Electrical Stimulation-Based Twitch Exercise Suppresses Progression of Immobilization-Induced Muscle Fibrosis via Downregulation of PGC-1?/VEGF Pathway

This study aimed to determine whether electrical stimulation-based twitch exercise is effective in inhibiting the progression of immobilization-induced muscle fibrosis. 19 Wistar rats were randomly divided into a control group (n=6), an immobilization group (n=6; with immobilization only), and a Belt group (n=7; with immobilization and twitch exercise through the belt electrode device, beginning 2 weeks after immobilization). The bilateral soleus muscles were harvested after the experimental period. The right soleus muscles were used for histological analysis, and the left soleus muscles were used for biochemical and molecular biological analysis. As a result, in the picrosirius red images, the perimysium and endomysium were thicker in both the immobilization and Belt groups compared to the control group. However, the perimysium and endomysium thickening were suppressed in the Belt group. The hydroxyproline content and alpha-SMA, TGF-beta1, and HIF-1alpha mRNA expressions were significantly higher in the immobilization and belt groups than in the control group. These expressions were significantly lower in the Belt group than in the immobilization group. The capillary-to-myofiber ratio and the mRNA expressions of VEGF and PGC-1alpha were significantly lower in the immobilization and belt groups than in the control group, these were significantly higher in the Belt group than in the immobilization group. From these results, Electrical stimulation-based twitch exercise using the belt electrode device may prevent the progression of immobilization-induced muscle fibrosis caused by downregulating PGC-1alpha/VEGF pathway, we surmised that this intervention strategy might be effective against the progression of muscle contracture. Keywords: Immobilization, Skeletal muscle, Fibrosis, Electrical stimulation-based twitch exercise, PGC-1alpha/VEGF pathway.

Skeletal Muscle Electrical Stimulation Prevents Progression of Disuse Muscle Atrophy via Forkhead Box O Dynamics Mediated by Phosphorylated Protein Kinase B and Peroxisome Proliferator-Activated Receptor gamma Coactivator-1alpha

Although electrical muscle stimulation (EMS) of skeletal muscle effectively prevents muscle atrophy, its effect on the breakdown of muscle component proteins is unknown. In this study, we investigated the biological mechanisms by which EMS-induced muscle contraction inhibits disuse muscle atrophy progression. Experimental animals were divided into a control group and three experimental groups: immobilized (Im; immobilization treatment), low-frequency (LF; immobilization treatment and low-frequency muscle contraction exercise), and high-frequency (HF; immobilization treatment and high-frequency muscle contraction exercise). Following the experimental period, bilateral soleus muscles were collected and analyzed. Atrogin-1 and Muscle RING finger 1 (MuRF-1) mRNA expression levels were significantly higher for the experimental groups than for the control group but were significantly lower for the HF group than for the Im group. Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) mRNA and protein expression levels in the HF group were significantly higher than those in the Im group, with no significant differences compared to the Con group. Both the Forkhead box O (FoxO)/phosphorylated FoxO and protein kinase B (AKT)/phosphorylated AKT ratios were significantly lower for the Im group than for the control group and significantly higher for the HF group than for the Im group. These results, the suppression of atrogin-1 and MuRF-1 expression for the HF group may be due to decreased nuclear expression of FoxO by AKT phosphorylation and suppression of FoxO transcriptional activity by PGC-1alpha. Furthermore, the number of muscle contractions might be important for effective EMS.

Role of LL-37 in Oral Bacterial DNA Accumulation in Dental Plaque

Dental plaque, a highly structured polymicrobial biofilm, persistently forms in the oral cavity and is a common problem affecting oral health. The role of oral defense factors in either collaborating or disrupting host-microbiome interactions remains insufficiently elucidated. This study aims to explore the role of LL-37, a critical antimicrobial peptide in the oral cavity, in dental plaque formation. Through immunostaining dental plaque specimens, we observed that LL-37 and DNA colocalized in the samples, appearing as condensed clusters. In vitro experiments revealed that LL-37 binds rapidly to oral bacterial DNA, forming high molecular weight, DNase-resistant complexes. This interaction results in LL-37 losing its inherent antibacterial activity. Further, upon the addition of LL-37, we observed a visible increase in the precipitation of bacterial DNA. We also discovered a significant correlation between the levels of the DNA-LL-37 complex and LL-37 within dental plaque specimens, demonstrating the ubiquity of the complex within the biofilm. By using immunostaining on dental plaque specimens, we could determine that the DNA-LL-37 complex was present as condensed clusters and small bacterial cell-like structures. This suggests that LL-37 immediately associates with the released bacterial DNA to form complexes that subsequently diffuse. We also demonstrated that the complexes exhibited similar Toll-like receptor 9-stimulating activities across different bacterial species, including Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, and Streptococcus salivarius. However, these complexes prompted dissimilar activities, such as the production of IL-1β in monocytic cells via both NLRP3 pathway-dependent and pathway-independent mechanisms. This study, therefore, reveals the adverse role of LL-37 in dental plaque, where it binds bacterial DNA to form complexes that may precipitate to behave like an extracellular matrix. Furthermore, the unveiled stimulating properties and species-dependent activities of the oral bacterial DNA-LL-37 complexes enrich our understanding of dental plaque pathogenicity and periodontal innate immune responses.

