Interleukin 1 receptor antagonist inhibits normal hematopoiesis and reduces lethality and bone marrow toxicity of 5-fluouracil in mouse

Selective protection of normal cells from chemotherapy, while killing drug-resistant cancer cells

Cancer therapy is limited by toxicity in normal cells and drug-resistance in cancer cells. Paradoxically, cancer resistance to certain therapies can be exploited for protection of normal cells, simultaneously enabling the selective killing of resistant cancer cells by using antagonistic drug combinations, which include cytotoxic and protective drugs. Depending on the mechanisms of drug-resistance in cancer cells, the protection of normal cells can be achieved with inhibitors of CDK4/6, caspases, Mdm2, mTOR, and mitogenic kinases. When normal cells are protected, the selectivity and potency of multi-drug combinations can be further enhanced by adding synergistic drugs, in theory, eliminating the deadliest cancer clones with minimal side effects. I also discuss how the recent success of Trilaciclib may foster similar approaches into clinical practice, how to mitigate systemic side effects of chemotherapy in patients with brain tumors and how to ensure that protective drugs would only protect normal cells (not cancer cells) in a particular patient.

Pyroptosis-Induced Inflammation and Tissue Damage

Programmed cell deaths are pathways involving cells playing an active role in their own destruction. Depending on the signaling system of the process, programmed cell death can be divided into two categories, pro-inflammatory and non-inflammatory. Pyroptosis is a pro-inflammatory form of programmed cell death. Upon cell death, a plethora of cytokines are released and trigger a cascade of responses from the neighboring cells. The pyroptosis process is a double-edged sword, could be both beneficial and detrimental in various inflammatory disorders and disease conditions. A physiological outcome of these responses is tissue damage, and sometimes death of the host. In this review, we focus on the inflammatory response triggered by pyroptosis, and resulting tissue damage in selected organs.

Engineering non-covalently assembled protein nanoparticles for long-acting gouty arthritis therapy

As an incurable metabolic disease, gouty arthritis (GA) requires long-term treatment with frequent drug administration several times per day. Compared to non-specific small organic medications, interleukin-1β (IL-1β) blocking therapies, such as IL-1 receptor antagonist (IL-1Ra), show great therapeutic potential in clinical trials of GA. However, IL-1Ra application is starkly limited due to its short half-life and poor bioavailability. Herein, we demonstrate a new type of nanotherapeutic formulation via noncovalent assembly of an engineered IL-1Ra chimera protein. PEGylation was employed to induce such assembly by exploiting electrostatic complexation and hydrophobic interactions. The engineered protein nanoparticles had a combination of biocompatibility, improved bioavailability and therapeutic performance. It showed extraordinary long-term anti-inflammatory effect and robust bio-efficacy for GA therapy in acute GA rat models. Strikingly, this nanoprotein system possesses an ultralong half-life of 27 hours and a bioavailability 7 times higher than that of pristine IL-1Ra, thus extending the dosing interval from several hours to more than 3 days. Therefore, our noncovalent assembly strategy via an engineered chimeric protein empowers the construction of potent delivery nanosystems for efficient GA treatment, and this might be adapted for other therapeutics to form long-acting formulations.

OVOL1 Regulates Psoriasis-Like Skin Inflammation and Epidermal Hyperplasia

Psoriasis is a common inflammatory skin disease characterized by aberrant inflammation and epidermal hyperplasia. Molecular mechanisms that regulate psoriasis-like skin inflammation remain to be fully understood. Here, we show that the expression of Ovol1 (encoding ovo-like 1 transcription factor) is upregulated in psoriatic skin, and its deletion results in aggravated psoriasis-like skin symptoms following stimulation with imiquimod. Using bulk and single-cell RNA sequencing, we identify molecular changes in the epidermal, fibroblast, and immune cells of Ovol1-deficient skin that reflect an altered course of epidermal differentiation and enhanced inflammatory responses. Furthermore, we provide evidence for excessive full-length IL-1α signaling in the microenvironment of imiquimod-treated Ovol1-deficient skin that functionally contributes to immune cell infiltration and epidermal hyperplasia. Collectively, our study uncovers a protective role for OVOL1 in curtailing psoriasis-like inflammation and the associated skin pathology.

