Novel biallelic SZT2 mutations in 3 cases of early-onset epileptic encephalopathy

The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.

CXorf48 is a potential therapeutic target for achieving treatment-free remission in CML patients

Although the introduction of tyrosine kinase inhibitors (TKIs) has improved overall survival of patients with chronic myeloid leukemia (CML), about half of the patients eventually relapse after cessation of TKIs. In contrast, the remainder of the patients maintain molecular remission without TKIs, indicating that the patients' immune system could control proliferation of TKI-resistant leukemic stem cells (LSCs). However, the precise mechanism of immunity against CML-LSCs is not fully understood. We have identified a novel immune target, CXorf48, expressed in LSCs of CML patients. Cytotoxic T cells (CTLs) induced by the epitope peptide derived from CXorf48 recognized CD34⁺CD38^- cells obtained from the bone marrow of CML patients. We detected CXorf48-specific CTLs in the peripheral blood mononuclear cells from CML patients who have discontinued imatinib after maintaining complete molecular remission for more than 2 years. Significantly, the relapse rate of CXorf48-specific CTL-negative patients was 63.6%, compared to 0% in CXorf48-specific CTL-positive patients. These results indicate that CXorf48 could be a promising therapeutic target of LSCs for immunotherapy to obtain durable treatment-free remission in CML patients.

IκBNS induces Muc5ac expression in epithelial cells and causes airway hyper-responsiveness in murine asthma models

BACKGROUND

In allergic asthma, environmental allergens including house dust mite (HDM) trigger pattern recognition receptors and activate downstream signaling pathways including NF-κB pathways not only in immune cells but also in airway epithelial cells. Recent studies have shown that NF-κB activation is regulated positively or negatively depending on the cellular context by IκBNS (encoded by the gene Nfkbid), one of atypical IκB proteins, in the nucleus. Therefore, we hypothesized that IκBNS expressed in immune cells or epithelial cells is involved in the regulation of asthmatic responses.

AIM

To determine the roles of IκBNS in HDM-induced asthmatic responses.

METHODS

Roles of IκBNS in HDM-induced airway inflammation and airway hyper-responsiveness (AHR) were examined by using IκBNS-deficient (Nfkbid^-/- ) mice. Roles of IκBNS expressed in hematopoietic cells and nonhematopoietic cells were separately evaluated by bone marrow chimeric mice. Roles of IκBNS expressed in murine tracheal epithelial cells (mTECs) were examined by air-liquid interface culture.

RESULTS

House dust mite-induced airway inflammation and AHR were exacerbated in mice lacking IκBNS in hematopoietic cells. In contrast, HDM-induced airway inflammation was exacerbated, but AHR was attenuated in mice lacking IκBNS in nonhematopoietic cells. The induction of Muc5ac, a representative mucin in asthmatic airways, was reduced in Nfkbid^-/- mTEC, whereas the induction of Spdef, a master regulator of goblet cell metaplasia, was not impaired in Nfkbid^-/- mTEC. Moreover, IκBNS bound to and activated the MUC5AC distal promoter in epithelial cells.

CONCLUSION

IκBNS is involved in inducing Muc5ac expression in lung epithelial cells and causing AHR in HDM-induced asthma models.

Comparison of postoperative biomechanical function between anatomic double-bundle and single-bundle ACL reconstructions using calcium phosphate-hybridized tendon grafts in goats

BACKGROUND

Calcium phosphate (CaP)-hybridized tendon grafts improved biomechanical function compared with untreated grafts after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the biomechanical function between anatomic double-bundle (DB) and single-bundle (SB) ACL reconstructions using CaP-hybridized tendon grafts at 6 months postoperatively in goats.

HYPOTHESIS

We hypothesized that the postoperative biomechanical function in the DB group will be better than that in the SB group.

MATERIALS AND METHODS

Knee kinematics and in situ forces in the grafts under applied anterior tibial load (ATL) of 50N and internal tibial torque (ITT) of 2.0 Nm at full extension, and 60° and 90° of knee flexion, and the histology of the tendon-bone interface were compared between the DB group (n=6) and SB group (n=6).

RESULTS

The in situ forces under ATL in the DB group at full extension and 90°of knee flexion were greater than those in the SB group. The in situ forces under ITT in the DB group at full extension and 60°of knee flexion were greater than those in the SB group. The in situ forces on the posterolateral bundle of the grafts under ATL and ITT in the DB group at full knee extension were greater than those on the posterior half of the grafts in the SB group. The histology did not differ significantly between the groups.

CONCLUSIONS

Although CaP-hybridized tendon grafts were used in both groups, the in situ forces under ATL and ITT in the DB group were greater than those in the SB group at 6 months postoperatively. The posterolateral bundle of the grafts in the DB group acted effectively against both ATL and ITT at full extension. The tendon-to-bone healing was similar in both groups.

STUDY DESIGN

Controlled laboratory study. Level 2.

Serum ferritin level is a prognostic marker in patients with peripheral T-cell lymphoma

INTRODUCTION

The prognostic value of serum ferritin level in patients with peripheral T-cell lymphoma (PTCL) remains unknown.

