Islet neogenesis associated protein (INGAP) protects pancreatic β cells from IL-1β and IFNγ-induced apoptosis

The goal of this study was to determine whether recombinant Islet NeoGenesis Associated Protein (rINGAP) and its active core, a pentadecapeptide INGAP104–118 (Ingap-p), protect β cells against cytokine-induced death. INGAP has been shown to induce islet neogenesis in diabetic animals, to stimulate β-cell proliferation and differentiation, and to improve islet survival and function. Importantly, Ingap-p has shown promising results in clinical trials for diabetes (phase I/II). However, the full potential of INGAP and its mechanisms of action remain poorly understood. Using rat insulinoma cells RINm5F and INS-1 treated with interleukin-1β (IL-1β) and interferon‐gamma (IFN‐γ), we demonstrate here that both rINGAP and Ingap-p inhibit apoptosis, Caspase-3 activation, inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, and explore the related signaling pathways. As expected, IL-1β induced nuclear factor kappa B (NF-κB), p38, and JNK signaling, whereas interferon‐gamma (IFN‐γ) activated the JAK2/STAT1 pathway and potentiated the IL-1β effects. Both rINGAP and Ingap-p decreased phosphorylation of IKKα/β, IkBα, and p65, although p65 nuclear translocation was not inhibited. rINGAP, used for further analysis, also inhibited STAT3, p38, and JNK activation. Interestingly, all inhibitory effects of rINGAP were observed for the cytokine cocktail, not IL-1β alone, and were roughly equal to reversing the potentiating effects of INFγ. Furthermore, rINGAP had no effect on IL-1β/NF-κB-induced gene expression (e.g., Ccl2, Sod2) but downregulated several IFNγ-stimulated (Irf1, Socs1, Socs3) or IFNγ-potentiated (Nos2) genes. This, however, was observed again only for the cytokine cocktail, not IFNγ alone, and rINGAP did not inhibit the IFNγ-induced JAK2/STAT1 activation. Together, these intriguing results suggest that INGAP does not target either IL-1β or IFNγ individually but rather inhibits the signaling crosstalk between the two, the exact mechanism of which remains to be investigated. In summary, our study characterizes the anti-inflammatory effects of INGAP, both protein and peptide, and suggests a new therapeutic utility for INGAP in the treatment of diabetes.

Peripheral Nerve Regeneration Using a Cytokine Cocktail Secreted by Skeletal Muscle-Derived Stem Cells in a Mouse Model

Severe peripheral nerve injury, which does not promise natural healing, inevitably requires clinical treatment. Here, we demonstrated the facilitation effect of peripheral nerve regeneration using a cytokine cocktail secreted by skeletal muscle-derived stem cells (Sk-MSCs). Mouse sciatic nerve was transected with a 6 mm gap and bridged collagen tube, and the culture supernatant of Sk-MSCs with 20% adult mouse serum (AMS)/Iscove’s modified Dulbecco’s medium (IMDM) was administered into the tube immediately after the operation, followed by an injection once a week for six weeks through the skin to the surrounding tube of the cytokine (CT) group. Similarly, 20% AMS/IMDM without cytokines was administered to the non-cytokine control (NT) group. Tension recovery in the plantar flexor muscles via electrical stimulation at the upper portion of the damaged nerve site, as well as the numerical recovery of axons and myelinated fibers at the damaged site, were evaluated as an index of nerve regeneration. Specific cytokines secreted by Sk-MSCs were compared with damaged sciatic nerve-derived cytokines. Six weeks after operation, significantly higher tension output and numerical recovery of the axon and myelinated fibers were consistently observed in the CT group, showing that the present cytokine cocktail may be a useful nerve regeneration acceleration agent. We also determined 17 candidate factors, which are likely included in the cocktail.

