lead optimization, guided by structure and focused on physico-chemical properties allowed us to solve inherent hERG and permeability liabilities, and provided compound 27, which subsequently impacted KG-1 tumor growth in a mouse model.

Anti-Inflammatory Effects of the Novel PIM Kinase Inhibitor KMU-470 in RAW 264.7 Cells through the TLR4-NF-κB-NLRP3 Pathway

PIM kinases, a small family of serine/threonine kinases, are important intermediates in the cytokine signaling pathway of inflammatory disease. In this study, we investigated whether the novel PIM kinase inhibitor KMU-470, a derivative of indolin-2-one, inhibits lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells. We demonstrated that KMU-470 suppressed the production of nitric oxide and inducible nitric oxide synthases that are induced by LPS in RAW 264.7 cells. Furthermore, KMU-470 inhibited LPS-induced up-regulation of TLR4 and MyD88, as well as the phosphorylation of IκB kinase and NF-κB in RAW 264.7 cells. Additionally, KMU-470 suppressed LPS-induced up-regulation at the transcriptional level of various pro-inflammatory cytokines such as IL-1β, TNF-α, and IL-6. Notably, KMU-470 inhibited LPS-induced up-regulation of a major component of the inflammasome complex, NLRP3, in RAW 264.7 cells. Importantly, PIM-1 siRNA transfection attenuated up-regulation of NLRP3 and pro-IL-1β in LPS-treated RAW 264.7 cells. Taken together, these findings indicate that PIM-1 plays a key role in inflammatory signaling and that KMU-470 is a potential anti-inflammatory agent.

VPR-254: an inhibitor of ROR-gamma T with potential utility for the treatment of inflammatory bowel disease

INTRODUCTION

Retinoic Acid Related Orphan Nuclear Receptor gamma T (RORγT) is a lineage specifying transcription factor for IL-17 expressing cells, which may contribute to the pathogenesis of Inflammatory Bowel Disease (IBD). VPR-254 is a selective in vitro inhibitor of RORγT.

AIMS

The main goals of our study were twofold: (1) To determine if ex vivo treatment with VPR-254 reduced relevant cytokine (IL-17 and IL-21) secretion from colonic strips of mice with colitis; (2) To determine if treatment of mice with VPR-254 attenuated parameters of colitis, using three murine IBD models.

METHODS

VPR-254 was evaluated ex vivo in a colonic strip assay, using tissue from mice with Dextran sulfate sodium (DSS)-induced colitis. In vivo, VPR-254 was evaluated for efficacy in DSS, Trintirobenzenesulfonic acid (TNBS) and Anti-CD40 antibody-induced murine models of colitis.

RESULTS

VPR-254 reduced the production of key pro-inflammatory cytokines (e.g., IL-17) in ex vivo and in vivo models of colitis. This small molecule inhibitor of RORγT also improved various morphometric and histological parameters associated with three diverse murine models of IBD.

CONCLUSION

Our results support the concept that an inhibitor of ROR-gamma T may have potential utility for the treatment of IBD.

Downregulation of microRNA-214 improves therapeutic potential of allogeneic bone marrow-derived mesenchymal stem cell by targeting PIM-1 in rats with acute liver failure

Acute liver failure (ALF) is a disease resulted from diverse etiology, which generally leads to a rapid degenerated hepatic function. However, transplantation bone marrow-derived mesenchymal stem cells (BMSCs) transplantation has been suggested to relieve ALF. Interestingly, microRNA-214 (miR-214) could potentially regulate differentiation and migration of BMSCs. The present study aims to inquire whether miR-214 affects therapeutic potential of BMSCs transplantation by targeting PIM-1 in ALF. 120 male Wistar rats were induced as ALF model rats and transplanted with BMSCs post-alteration of miR-214 or PIM-1 expression. Further experiments were performed to detect biochemical index (alanine aminotransferase [ALT], aspartate transaminase [AST], total bilirubin [TBiL]), and expression of miR-214, PIM-1, hepatocyte growth factor (HGF), caspase 3, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) in rat serum. Apart from the above detection, apoptosis of hepatocytes and Ki67 protein expression in hepatic tissues of rats were additionally assessed. After BMSCs transplantation with miR-214 inhibition, a decreased expression of ALT, AST, and TBiL yet an increased expression of HGF was shown, coupled with a decline in the expression of caspase 3, TNF-α, and IL-10. Meanwhile, alleviated hepatic injury and decreased apoptotic index of hepatic cells were observed and the positive rate of Ki67 protein expression was significantly increased. Moreover, miR-214 and caspase 3, TNF-α, and IL-10 decreased notably, while PIM-1 was upregulated in response to miR-214 inhibition. Strikingly, the inhibition of PIM-1 reversed effects triggered by miR-214 inhibition. These findings indicated that downregulation of miR-214 improves therapeutic potential of BMSCs transplantation by upregulating PIM-1 for ALF.