Clodronate-liposomes aggravate irradiation-induced myelosuppression by promoting myeloid differentiation

PURPOSE

Clodronate-liposomes (Clod-Lip) is an effective candidate drug for treating chronic myelomonocytic leukemia, autoimmune hemolytic anemia and immune thrombocytopenic purpura in mice experiments. But its role in hematopoietic recovery after acute myelosuppression is still unknown. We aim to explore the function and underlining mechanisms of Clod-Lip on hematopoietic reconstitution after sublethal dose irradiation in mice.

MATERIALS AND METHODS

Mice at 8-10 weeks received a total-body sublethal dose γ-irradiation (TBI) and injected with Clod-Lip or PBS-Liposomes (PBS-Lip) every 4 days after TBI. The survival rate of each group was recorded. Flow cytometry was used to analyze changes in hematopoietic stem cells and their progenies in bone marrow. ELISA and RT-qPCR were used for the analysis of hematopoietic regulatory factors. Regarding IL-1β inhibition, 25 mg/kg diacerein or an equal volume of DMSO was intraperitoneally injected into mice every day after TBI.

RESULTS

In sublethal dose-irradiated mice, Clod-Lip reduced the survival rate, the total number of bone marrow and hematopoietic stem cells, delayed peripheral blood recovery of red blood cells and platelets. However, it could increase the number of CMP, MEP and myeloid cells, which suggested that Clod-Lip could induce HSC to myeloid differentiation in vivo. We further verified that Clod-Lip may induce myeloid differentiation by bone marrow microenvironmental factor IL-1β.

CONCLUSIONS

In summary, this study suggested that Clod-Lip may aggravate inhibitor effect of hematopoietic function and promote myeloid differentiation in myelosuppression mice model.

IL-1Ra protects hematopoietic cells from chemotoxicity through p53-induced quiescence

The protection of constantly proliferating gut epithelia and hematopoietic tissues from cytotoxicity could improve conventional chemotherapy efficacy and widen its therapeutic window. Previously, we reported that, in mouse models, pretreatment of recombinant human IL-1 receptor antagonist (rhIL-1Ra) protected both types of vulnerable tissues from chemotherapeutics. Here, we showed that rhIL-1Ra treatment up-regulated the protein levels of phosphorylated p38, p53, and p21 and induced transient hematopoietic stem/progenitor cell (HS/PC) quiescence. Knockout of IL-1 receptor I (IL-1RI), p53, or p21 alleles and pharmacological inactivation of p38 mapped the rhIL-1Ra pathway in the induction of HS/PC quiescence. Therefore, rhIL-1Ra administration before but not after chemotherapy alleviated 5-fluorouracil-induced neutropenia. In addition, in vivo and in vitro cell proliferation assays revealed that the rhIL-1Ra treatment did not affect cancer cell proliferation or chemosensitivity. Lastly, we propose an IL-1/IL-1Ra pathway (IL-1RI → p38 → p53 → p21), which regulates HS/PC quiescence. The rhIL-1Ra may provide a new route for p53-based cyclotherapy, which spares normal cells but kills cancer cells during chemotherapy.-Ye, H., Qian, L., Zhu, S., Deng, S., Wang, X., Zhu, J., Chan, G. L., Yu, Y., Han, W. IL-1Ra protects hematopoietic cells from chemotoxicity through p53-induced quiescence.

rhIL-1Ra reduces hepatocellular apoptosis in mice with acute liver failure mainly by inhibiting the activities of Kupffer cells