Cytoprotective effects of combination of gypenosides and Costus pictus D.Don extract in BRIN-BD11 β-cells

Ethnopharmacological RelevanceGypenosides and Costus pictus D.Don are used as an anti-diabetic herbal remedy in China and India respectively. However, the synergistic effect of these two extracts on β-cell protection is not yet elucidated.IntroductionIn Type 2 diabetes mellitus (T2DM), pro-inflammatory cytokines and lipotoxicity are known causes of pancreatic β-cell dysfunction and impaired insulin secretion and eventually β-cell death. Thus, any cytoprotective drug supplements can protect the β-cell and may help in T2DM treatment. Gypenosides, extracted from the Chinese medicinal herb Gynostemma pentaphyllum and the leaf extract from an Indian medicinal herb Costus pictus D. Don are used in traditional medicine due to their insulin secretory properties. In our previous studies, both extracts have shown significant cytoprotective effects in insulin-secreting BRIN-BD11 cells. In the present study, we aim to investigate the synergistic effects of a combination of these extracts on BRIN-BD11 β-cell protection.MethodsCombination of extracts was prepared by adding Gypenosides with Costus pictus at 2:1 to a concentration of 18.75mg/ml. Cell viability was determined by MTT assay following treatment with combination and/or palmitate and cytokine cocktail for 24-48h. Following 24h treatment, proliferation was measured by Ki67 staining and cytoprotective gene expression was quantified by qPCR.ResultsCombination treatment of 25µg/ml enhanced cell viability both at 24h (n=8; P<0.05) and 48h (n=8; P<0.0001) treatment. Over 24h, combination treatment (25&12.5 µg/ml) showed a significant protective effect against 125µM and 250µM palmitate induced (P<0.0001) and cytokine cocktail-(TNFα 1000U, IL-1β 50U & IFNγ 1000U) (P<0.0001 & P<0.01 respectively) induced toxicity. Combination treatment over 24h increased expression of antioxidant genes Nrf2 (P<0.001), Cat (P<0.001) and Sod1 (P<0.05) along with pro-proliferative Erk1 (P<0.01) while pro-inflammatory Nfkb1 expression was reduced(P<0.001).ConclusionThe results suggest that a combination of gypenosides and costus pictus may protect β-cells against inflammatory cytokines and lipotoxicity caused by saturated free fatty acids associated with obesity and diabetes.

Long-term high-yield skeletal muscle stem cell expansion through staged perturbation of cytokine signaling in a soft hydrogel culture platform

Muscle stem cells (MuSCs) are an essential stem cell population for skeletal muscle homeostasis and regeneration throughout adulthood. MuSCs are an ideal candidate for cell therapies for chronic and acute muscle injuries and diseases given their inherent ability to self-renew and generate progenitor cells capable of myogenic commitment and fusion. Given their rarity and propensity to lose stem-cell potential in prolonged culture, methods for ex vivo MuSC expansion that achieve clinical-scale stem cell yields represent a critical unmet need in muscle cell-therapeutic development. Here, we tested a microenvironment engineering approach to achieve long-term adult mouse MuSC expansion suitable for clinical demands through the combined optimization of techniques previously reported to achieve small-yield MuSC expansion in short-term cultures. We developed an optimized protocol for high-yield MuSC expansion through the combination of inflammatory cytokine and growth factor co-stimulation, temporally-staged inhibition of the p38α/β mitogen activated protein kinase signaling pathway, and modulation of substrate rigidity in long-term hydrogel cultures. We found that, on soft, muscle-mimicking (12 kPa) hydrogel substrates, a mixture of the cytokines TNF-α, IL-1α, IL-13, and IFN-γ and the growth factor FGF2 stimulated robust exponential proliferation of adult MuSCs from both wildtype and mdx dystrophic mice for up to five weeks of culture that was accompanied by a phenotype shift towards committed myocytes. After observing that the temporal variation in myogenic commitment coincided with an oscillatory activation of p38α/β signaling, we tested a late-stage p38α/β inhibition strategy and found that blocking p38α/β signaling after three weeks, but not earlier, substantially enhanced cell yield, stem-cell phenotypes, and, critically, preserved transplantation potential for up to five weeks of FGF2/cytokine mix culture on soft hydrogels. Notably, this retention of transplant engraftment potency was not observed on traditional plastic substrates. We estimate that this protocol achieves >108-fold yield in Pax7+ stem cells from each starting MuSC, which represents a substantial improvement in stem-cell yield from long-term cultures compared to established methods.HighlightsTNF-α/IL-1α/IL-13/IFN-γ cytokine cocktail supports prolonged MuSC proliferation ex vivo but induces differentiation.Cytokine cocktail regulates cell signaling with varied prolonged activation signatures.Effects of p38α/β inhibition on cytokine-induced MuSC expansion are stage-dependent.Soft hydrogels with late-stage p38α/β inhibition expand functional Pax7+ MuSCs long-term.Short summaryCosgrove and colleagues develop a long-term muscle stem cell expansion protocol by combining a tunable stiffness hydrogel substrate, an inflammatory cytokine cocktail, and targeted inhibition of p38 MAPK signaling. They show that soft, muscle-mimicking hydrogels with delayed p38 inhibition yield robust quantities of Pax7+ functional muscle stem cells.