Pim-1 as a Therapeutic Target in Lupus Nephritis

OBJECTIVE

Lupus nephritis (LN) is a major determinant of morbidity and mortality in systemic lupus erythematosus (SLE). Pim-1 regulates lymphocyte proliferation and activation. The role of Pim-1 in autoimmune disease remains unclear. This study was undertaken to test the hypothesis that inhibition of Pim-1 would have therapeutic potential in patients with LN.

METHODS

Pim-1 expression was analyzed in lupus-prone (NZB × NZW)F1 mice (n = 6), human peripheral blood mononuclear cells (PBMCs) from SLE patients (n = 10), and glomeruli from patients with LN (n = 8). The therapeutic effect of the Pim-1 inhibitor AZD1208 was assessed in the same murine lupus model (n = 10 mice per group). In vitro analysis was conducted to explore the mechanisms of action of Pim-1 in mouse and human podocytes after Pim-1 expression had been induced by anti-double-stranded DNA (anti-dsDNA) antibody-positive serum. Finally, MRL/lpr mice were used to confirm the therapeutic effects of Pim-1 inhibition in vivo (n = 10 mice per group).

RESULTS

Up-regulation of Pim-1 was seen in renal lysates from diseased (NZB × NZW)F1 mice and in PBMCs from patients with SLE and renal biopsy tissue from patients with LN, relative to their control counterparts (each P < 0.05). The Pim-1 inhibitor AZD1208 reduced the severity of proteinuria, glomerulonephritis, renal immune complex deposits, and serum anti-dsDNA antibody levels, concomitant with the suppression of NFATc1 expression and NLRP3 inflammasome activation, in diseased (NZB × NZW)F1 mice (each P < 0.05 versus controls). Moreover, in mouse and human podocytes, Pim-1 knockdown with targeted small interfering RNA (siRNA) suppressed NFATc1 and NLRP3 inflammasome signaling in the presence of anti-dsDNA-positive serum (each P < 0.05 versus control siRNA). Mechanistically, Pim-1 modulated NLRP3 inflammasome activation through intracellular Ca²⁺ (P < 0.05 versus normal controls). The therapeutic effect of Pim-1 blockade was replicated in MRL/lpr mice.

CONCLUSION

These data identify Pim-1 as a critical regulator of LN pathogenesis in patients with SLE. Targeting of the Pim-1/NFATc1/NLRP3 pathway might therefore have therapeutic potential in human LN.

PIM1 inhibitor SMI-4a attenuated lipopolysaccharide-induced acute lung injury through suppressing macrophage inflammatory responses via modulating p65 phosphorylation

