Inhibitory effect of Zingiber cassumunar Roxb. (Phlai) on nasal cytokine productions and eosinophilic recruitment in patients with allergic rhinitis.

BACKGROUND: Zingiber cassumunar Roxb. (Phlai) has been used for the treatment of allergies including allergic rhinitis (AR). Although the anti-histamine effects have been reported, assessment of nasal cytokine and eosinophil production had not been investigated. OBJECTIVE: This study aimed to examine the effect of Phlai on alterations in nasal pro-inflammatory cytokine levels and eosinophil counts in nasal mucosa. METHODS: This was a randomized, double-blind, three-way crossover study. Nasal concentrations of cytokines, namely interleukin (IL)-4, IL-5, IL-13 and interferron-gamma (IFN-γ), nasal smear eosinophilia as well as total nasal symptom score (TNSS) were evaluated before and after a 4 weeks treatment with 200 mg Phlai capsules or placebo in 30 AR patients. RESULTS: We observed significant (p < 0.05) reduction in IL-5, IL-13 as well as the number of eosinophils in subjects given Phlai. The degree of improvement of TNSS after Phlai treatment was initially manifested in week 2 with the greatest effect in week 4. In contrast, there were no significant differences in all nasal cytokines, eosinophil counts or TNSS between before and after receiving placebo. CONCLUSIONS: These findings provided the first evidence for the anti-allergic effect of Phlai which possibly involved inhibition of nasal pro-inflammatory cytokines production and eosinophilic recruitment. Phlai thus represents a promising herbal medicine for alleviating inflammation and AR symptoms.

Antituberculosis drug-induced non-blistering systemic severe reactions: A 10-year (2012-2022) literature review.

Drug reaction with eosinophilia and systemic symptoms (DRESS) and drug-induced liver injury (DILI) can hamper therapeutic strategy, contribute to multiple drug resistance and serious public health burden. Diagnosis (including allergy assessment) and management of these two severe hypersensitivity reactions in clinical practice are somewhat difficult and published scientific evidence is rather weak and limited. The first step is always represented by stopping all anti-tuberculosis (TB) drugs, treating reaction with systemic corticosteroids, and identifying the offending drug, even if it is often complicated by the patient's simultaneous intake of antibiotics. Patch tests and in vitro tests, such as lymphocyte transformation test, could bridge this diagnostic gap, but the available data are scarce and their sensitivity low. The re-challenge test is often necessary but places patients at risk for serious adverse reactions. The desensitization protocols are quite varied and not universally accepted. In this narrative review, we provide an update to the literature data on the management of DRESS and DILI with particular attention to the allergological work-up in the last decade.

Investigation on the physical properties and biocompatibility of zirconia-alumina-silicate@diopside composite materials and its in vivo toxicity study in embryonic zebrafish.

Bioceramic materials have a wide range of applications in the biomedical field, such as in the repair of bone defects and dental surgery. Silicate-based bioceramics have attracted biomedical researchers' interest due to their bioactivity and biodegradability. In this study, extended the scope of ZAS utilization in bone tissue engineering by introducing calcium-magnesium-silicate (diopside, CMS) as an interface material aim to develop a machinable bioceramic composite (ZASCMS) by the sol-gel method. The physicochemical characterization, in vitro biological properties and in vivo zebrafish cytotoxicity study of ZAS-based composites as a function of CMS contents, 0, 25, 50, 75 and 100 wt%, were performed. Results showed that the as-prepared ZASCMS possessed porous architecture with well-interconnected pore structure. Results also revealed that the mechanical properties of ZASCMS composite materials were gradually improved with increasing CMS contents. The ZASCMS composites with more than 50 wt% CMS had the highest compressive strength and modulus of 6.78 ± 0.62 MPa and 340.10 ± 16.81 MPa, respectively. Regarding in vitro bioactivities, the composite scaffolds were found to stimulate osteoblast-like UMR-106 cell adhesion, growth, and proliferation. The antibacterial activity of the ZASCMS composite scaffolds was tested against Staphylococcus epidermidis (S. epidermidis) and Escherichia coli (E. coli) also exhibited an antibacterial property. Furthermore, the in vivo studies using embryonic zebrafish were exposed to as-prepared particles (0-500 µg mL-1) and showed that the synthesized ZAS, CMS and ZASCMS composite particles were non-toxic based on the evaluation of survivability, hatching rate and embryonic morphology. In conclusions, our results indicated that the synthesized composite exhibited their biological properties and antibacterial activity, which could well be a promising material with high potential to be applied in orthopaedic and dental tissue engineering.

