Tissue expression and cellular localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA in male mice

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an ubiquitous antioxidant enzyme, but the exact expression pattern in mammalian tissues is still unknown. The expression and cellular localization of PHGPx mRNA were examined in male mice using real time-polymerase chain reaction and in situ hybridization techniques. The rank order of PHGPx mRNA expression across tissues exhibiting substantial levels of expression was:testes ≫ heart > cerebrum ≥ ileum > stomach = liver = jejunum ≥ epididymis. In testes, PHGPx mRNA was highly expressed in spermiogenic cells and Leydig cells. The signal was also expressed in the molecular layer, Purkinje cell layer, and white matter of cerebellum, the pituicytes of neurohypophysis, the parafollicular cells and follicular basement membrane of thyroid, the exocrine portion of pancreas, the tubular epithelium of kidney, the smooth muscle cells of arteries, and the red pulp of spleen. In the gastrointestinal tract, PHGPx mRNA expression was mainly observed in the keratinized surface epithelium of forestomach, the submucosal glands and serosa layers, and further the Paneth cells of intestines. PHGPx mRNA appeared to be ubiquitously expressed in the parenchyma of heart, liver, and lung. These results indicate that PHGPx exhibits a cell- and tissue-specific expression pattern in mice.     

Laurus nobilis leaf extract controls inflammation by suppressing NLRP3 inflammasome activation

Laurus nobilis Linn. (Lauraceae), commonly known as Bay, has been used as a traditional medicine in the Mediterranean and Europe to treat diverse immunological disorders. Although the effects of L. nobilis on immunosuppression have been reported, the detailed underlying mechanism remains unclear. In this study, to elucidate the anti-inflammatory mechanism of L. nobilis, we examined the effect of L. nobilis leaf extract on inflammasome activation in mouse bone marrow-derived macrophages. L. nobilis leaf extract inhibited NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation, which was associated with caspase-1 activation, interleukin-1β secretion, and apoptosis-associated speck-like protein containing a CARD (ASC) pyroptosome complex formation. We also observed that 1,8-cineole, the major component of L. nobilis extract, consistently suppressed NLRP3 inflammasome activation. Furthermore, L. nobilis leaf extract attenuated the in vivo expression of proinflammatory cytokines in an acute lung injury mouse model. Our results provide the first evidence that L. nobilis leaf extract modulates inflammatory signaling by suppressing inflammasome activation.     

Regulation of N-type Voltage-Gated Calcium Channels and Presynaptic Function by Cyclin-Dependent Kinase 5

N-type voltage-gated calcium channels localize to?presynaptic nerve terminals and mediate key events?including synaptogenesis and neurotransmission.?While several kinases have been implicated in the modulation of calcium channels, their impact on presynaptic functions remains unclear. Here we report that the N-type calcium channel is a substrate for cyclin-dependent kinase 5 (Cdk5). The pore-forming α(1) subunit of the N-type calcium channel is phosphorylated in the C-terminal domain, and phosphorylation results in enhanced calcium influx due to increased channel open probability. Phosphorylation of the N-type calcium channel by Cdk5 facilitates neurotransmitter release and alters presynaptic plasticity by increasing the number of docked vesicles at the synaptic cleft. These effects are mediated by an altered interaction between N-type calcium channels and RIM1, which tethers presynaptic calcium channels to the active zone. Collectively, our results highlight a molecular mechanism by which N-type calcium channels are regulated by Cdk5 to affect presynaptic function.     

Hand breakaway strength model-effects of glove use and handle shapes on a person's hand strength to hold onto handles to prevent fall from elevation

This study developed biomechanical models for hand breakaway strength that account for not only grip force but also hand-handle frictional coupling in generation of breakaway strength. Specifically, models for predicting breakaway strength for two commonly-used handle shapes (circular and rectangular handles) and varying coefficients of friction (COF) between the hand and handle were proposed. The models predict that (i) breakaway strength increases with increasing COF and (ii) a circular handle with a 50.8 mm-diameter results in greater mean breakaway strength than a handle with a rectangular cross-section of 38.1 by 38.1 mm for COFs greater than 0.42. To test these model predictions, breakaway strengths of thirteen healthy young adults were measured for three frequently-encountered COF conditions (represented by three glove types of polyester (COF=0.32), bare hand (COF=0.50), and latex (COF=0.74) against an aluminum handle) and for the two handle shapes. Consistent with the model predictions, mean breakaway strength increased with increasing COF and was greater for the circular than rectangular handle for COFs of 0.50 and 0.74. Examination of breakaway strength normalized to body weight reveals that modification of COF and handle shapes could influence whether one can hold his/her body using the hands or not (thus must fall), highlighting the importance of considering these parameters for fall prevention. The biomechanical models developed herein have the potential to be applied to general handle shapes and COF conditions. These models can be used to optimize handle design to maximize breakaway strength and minimize injuries due to falls from ladders or scaffolds.     