PIM kinase is involved in the cellular processes of growth, differentiation and apoptosis. However, the role of PIM1 in lipopolysaccharide (LPS)-induced acute lung injury (ALI) remains largely unknown. A trend of PIM1 in the lung tissue of LPS-induced ALI at different time points was detected. Histology, wet/dry (W/D) ratio, inflammatory cells in the bronchoalveolar lavage fluid (BALF) and survival rate analyses were performed when mice received the PIM1 inhibitor SMI-4a intratracheally 3 h before LPS administration. Cytokine production in vivo and in vitro was measured after SMI-4a pretreatment. NF-κB subunit p65 expression in nuclei and phosphorylation at Ser276 in lung tissues or cells were detected by Western blot analysis. The results showed that PIM1 mRNA and protein were upregulated in the lung tissue of LPS-induced ALI. The PIM1 inhibitor SMI-4a markedly improved the survival rate after lethal LPS administration, reduced the severity of lung edema, attenuated the histologic injuries of the lung tissue and reduced the counts of infiltrated inflammatory cells in the BALF. The PIM1 inhibitor SMI-4a suppressed the production of cytokines in LPS-treated RAW264.7 cell supernatants and BALF. Furthermore, LPS administration upregulated the levels of nuclear p65 and phosphorylated p65 (p-p65) at Ser276, whereas pretreatment with the PIM1 inhibitor SMI-4a reduced p65 upregulation in the nucleus and p-p65 at Ser276. Taken together, these data indicate that the PIM1 inhibitor SMI-4a may serve as a promising therapeutic strategy for LPS-induced ALI by suppressing macrophage production of cytokines via a reduction of p65 activities.

Discovery of N-substituted 7-azaindoles as Pan-PIM kinases inhibitors - Lead optimization - Part III

N-substituted azaindoles were discovered as promising pan-PIM inhibitors. Lead optimization is described en route toward the identification of a clinical candidate. Modulation of physico-chemical properties allowed to solve inherent hERG and permeability liabilities. Compound 17 showed tumor growth inhibition in a KG1 tumor-bearing mouse model.

Exclusive enteral nutrition protects against inflammatory bowel disease by inhibiting NF‑κB activation through regulation of the p38/MSK1 pathway

Although enteral nutrition therapy for inflammatory bowel disease has been confirmed to be an effective treatment method, the exact mechanism responsible for the effects of enteral nutrition remains unclear. The aim of the present study was to investigate the protective effect of exclusive enteral nutrition (EEN) against colitis, and to elucidate the potential mechanisms by inhibiting p65 activation via regulating the p38/mitogen‑ and stress‑activated protein kinase‑1 (MSK1) pathway. Experiments were performed by establishing dextran sulfate sodium (DSS)‑mice colitis and picrylsulfonic acid solution (TNBS)‑induced rat colitis, and the results demonstrated that EEN treatment attenuated body weight loss, colon length shortening and colonic pathological damage caused by colitis. EEN also inhibited inflammatory cells infiltration and decreased myeloperoxidase and inducible nitric oxide synthase activities. Furthermore, EEN significantly reduced the production of pro‑inflammatory mediators in serum and the colon. Mechanically, EEN suppressed activation of p65 by inhibiting the p38/MSK1 pathway. In conclusion, the present study demonstrated that EEN attenuated DSS‑ and TNBS‑induced colitis by inhibiting p65 activation via regulating the p38/MSK1 pathway, thus suggesting that EEN is effective in the treatment of colitis.

Inhibition of PIM1 kinase attenuates inflammation-induced pro-labour mediators in human foetal membranes in vitro

STUDY QUESTION

Does proviral integration site for Moloney murine leukaemic virus (PIM)1 kinase play a role in regulating the inflammatory processes of human labour and delivery?

SUMMARY ANSWER

PIM1 kinase plays a critical role in foetal membranes in regulating pro-inflammatory and pro-labour mediators.

WHAT IS KNOWN ALREADY

Infection and inflammation have strong causal links to preterm delivery by stimulating pro-inflammatory cytokines and collagen degrading enzymes, which can lead to rupture of membranes. PIM1 has been shown to have a role in immune regulation and inflammation in non-gestational tissues; however, its role has not been explored in the field of human labour.

STUDY DESIGN, SIZE, DURATION

PIM1 expression was analysed in myometrium and/or foetal membranes obtained at term and preterm (n = 8-9 patients per group). Foetal membranes, freshly isolated amnion cells and primary myometrial cells were used to investigate the effect of PIM1 inhibition on pro-labour mediators (n = 5 patients per treatment group).