In clinic, there is still no drug that can significantly improve the survival rate of patients with acute liver failure (ALF). We have confirmed that recombinant human IL-1 receptor antagonist (rhIL-1Ra) significantly improves the survival rate of acetaminophen (APAP)-induced ALF mice by reducing hepatocellular apoptosis. Here, we investigated the mechanism of this and the key target cells of rhIL-1Ra. In vivo, APAP-induced ALF mice were treated with rhIL-1Ra and gadolinium chloride (Gdcl₃), respectively. Survival rates of mice, serum IL-1Ra and IL-1β levels, IL-1 receptor type I (IL-1RI) and CD163 expression in the livers, and the phagocytic activities of Kupffer cells (KCs) were investigated. Additionally, the proliferation of hepatocytes and KCs in co-culture conditions with the serum of ALF mice were investigated in vitro. In this study, a large number of activated large KCs were found in liver lobe region III. Both GdCl₃ and rhIL-1Ra significantly decreased the quantity of large KCs. In all of the mice, hepatocytes and liver non-parenchymal cells other than KCs expressed low levels of IL-1RI, whereas large KCs expressed high levels of IL-1RI. The high ratio of endogenous IL-1Ra/IL-1β was related to rhIL-1Ra function. Additionally, the phagocytic activities of KCs were significantly inhibited by GdCl₃ and rhIL-1Ra. In vitro, the proliferation of hepatocytes in co-culture conditions were significantly inhibited by KCs. In conclusion, large KCs were the key target cells of rhIL-1Ra, and rhIL-1Ra could play its role of reducing hepatocellular apoptosis mainly by inhibiting the activities of KCs.

The protective effects of Aquilariae Lignum Resinatum extract on 5-Fuorouracil-induced intestinal mucositis in mice

BACKGROUND

Aquilariae Lignum Resinatum as a traditional Chinese medicine is used in prescription for treatment of gastrointestinal diseases. Phytochemical investigations show that there are many anti-ulcer and anti-inflammatory ingredients in A. agallocha methanol extract (AEE). However, scarce data is available about the constituents absorbed into the blood, activity and mechanisms of AEE on intestinal mucositis.

HYPOTHESIS/PURPOSE

To analyze the bioactive constituents of AEE absorbed in the blood, and further explore the potential mechanisms of the protection against chemotherapy-induced intestinal mucositis.

METHODS

The serum pharmacochemistry using UHPLC-Q-TOF/MS was performed to screen the bioactive compounds of AEE absorbed in serum. The intestinal mucositis was induced by 5-Fuorouracil (5-Fu) and treated with AEE. The severity of intestinal mucositis was evaluated based on body weight, food-intake and diarrhea. Furthermore, the mechanism of AEE was investigated involved in the pathogenesis of mucositis on repairing injury of intestinal mucosa, immune functions, and inflammatory response.

RESULTS

Altogether, 11 components were identified or tentatively characterized in dosed plasma. In pharmacodynamics study, intestinal mucositis caused by 5-Fu was effectively attenuated after AEE treatment. AEE treatment improved food-intake and injury of the intestinal mucosa, relieved body weight loss and severe diarrhea through up-regulating expression of proliferating cell nuclear antigen (PCNA) and inhibiting the levels of cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) in ileum segments.

CONCLUSIONS

AEE protected against 5-Fu-induced intestinal mucositis (IM) in mice through mechanisms that involved in promoting the enterocyte proliferative activity, maintaining the integrity of tight junction proteins, inhibiting oxidative stress and ameliorating the inflammatory disturbances. Accordingly, A. agallocha may be a promising therapeutic candidate used for the prevention of IM during cancer chemotherapy.

Transcriptome Profiling Analysis Reveals the Potential Mechanisms of Three Bioactive Ingredients of Fufang E'jiao Jiang During Chemotherapy-Induced Myelosuppression in Mice

Although multiple bioactive components have been identified in Fufang E’jiao Jiang (FEJ), their hematopoietic effects and molecular mode of action in vivo are still not fully understood. In the current study, we analyzed the effects of martynoside, R-notoginsenoside R2 (R2), and 20S-ginsenoside Rg2 (Rg2) in a 5-fluorouracil-induced myelosuppression mouse model. Bone marrow nucleated cells (BMNCs) counts, hematopoietic progenitor cell colony-forming unit (CFU) assay, as well as flow cytometry analysis of Lin^-/c-kit⁺/Sca-1⁺ hematopoietic stem cell (HSC) population were conducted, and bone marrow cells were subjected to RNA sequencing. The transcriptome data were processed based on the differentially expressed genes. The results of the analysis show that each of the three compounds stimulates BMNCs and HSC growth, as well as burst-forming unit-erythroid and colony-forming unit granulocyte-monocyte colony expansion. The most relevant transcriptional changes appeared to be involved in regulation of hematopoietic cell lineage, NF-κB and TNF-α signaling, inhibition of inflammation, and acceleration of hematopoietic cell recovery. Notably, the individual compounds shared similar but specified transcriptome profiles. Taken together, the hematopoietic effects for the three tested compounds of FEJ are confirmed in this myelosuppression mouse model. The transcriptome maps of these effects provide valuable information concerning their underlying mechanisms and provide a framework for the continued study of the complex mode of action of FEJ.