Running exercise with and without calcium supplementation from tuna bone reduced bone impairment caused by low calcium intake in young adult rats.

Inadequate calcium intake during childhood and adolescence is detrimental to bone metabolism. Here, we postulated that calcium supplement prepared from tuna bone with tuna head oil should benefit for skeletal development than CaCO3. Forty female 4-week-old rats were divided into calcium-replete diet (0.55% w/w, S1, n = 8) and low-calcium groups (0.15% w/w for 2 weeks; L; n = 32). Then L were subdivided into 4 groups (8/group), i.e., remained on L, L + tuna bone (S2), S2 + tuna head oil + 25(OH)D3 and S2 + 25(OH)D3. Bone specimens were collected at week 9. We found that 2 weeks on low calcium diet led to low bone mineral density (BMD), reduced mineral content, and impaired mechanical properties in young growing rats. Intestinal fractional calcium absorption also increased, presumably resulting from higher plasma 1,25(OH)2D3 (1.712 ± 0.158 in L vs. 1.214 ± 0.105 nM in S1, P < 0.05). Four-week calcium supplementation from tuna bone further increased calcium absorption efficacy, which later returned to the basal level by week 9. Calcium supplementation successfully restored BMD, bone strength and microstructure. However, 25(OH)D3 + tuna head oil + tuna bone showed no additive effect. Voluntary running also effectively prevented bone defects. In conclusion, both tuna bone calcium supplementation and exercise are effective interventions for mitigating calcium-deficient bone loss.

Development of Biomaterials Based on Biomimetic Trace Elements Co-Doped Hydroxyapatite: Physical, In Vitro Osteoblast-like Cell Growth and In Vivo Cytotoxicity in Zebrafish Studies.

Synthesized hydroxyapatite (sHA)-calcium phosphate (CaP) based biomaterials play a vital role and have been widely used in the process of bone regeneration for bone defect repair, due to their similarities to the inorganic components of human bones. However, for bone tissue engineering purpose, the composite components, physical and biological properties, efficacy and safety of sHA still need further improvements. In this work, we synthesized inhomogeneous hydroxyapatite based on biomimetic trace elements (Mg, Fe, Zn, Mn, Cu, Ni, Mo, Sr, Co, BO33-, and CO32-) co-doped into HA (THA) (Ca10-δMδ(PO4)5.5(CO3)0.5(OH)2, M = trace elements) via co-precipitation from an ionic solution. The physical properties, their bioactivities using in vitro osteoblast cells, and in vivo cytotoxicity using zebrafish were studied. By introducing biomimetic trace elements, the as-prepared THA samples showed nanorod (needle-like) structures, having a positively charged surface (6.49 meV), and showing paramagnetic behavior. The bioactivity studies demonstrated that the THA substrate can induce apatite particles to cover its surface and be in contact with surrounding simulated body fluid (SBF). In vitro biological assays revealed that the osteoblast-like UMR-106 cells were well-attached with growth and proliferation on the substrate's surface. Upon differentiation, enhanced ALP (alkaline phosphatase) activity was observed for bone cells on the surface of the THA compared with that on the control substrates (sHA). The in vivo performance in embryonic zebrafish studies showed that the synthesized THA particles are nontoxic based on the measurements of essential parameters such as survivability, hatching rate, and the morphology of the embryo. The mechanism of the ions release profile using digital conductivity measurement revealed that sustained controlled release was successfully achieved. These preliminary results indicated that the synthesized THA could be a promising material for potential practical applications in bone tissue engineering.

CFTR-mediated anion secretion in parathyroid hormone-treated Caco-2 cells is associated with PKA and PI3K phosphorylation but not intracellular pH changes or Na+/K+-ATPase abundance.