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Foetal membranes, from term and preterm, were obtained from non-labouring and labouring women, and from preterm pre-labour rupture of membranes (PPROM) (n = 9 per group). Amnion was collected from women with and without preterm chorioamnionitis (n = 8 per group). Expression of PIM1 kinase was determined by qRT-PCR and western blotting. To determine the effect of PIM1 kinase inhibition on the expression of pro-inflammatory and pro-labour mediators induced by bacterial products lipopolysaccharide (LPS) (10 μg/ml) and flagellin (1 μg/ml) and pro-inflammatory cytokine tumour necrosis factor (TNF) (10 ng/ml), chemical inhibitors SMI-4a (20 μM) and AZD1208 (50 μM) were used in foetal membrane explants and siRNA against PIM1 was used in primary amnion cells. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

PIM1 expression was significantly increased in foetal membranes after spontaneous term labour compared to no labour at term and in amnion with preterm chorioamnionitis compared to preterm with no chorioamnionitis. There was no change in PIM1 expression with preterm labour or PPROM compared to preterm with no labour or PPROM. In human foetal membranes, PIM1 inhibitors SMI-4a and AZD1208 significantly decreased the expression of pro-inflammatory cytokine interleukin-6 (IL6) and chemokines CXCL8 and CCL2 mRNA and release, prostaglandin prostaglandin F2α (PGF2α) release, adhesion molecule intercellular adhesion molecule 1 mRNA expression and release, and oxidative stress marker 8-isoprostane release after stimulation with either LPS or flagellin. Primary amnion cells transfected with PIM1 siRNA also showed decreased expression of IL6, CXCL8 and CCL2, PTGS2 mRNA and PGF2α release, and matrix metalloproteinase-9 (MMP9) expression, when stimulated with TNF.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The conclusions were drawn from in vitro experiments using foetal membrane explants and primary cells isolated from amnion. Animal models are necessary to determine whether PIM1 kinase inhibitors can prevent spontaneous preterm birth in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

PIM1 kinase inhibitors may provide a novel therapeutic approach for preventing spontaneous preterm birth.

STUDY FUNDING/COMPETING INTEREST(S)

Associate Professor Martha Lappas is supported by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; grant no. 1047025). Funding for this study was provided by the NHMRC (grant no. 1058786), Norman Beischer Medical Research Foundation and the Mercy Research Foundation. The authors have no conflict of interest.

Identification and molecular characterization of the Pim1 serine/threonine kinase homolog in Litopenaeus vannamei

The Pim1 serine/threonine kinase is associated with multiple cellular functions including proliferation, survival, differentiation, apoptosis, tumorigenesis, immune regulation and inflammation in vertebrates. However, little is known about the role of Pim1 in invertebrate immunity. In this study, we identified and characterized for the first time, a Pim1 (LvPim1) gene in Litopenaeus vannamei, with a full-length cDNA of 2352 bp and a 1119 bp open reading frame (ORF) encoding a putative protein of 372 amino acids, which contains a typical serine/threonine kinase domain. Sequence and phylogenetic analysis revealed that LvPim1 shared a close evolutionary relationship with Pim1 from vertebrates. Real-time qPCR analysis showed that LvPim1 was widely expressed in all tissues tested; with its transcript level induced in hepatopancreas and hemocytes upon challenge with Vibrio parahaemolyticus, Streptoccocus iniae, lipopolysaccharide (LPS), and white spot syndrome virus (WSSV), thus, suggesting its probable involvement in shrimp immune response. Moreover, knockdown of LvPim1 resulted in increased hemocytes apoptosis; shown by high caspase3/7 activity, coupled with increase in pro-apoptotic LvCaspase3 and LvCytochrome C, and decrease in pro-survival LvBcl2, LvIAP1, and LvIAP2 mRNA expression in hemocytes. Finally, LvPim1 knockdown renders shrimps more susceptible to V. parahaemolyticus infection. Taken together, our present data strongly suggest that LvPim1 is involved in modulating shrimp resistance to pathogen infection, promote hemocytes survival, and therefore plays a role in shrimp immune response.

Discovery of N-substituted 7-azaindoles as Pan-PIM kinase inhibitors - Lead series identification - Part II

N-Substituted azaindoles have been discovered as pan-PIM kinase inhibitors. Initial SAR, early ADME and PK/PD data of a series of compounds is described and led to the identification of promising pan-PIM inhibitors which validated our interest in the 7-azaindole scaffold and led us to pursue the identification of a clinical candidate.