Effect of NLRP3 deficiency on cytotoxic and IL-1β-producing activities of synthetic candidalysin peptide

OBJECTIVES

Candidalysin (CL), a hydrophobic peptide toxin secreted by Candida albicans, is a key virulence factor that contributes to cytolysis, tissue damage, and immune activation. CL is thought to exert some of its biological activities, including IL-1β production, through the activation of the NLRP3-inflammasome pathway. To date, the mechanism by which CL affects human NLRP3 is not fully understood. We investigated specific activities of synthetic CL peptides using human-derived NLRP3-deficient cells.

METHODS

Two distinct synthetic CL peptide solutions were prepared: CLd, with CL completely solubilized as nanoparticles in dimethyl sulfoxide, and CLw, with CL partly solubilized in water, and including insoluble microparticles. THP-1 human monocytic cells and NLRP3-deficient THP-1 cells were differentiated into macrophages and stimulated with these peptide solutions. Cell membrane damage, lactate dehydrogenase release, IL-1β production, and caspase-1 activation in stimulated cells were subsequently evaluated.

RESULTS

Both CLd and CLw exhibited cytotoxic activities independent of NLRP3. Importantly, CLd induced IL-1β production and caspase-1 activation in an NLRP3-independent manner, whereas these activities in CLw-stimulated cells were entirely NLRP3-dependent, suggesting that the NLRP3-dependent response might be triggered by insoluble microparticles.

CONCLUSIONS

Our results demonstrate that inherent CL activities can cause cell damage and IL-1β production in an NLRP3-independent manner. Our research advances the elucidation of the role of NLRP3 in CL biological activity, underscoring the necessity for further exploration of the precise mechanisms underlying the NLRP3-independent effects of CL and providing novel insights into the complexity of host-pathogen interactions.

Radiation-Induced Changes Associated with Obliteration of Brain AVMs after Repeat Radiosurgery

BACKGROUND AND PURPOSE

Radiation-induced changes can occur after stereotactic radiosurgery for brain AVMs, potentially causing symptomatic complications. We evaluated the incidence of such changes and the efficacy of repeat gamma knife radiosurgery for incompletely obliterated AVMs.

MATERIALS AND METHODS

We retrospectively evaluated 150 patients who underwent gamma knife radiosurgery for AVMs between 2002 and 2020; twenty-five underwent further radiosurgical procedures for incompletely obliterated AVMs. We recorded the median margin doses at the first (median, 20 Gy; range, 12-23 Gy; AVM volume, 0.026-31.3 mL) and subsequent procedures (median, 18 Gy; range, 12-23 Gy; AVM volume, 0.048-9.2 mL).

RESULTS

After the first treatment, radiologic radiation-induced changes developed in 48 (32%) patients, eight of whom had symptomatic changes. After repeat gamma knife radiosurgery, 16 of 25 patients achieved complete AVM obliteration (64%). The development of radiation-induced changes after the first treatment was significantly associated with successful obliteration by subsequent radiosurgery (OR = 24.0, 95% CI 1.20-483, P  = .007). Radiation-induced changes occurred in only 5 (20%) patients who underwent a second gamma knife radiosurgery, one of whom experienced transient neurologic deficits. Between the first and repeat gamma knife radiosurgery procedures, there was no significant difference in radiologic and symptomatic radiation-induced changes (P  = .35 and P  = 1.0, respectively).

CONCLUSIONS

Radiation-induced changes after the first gamma knife radiosurgery were associated with AVM obliteration after a repeat procedure. The risk of symptomatic radiation-induced changes did not increase with retreatment. When the first procedure fails to achieve complete AVM obliteration, a favorable outcome can be achieved by a repeat gamma knife radiosurgery, even if radiation-induced changes occur after the first treatment.

Larger Posterior Revascularization Associated with Reduction of Choroidal Anastomosis in Moyamoya Disease: A Quantitative Angiographic Analysis

BACKGROUND AND PURPOSE

Choroidal anastomosis, a hemorrhage-prone periventricular collateral manifestation in Moyamoya disease, outflows to the cortex posterior to the central sulcus. The objective of the present study was to test whether the angiographic extent of revascularization posterior to the central sulcus contributes to the postoperative reduction of choroidal anastomosis.

MATERIALS AND METHODS

This retrospective cohort study included choroidal anastomosis-positive hemispheres before direct bypass surgery. The postoperative reduction of choroidal anastomosis was determined by a consensus of 2 raters according to the previous research. An imaging software automatically traced the angiographic revascularization area, which was subsequently divided into anterior and posterior parts by an anatomic line corresponding to the central sulcus. Each area was quantitatively measured as a percentage relative to the whole supratentorial area.

RESULTS

Postoperative reduction of choroidal anastomosis was achieved in 68 (85.0%) of the 80 included hemispheres. The revascularization area posterior to the central sulcus was significantly larger in the hemispheres with reduction than in those with no reduction (mean, 15.2% [SD, 7.1%] versus 4.2% [SD, 3.4%], P < .001), whereas no significant difference was observed in the revascularization area anterior to the central sulcus. Multivariate analysis revealed that the revascularization area posterior to the central sulcus was the only significant factor associated with reduction (OR, 1.57; 95% CI, 1.21-2.03, for every 1% increase).

CONCLUSIONS

The results suggest that a larger revascularization posterior to the central sulcus is associated with postoperative reduction of choroidal anastomosis regardless of the extent of anterior revascularization. It might facilitate optimal selection of the revascularization site for preventing hemorrhage.