Parathyroid hormone (PTH) has previously been shown to enhance the transepithelial secretion of Cl- and HCO3 - across the intestinal epithelia including Caco-2 monolayer, but the underlying cellular mechanisms are not completely understood. Herein, we identified the major signaling pathways that possibly mediated the PTH action to its known target anion channel, i.e., cystic fibrosis transmembrane conductance regulator anion channel (CFTR). Specifically, PTH was able to induce phosphorylation of protein kinase A and phosphoinositide 3-kinase. Since the apical HCO3 - efflux through CFTR often required the intracellular H+/HCO3 - production and/or the Na+-dependent basolateral HCO3 - uptake, the intracellular pH (pHi) balance might be disturbed, especially as a consequence of increased endogenous H+ and HCO3 - production. However, measurement of pHi by a pH-sensitive dye suggested that the PTH-exposed Caco-2 cells were able to maintain normal pH despite robust HCO3 - transport. In addition, although the plasma membrane Na+/K+-ATPase (NKA) is normally essential for basolateral HCO3 - uptake and other transporters (e.g., NHE1), PTH did not induce insertion of new NKA molecules into the basolateral membrane as determined by membrane protein biotinylation technique. Thus, together with our previous data, we concluded that the PTH action on Caco-2 cells is dependent on PKA and PI3K with no detectable change in pHi or NKA abundance on cell membrane.

Nephrectomy Does not Exacerbate Cancellous Bone loss in Thalassemic Mice.

Patients with ß-thalassemia have an increased risk of developing chronic kidney disease which is associated with osteoporosis and periodontitis. The purpose of this study was to evaluate mandibular and femoral bone change in heterozygous ß-globin knockout (BKO) mice following 5/6 nephrectomy (Nx). Female and male BKO mouse blood smears demonstrated microcytic hypochromic anemia. Serum urea nitrogen, creatinine, calcium, and phosphorus levels were not changed in BKO mice. Nx increased the serum levels of urea nitrogen in both wild type (WT) and BKO mice and the level was much higher in BKO males. Serum level of creatinine was increased in Nx WT but not BKO mice. However, serum calcium and phosphorus levels were not altered. Nx induced comparable renal fibrosis in BKO mice and WT controls. Bone loss was observed in mandibular cancellous bone but not cortical bone of both male and female BKO mice. Nx decreased cancellous bone volume and cortical thickness in WT. Interestingly, BKO mice were resistant to Nx-induced cancellous bone loss. However, cortical thickness and cortical bone mineral density were reduced in Nx male BKO mice. Nx increased mRNA levels of type I collagen, Osx and Trap in WT but not BKO mice. Similarly, Nx reduced cancellous bone volume in femurs and increased osteoblast number and osteoclast number in WT not BKO mice. Serum FGF23 and erythropoietin levels were markedly increased in BKO mice. Nx decreased serum erythropoietin but not FGF23 levels. Since WT treated with erythropoietin exhibited a significant reduction in cancellous bone volume, it was possible that lower level of erythropoietin in Nx BKO mice prevented the Nx-induced cancellous bone loss.

Effect of zirconia-mullite incorporated biphasic calcium phosphate/biopolymer composite scaffolds for bone tissue engineering.

New bioactive scaffolds with improved mechanical properties, biocompatibility and providing structural support for bone tissue are being developed for use in the treatment of bone defects. In this study, we have synthesized bioactive scaffolds consisting of biphasic calcium phosphate (BCP) and zirconia-Mullite (2ZrO2·[3Al2O3 ·2 SiO2] (ZAS)) (BCPZAS) combined with polymers matrix of polycaprolactone (PCL)-alginate (Alg)-chitosan (Chi) (Chi/Alg-PCL) (BCPZAS@Chi/Alg-PCL). The composite material scaffolds were prepared by a blending technique. The microstructure, mechanical, bioactivity and in vitro biological properties with different ratios of BCP to ZAS of 1:0, 3:1, 1:1, 1:3 and 0:1 wt% in polymer matrix were analyzed. Microstructure analysis showed a successful incorporation of the BCPZAS particles with an even distribution of them within the polymer matrix. The mechanical properties were found to gradually decrease with increasing the ratio of ZAS particles in the scaffolds. The highest compressive strength was 42.96 ± 1.01MPa for the 3:1 wt% BCP to ZAS mixing. Bioactivity test, the BCPZAS@Chi/Alg-PCL composite could induce apatite formation in simulate body fluid (SBF). In-vitro experiment using UMR-106 osteoblast-like cells on BCPZAS@Chi/Alg-PCL composite scaffold showed that there is cell attachment to the scaffolds with proliferation. These experimental results demonstrate that the BCPZAS@Chi/Alg-PCL composite especially for the BCP:ZAS at 3:1 wt% could be utilized as a scaffold for bone tissue engineering applications.