METHODS

We retrospectively analyzed clinical data from 78 consecutive patients with newly diagnosed PTCL that were treated with anthracycline-containing regimens between 1998 and 2011.

RESULTS

The patients consisted of 50 males and 28 females with a median age of 64 years (range, 16-83 years). The subtypes of PTCL were 39 PTCL, not otherwise specified and 39 angioimmunoblastic T-cell lymphoma (AITL). The median observation period for the surviving patients was 50 months. The overall survival (OS) was poorer in patients with serum ferritin level above the upper normal limit (n = 28), compared with patients with serum ferritin level within normal range (n = 50; 4-year OS: 23% vs. 72%; P < 0.001). In the multivariate analysis, poor performance status (P = 0.006) and elevated serum ferritin level (P = 0.018) were independent risk factors for poor OS.

CONCLUSION

Serum ferritin level is a useful prognostic marker for PTCL.

Electrostatic model of the energy-bending within organic semiconductors: experiment and simulation

The interfacial properties between electrodes and the various organic layers that comprise an organic electronic device are of direct relevance in understanding charge injection, extraction and generation. The energy levels and energy-bending of three interfaces; indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (

PEDOT

PSS), ITO/poly(N-vinylcarbazole) (PVK) and

PEDOT

PSS/PVK were measured using ultraviolet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS). By decoupling the vacuum shift and energy-bending, the energy-bending at these interfaces can be simulated using an electrostatic model that takes into account the energetic disorder of the polymers. The model is further extended to include blended mixtures of semiconductors at differing concentrations and it was found that a very good agreement exists between the experiment and theory for all interfaces. This suggests that the electrostatic model can be used to describe energy-bending at the interface between any organic semiconductors. Further investigation into the effect of the Gaussian density of states width on energy-bending is warranted.

Creation of a Thermally Tolerant Peroxidase

An artificial peroxidase with thermal tolerance and high catalytic activity has been successfully prepared by mutagenesis of an electron transfer protein, cytochrome c552 from Thermus thermophilus. The mutant enzymes were rationally designed based on the general peroxidase mechanism and spectroscopic analyses of an active intermediate formed in the catalytic reaction. Stopped flow UV-vis spectroscopy and EPR spectroscopy with a rapid freezing sample technique revealed that the initial double mutant, V49D/M69A, which was designed to reproduce the peroxidase mechanism, formed an active oxo-ferryl heme intermediate with a protein radical predominantly localized on Tyr45 during the catalytic reaction. The magnetic power saturation measurement obtained from EPR studies showed little interaction between the oxo-ferryl heme and the tyrosyl radical. Kinetics studies indicated that the isolated oxo-ferryl heme component in the active intermediate was a possible cause of heme degradation during the reaction with H2O2. Strong interaction between the oxo-ferryl heme and the radical was achieved by replacing Tyr45 with tryptophan (resulting in the Y45W/V49D/M69A mutant), which was similar to a tryptophanyl radical found in active intermediates of some catalase-peroxidases. Compared to the protein radical intermediates of V49D/M69A mutant, those of the Y45W/V49D/M69A mutant showed higher reactivity to an organic substrate than to H2O2. The Y45W/V49D/M69A mutant exhibited improved peroxidase activity and thermal tolerance.

Na(+) /Ca(2+) exchanger-heterozygote knockout mice display increased relaxation in gastric fundus and accelerated gastric transit in vivo

BACKGROUND

For the contraction and relaxation of gastric smooth muscles to occur, the intracellular Ca(2+) concentration must be increased and decreased, respectively. The Na(+) /Ca(2+) exchanger (NCX) is a plasma membrane transporter that is involved in regulating intracellular Ca(2+) concentrations.

METHODS

To determine the role of NCX in gastrointestinal tissues, we examined electric field stimulation (EFS)-induced relaxations in the circular muscles of the gastric fundus in NCX1 and NCX2 heterozygote knockout mice (HET).

KEY RESULTS

The myenteric plexus layers and the longitudinal and circular muscle layers in the gastric fundus of wild-type mice (WT) were strongly immunoreactive to NCX1 and NCX2. EFS induced a transient relaxation that was apparent during the stimulus and a sustained relaxation that persisted after the end of the stimulus. The amplitudes of EFS-induced transient relaxation and sustained relaxation were greater in NCX1 HET and NCX2 HET than in WT. When an inhibitor of nitric oxide synthase was added following the EFS, neither NCX1 HET nor NCX2 HET exhibited transient relaxation, similar to WT. Furthermore, when a PACAP antagonist was added following the EFS, sustained relaxation in NCX1 HET and NCX2 HET was not observed, similar to WT. Next, we examined the effect of NCX heterozygous deficiency on relaxation in response to NO and PACAP in smooth muscles. The magnitude of NOR-1- and PACAP-induced relaxations in NCX1 HET and NCX2 HET was similar to that of WT.

CONCLUSIONS & INFERENCES

In this study, we demonstrate that NCX1 and NCX2 expressed in neurons regulate the motility in the gastric fundus.