Anatomical reconstruction of the Posterolateral Corner of the knee preserving dynamic function of the popliteus tendon complex

Almost cases of Posterolateral Corner (PLC) injuries are combined injuries involving the anterior or posterior cruciate ligament. Although numerous techniques of PLC reconstruction have been reported, it is unknown whether these techniques reconstruct PLC sufficiently. The anatomy of PLC is complex of tendon-muscle and ligament. The major structures are the fibular collateral ligament (FCL) and the Popliteus Tendon Complex. The latter comprises the popliteus tendon-muscle and the popliteo-fibular ligament (PFL). The FCL and PFL are static stabilizers, whereas the popliteus tendon-muscle is a dynamic stabilizer. The most of current PLC reconstructions statically restore all component parts, therefore not true “anatomically”. We describe an operative technique to reconstruct PLC anatomically. Our technique preserves dynamic stability of the popliteus tendon-muscle and reconstructs the PFL and FCL selectively.Semitendinosus tendon is harvested, and almost used for the anterior or posterior cruciate ligament reconstruction. Gracilis tendon or contralateral semitendinosus tendon is used for PLC. Femoral bone tunnel for FCL is prepared at anatomical insertion. Fibular bone tunnel is prepared to connect PFL insertion with FCL insertion. One end of the graft is sutured to the popliteus tendon. The other end is passed though the fibular tunnel, and fixed at the femoral tunnel. The interference screws are used at each tunnel. One half of the graft composes PFL part, the other half composes FCL part.

Advantages of this technique are preservation of dynamic popliteus tendon-muscle function, and simplifying preparation.

Effect of Myd88 deficiency on gene expression profiling in salivary glands of female non-obese diabetic (NOD) mice

OBJECTIVES

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by inflammatory lesions in the salivary and lacrimal glands, which are caused by distinct lymphocytic infiltrates. Female non-obese diabetic (NOD) mice spontaneously develop inflammatory lesions of the salivary glands with SS-like pathological features. Previous studies have shown that MyD88, a crucial adaptor protein that activates innate immune signaling, affects lymphocytic infiltration, but its detailed role remains unclear. In this study, we investigated the role of MyD88 through gene expression profiling in the early phase of pathogenesis in the salivary glands of female NOD mice.

METHODS

Submandibular glands collected from 10-week-old female wild-type and Myd88-deficient NOD mice were used for RNA preparation, followed by microarray analysis. The microarray dataset was analyzed to identify Myd88-dependent differentially expressed genes (DEGs). Data generated were used for GO enrichment, KEGG pathway, STRING database, and INTERFEROME database analyses.

RESULTS

Myd88 deficiency was found to affect 230 DEGs, including SS-associated genes, such as Cxcl9 and Bpifa2. Most of the DEGs were identified as being involved in immunological processes. KEGG pathway analysis indicated that the DEGs were putatively involved in autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. Furthermore, the DEGs included 149 interferon (IFN)-regulated genes.

CONCLUSIONS

MyD88 is involved in the expression of specific genes associated with IFN-associated immunopathological processes in the salivary glands of NOD mice. Our findings are important for understanding the role of MyD88-dependent innate immune signaling in SS manifestation.

Naringenin suppresses Toll-like receptor 2-mediated inflammatory responses through inhibition of receptor clustering on lipid rafts

Toll-like receptors (TLRs) are important innate immune receptors that sometimes cause excessive inflammatory responses and a perpetuated inflammatory loop that can be involved in inflammatory and autoimmune diseases. TLR2 recognizes bacterial lipoproteins in association with TLR1 or TLR6, and triggers inflammatory responses through activation of the transcription factor NF-κB. Naringenin, a type of citrus flavonoid, has been shown to possess anti-inflammatory properties, but its detailed action against TLR2 remains to be fully elucidated. The present study was designed to determine whether naringenin affects the inflammatory responses triggered by TLR2. Naringenin inhibited proinflammatory cytokine production and attenuated NF-κB activation in cells stimulated with a synthetic triacylated-type lipopeptide known as a TLR2/TLR1 ligand, as well as a synthetic diacylated-type lipopeptide known as a TLR2/TLR6 ligand. Moreover, a similar inhibitory effect was observed in cells stimulated with a crude lipophilic fraction extracted from Staphylococcus aureus cell walls and in cells stimulated with S. aureus cells. Furthermore, we showed that such an effect is caused by inhibition of TLR2 clustering in lipid rafts on the cell membrane. These results suggest that naringenin suppresses the inflammatory responses induced by TLR2 signal transduction. Our findings indicate a novel anti-inflammatory property of naringenin, mediated through the regulation of cell surface TLR2 functioning.

Citrobacter koseri stimulates dendritic cells to induce IL-33 expression via abundant ATP production

Introduction. Food allergies (FAs) occur due to intestinal immune dysfunction elicited by dysbiotic conditions. It was previously determined by us that Citrobacter species propagate in the faeces of mice with FAs and worsen allergic symptoms by inducing the allergenic cytokine IL-33. Dendritic cells can play important roles in regulation of FA responses.Hypothesis. Citrobacter species propagating in intestines of mice worsen allergic symptoms by stimulating dendritic cells to induce IL-33 expression.Aim. The aim of the present study was to analyse whether C. koseri stimulates dendritic cells to induce IL-33 expression.Methodology. IL-33 expression was evaluated in a DC2.4 mouse dendritic cell line stimulated by live or heat-inactivated C. koseri JCM1658, ATP, LPS extracted from C. koseri JCM1658 or other enterobacteria by real-time PCR. The ATP concentration and number of live bacteria in the culture supernatant were measured simultaneously.Results. Live C. koseri JCM1658 induced higher levels of IL-33 expression than other enterobacteria tested, but such a response was not elicited by heat-inactivated C. koseri JCM1658. LPS extracted from C. koseri JCM1658 did not induce IL-33 expression and suppressed live C. koseri JCM1658-induced IL-33 expression via the activation of Toll-like receptor 4 signalling. Furthermore, ATP produced by C. koseri JCM1658 stimulated dendritic cells to induce IL-33 expression by stimulating the P2X₇ receptor, and LPS attenuated extracellular ATP-induced IL-33 expression. C. koseri JCM1658 was observed to proliferate more vigorously and produce more ATP than other enterobacteria.Conclusion. C. koseri acts as an allergenic bacterium through ATP production, stimulating dendritic cells to induce IL-33 expression, while LPS released from inactivated C. koseri JCM1658 attenuates this allergenicity.