P0046ZHX2 DOWNREGULATION DUE INSERTIONS AND DELETIONS IN THE HAS2-ZHX2 INTERGENIC REGION PREDISPOSE TO PODOCYTE DISEASE RELAPSE

Background and Aims ZHX2 transcriptional factor is normally found in podocyte membrane forming complexes with ZHX1 and APA or ZHX3 and Ephrin B1. Altered ZHX2 expression disrupts these interactions and is related with the worsening of different primary glomerular diseases such as focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). A small percentage of Hodgkin lymphoma (HL) patients develop nephrotic syndrome (NS). Studies of Reed-Sternberg cell line L-1236 reveals a chromosomal rearrangement that leads to ZHX2 downregulation suggesting a possible role of ZHX2 in the development of NS in these patients. Human podocyte disease relapse is common after a common cold probably mediated by cytokines released by immune cells and the rhinovirus. Our aim is to study how the presence of insertions and deletions (InDels) between HAS2 and ZHX2 in patients with MCD, FSGS and HL could alter ZHX2 expression and the implication in podocyte disease relapse after a common cold and in HL. Method Genomic DNA between HAS2 and ZHX2 (Chr8:122624000-124001000 from UCSC hg19 GRCh37) was sequenced from 28 NS patients and 27 controls using Agilent Custom capture and high throughput Illumina sequencing. The CLC Genomics software was used to identify InDels (3-20 bp) present exclusively in patients. One of the identified InDels was replicated in human podocytes using CRISPR Cas9 and homology directed repair technology to study changes in ZHX2. A common cold cytokine cocktail containing IL-2, IL-4R, IL-6, IL-10, INF-γ, TNF-α and ICAM-1 was injected into control (BALB/c, n=5) and ZHX2 deficient mice (BALB/cJ, n=5) (Dose X); podocyte specific ZHX2 deficient (ZHX2 flox/flox cre+/+, n=3) and floxed control mice (ZHX2 flox/flox, n=3) (dose X/15). Buffalo Mna (B. Mna) rats were also injected with the cytokine cocktail (X/50) to study relapse in FSGS (n=7). Cell supernatant from HL Reed Sternberg cells (L-1236) (200µg of total protein) was injected into BALB/c (n=5) and BALB/cJ mice (n=5) and kidney function was assessed. Results Multiple InDels were found exclusively in the patient population, two of them, shared by two or more patients. The insertion at 122,533,694 was presented in patients with MCD, FSGS and HL with NS and also in L-1236 cells. This insertion was replicated in human podocytes using CRISPR/Cas9 (CRISPR B). Another insertion noted both in patients and controls was generated for comparison (CRISPR A). A reduced ZHX2 expression was detected in CRISPR B but not in CRISPR A single cell clones. The shared insertion at 122,787,088 was presented within the ZHX2 gene intron 1. BALB/cJ mice has lower ZHX2 expression in liver and podocytes due to an insertion in intron 1. To study whether this insertion could be related with relapse of MCD and FSGS following a common cold, a cytokine cocktail was injected into BALB/cJ and BALB/c mice. BALB/cJ mice developed acute albuminuria after cytokine treatment (65.3±24.3 μg per 18h), but not control BALB/c mice (10.8±1.5 μg per 18h), when compared with baseline values (BALB/cJ 5.1±1.1 μg per 18h; BALB/c 6.5±1.1 μg per 18h) (p&lt;0.05). BALB/cJ mice had also higher nuclear expression of ZHX1. The cytokine cocktail also induced albuminuria in ZHX2 flox/flox/cre+/+ mice but not in control ZHX2 flox/flox, suggesting that ZHX2 deficiency in podocytes is responsible of kidney injury after cytokine injection. To study common cold related relapse in FSGS, B. Mna rats were injected with a rat cytokine cocktail, showing a significant increase in proteinuria (61.5±4.2 mg per 18h) compared with baseline (47±4.1 mg per 18h). Cell culture supernatant from L-1236 was injected into BALB/cJ and BALB/c mice to study the effect of secreted soluble mediators in NS. L-1236 supernatant (200 µg) had a nephrogenic effect in ZHX2 deficient mice but not in controls. Conclusion InDels between HAS2 and ZHX2 genes presented in patients with MCD, FSGS and HL, alter ZHX2 expression and are related to relapse following a common cold and in HL.

