BackgroundNucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is associated with metabolic disorder and cell death, which are important triggers in diabetic cardiomyopathy (DCM). We aimed to explore whether NLRP3 inflammasome activation contributes to DCM and the mechanism involved.MethodsType 2 diabetic rat model was induced by high fat diet and low dose streptozotocin. The characteristics of type 2 DCM were evaluated by metabolic tests, echocardiography and histopathology. Gene silencing therapy was used to investigate the role of NLRP3 in the pathogenesis of DCM. High glucose treated H9c2 cardiomyocytes were used to determine the mechanism by which NLRP3 modulated the DCM. The cell death in vitro was detected by TUNEL and EthD-III staining. TXNIP-siRNA and pharmacological inhibitors of ROS and NF-kB were used to explore the mechanism of NLRP3 inflammasome activation.ResultsDiabetic rats showed severe metabolic disorder, cardiac inflammation, cell death, disorganized ultrastructure, fibrosis and excessive activation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase-1, activated caspase-1 and mature interleukin-1β (IL-1β). Evidence for pyroptosis was found in vivo, and the caspase-1 dependent pyroptosis was found in vitro. Silencing of NLRP3 in vivo did not attenuate systemic metabolic disturbances. However, NLRP3 gene silencing therapy ameliorated cardiac inflammation, pyroptosis, fibrosis and cardiac function. Silencing of NLRP3 in H9c2 cardiomyocytes suppressed pyroptosis under high glucose. ROS inhibition markedly decreased nuclear factor-kB (NF-kB) phosphorylation, thioredoxin interacting/inhibiting protein (TXNIP), NLRP3 inflammasome, and mature IL-1β in high glucose treated H9c2 cells. Inhibition of NF-kB reduced the activation of NLRP3 inflammasome. TXNIP-siRNA decreased the activation of caspase-1 and IL-1β.ConclusionNLRP3 inflammasome contributed to the development of DCM. NF-κB and TXNIP mediated the ROS-induced caspase-1 and IL-1β activation, which are the effectors of NLRP3 inflammasome. NLRP3 gene silencing may exert a protective effect on DCM.

Slow synaptic excitation (slow EPSP) in enteric neurones is recorded as a slowly activating depolarization of the membrane potential in specific populations of enteric neurones when neurotransmitters are released experimentally by focal electrical stimulation of presynaptic axons in the myenteric and submucosal plexuses (reviewed by Surprenant, 1989;Wood, 1994;Galligan, 1998;Gershon, 1998). Mediators released to the enteric nervous system in paracrine fashion from non-neuronal cell types (e.g. histamine and cytokines from enteric mast cells) can evoke responses that mimic slow synaptic excitation (Wood, 1992;Liu et al. 2003). Two kinds of slow EPSPs are recorded in enteric neurones. An increase in input resistance is associated with the depolarization and augmented excitability for one kind of slow EPSP. The input resistance decreases or remains unchanged during the depolarization and augmented excitability of the second kind. Slow EPSPs with increased input resistance are found generally in AH-type neurones with multipolar Dogiel Type II morphology. Most evidence suggests that the principal ionic mechanism for this type of slow EPSP is suppression of resting Ca 2+ -dependent K + conductance that accounts for the membrane depolarization, increased input resistance, and suppression of the Ca 2+ component of the rising phase of the action potential (e.g. Grafe et al. 1980). Signal transduction for the slow EPSP with increased input resistance involves coupling of metabotropic receptors through heterotrimeric G proteins to adenylate cyclase, and elevation of intraneuronal cyclic adenosine monophosphate (Palmer et al. 1986(Palmer et al. , 1987.Whereas slow EPSPs characterized by increased input resistance during the depolarizing response predominate in AH-type neurones in the myenteric plexus, slow EPSPs characterized by decreased input resistance are routinely found in S-type uniaxonal neurones in the small and large intestinal submucosal plexus. Likewise, application of putative neurotransmitters and paracrine mediators (e.g. serotonin, ATP and substance P) evoke slowly activating depolarizing responses associated with decreased input resistance in S-type neurones in the submucosal plexus.This report presents evidence that synaptically released ATP acts at P2Y 1 purinergic receptors to evoke slow EPSPs that are characterized by decreased input resistance in the submucosal plexus. The evidence suggests that the signal transduction cascade for the submucosal P2Y 1 receptor includes activation of phospholipase C, release of inositol 1,4,5-trisphosphate and elevation of cytosolic free Ca

Hu proteins, together with neurone-specific enolase (NSE), protein gene product 9.5 (PGP-9.5), microtubule-associated protein-2 (MAP-2) and tubulin beta III isoform, were evaluated immunohistochemically as neuronal markers in whole-mount preparations and cultures obtained from the myenteric plexus of guinea-pig small intestine. Anti-Hu immunostaining marked the ganglion cell somas and nuclei without staining of the neuronal processes in the whole-mounts and cultures. The ganglion cell bodies were not obscured by staining of multiple neuronal fibres and this facilitated accurate counting of the neurones. MAP2 immunostaining also provided clear images of individual neurones in both whole mounts and cultures. Immunoreactivity for NSE, PGP-9.5 and tubulin beta III isoform provided sharp images of the ganglion cells in culture, but not in whole-mount preparations. Strong staining of the neuronal processes in the whole-mount preparations obscured the profiles of the ganglion cell bodies to such an extent that accurate counting of the total neuronal population was compromised. Anti-Hu immunostaining was judged to be an acceptable method for obtaining reliable estimates of total numbers of myenteric neurones in relation to other specific histochemical properties such as histamine binding.

The beneficial effect of RSV on DCM depended on inhibited NLRP3 inflammasome, and correlated with suppression of the MAPKs.

Background BCMA-specific chimeric antigen receptor-T cells (CAR-Ts) have exhibited remarkable efficacy in refractory or relapsed multiple myeloma (RRMM); however, primary resistance and relapse exist with single-target immunotherapy. Bispecific CARs are proposed to mitigate these limitations. Methods We constructed a humanized bispecific BM38 CAR targeting BCMA and CD38 and tested the antimyeloma activity of BM38 CAR-Ts in vitro and in vivo. Twenty-three patients with RRMM received infusions of BM38 CAR-Ts in a phase I trial. Results BM38 CAR-Ts showed stronger in vitro cytotoxicity to heterogeneous MM cells than did T cells expressing an individual BCMA or CD38 CAR. BM38 CAR-Ts also exhibited potent antimyeloma activity in xenograft mouse models. In the phase I trial, cytokine release syndrome occurred in 20 patients (87%) and was mostly grade 1–2 (65%). Neurotoxicity was not observed. Hematologic toxicities were common, including neutropenia in 96% of the patients, leukopenia in 87%, anemia in 43% and thrombocytopenia in 61%. At a median follow-up of 9.0 months (range 0.5 to 18.5), 20 patients (87%) attained a clinical response and minimal residual disease-negativity (≤ 10–4 nucleated cells), with 12 (52%) achieving a stringent complete response. Extramedullary plasmacytoma was eliminated completely in 56% and partially in 33% and of 9 patients. The median progression-free survival was 17.2 months. Two relapsed patients maintained BCMA and CD38 expression on MM cells. Notably, BM38 CAR-Ts cells were detectable in 77.8% of evaluable patients at 9 months and 62.2% at 12 months. Conclusion Bispecific BM38 CAR-Ts were feasible, safe and significantly effective in patient with RRMM. Trial registration: Chictr.org.cn ChiCTR1800018143.