Muscle Tissue Damage and Recovery After EV71 Infection Correspond to Dynamic Macrophage Phenotypes

Enterovirus 71 (EV71) is a positive single-stranded RNA virus from the enterovirus genus of the Picornaviridae family. Most young children infected with EV71 develop mild symptoms of hand, foot and mouth disease, but some develop severe symptoms with neurological involvement. Limb paralysis from EV71 infection is presumed to arise mainly from dysfunction of motor neurons in the spinal cord. However, EV71 also targets and damages skeletal muscle, which may also contribute to the debilitating symptoms. In this study, we have delineated the impacts of EV71 infection on skeletal muscle using a mouse model. Mouse pups infected with EV71 developed limb paralysis, starting at day 3 post-infection and peaking at day 5-7 post-infection. At later times, mice recovered gradually but not completely. Notably, severe disease was associated with high levels of myositis accompanied by muscle calcification and persistent motor end plate abnormalities. Interestingly, macrophages exhibited a dynamic change in phenotype, with inflammatory macrophages (CD45⁺CD11b⁺Ly6C^hi) appearing in the early stage of infection and anti-inflammatory/restorative macrophages (CD45⁺CD11b⁺Ly6C^low/-) appearing in the late stage. The presence of inflammatory macrophages was associated with severe inflammation, while the restorative macrophages were associated with recovery. Altogether, we have demonstrated that EV71 infection causes myositis, muscle calcification and structural defects in motor end plates. Subsequent muscle regeneration is associated with a dynamic change in macrophage phenotype.

TLR7 Is Critical for Anti-Viral Humoral Immunity to EV71 Infection in the Spinal Cord

Enterovirus 71 (EV71) is a positive single-stranded RNA (ssRNA) virus from the enterovirus genus of Picornaviridae family and causes diseases ranged from the mild disease of hand, foot and mouth disease (HFMD) to the severe disease of neurological involvement in young children. TLR7 is an intracellular pattern recognition receptor (PRR) recognizing viral ssRNA. In this study, we investigated the role of TLR7 in EV71 infection in mouse pups (10-12 days old) and found that wild-type (WT) and TLR7 knock-out (TLR7KO) mice infected with EV71 showed similar limb paralysis at the onset and peak of the disease, comparable loss of motor neurons, and similar levels of antiviral molecules in the spinal cord. These results suggest that TLR7 is not the absolute PRR for EV71 in the spinal cord. Interestingly, TLR7KO mice infected with EV71 exhibited significantly delayed recovery from limb paralysis compared with WT mice. TLR7KO mice infected with EV71 showed significantly decreased levels of IgM and IgG2, important antibodies for antiviral humoral immunity. Furthermore, TLR7KO mice infected with EV71 showed a decrease of germinal center B cells in the spleen compared with WT mice. Altogether, our study suggests that TLR7 plays a critical role in anti-viral humoral immunity rather than in being a PRR in the spinal cord during EV71 infection in young mice.

IRF1 regulates IFN-λ1 expression in MDA5-mediated suppression of the HBV replication

MDA5, a member of the RIG-I like receptor family, has been shown to sense HBV DNA and trigger the production of anti-viral molecules to clear the virus. However, the mechanism underlying the suppression of HBV replication mediated by MDA5 signaling remains to be investigated. Our transcriptome analysis using RNA-seq revealed that IFN-λ1, a member of type III interferons, was the most upregulated molecule in Huh7 cells co-transfected with HBV DNA and MDA5 expression plasmid compared to with HBV DNA and RIG-I expression plasmid. Here we aim to investigate the IFN-λ1 expression in MDA5-mediated suppression of HBV replication. Huh7 cells co-transfected with HBV DNA and MDA5 expression plasmid led to increased IFN-λ1 expression associated with decreased HBsAg and HBV RNA. On the other hand, knockdown of MDA5 dramatically impaired IFN-λ1 expression. We next investigated the transcription factors involved in regulating IFN-λ1 expression. IRF1, but not IRF3 and IRF7, was upregulated in Huh7 cells co-transfected with HBV DNA and MDA5 expression plasmid. Knockdown of IRF1 led to reduced IFN-λ1 expression along with reduced inhibitory effect on HBV replication. The promoter region of IFN-λ1 contains ISREs, potential sites for IRF binding. However, ChIP and luciferase reporter assays showed no evidence of direct binding of IRF1 to the ISRE sites of IFN-λ1 promoter. Therefore, it is likely that IRF1 regulates MDA5-mediated IFN-λ1 expression through other mechanism. Mechanism(s) on IRF1 regulating IFN-λ1 expression in MDA5-mediated suppression of HBV replication is currently under investigation.