Anomalous bone changes in ovariectomized type 2 diabetic rats: inappropriately low bone turnover with bone loss in an estrogen-deficient condition.

Estrogen deprivation accelerates bone resorption, leading to imbalance of bone remodeling and osteoporosis in postmenopausal women. In the elderly, type 2 diabetes mellitus (T2DM) frequently coexists as an independent factor of bone loss. However, little is known about the skeletal changes in a combined condition of estrogen deficiency and T2DM. Herein, we performed ovariectomy (OVX) in nonobese Goto-Kakizaki (GK) T2DM rats to examine changes associated with calcium and phosphate metabolism and bone microstructures and strength. As expected, wild-type (WT) rats subjected to ovariectomy (OVX-WT) had low trabecular bone volume and serum calcium with increased dynamic histomorphometric and serum bone markers, consistent with the high turnover state. T2DM in GK rats also led to low trabecular volume and serum calcium. However, the dynamic histomorphometric markers of bone remodeling were unaffected in these GK rats, indicating the distinct mechanism of T2DM-induced bone loss. Interestingly, OVX-GK rats were found to have anomalous and unique changes in bone turnover-related parameters, i.e., decreased osteoblast and osteoclast surfaces with lower COOH-terminal telopeptide of type I collagen levels compared with OVX-WT rats. Furthermore, the levels of calciotropic hormones, i.e., parathyroid hormone and 1,25(OH)2D3, were significantly decreased in OVX-GK rats. Although the OVX-induced bone loss did not further worsen in GK rats, a three-point bending test indicated that OVX-GK bones exhibited a decrease in bone elasticity. In conclusion, T2DM and estrogen deficiency both led to microstructural bone loss, the appearance of which did not differ from each factor alone. Nevertheless, the combination worsened the integrity and suppressed the turnover, which might eventually result in adynamic bone disease.

Factors inhibiting intestinal calcium absorption: hormones and luminal factors that prevent excessive calcium uptake.

Besides the two canonical calciotropic hormones, namely parathyroid hormone and 1,25-dihydroxyvitamin D [1,25(OH)2D3], there are several other endocrine and paracrine factors, such as prolactin, estrogen, and insulin-like growth factor that have been known to directly stimulate intestinal calcium absorption. Generally, to maintain an optimal plasma calcium level, these positive regulators enhance calcium absorption, which is indirectly counterbalanced by a long-loop negative feedback mechanism, i.e., through calcium-sensing receptor in the parathyroid chief cells. However, several lines of recent evidence have revealed the presence of calcium absorption inhibitors present in the intestinal lumen and extracellular fluid in close vicinity to enterocytes, which could also directly compromise calcium absorption. For example, luminal iron, circulating fibroblast growth factor (FGF)-23, and stanniocalcin can decrease calcium absorption, thereby preventing excessive calcium uptake under certain conditions. Interestingly, the intestinal epithelial cells themselves could lower their rate of calcium uptake after exposure to high luminal calcium concentration, suggesting a presence of an ultra-short negative feedback loop independent of systemic hormones. The existence of neural regulation is also plausible but this requires more supporting evidence. In the present review, we elaborate on the physiological significance of these negative feedback regulators of calcium absorption, and provide evidence to show how our body can efficiently restrict a flood of calcium influx in order to maintain calcium homeostasis.

Fabrication of biocomposite scaffolds made with modified hydroxyapatite inclusion of chitosan-grafted-poly(methyl methacrylate) for bone tissue engineering.