Inflammasome as a Therapeutic Target for Cancer Prevention and Treatment

Chronic inflammation is a critical modulator of carcinogenesis through secretion of inflammatory cytokines, which leads to the formation of an inflammatory microenvironment. In this process, the inflammasome plays an important role in the expression and activation of interleukin (IL)-1β and IL-18 to promote cancer development. The inflammasome is a multiprotein complex consisting of several nucleotide-binding domain and leucine-rich repeat containing receptor, adaptor proteins, and caspase 1 (CASP1). It senses the various intracellular (damage-associated molecular patterns) and extracellular (pathogen-associated molecular patterns) stimuli. A primed inflammasome recruits adaptor proteins, activates CASP1 to enhance the proteolytic cleavage of pro-IL-1β and IL-18, and sends the signal to respond to each insult. Depending on stimuli and cell contexts, several inflammasomes are closely associated with the initiation and promotion of carcinogenesis. In contrast, inflammasomes also show an ambivalent effect on carcinogenesis by enhancing inflammatory cell death (pyroptosis) and repairing damaged tissues. Although the inflammasome plays a controversial role in carcinogenesis, it may be a promising target for human cancer prevention and treatment. A more in-depth study on the role of the inflammasome in carcinogenesis, based on stimuli, cell contexts, and cancer stages, can lead to the development of novel therapeutic strategies against malignant human cancers.

Interleukin-1β as emerging therapeutic target in hematological malignancies and potentially in their complications

Interleukin-1β (IL-1β) is a pleiotropic cytokine that exerts multiple roles in both physiological and pathological conditions. It is produced by different cell subsets, and drives a wide range of inflammatory responses in numerous target cells. Enhanced IL-1β signaling is a common event in patients of hematological malignancies. Recent body of evidence obtained in preclinical models shows the pathogenic role of these alterations, and the promising therapeutic value of IL-1 targeting. In this review, we further highlight a potential contribution of IL-1β linking to complications and autoimmune disease that should be investigated in future studies. Hence, drugs that target IL-1 may be helpful to improve outcome or reduce morbidity in patients. Some of them are FDA-approved, and used efficiently against autoimmune diseases, like IL-1 receptor antagonist. In the clinic, however, this agent seems to have limited properties. Current improved drugs will allow to determine the true potential of IL-1 and IL-1β targeting as therapy in hematological malignancies and their related complications.

The TIR/BB-loop mimetic AS-1 prevents non-alcoholic steatohepatitis and hepatic insulin resistance by inhibiting NLRP3-ASC inflammasome activation

BACKGROUND AND PURPOSE

Non-alcoholic steatohepatitis (NASH) is characterized by excessive intracellular lipid accumulation, inflammation and hepatic insulin resistance. As the incidence of NASH is increasing worldwide, there is an urgent need to find novel interventional approaches. The pro-inflammatory cytokine IL-1β, generated and released from Kupffer cells, is considered to initiate the development of NASH. AS-1, a synthetic low-molecule mimetic of myeloid differentiation primary response gene 88 (MyD88), disrupts the interaction between the IL-1 receptor and MyD88. Here, we investigated whether AS-1 could attenuate the pathogenesis of NASH with an emphasis on hepatic insulin resistance.

EXPERIMENTAL APPROACH

Eight-week-old db/db mice were fed a control diet or a methionine- and choline-deficient (MCD) diet. AS-1 (50 mg·kg^-1 ) or vehicle was administered i.p.