Placental Pim-1 expression is increased in obesity and regulates cytokine- and toll-like receptor-mediated inflammation

INTRODUCTION

Obesity is a growing epidemic, and as a consequence the number of obese pregnancies has also increased. Pregnancy is characterised by maternal and placental inflammation which is intensified with maternal obesity. The proviral integration site for Moloney murine leukemic virus (Pim)-1 protein is a serine/threonine kinase involved in a wide range of inflammatory diseases. In relation to obesity, however, its role has not been elucidated in human placenta. The aims were to determine the placental expression of Pim-1 with pre-existing maternal obesity and its role in regulating placental inflammation associated with obesity.

METHODS

Human placenta was obtained at the time of term Caesarean section from lean and pre-existing obese pregnant women to determine the effect of maternal obesity on Pim-1 expression. To determine the effect of Pim-1 on the inflammatory response induced by bacterial endotoxin LPS and pro-inflammatory cytokines TNF-α or IL-1β, the chemical inhibitor SMI-4a and siRNA were used.

RESULTS

Pim-1 protein and mRNA expression was significantly increased in placenta of obese women. SMI-4a significantly suppressed the expression and release of pro-inflammatory cytokine IL-6 and chemokines GRO-α and MCP-1 when stimulated with LPS or TNF-α in placenta. Primary trophoblast cells transfected with Pim-1 siRNA had decreased expression and release of pro-inflammatory cytokines IL-1β, IL-6, chemokines GRO-α and MCP-1, when stimulated with LPS, TNF-α or IL-1β.

DISCUSSION

The findings from this study implicate Pim-1 may contribute to placental inflammation in pregnancies complicated by maternal obesity. Thus, therapeutic targets for Pim-1 may improve fetal outcomes complicated by obese pregnancies.

Expression of Pim-1 in classically activated macrophages induced with lipopolysaccharides

AIM: To explore the expression of Pim-1 mRNA and protein during the activation of macrophage and to assess whether inhibition of four key signaling molecules phosphatidylinositol 3-kinase (PI3K), P38 mitogen-activated protein kinase (P38MAPK), Janus kinase 2 (JAK2), and ERK kinase (MEK1/2) may influence the expression of Pim-1 protein.

METHODS: Pim-1 mRNA and protein expression was examined by real-time PCR and Western blot, respectively, in macrophage cells treated with lipopolysaccharides (LPS) for 0, 1, 2, 4, 8, 12, and 24 h. After macrophage cells were treated with inhibitor of PI3K (LY294002), P38MAPK (SB203580), MEK1/2 (AG490) or JAK2 (AG490), LPS induced up-regulation of Pim-1 expression was examined by Western blot.

RESULTS: Expression of Pim-1 changed with the time of LPS treatment. Pim-1 mRNA and protein expression was rapidly induced after LPS treatment for 1 h. Pim-1 mRNA expression reached the peak at 2 h (six-fold of the basal level), and fell back to the basal level at 12 h. Pim-1 expression was on the constant rise from 1 h to 8 h, and dropped to the basic level at 12 h. All inhibitors of the four key signaling molecules down-regulated LPS induced expression of Pim-1 protein.

CONCLUSION: Up-regulation of Pim-1 is an early event of classical activation of macrophages. Inhibitors for PI3K, P38MAPK, JAK2 and MEK1/2 suppress Pim-1 protein expression. Pim-1 may be the downstream signal molecule of PI3K, P38MAPK, JAK2 and MEK1/2 signalling pathway.

Protective and reparative effects of peptides from soybean β-conglycinin on mice intestinal mucosa injury

Peptides derived from alcalase digestion of soybean β-conglycinin, containing 8.52% carbohydrate, exhibits an inhibition effect on pathogen adhesion or translocation to intestinal cells in vitro. In this study, the protective and reparative effects of β-conglycinin peptides on intestinal mucosa injury in vivo were studied using mice with dextran sulfate sodium (DSS)-induced intestinal mucosa injury. The results showed that β-conglycinin peptides contained approximately 21.77% glutamic acid (Glu), and significantly reduced the histological injury in mice both in the protective and reparative experiments. The myeloperoxidase activity of mice treated with β-conglycinin peptides decreased compared with those treated DSS in the positive control group. Immunohistochemical analysis also showed that β-conglycinin peptides inhibited the expression of inflammatory factor NF-κB/p65. These results suggested that peptides derived from soybean β-conglycinin exhibited protective and reparative effects on mice intestinal mucosa injury.