Canine mesenchymal stem cells are effectively labeled with silica nanoparticles and unambiguously visualized in highly autofluorescent tissues

ABSTRACT: BACKGROUND: Developing a long-term labeling method is critical and much needed to understand the fate, migration, and contribution in tissue regeneration. Silica nanoparticles have been developed recently and have been demonstrated to be biocompatible and to have high labeling capacity. Thus, this study was designed to assess the suitability of silica nanoparticles for canine MSCs and fluorescence efficiency in a highly autofluorescent tissue. RESULTS: Development of a method for long-term labeling of cells is critical to elucidate transplanted cell fate and migration as well as the contribution to tissue regeneration. Silica nanoparticles have been recently developed and demonstrated to be biocompatible with a high labeling capacity. Thus, our study was designed to assess the suitability of silica nanoparticles for labeling canine mesenchymal stem cells (MSCs) and the fluorescence efficiency in highly autofluorescent tissue.We examined the effect of silica nanoparticle labeling on stem cell morphology, viability and differentiation as compared with those of unlabeled control cells. After 4 h of incubation with silica nanoparticles, they were internalized by canine MSCs without a change in the morphology of cells compared with that of control cells. The viability and proliferation of MSCs labeled with silica nanoparticles were evaluated by a WST-1 assay and trypan blue exclusion. No effects on cell viability were observed, and the proliferation of canine MSCs was not inhibited during culture with silica nanoparticles. Furthermore, adipogenic and osteogenic differentiation of silica nanoparticle-labeled canine MSCs was at a similar level compared with that of unlabeled cells, indicating that silica nanoparticle labeling did not alter the differentiation capacity of canine MSCs. Silica nanoparticle-labeled canine MSCs were injected into the kidneys of BALB/c mice after celiotomy, and then the mice were sacrificed after 2 or 3 weeks. The localization of injected MSCs was closely examined in highly autofluorescent renal tissues. Histologically, canine MSCs were uniformly and completely labeled with silica nanoparticles, and were unambiguously imaged in histological sections. CONCLUSIONS: The results of the current study showed that silica nanoparticles are useful as an effective labeling marker for MSCs, which can elucidate the distribution and fate of transplanted MSCs.     

Diastolic suction in heart failure: Impact of left ventricular geometry,untwist, and flow mechanics

Aims

Vector flow mapping (VFM) can be used to assess intraventricular hemodynamics quantitatively. This study assessed the magnitude of the suction flow kinetic energy with VFM and investigated the relation between left ventricular (LV) function and geometry in patients with an estimated elevated LV filling pressure.

Materials and methods

We studied 24 subjects with an elevated LV filling pressure (EFP group) and 36 normal subjects (normal group). Suction was defined as flow directed toward the apex during the period from soon after systolic ejection to before mitral inflow. The flow kinetic energy index was quantified as the sum of the product of the blood mass and velocity vector and its magnitude to the peak value was measured.

Key findings

Suction flow was observed in 12 (50%) EFP-group patients and 36 (100%) normal-group subjects. The magnitude of the suction kinetic energy index was significantly smaller in EFP versus normal group (2.7 ± 3.8 vs. 5.7 ± 4.4 g/s/cm², P < 0.01). The EFP-group patients with suction had a smaller LV end-systolic volume (ESV) (P < 0.01), greater ellipsoidal geometry (P < 0.05) and untwisting rate (P < 0.01) than the EFP-group patients without suction. A regression analysis indicated a significant linear relation between the suction kinetic energy index and LVEF (r = 0.43, P = 0.04), ESV (r = − 0.40, P = 0.05), eccentricity index (r = 0.44, P = 0.04), and untwisting rate (r = 0.51, P = 0.04).

Significance

The magnitude of the suction flow kinetic energy index derived from VFM may allow the quantitative assessment of the suction flow, which correlates with LV systolic function, geometry, and untwisting mechanics.