Cortical Distribution of Fragile Periventricular Anastomotic Collateral Vessels in Moyamoya Disease: An Exploratory Cross-Sectional Study of Japanese Patients with Moyamoya Disease

BACKGROUND AND PURPOSE

Collateral vessels in Moyamoya disease represent potential sources of bleeding. To test whether these cortical distributions vary among subtypes, we investigated cortical terminations using both standardized MR imaging and MRA.

MATERIALS AND METHODS

Patients with Moyamoya disease who underwent MR imaging with MRA in our institution were enrolled in this study. MRA was spatially normalized to the Montreal Neurological Institute space; then, collateral vessels were measured on MRA and classified into 3 types of anastomosis according to the parent artery: lenticulostriate, thalamic, and choroidal. We also obtained the coordinates of collateral vessel outflow to the cortex. Differences in cortical terminations were compared among the 3 types of anastomosis.

RESULTS

We investigated 219 patients with Moyamoya disease, and a total of 190 collateral vessels (lenticulostriate anastomosis, n = 72; thalamic anastomosis, n = 21; choroidal anastomosis, n = 97) in 46 patients met the inclusion criteria. We classified the distribution patterns of collateral anastomosis as follows: lenticulostriate collaterals outflowing anteriorly (P < .001; 95% CI, 67.0-87.0) and medially (P < .001; 95% CI, 11.0-24.0) more frequently than choroidal collaterals; lenticulostriate collaterals outflowing anteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 34.0-68.0); and choroidal collaterals outflowing posteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 14.0-34.0). Lenticulostriate anastomoses outflowed to the superior or inferior frontal sulcus and interhemispheric fissure. Thalamic anastomoses outflowed to the insular cortex and cortex around the central sulcus. Choroidal anastomoses outflowed to the cortex posterior to the central sulcus and the insular cortex.

CONCLUSIONS

Cortical distribution patterns appear to differ markedly among the 3 types of collaterals.

Streptococcal H2O2 inhibits IgE-triggered degranulation of RBL-2H3 mast cell/basophil cell line by inducing cell death

Mast cells and basophils are central players in allergic reactions triggered by immunoglobulin E (IgE). They have intracellular granules containing allergic mediators (e.g., histamine, serotonin, inflammatory cytokines, proteases and β-hexosaminidase), and stimulation by IgE-allergen complex leads to the release of such allergic mediators from the granules, that is, degranulation. Mast cells are residents of mucosal surfaces, including those of nasal and oral cavities, and play an important role in the innate defense system. Members of the mitis group streptococci such as Streptococcus oralis, are primary colonizers of the human oral cavity. They produce hydrogen peroxide (H₂O₂) as a by-product of sugar metabolism. In this study, we investigated the effects of streptococcal infection on RBL-2H3 mast cell/basophil cell line. Infection by oral streptococci did not induce degranulation of the cells. Stimulation of the RBL-2H3 cells with anti-dinitrophenol (DNP) IgE and DNP-conjugated human serum albumin triggers degranulation with the release of β-hexosaminidase. We found that S. oralis and other mitis group streptococci inhibited the IgE-triggered degranulation of RBL-2H3 cells. Since mitis group streptococci produce H₂O₂, we examined the effect of S. oralis mutant strain deficient in producing H₂O_2, and found that they lost the ability to suppress the degranulation. Moreover, H₂O₂ alone inhibited the IgE-induced degranulation. Subsequent analysis suggested that the inhibition of degranulation was related to the cytotoxicity of streptococcal H₂O₂. Activated RBL-2H3 cells produce interleukin-4 (IL-4); however, IL-4 production was not induced by streptococcal H₂O₂. Furthermore, an in vivo study using the murine pollen-induced allergic rhinitis model suggested that the streptococcal H₂O₂ reduces nasal allergic reaction. These findings reveal that H₂O₂ produced by oral mitis group streptococci inhibits IgE-stimulated degranulation by inducing cell death. Consequently, streptococcal H₂O₂ can be considered to modulate the allergic reaction in mucosal surfaces.

Identification of the Bleeding Point in Hemorrhagic Moyamoya Disease Using Fusion Images of Susceptibility-Weighted Imaging and Time-of-Flight MRA

BACKGROUND AND PURPOSE

The location of intracerebral hemorrhage in Moyamoya disease is a prognostic factor for rebleeding and the degree of preventive effects obtainable with bypass surgery. We evaluated whether the bleeding point and responsible vessel were detectable using fusion images of SWI and time-of-flight MRA performed during chronic-phase hemorrhage.

MATERIALS AND METHODS

We retrospectively enrolled 42 patients with hemorrhagic Moyamoya disease (48 hemorrhagic events). Fusion images of SWI and MRA were made using workstations, and we defined the bleeding point as the point at which the signal of an abnormally extended artery on MRA overlapped the hypointense area on SWI. Two independent raters identified the bleeding point, and classified the location and responsible vessels.