Creating and Testing a CD207+ Langerhans Cell Histiocytosis-like Cell Line

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by pathological CD207+ dendritic cells (DCs) with persistent mitogen-activated protein kinase (MAPK) activation. Investigations into LCH have historically been challenged by the small percentage of pathologic CD207+ DCs. No cell lines with morphology or function representing LCH lesion CD207+ DCs currently exist. We utilized four strategies to generate cell line(s) mimicking differentiated LCH pathogenic cells. First, CD207+ cells were isolated from the lesion of an LCH patient and cultured in a cytokine cocktail. The cells maintained CD1a and CD207 expression for two weeks, after which there were significant changes in cell morphology and progression to cell death. When a similar approach was implemented to isolate and culture skin CD207+ cells, the cells were viable for only three days, supporting the potential role for somatic activating MAPK mutations in LCH lesion DCs to prolong viability. CD207+ cells were then isolated from HLA-DR+ (lineage negative) cells from the lymphoid stroma of healthy tonsils (tCD207+). The tCD207+ cells were transduced with a lentivirus encoding human telomerase reverse transcriptase (hTERT). These cells, also lacking MAPK activating mutations, died two weeks post-transduction. A fourth approach has been more successful in which tCD207+ cells were cultured in a cytokine cocktail which provided MAPK pathway stimulation. The cells retained CD207 expression and survived in culture for over two weeks. The cells were then immortalized using a lentivirus encoding HOXA9. Immortalized cells maintained CD207 expression. Allele specific MAPK pathway mutations (BRAF and MAP2K1) are being generated by class II CRISPR/Cpf1 genome editing as Cpf1 has been shown to have robust activity to induce specific disruption of only mutant, but not wild-type, BRAF allele. The phenotypic and genomic characteristics of the immortalized cells expressing the different MAPK pathway mutations will be assessed by RHG-banding cytogenetic analysis, fluorescence in situ hybridization, gene expression analysis, and immuno‐cytochemistry and results will be compared to cells isolated from LCH lesions to confirm whether the established cell line may be a viable in vitro mimic of the LCH lesion DC. Disclosures No relevant conflicts of interest to declare.

NF-κB activation triggers NK-cell stimulation by monocyte-derived dendritic cells

Background: In therapeutic cancer vaccination, monocyte-derived dendritic cells (moDCs) efficiently activate specific T-cell responses; however, optimizing the activation of innate immune cells could support and improve the antitumor effects. A major disadvantage of moDCs matured with the standard cytokine cocktail (consisting of IL-1β, IL-6, TNFα, and PGE2) is their inability to secrete IL-12p70. IL-12 prominently activates natural killer (NK) cells, which are crucial in innate antitumor immunity, as they act as helper cells for the induction of a cytotoxic T lymphocyte (CTL) response and are also able to directly kill the tumor. Methods: Previously we have shown that triggering the NF-κB pathway in moDCs by transfection of mRNA encoding constitutively active IKKβ (caIKKβ) led to IL-12p70 secretion and improved the dendritic cells’ capability to activate and expand CTLs with a memory-like phenotype. In this study, we examined whether such dendritic cells could activate autologous NK cells. Results: moDCs matured with the standard cytokine cocktail followed by transfection with the caIKKβ-RNA were able to activate autologous NK cells, detected by the upregulation of CD54, CD69, and CD25 on the NK cells, their ability to secrete IFNγ, and their high lytic activity. Moreover, the ability of NK-cell activation was not diminished by simultaneous T-cell activation. Conclusion: The capacity of caIKKβ-DCs to activate both the adaptive and innate immune response indicates an enhanced potential for clinical efficacy.