In the present study, composite scaffolds of chitosan-graft-poly(methyl methacrylate) (Chi-g-PMMA) and mineral ions-loaded hydroxyapatite (mHA) (obtained by the hydrothermal treatment of hydroxyapatite (HA) in a simulated body fluid (SBF) solution (mHA@Chi-g-PMMA)) were prepared by the blending method. The physical properties, bioactivity, biological properties and their capabilities for sustained drug and protein release were studied. Physicochemical analysis showed a successful incorporation of the mineral ions in the HA particles and a good distribution of the mHA within the Chi-g-PMMA polymer matrix. The compressive strength and the Young's modulus were 15.760 ± 0.718 and 658.452 ± 17.020 MPa, respectively. In bioactivity studies, more apatite formation on the surface were seen after immersion in the SBF solution. In vitro growth experiments using UMR-106 osteoblast-like cells on the mHA@Chi-g-PMMA scaffold case showed that the attachment, viability and proliferation of the cells on the scaffolds had improved after 7 d of immersion. The in vitro release of two compounds (the cancer drug, doxorubicin (DOX)) and bovine serum albumin (BSA)), which had been attached to separate mHA@Chi-g-PMMA scaffolds, were studied to determine their suitability as drug delivery vehicles. It was found that the sustained release of DOX was 73.95% and of BSA was 57.27% after 25 h of incubation. These experimental results demonstrated that the mHA@Chi-g-PMMA composite can be utilized as a scaffold for bone cells ingrowth and also be used for drug delivery during the bone repairing.

Prolonged exposure to 1,25(OH)2D3 and high ionized calcium induces FGF-23 production in intestinal epithelium-like Caco-2 monolayer: A local negative feedback for preventing excessive calcium transport.

Overdose of oral calcium supplement and excessive intestinal calcium absorption can contribute pathophysiological conditions, e.g., nephrolithiasis, vascular calcification, dementia, and cardiovascular accident. Since our previous investigation has indicated that fibroblast growth factor (FGF)-23 could abolish the 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]-enhanced calcium absorption, we further hypothesized that FGF-23 produced locally in the enterocytes might be part of a local negative feedback loop to regulate calcium absorption. Herein, 1,25(OH)2D3 was found to enhance the transcellular calcium transport across the epithelium-like Caco-2 monolayer, and this stimulatory effect was diminished by preceding prolonged exposure to high-dose 1,25(OH)2D3 or high concentration of apical ionized calcium. Pretreatment with a neutralizing antibody for FGF-23 prevented this negative feedback regulation of calcium hyperabsorption induced by 1,25(OH)2D3. FGF-23 exposure completely abolished the 1,25(OH)2D3-enhanced calcium transport. Western blot analysis revealed that FGF-23 expression was upregulated in a dose-dependent manner by 1,25(OH)2D3 or apical calcium exposure. Finally, calcium-sensing receptor (CaSR) inhibitors were found to prevent the apical calcium-induced suppression of calcium transport. In conclusion, prolonged exposure to high apical calcium and calcium hyperabsorption were sensed by CaSR, which, in turn, increased FGF-23 expression to suppress calcium transport. This local negative feedback loop can help prevent unnecessary calcium uptake and its detrimental consequences.

Fortified tuna bone powder supplementation increases bone mineral density of lactating rats and their offspring.

BACKGROUND: Breastfeeding leads to bone calcium loss for milk production, resulting in progressive maternal osteopenia. Calcium supplement from natural sources has been postulated to be more beneficial to bone health than purified CaCO3 because natural sources also contain other nutrients such as certain amino acids that might enhance calcium metabolism. Herein, we examined the effect of calcium supplementation from tuna bone powder and CaCO3 on bones of dams and the offspring. RESULTS: Both forms of calcium supplement, i.e. tuna bone powder and CaCO3 , increased maternal bone mineral density (BMD). However, bone histomorphometry revealed that only tuna bone had beneficial effect on maternal bone microstructure, i.e. increased bone formation, decreased bone resorption and increased in bone volume. Regarding the mechanical properties, the decreased ultimate load in non-supplement lactating mothers was restored to the load seen in nulliparous animals by calcium supplementation. Moreover, both tuna bone and CaCO3 supplementation in mothers led to increased milk calcium concentration and consequently increased BMD in the growing offspring. CONCLUSION: Calcium supplement from tuna bone powder was effective in preventing maternal osteopenia. Tuna bone, which is a readily available fishing industrial waste, is a good alternative source of calcium supplement that increases BMD in both lactating mothers and the neonates. © 2017 Society of Chemical Industry.