RESULTS

The bleeding point was detectable at a frequency of 79.2% by rater 1. Agreement for the presence of a bleeding point was high (interrater κ = 0.83; 95% CI, 0.65-1; intrarater κ = 0.86; 95% CI, 0.68-1). The frequency of a periventricular location of the bleeding point was 65.8% by rater 1, and agreement on the location was again high (interrater κ = 0.92; 95% CI, 0.82-1; intrarater κ = 0.85; 95% CI, 0.72-0.99). The choroidal artery was the most frequent responsible vessel (57.9% by rater 1), and agreement on the responsible vessel was high (interrater κ = 0.84; 95% CI, 0.69-1; intrarater κ = 0.90; 95% CI, 0.78-1).

CONCLUSIONS

Detection of the bleeding point in hemorrhagic Moyamoya disease using SWI and MRA fusion images offers highly reproducible results.

Daidzein-rich isoflavone aglycones inhibit cell growth and inflammation in endometriosis

Endometriosis is an estrogen-dependent disease, and isoflavones interact with estrogen receptors. The purposes of this study are to investigate the in vitro and in vivo effects of daidzein-rich isoflavone aglycones (DRIAs), dietary supplements, on cellular proliferation in endometriosis. Stromal cells isolated from ovarian endometrioma (OESCs) and normal endometrium (NESCs) were cultured with DRIAs, i.e., each of the DRIA components (daidzein, genistein, or glycitein), or isoflavone glycosides (IG; DRIA precursors). A mouse model of endometriosis was established by transplanting donor-mouse uterine fragments into recipient mice. Our results showed that DRIAs (0.2-20 μM) inhibited the proliferation of OESCs (P < 0.05 for 0.2 μM; P < 0.01 for 2 and 20 μM) but not of NESCs. However, daidzein, genistein, glycitein, and IG did not inhibit their proliferation. DRIA-induced suppression was reversed by inhibition of the estrogen receptor (ER)β by an antagonist, PHTPP, or by ERβ siRNA (P < 0.05), but not by MPP, an ERα antagonist. In OESCs, DRIAs led to reduced expression of IL-6, IL-8, COX-2, and aromatase, as well as reduced aromatase activity, serum glucocorticoid-regulated kinase levels, and PGE₂ levels (P < 0.05). Western blot and immunofluorescence assays revealed that DRIAs inhibited TNF-α-induced IκB phosphorylation and p65 uptake into the nuclei of OESCs. In the mouse model, a DRIA-containing feed significantly decreased the number, weight, and Ki-67 proliferative activity of endometriosis-like lesions compared to in mice fed with an IG-containing feed and the control feed (P < 0.01). In conclusion, DRIAs inhibit cellular proliferation in endometriosis, thus representing a potential therapeutic option for the management of endometriosis.

Influence of excess branched-chain amino acid uptake by Streptococcus mutans in human host cells

Oral streptococci, including cariogenic bacterium Streptococcus mutans, comprise a large percentage of human supragingival plaque, which contacts both tooth surfaces and gingiva. Eukaryotic cells are able to take up macromolecules and particles, including bacteria, by endocytosis. Increasing evidence indicates endocytosis may be used as an entry process by bacteria. We hypothesized that some endocytosed bacteria might survive and obtain nutrients, such as amino acids, until they are killed. To verify this hypothesis, we focused on bacterial utilization of branched-chain amino acids (BCAAs; isoleucine, leucine and valine) in host cells. A branched-chain aminotransferase, IlvE (EC 2.6.1.42), has been suggested to play an important role in internal synthesis of BCAAs in S. mutans UA159. Therefore, we constructed an ilvE-deficient S. mutans 109c strain and confirmed that it had similar growth behavior as reported previously. 14C radioactive leucine uptake assays showed that ilvE-deficient S. mutans took up more leucine both inside and outside of host cells. We further clarified that a relative decrease of BCAAs in host cells caused enhanced endocytic and autophagic activity. In conclusion, S. mutans is endocytosed by host cells and may survive and obtain nutrients, such as BCAAs, inside the cells, which might affect cellular functions of host cells.

The influence of aging on the effectiveness of heat stress in preventing disuse muscle atrophy

This study examined the aging effect on disuse muscle atrophy prevention using heat stress. Wistar rats aged 7 and 60 weeks were divided into three groups as follows: control, immobilized (Im), and immobilized and heat stressed (ImH). Heat stress was given by immersing the hindlimbs in hot water (42 °C) for 60 min, once in every 3 days and the gastrocnemius (GAS) and soleus (SOL) muscles were extracted after 14 days. Muscle-fiber types were classified using ATPase staining. Heat shock protein 70 (HSP70) was assessed through Western blotting. In GAS muscle of both groups and SOL muscle of 7-week-old rats, the fiber diameter of each muscle type in the ImH group significantly increased compared with that in the Im group. However, this could not be observed in the SOL muscle of the 60-week-old rats. The increased percentage of type-I fibers and variability of types I and II muscle-fiber diameter were evident in the SOL muscle of the 60-week rats. HSP70 was significantly elevated in the ImH group compared with in the Im group in both muscle types of both age groups. Thus, effectiveness of heat stress in the prevention of disuse muscle atrophy appears unsatisfactory in aging muscle fibers.