Suppression of polyglutamine protein toxicity by co-expression of a heat-shock protein 40 and a heat-shock protein 110

A network of heat-shock proteins mediates cellular protein homeostasis, and has a fundamental role in preventing aggregation-associated neurodegenerative diseases. In a Drosophila model of polyglutamine (polyQ) disease, the HSP40 family protein, DNAJ-1, is a superior suppressor of toxicity caused by the aggregation of polyQ containing proteins. Here, we demonstrate that one specific HSP110 protein, 70 kDa heat-shock cognate protein cb (HSC70cb), interacts physically and genetically with DNAJ-1 in vivo, and that HSC70cb is necessary for DNAJ-1 to suppress polyglutamine-induced cell death in Drosophila. Expression of HSC70cb together with DNAJ-1 significantly enhanced the suppressive effects of DNAJ-1 on polyQ-induced neurodegeneration, whereas expression of HSC70cb alone did not suppress neurodegeneration in Drosophila models of either general polyQ disease or Huntington's disease. Furthermore, expression of a human HSP40, DNAJB1, together with a human HSP110, APG-1, protected cells from polyQ-induced neural degeneration in flies, whereas expression of either component alone had little effect. Our data provide a functional link between HSP40 and HSP110 in suppressing the cytotoxicity of aggregation-prone proteins, and suggest that HSP40 and HSP110 function together in protein homeostasis control.

Elderly patients with resected stage II, IIIA non-small cell lung cancer, increased referral rate to medical oncologists, 1992-2002

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Background: Resectable non-small-cell lung cancer (NSCLC) has been once considered as a surgical disease and therefore managed by surgeons alone, as the primary therapeutic option was surgical resection. However, it is now widely accepted that the optimal care for NSCLC requires a multidisciplinary care approach between surgeons, radiation oncologists and medical oncologists. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) Program, we identified 3266 patients over 66 years with Stage II, IIIA NSCLC who underwent resection between 1992 and 2002. We examined the trend of medical oncology referral, indentified the predictors associated with medical oncology referral and subsequent use of adjuvant chemotherapy. Results: From 1992 to 2002, 1562 patients (47.8%) with resected stage II, IIIA NSCLC were referred to the medical oncologists; there was a steady rising trend in the proportion of the patients referral to medical oncology over the ten year period. The medical oncology referral rate increased from 26.9% in 1992 to 60.5% in 2002 (P<0.001). This change has paralleled to a rising trend in use of adjuvant chemotherapy in same population during same period. Among those seen by oncologists, 518 (33.2%) of patients received adjuvant chemotherapy. Female, white race, younger age, advanced tumor stage, adenocarcinoma, later year of diagnosis and being married were strong predictors to be seen by a medical oncologist. Patients older than 70 years of age, African American race and living in certain SEER geographic region were less likely to be referred to medical oncologists. Patients who had a medical oncology consultation were more likely to receive adjuvant chemotherapy (adjusted odds ratio [OR], 5.14; 95% CI, 4.11 to 6.43). Conclusions: The medical oncology referral rate doubled during last decade. Access to medical oncology consultation is linked to the use of adjuvant chemotherapy in the patients with resected Stage II, IIIA NSCLC. The steady increase in referral to medical oncologists paralleled an increase in the use of adjuvant chemotherapy. This changing pattern of medical oncology referral may mirror the changing attitude and perception towards to the benefits of adjuvant chemotherapy in the community.

No significant financial relationships to disclose.

Complement activation by neurofibrillary tangles in Alzheimer's disease

Brain inflammation is widely documented to occur in Alzheimer's disease (AD), but its sources are still incompletely understood. Here, we present in vitro and in situ evidence that, like amyloid beta peptide (Abeta), tau, the major protein constituent of the neurofibrillary tangle, is a potent, antibody-independent activator of the classical complement pathway. Complement activation, in turn, is known to drive numerous inflammatory responses, including scavenger cell activation and cytokine production. Because Abeta deposits and extracellular tangles are present from early preclinical to terminal stages of AD, their ability to activate complement provides a ready mechanism for initiating and sustaining chronic, low-level inflammatory responses that may cumulate over the disease course.

CT appearance of ectopic pancreas: a case report

The appearance of ectopic pancreas on computed tomography (CT) is described in a 47-year-old man with bowel obstruction. The enhancement pattern of ectopic pancreas after intravenous iodine contrast administration is the same as that of leiomyoma or carcinoid. This CT finding has not been reported previously to our knowledge.

A cysteine-rich isoform of neuregulin controls the level of expression of neuronal nicotinic receptor channels during synaptogenesis

We report here that neuregulin (NRG) isoforms with a conserved cysteine-rich domain (CRD) in their N terminus regulate expression of nicotinic acetylcholine receptors (nAChRs) at developing interneuronal synapses and report the isolation of transmembrane NRG isoforms with this CRD within the N-terminal portion. CRD-NRG mRNA and immunoreactive protein are detected early in developing presynaptic (visceral motor) neurons. The levels of expression of CRD-NRG peak prior to the formation of synapses with their postsynaptic partners, the ganglionic sympathetic neurons. Recombinant CRD-NRG mimics the effects of presynaptic input on target neurons. Functional deletion of CRD-NRG from presynaptic neurons abolishes the upregulation of nAChR expression induced by input-derived soluble material. Thus, CRD-NRG appears to be both a necessary and a sufficient signal for the control of neuronal nAChR expression during synaptogenesis.

Absence of biomagnetic effects in Nitella

The ability of N. flexilis and N. translucens to survive exposure to magnetic fields up to 1.6 T for extended periods of time was tested. Internodal cells subjected to such fields for as long as 72 h showed no evidence of damage. The active response of internodal cells was studied using an especially constructed sample chamber which allowed the use of intracellular microelectrodes. Action potentials in longitudinal and transverse fields as large as 2.0 T appeared identical to those in zero field. The results are in sharp contrast to observations reported by Arajs et al. (1975, Proceedings of the International Conference on Magnetism and Magnetic Materials).