Insulin does not rescue cortical and trabecular bone loss in type 2 diabetic Goto-Kakizaki rats.

In type 2 diabetes mellitus (T2DM), the decreased bone strength is often associated with hyperglycemia and bone cell insulin resistance. Since T2DM is increasingly reported in young adults, it is not known whether the effect of T2DM on bone would be different in young adolescents and aging adults. Here, we found shorter femoral and tibial lengths in 7-month, but not 13-month, Goto-Kakizaki (GK) T2DM rats as compared to wild-type rats. Bone µCT analysis showed long-lasting impairment of both cortical and trabecular bones in GK rats. Although insulin treatment effectively improved hyperglycemia, it was not able to rescue trabecular BMD and cortical thickness in young adult GK rats. In conclusion, insulin treatment and alleviation of hyperglycemia did not increase BMD of osteopenic GK rats. It is likely that early prevention of insulin resistance should prevail over treatment of full-blown T2DM-related osteopathy.

Agomelatine, venlafaxine, and running exercise effectively prevent anxiety- and depression-like behaviors and memory impairment in restraint stressed rats.

Several severe stressful situations, e.g., natural disaster, infectious disease out break, and mass casualty, are known to cause anxiety, depression and cognitive impairment, and preventive intervention for these stress complications is worth exploring. We have previously reported that the serotonin-norepinephrine-dopamine reuptake inhibitor, venlafaxine, as well as voluntary wheel running are effective in the treatment of anxiety- and depression-like behaviors in stressed rats. But whether they are able to prevent deleterious consequences of restraint stress in rats, such as anxiety/depression-like behaviors and memory impairment that occur afterward, was not known. Herein, male Wistar rats were pre-treated for 4 weeks with anti-anxiety/anti-depressive drugs, agomelatine and venlafaxine, or voluntary wheel running, followed by 4 weeks of restraint-induced stress. During the stress period, rats received neither drug nor exercise intervention. Our results showed that restraint stress induced mixed anxiety- and depression-like behaviors, and memory impairment as determined by elevated plus-maze, elevated T-maze, open field test (OFT), forced swimming test (FST), and Morris water maze (MWM). Both pharmacological pre-treatments and running successfully prevented the anxiety-like behavior, especially learned fear, in stressed rats. MWM test suggested that agomelatine, venlafaxine, and running could prevent stress-induced memory impairment, but only pharmacological treatments led to better novel object recognition behavior and positive outcome in FST. Moreover, western blot analysis demonstrated that venlafaxine and running exercise upregulated brain-derived neurotrophic factor (BDNF) expression in the hippocampus. In conclusion, agomelatine, venlafaxine as well as voluntary wheel running had beneficial effects, i.e., preventing the restraint stress-induced anxiety/depression-like behaviors and memory impairment.

Estrogen deprivation aggravates cardiac hypertrophy in nonobese Type 2 diabetic Goto-Kakizaki (GK) rats.