Caveolin-1, a binding protein of CD26, is essential for the anti-inflammatory effects of dipeptidyl peptidase-4 inhibitors on human and mouse macrophages

We previously reported that inhibition of dipeptidyl peptidase (DPP)-4, the catalytic site of CD26, prevents atherosclerosis in animal models through suppression of inflammation; however, the underlying molecular mechanisms have not been fully elucidated. Caveolin-1 (Cav-1), a major structural protein of caveolae located on the surface of the cellular membrane, has been reported to modulate inflammatory responses by binding to CD26 in T cells. In this study, we investigated the role of Cav-1 in the suppression of inflammation mediated by the DPP-4 inhibitor, teneligliptin, using mouse and human macrophages. Mouse peritoneal macrophages were isolated from Cav-1^+/+ and Cav-1^-/- mice after stimulation with 3% thioglycolate. Inflammation was induced by the toll-like receptor (TLR)4 agonist, lipopolysaccharide (LPS), isolated from Escherichia coli. The expression of pro-inflammatory cytokines was determined using reverse transcription-polymerase chain reaction. Co-expression of Cav-1 and CD26 was detected using immunohistochemistry in both mouse and human macrophages. Teneligliptin treatment (10 nmol/L) suppressed the LPS-induced expression of interleukin (IL)-6 (70%) and tumor necrosis factor-α (37%) in peritoneal macrophages isolated from Cav-1^+/+ mice. However, teneligliptin did not have any effect on the macrophages from Cav-1^-/- mice. In human monocyte/macrophage U937 cells, teneligliptin treatment suppressed LPS-induced expression of pro-inflammatory cytokines in a dose-dependent manner (1-10 nmol/L). These anti-inflammatory effects of teneligliptin were mimicked by gene knockdown of Cav-1 or CD26 using small interfering RNA transfection. Furthermore, neutralization of these molecules using an antibody against CD26 or Cav-1 also showed similar suppression. Teneligliptin treatment specifically inhibited TLR4 and TLR5 agonist-mediated inflammatory responses, and suppressed LPS-induced phosphorylation of IL-1 receptor-associated kinase 4, a downstream molecule of TLR4. Next, we determined whether teneligliptin could directly inhibit the physical interaction between Cav-1 and CD26 using the Biacore system. Binding of CD26 to Cav-1 protein was detected. Unexpectedly, teneligliptin also bound to Cav-1, but did not interfere with CD26-Cav-1 binding, suggesting that teneligliptin competes with CD26 for binding to Cav-1. In conclusion, we demonstrated that Cav-1 is a target molecule for DPP-4 inhibitors in the suppression of TLR4-mediated inflammation in mouse and human macrophages.

Identification of ecdysteroidogenic enzyme genes and their expression during pupal diapause in the cabbage armyworm, Mamestra brassicae

In this study, we identified ecdysteroidogenic enzymes in the cabbage armyworm, Mamestra brassicae, and demonstrated reduced expression of these genes during diapause. Some insects employ a temporary developmental arrest, diapause, to survive in severe environments. The titres of the moulting hormone ecdysteroid were reduced in diapause pupae of M. brassicae; therefore, ecdysteroidogenesis might be suppressed by a diapause-specific mechanism. To clarify expression changes of ecdysteroidogenic enzyme genes during diapause in M. brassicae, we first identified the genes for seven ecdysteroidogenic enzymes: Neverland, Non-molting glossy (Nm-g), CYP307A1 (Spook), CYP306A1 (Phantom), CYP302A1 (Disembodied), CYP315A1 (Shadow) and CYP314A1 (Shade). Enzymatic assays using heterologous expression in Drosophila Schneider 2 (S2) cells and analysis of mRNA distribution indicated that the identified genes were ecdysteroidogenic enzymes of M. brassicae. Expression levels of these ecdysteroidogenic enzyme genes were compared between prothoracic glands in different pupal stages throughout diapause. Immediately after pupation, diapause-destined pupae showed similar expression levels of ecdysteroidogenic enzyme genes to those of nondiapause pupae. All of these genes showed reduced gene expression after diapause initiation. Expression was immediately increased in diapause-destined pupae at the postdiapause quiescence phase. These results indicate that reduced expression of ecdysteroidogenic enzyme genes suppresses ecdysteroidogenesis and maintains developmental arrest during diapause.

Microarray analysis of macrophage response to infection with Streptococcus oralis reveals the immunosuppressive effect of hydrogen peroxide

Oral streptococci including mitis group streptococci are commensal residents and are also the first to colonize the oral cavity. However, various species of these oral streptococci have the potential to invade the host and occasionally lead to severe infectious disease such as cardiovascular diseases. Oral streptococci have close interactions with the host immune system including macrophages at the oral mucosal surface. One notable common trait of oral streptococcus including Streptococcus oralis (S. oralis) is the production of hydrogen peroxide (H₂O₂). Using a comprehensive microarray approach, we sought to understand the innate immune response profiling affected by H₂O₂ production from oral streptococci. We compared the gene expression patterns of macrophages infected with S. oralis wild type (WT) and streptococcal pyruvate oxidase knockout (SpxB-KO), a strain that does not produce H₂O₂. We found that H₂O₂ from S. oralis suppressed proinflammatory gene expression such as TNF-α, that is induced in response to infection, and activated the cellular stress genes such as Egr-1 in response to oxidative stress. A comparative gene ontology analysis of S. oralis WT and SpxB-KO strains revealed that during infection, down regulated genes were closely related to the processes involved in the host defense reaction and up regulated genes were related with the cellular stress responses. Using qPCR analysis, we also confirmed the same pattern of expression changes such as TNF-α, IL-6 and Egr-1. Furthermore, supernatant from SpxB-KO could not suppress the expression of TNF-α in macrophages stimulated with LPS. These findings suggested that H₂O₂ production from S. oralis leads to the suppression of inflammatory responses and NF-κB signaling pathways in macrophages as well as the induction of the oxidative stress response. We concluded that streptococcal H₂O₂ production has the beneficial effects of modulating the innate immune response, thereby stabilizing streptococcal colonization at the mucosal surface and even in the bloodstream leading to cardiovascular disease after invasion, in addition to the commensal role to compete other bacterial species as initial colonizer at oral cavity.