The synthetic triterpenoid (CDDO-Im) inhibits STAT3, as well as IL-17, and improves DSS-induced colitis in mice

INTRODUCTION

Synthetic triterpenoids inhibit IL-17 and improve autoimmune disease in mice. A prototype triterpenoid, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl] imidazole (CDDO-Im), also inhibits signal transducer and activator of transcription 3 (STAT3) activation.

AIMS

The goals of our study were twofold: (1) To determine if ex vivo treatment with CDDO-Im attenuated colonic IL-17 secretion from isolated splenocytes and colonic strips; (2) To determine if oral treatment with CDDO-Im improved DSS-induced colitis in mice.

METHODS

Splenocytes were isolated from male Balb/c mice. Colitis was induced in rodents, with either trinitrobenzene sulfonic acid or dextran sulfate sodium (DSS). Colonic strips were collected 5 or 6 days after colitis induction. Splenocytes or colonic strips were exposed to CDDO-Im (0.5-2 μM) concomitantly with IL-23 + IL-1β. Supernatants were collected after 48 or 24 h, and IL-17 was measured by ELISA. Using a DSS colitis model, mice were dosed orally with vehicle or CDDO-Im (20 mg/kg) over a 5-day period. Subsequently, various parameters of colitis were determined on study day 6.

RESULTS

Ex vivo treatment with CDDO-Im inhibited IL-17 secretion from splenocytes and colonic strips. The IC50 values were ≤0.62 μM. In vivo, CDDO-Im improved the altered colonic histology, and cytokine (IL-6, and IL-17) contents. Colonic STAT3 activation was also significantly reduced by CDDO-Im treatment. CDDO-Im attenuated IL-17 secretion in ex vivo models of inflammation. In vivo, histological and biochemical parameters of colitis were improved in CDDO-Im treated mice.

CONCLUSION

CDDO-Im has a unique pharmacological profile, which supports further testing in animal models of IBD.

Inhibition of IL-17 as a pharmacological approach for IBD

Several experimental approaches have been utilized, in order to critically examine the roles of IL-17 family members in intestinal inflammation. These approaches have included: (1) the use of IL-17A and IL-17F-deficient mice, (2) specific antibodies directed against IL-17, (3) an IL-17 vaccine, (4) methods to block the IL-17 receptor and (5) small-molecule inhibitors of IL-17. Previous studies found somewhat conflicting results in preclinical models of Inflammatory Bowel Disease (IBD), using specific strains of IL-17-deficient mice. This paper will review the preclinical results using various pharmacological approaches [specific IL-17 antibodies, an IL-17 receptor fusion protein, IL-12/IL-23 p40 subunit and IL-17 vaccine approaches, as well as a small molecule inhibitor (Vidofludimus)] to inhibit IL-17 in animal models of IBD. Recent clinical results in patients with IBD will also be discussed for Secukinumab (an IL-17A antibody), Brodalumab (an IL-17 receptor antibody) and two small-molecule drugs (Vidofludimus and Tofacitinib), which inhibit IL-17 as part of their overall pharmacological profiles. This review paper will also discuss some pharmacological lessons learned from the preclinical and clinical studies with anti-IL-17 drugs, as related to drug pharmacodynamics, IL-17 receptor subtypes and other pertinent factors. Finally, future pharmacological approaches of interest will be discussed, such as: (1) Retinoic acid receptor-related orphan nuclear receptor gamma t (Rorγt) antagonists, (2) Retinoic acid receptor alpha (RARα) antagonists, (3) Pim-1 kinase inhibitors and (4) Dual small-molecule inhibitors of NF-κB and STAT3, like synthetic triterpenoids.