KEY RESULTS

AS-1 administration significantly ameliorated NASH as evidenced by alanine aminotransferase levels and CD68 levels in livers of MCD-fed mice. AS-1 inhibited the MCD diet-induced activation of caspase 1 and the NLRP3-ASC inflammasome, and also reduced the enhanced levels of ROS, malondialdehyde, 3-nitrotyrosine, NADPH oxidase complex and CYP reductase-associated cytochrome p450 2E1 (CYP2E1) expression in the liver. In addition, AS-1 decreased ROS, inflammasome activation and IL-1β production in free fatty acid-LPS-treated Kupffer cells. Finally, pretreatment with AS-1 significantly ameliorated gluconeogenesis and insulin desensitization induced by IL-1β, probably by blocking the interaction between MyD88 and the IL-1 receptor.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that AS-1 can ameliorate NASH and hepatic insulin resistance and could be considered as a potential strategy for the prevention and treatment of NASH.

Fight or flight: regulation of emergency hematopoiesis by pyroptosis and necroptosis

PURPOSE OF REVIEW

A feature of the innate immune response that is conserved across kingdoms is the induction of cell death. In this review, we discuss the direct and indirect effects of increased inflammatory cell death, including pyroptosis - a caspase-1-dependent cell death - and necroptosis - a receptor-interacting protein kinase 3/mixed lineage kinase domain-like protein-dependent, caspase-independent cell death - on emergency hematopoiesis.

RECENT FINDINGS

Activation of nonapoptotic cell death pathways during infection can trigger release of cytokines and/or damage-associated molecular patterns such as interleukin (IL)-1α, IL-1β, IL-18, IL-33, high-mobility group protein B1, and mitochondrial DNA to promote emergency hematopoiesis. During systemic infection, pyroptosis and necroptosis can directly kill hematopoietic stem and progenitor cells, which results in impaired hematopoiesis, cytopenia, and immunosuppression. Although originally described as discrete entities, there now appear to be more intimate connections between the nonapoptotic and death receptor signaling pathways.

SUMMARY

The choice to undergo pyroptotic and necroptotic cell death constitutes a rapid response system serving to eliminate infected cells, including hematopoietic stem and progenitor cells. This system has the potential to be detrimental to emergency hematopoiesis during severe infection. We discuss the potential of pharmacological intervention for the pyroptosis and necroptosis pathways that may be beneficial during periods of infection and emergency hematopoiesis.

Mouse Resistin (mRetn): cloning, expression and purification in Escherichia coli and the potential regulative effects on murine bone marrow hematopoiesis

Background

Resistin (Retn) is a cytokine which has a controversial physiological role regarding its involvement with obesity and type II diabetes mellitus. Recently, murine Retn was found to be a possibly potential regulator of hematopoiesis in mice shown in the screening results of a set of gene chips which mapped the expression level of murine genes during regeneration of impaired bone marrow (BM) by 5-fluorouracil.

Results

Recombinant mice Retn was expressed in Escherichia coli and purified using ion exchange chromatography. Totally 11.4 mg rmRetn was obtained from 500 ml culture with endotoxin level less than 1.0 EU/ug. The purity of recombinant murine Resistin reached to at least 97.6 % via SDS-PAGE analysis and HPLC. The protein possessed chemotaxis effects in the mouse aortic endothelial cells in vitro in transwell analysis. In vitro, rmRetn could up regulate the CFU number of mice BM and after rmRetn was administered, the cell number of murine bone marrow was significantly increased in vivo after chemotherapy. Finally, rmRetn was found able to protect mice from the chemotoxicity of 5-fluorouracil.

Conclusions

The discovery demonstrated a new function of murine Retn and suggested that it could potentially accelerate bone marrow regeneration post chemotherapy.

Recombinant interleukin-1 receptor antagonist attenuates the severity of chronic pancreatitis induced by TNBS in rats

Chronic pancreatitis (CP) is a common disease in the department of gastroenterology, with the main symptoms of exocrine and/or endocrine insufficiency and abdominal pain. The pathogenic mechanism of CP is still not fully clarified and the aims of treatment now are to relieve symptoms. In this study, we attempted to find a connection between interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1Ra) in trinitrobenzene sulfonic acid (TNBS)-induced chronic pancreatitis, and then the therapeutic effect of recombinant IL-1Ra was also detected in the CP model. Chronic pancreatitis was induced by intraductal infusion of TNBS in SD rats followed by a consecutive administration of rIL-1Ra, and the histological changes and collagen content in the pancreas were measured, as well as the abdominal hypersensitivity. We found that rhIL-1Ra could attenuate the severity of chronic pancreatic injury, modulate the extracellular matrix secretion, focal proliferation and apoptosis, and cellular immunity in TNBS-induced CP. Interestingly, rIL-1Ra could also block the pancreatitis-induced referred abdominal hypersensitivity. In conclusion, IL-1Ra may play a protective role in CP and rIL-1Ra would be a potential therapeutic target for the treatment of CP, while its possible mechanisms and clinical usage still need further investigation.