Nucleases from Prevotella intermedia can degrade neutrophil extracellular traps

Periodontitis is an inflammatory disease caused by periodontal bacteria in subgingival plaque. These bacteria are able to colonize the periodontal region by evading the host immune response. Neutrophils, the host's first line of defense against infection, use various strategies to kill invading pathogens, including neutrophil extracellular traps (NETs). These are extracellular net‐like fibers comprising DNA and antimicrobial components such as histones, LL‐37, defensins, myeloperoxidase, and neutrophil elastase from neutrophils that disarm and kill bacteria extracellularly. Bacterial nuclease degrades the NETs to escape NET killing. It has now been shown that extracellular nucleases enable bacteria to evade this host antimicrobial mechanism, leading to increased pathogenicity. Here, we compared the DNA degradation activity of major Gram‐negative periodontopathogenic bacteria, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. We found that Pr. intermedia showed the highest DNA degradation activity. A genome search of Pr. intermedia revealed the presence of two genes, nucA and nucD, putatively encoding secreted nucleases, although their enzymatic and biological activities are unknown. We cloned nucA‐ and nucD‐encoding nucleases from Pr. intermedia ATCC 25611 and characterized their gene products. Recombinant NucA and NucD digested DNA and RNA, which required both Mg²⁺ and Ca²⁺ for optimal activity. In addition, NucA and NucD were able to degrade the DNA matrix comprising NETs.

Human monoclonal antibodies against the complex of phosphatidylserine and prothrombin from patients with the antiphospholipid antibodies

The presence of antibodies against the complex of prothrombin and phosphatidylserine (aPS/PT) more significantly correlates with manifestations of antiphospholipid syndrome (APS) and with the presence of lupus anticoagulants (LA) than antibodies against prothrombin bound to oxygenated polystyrene (aPT-A). To investigate immunological specificities and functional activities of aPS/PT, four monoclonal aPS/PT, designated as HG-4, KE-6, KF-5 and KF-6, from two patients with antiphospholipid antibodies (aPL) were established and characterized. Three of these antibodies (HG-4, KF-5 and KF-6) recognized the complex of phosphatidylserine and prothrombin, but did not react to prothrombin directly coated on oxygenated plates. KE-6 bound not only to the complex of phosphatidylserine and prothrombin but also to prothrombin on oxygenated plates. None of them showed the binding activity to prothrombin directly coated on non-oxygenated plates. HG-4, KE-6 and KF-5 had LA-like activity. The findings support the hypothesis that autoimmune aPS/PT recognize the cryptic epitopes or neoepitopes exposed upon interaction between prothrombin and phosphatidylserine, and that aPS/PT are, at least in part, responsible for LA activity. Lupus (2007) 16, 509—516.

Phytochrome Signaling Is Mediated by PHYTOCHROME INTERACTING FACTOR in the Liverwort Marchantia polymorpha

Phytochromes are red light (R) and far-red light (FR) receptors that play important roles in many aspects of plant growth and development. Phytochromes mainly function in the nucleus and regulate sets of genes by inhibiting negatively acting basic helix-loop-helix transcription factors named PHYTOCHROME INTERACTING FACTORs (PIFs) in Arabidopsis thaliana Although R/FR photoreversible responses and phytochrome genes are well documented in diverse lineages of plants, the extent to which phytochrome signaling is mediated by gene regulation beyond angiosperms remains largely unclear. Here, we show that the liverwort Marchantia polymorpha, an emerging model basal land plant, has only one phytochrome gene, Mp-PHY, and only one PIF gene, Mp-PIF These genes mediate typical low fluence responses, which are reversibly elicited by R and FR, and regulate gene expression. Mp-phy is light-stable and translocates into the nucleus upon irradiation with either R or FR, demonstrating that the single phytochrome Mp-phy exhibits combined biochemical and cell-biological characteristics of type I and type II phytochromes. Mp-phy photoreversibly regulates gemma germination and downstream gene expression by interacting with Mp-PIF and targeting it for degradation in an R-dependent manner. Our findings suggest that the molecular mechanisms for light-dependent transcriptional regulation mediated by PIF transcription factors were established early in land plant evolution.

Use of a Latent Topic Model for Characteristic Extraction from Health Checkup Questionnaire Data

OBJECTIVES

When patients complete questionnaires during health checkups, many of their responses are subjective, making topic extraction difficult. Therefore, the purpose of this study was to develop a model capable of extracting appropriate topics from subjective data in questionnaires conducted during health checkups.

METHODS

We employed a latent topic model to group the lifestyle habits of the study participants and represented their responses to items on health checkup questionnaires as a probability model. For the probability model, we used latent Dirichlet allocation to extract 30 topics from the questionnaires. According to the model parameters, a total of 4381 study participants were then divided into groups based on these topics. Results from laboratory tests, including blood glucose level, triglycerides, and estimated glomerular filtration rate, were compared between each group, and these results were then compared with those obtained by hierarchical clustering.

RESULTS

If a significant (p < 0.05) difference was observed in any of the laboratory measurements between groups, it was considered to indicate a questionnaire response pattern corresponding to the value of the test result. A comparison between the latent topic model and hierarchical clustering grouping revealed that, in the latent topic model method, a small group of participants who reported having subjective signs of urinary disorder were allocated to a single group.

CONCLUSIONS

The latent topic model is useful for extracting characteristics from a small number of groups from questionnaires with a large number of items. These results show that, in addition to chief complaints and history of past illness, questionnaire data obtained during medical checkups can serve as useful judgment criteria for assessing the conditions of patients.

Heat treatment inhibits skeletal muscle atrophy of glucocorticoid-induced myopathy in rats

The purpose of this study was to investigate the influence of heat treatment on glucocorticoid (GC)-induced myopathy. Eight-week-old Wistar rats were randomly assigned to the control, Dex, and Dex + Heat groups. Dexamethasone (2 mg/kg) was injected subcutaneously 6 days per week for 2 weeks in the Dex and Dex + Heat group. In the Dex + Heat group, heat treatment was performed by immersing hindlimbs in water at 42 °C for 60 min, once every 3 days for 2 weeks. The extensor digitorum longus muscle was extracted following 2 weeks of experimentation. In the Dex + Heat group, muscle fiber diameter, capillary/muscle fiber ratio, and level of heat shock protein 72 were significantly higher and atrogene expression levels were significantly lower than in the Dex group. Our results suggest that heat treatment inhibits the development of GC-induced myopathy by decreasing atrogene expression and increasing angiogenesis.

Induction of tissue-specific stem cells by reprogramming factors, and tissue-specific selection

Although induced pluripotent stem (iPS) cells have significant implications for overcoming most of the ethical issues associated with embryonic stem (ES) cells, there are still several unresolved issues related to the use of iPS cells for clinical applications, such as teratoma formation. In this study, we were able to generate tissue-specific stem (induced tissue-specific stem; iTS) cells from the pancreas (iTS-P) or liver (iTS-L) by transient overexpression of reprogramming factors, combined with tissue-specific selection. The generation of iTS cells was easier than that of iPS cells. The iTS-P/iTS-L cells express genetic markers of endoderm and pancreatic/hepatic progenitors and were able to differentiate into insulin-producing cells/hepatocytes more efficiently than ES cells. Subcutaneous transplantation of both types of iTS cells into immunodeficient mice resulted in no teratoma formation. The technology used for the transient overexpression of reprogramming factors and tissue-specific selection may be useful for the generation of other tissue-specific stem cells, and the generation of iTS cells could have important implications for the clinical application of stem cells.

Prediction model for glucose metabolism based on lipid metabolism

OBJECTIVES

We developed a robust, long-term clinical prediction model to predict conditions leading to early diabetes using laboratory values other than blood glucose and insulin levels. Our model protects against missing data and noise that occur during long-term analysis.

METHODS

RESULTS of a 75-g oral glucose tolerance test (OGTT) were divided into three groups: diabetes, impaired glucose tolerance (IGT), and normal (n = 114, 235, and 325, respectively). For glucose metabolic and lipid metabolic parameters, near 30-day mean values and 10-year integrated values were compared. The relation between high-density lipoprotein cholesterol (HDL-C) and variations in HbA1c was analyzed in 158 patients. We also constructed a state space model consisting of an observation model (HDL-C and HbA1c) and an internal model (disorders of lipid metabolism and glucose metabolism) and applied this model to 116 cases.

RESULTS

The root mean square error between the observed HbA1c and predicted HbA1c was 0.25.

CONCLUSIONS

In the observation model, HDL-C levels were useful for prediction of increases in HbA1c. Even with numerous missing values over time, as occurs in clinical practice, clinically valid predictions can be made using this state space model.

Different expression patterns of hepatic cytochrome P450 s during anaphylactic or lipopolysaccharide-induced inflammation

Certain physiological states and diseases can alter the expression and activity of cytochrome P450 s (CYPs), which have the potential to cause unexpected adverse effects. We previously demonstrated that lipopolysaccharide (LPS)-induced inflammation attenuates the induction of CYPs by xenobiotics in mouse liver. In this study, to investigate whether anaphylaxis-induced inflammation affects the hepatic CYPs' expression, we examined the effects of ovalbumin (OVA)-induced anaphylaxis on constitutive CYP mRNA and protein expressions. We also compared these effects with those obtained with LPS treatment. In addition, we examined the tumor necrosis factor (TNF) alpha and interleukin (IL)-113 mRNA levels, because these cytokines are known to be induced by LPS treatment and anaphylactic reactions. LPS treatment decreased the constitutively expressed Cyp1a2, Cyp2c29, and Cyp3al 1 mRNAs, and increased the TNFalpha and IL-1beta mRNAs. LPS treatment also decreased the CYP1A2 and CYP3A protein levels. Anaphylaxis, on the other hand, did not change the levels of the constitutively expressed Cyp1a2, Cyp2c29, or Cyp3a1 1 mRNAs, although it increased the TNFalpha and IL-1beta mRNAs, as observed in the LPS-treated mice. These results suggest that anaphylaxis-induced inflammation had less effect than LPS-induced inflammation on these CYPs in the liver. In contrast, we observed that the expressions of Cyp2b10 mRNA and its protein were quite different from those of the other CYPs in both the anaphylactic and LPS-treated mice. Our findings strongly suggest that the alteration of the constitutive CYPs' expression levels during inflammation varies according to the immunostimulation pathway.