Recombinant human interleukin-1 receptor antagonist reduces acute lethal toxicity and protects hematopoiesis from chemotoxicity in vivo

Cyclophosphamide (CY), targeting to fast dividing cells, results in bone marrow (BM) suppression, which is the most common side effect of cancer chemotherapy. Interleukin-1 receptor antagonist (IL-1Ra), activated by variety of chemotherapeutic drugs, is a natural inhibitor of interleukin-1 (IL-1) and blocks the functional IL-1 receptor signaling. Our previous studies showed the protective effect of recombinant murine IL-1Ra on hematopoiesis in mice after treatment with chemotherapeutic agent 5-fluorouracil. In this report, we demonstrate that the pretreatment use of recombinant human IL-1Ra (rhIL-1Ra) significantly alleviated chemotherapy-induced peripheral blood injury in mice, and reduced the incidence and severity of neutropenia in beagle dogs. Moreover, acute lethal toxicity in single and repeated CY treatment was markedly reduced by rhIL-1Ra administration. The chemoprotective role of rhIL-1Ra is attributed to the attenuated BM damage, accelerated recovery of BM cells, and enhanced survival of hematopoietic progenitor cells which expressed high level of aldehyde dehydrogenase and IL-1 receptor type I. Thus, our data strongly suggest that the prophylactic use of exogenous rhIL-1Ra renders BM primitive hematopoietic cells resistant to chemotherapy, which provides novel strategies to prevent BM suppression in clinical settings.

Delayed resolution of lung inflammation in Il-1rn-/- mice reflects elevated IL-17A/granulocyte colony-stimulating factor expression

IL-1 has been associated with acute lung injury (ALI) in both humans and animal models, but further investigation of the precise mechanisms involved is needed, and may identify novel therapeutic targets. To discover the IL-1 mediators essential to the initiation and resolution phases of acute lung inflammation, knockout mice (with targeted deletions for either the IL-1 receptor-1, i.e., Il-1r1(-/-), or the IL-1 receptor antagonist, i.e., Il-1rn(-/-)) were exposed to aerosolized LPS, and indices of lung and systemic inflammation were examined over the subsequent 48 hours. The resultant cell counts, histology, protein, and RNA expression of key cytokines were measured. Il-1r1(-/-) mice exhibited decreased neutrophil influx, particularly at 4 and 48 hours after exposure to LPS, as well as reduced bronchoalveolar lavage (BAL) expression of chemokines and granulocyte colony-stimulating factor (G-CSF). On the contrary, Il-1rn(-/-) mice demonstrated increased BAL neutrophil counts, increased BAL total protein, and greater evidence of histologic injury, all most notably 2 days after LPS exposure. Il-1rn(-/-) mice also exhibited higher peripheral neutrophil counts and greater numbers of granulocyte receptor-1 cells in their bone marrow, potentially reflecting their elevated plasma G-CSF concentrations. Furthermore, IL-17A expression was increased in the BAL and lungs of Il-1rn(-/-) mice after exposure to LPS, likely because of increased numbers of γδ T cells in the Il-1rn(-/-) lungs. Blockade with IL-17A monoclonal antibody before LPS exposure decreased the resultant BAL neutrophil counts and lung G-CSF expression in Il-1rn(-/-) mice, 48 hours after exposure to LPS. In conclusion, Il-1rn(-/-) mice exhibit delayed resolution in acute lung inflammation after exposure to LPS, a process that appears to be mediated via the G-CSF/IL-17A axis.

Recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) attenuates caerulein-induced chronic pancreatitis in mice

Chronic pancreatitis is a progressive inflammatory disease featuring irreversible irregular scarring of the exocrine parenchyma characterized by acinar destruction and fibrosis subsequent to inflammation in the pancreas. Despite decades of research, the knowledge is limited to the treatment of this disease. After finding a connection between interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1Ra) in caerulein-induced chronic pancreatitis, we assumed that recombinant human IL-1Ra (rhIL-1Ra), the natural antagonist of IL-1β, might have a protective role in chronic pancreatitis in mice. Chronic pancreatitis was induced by repetitive intraperitoneal injections of caerulein in C57/BL mice followed by a consecutive administration of rhIL-1Ra (10mg/kg). Collagen content and histological changes in the pancreas as well as serum amylase and lipase were measured. We found that rhIL-1Ra significantly decreased the hydroxyproline and the fibrotic area in the pancreas after the caerulein challenge. Caerulein-induced serum amylase elevation and tissue damage were also attenuated in rhIL-1Ra treated mice. Our results reveal a potential role of rhIL-1Ra in protecting mice against caerulein-induced chronic pancreatitis and lead to a conclusion that this protein may be a potential candidate agent for the treatment of chronic pancreatitis in humans.

Identification of hub genes related to the recovery phase of irradiation injury by microarray and integrated gene network analysis

BACKGROUND

Irradiation commonly causes long-term bone marrow injury charactertized by defective HSC self-renewal and a decrease in HSC reserve. However, the effect of high-dose IR on global gene expression during bone marrow recovery remains unknown.

METHODOLOGY

Microarray analysis was used to identify differentially expressed genes that are likely to be critical for bone marrow recovery. Multiple bioinformatics analyses were conducted to identify key hub genes, pathways and biological processes.

PRINCIPAL FINDINGS

1) We identified 1302 differentially expressed genes in murine bone marrow at 3, 7, 11 and 21 days after irradiation. Eleven of these genes are known to be HSC self-renewal associated genes, including Adipoq, Ccl3, Ccnd1, Ccnd2, Cdkn1a, Cxcl12, Junb, Pten, Tal1, Thy1 and Tnf; 2) These 1302 differentially expressed genes function in multiple biological processes of immunity, including hematopoiesis and response to stimuli, and cellular processes including cell proliferation, differentiation, adhesion and signaling; 3) Dynamic Gene Network analysis identified a subgroup of 25 core genes that participate in immune response, regulation of transcription and nucleosome assembly; 4) A comparison of our data with known irradiation-related genes extracted from literature showed 42 genes that matched the results of our microarray analysis, thus demonstrated consistency between studies; 5) Protein-protein interaction network and pathway analyses indicated several essential protein-protein interactions and signaling pathways, including focal adhesion and several immune-related signaling pathways.

CONCLUSIONS

Comparisons to other gene array datasets indicate that global gene expression profiles of irradiation damaged bone marrow show significant differences between injury and recovery phases. Our data suggest that immune response (including hematopoiesis) can be considered as a critical biological process in bone marrow recovery. Several critical hub genes that are key members of significant pathways or gene networks were identified by our comprehensive analysis.

Interleukin 1 receptor antagonist reduces lethality and intestinal toxicity of 5-Fluorouracil in a mouse mucositis model

Chemotherapy induced intestinal mucositis is still an unmet medical problem. 5-fluorouracil (5-Fu), a chemotherapy drug, was used to create the animal model of mucositis. Global gene expression array was applied to identify genetic signals involved in the pathogenesis of mucositis. Interleukin 1 receptor antagonist (IL-1Ra) was one of the candidates with the characteristic gene expression profile. Its temporal expression pattern correlated to the damage and regeneration phase of the small intestine after a single injection of 5-Fu to mice. Administration of recombinant IL-1Ra to the mouse model of intestinal mucositis induced by 5-Fu demonstrated its therapeutic effects to the symptoms and pathology of the disease. The IL-1Ra treatment reduced the acute lethality, accelerated their body weight recovery, and eliminated severe diarrhea. The symptomatic benefits were supported by the pathological benefits, in which the mice treated with IL-1Ra has less damage and faster recovery of the structure integrity of their small intestine than that of the mice treated with vehicle control. To deliver the therapeutics to the unmet medical condition, further mechanism and translational studies of IL-1Ra in the settings of chemotherapy induced intestinal mucositis are warranted.