Both Type 2 diabetes mellitus (T2DM) and estrogen deprivation have been shown to be associated with the development of cardiovascular disease and adverse cardiac remodeling. However, the role of estrogen deprivation on adverse cardiac remodeling in nonobese T2DM rats has not been clearly elucidated. We hypothesized that estrogen-deprivation aggravates adverse cardiac remodeling in Goto-Kakizaki (GK) rats. Wild-type (WT) and GK rats at the age of 9 months old were divided into two subgroups to have either a sham operation (WTS, GKS) or a bilateral ovariectomy (WTO, GKO) (n = 6/subgroup). Four months after the operation, the rats were killed, and the heart was excised rapidly. Metabolic parameters, cardiomyocytes hypertrophy, cardiac fibrosis, and biochemical parameters were determined. GK rats had hyperglycemia with hypoinsulinemia, and estrogen deprivation did not increase the severity of T2DM. Cardiac hypertrophy, cardiac oxidative stress, and phosphor-antinuclear factor κB were higher in WTO and GKS rats than WTS rats, and they markedly increased in GKO rats compared with GKS rats. Furthermore, cardiac fibrosis, transforming growth factor-ß, Bax, phosphor-p38, and peroxisome proliferator- activated receptor γ coactivator-1α expression were increased in GKS and GKO rats compared with the lean rats. However, mitochondrial dynamics proteins including dynamin-related protein 1 and mitofusin-2 were not altered by T2DM and estrogen deprivation. Although estrogen deprivation did not aggravate T2DM in GK rats, it increased the severity of cardiac hypertrophy by provoking cardiac inflammation and oxidative stress in nonobese GK rats.

CFTR-mediated anion secretion across intestinal epithelium-like Caco-2 monolayer under PTH stimulation is dependent on intermediate conductance K+ channels.

Parathyroid hormone (PTH), a pleiotropic hormone that maintains mineral homeostasis, is also essential for controlling pH balance and ion transport across renal and intestinal epithelia. Optimization of luminal pH is important for absorption of trace elements, e.g., calcium and phosphorus. We have previously demonstrated that PTH rapidly stimulated electrogenic [Formula: see text] secretion in intestinal epithelial-like Caco-2 monolayers, but the underlying cellular mechanism, contributions of other ions, particularly Cl- and K+, and long-lasting responses are not completely understood. Herein, PTH and forskolin were confirmed to induce anion secretion, which peaked within 1-3 min (early phase), followed by an abrupt decay and plateau that lasted for 60 min (late phase). In both early and late phases, apical membrane capacitance was increased with a decrease in basolateral capacitance after PTH or forskolin exposure. PTH also induced a transient increase in apical conductance with a long-lasting decrease in basolateral conductance. Anion secretion in both phases was reduced under [Formula: see text]-free and/or Cl--free conditions or after exposure to carbonic anhydrase inhibitor (acetazolamide), CFTR inhibitor (CFTRinh-172), Na+/H+ exchanger (NHE)-3 inhibitor (tenapanor), or K+ channel inhibitors (BaCl2, clotrimazole, and TRAM-34; basolateral side), the latter of which suggested that PTH action was dependent on basolateral K+ recycling. Furthermore, early- and late-phase responses to PTH were diminished by inhibitors of PI3K (wortmannin and LY-294002) and PKA (PKI 14-22). In conclusion, PTH requires NHE3 and basolateral K+ channels to induce [Formula: see text] and Cl- secretion, thus explaining how PTH regulated luminal pH balance and pH-dependent absorption of trace minerals.

Evaluation of bioactive glass incorporated poly(caprolactone)-poly(vinyl alcohol) matrix and the effect of BMP-2 modification.

Composite materials having mechanical and biological properties similar to those of human bones are needed for bone regeneration and repair. In the present study, composites were made by incorporating bioactive glass (BG) into polycaprolactone (PCL)-polyvinyl alcohol (PVA) (PCLPVA) matrix. Composites with different BG contents of 10, 25 and 50wt% were fabricated by an in-situ blending method. Physicochemical properties measurements found that the composite with 50wt% BG in the PCLPVA organic matrix exhibited the best mechanical properties (compressive strength and compressive young's modulus up to 32.26MPa and 530.91MPa, respectively). We investigated the effects of the BG content on cell adhesion, proliferation and osteogenic activity of UMR-106 cells grown on the scaffolds using in vitro cell culture assay. The composite scaffolds having 25wt% BG showed a significant increase in their cell adhesion capability and a faster cell proliferation. They also exhibited cell adhesion and spreading morphology after only 5days of culturing. For these reasons, we chose to attach the bone morphogenetic protein (BMP)-2 to this composite. The resulting composite (labeled BMP-2-loaded PCLPVABG25) showed significant improvement in the UMR-106 cells adhesion, in the enhancement in osteogenic differentiation and osteoinductivity of this composite.

Fibroblast growth factor-21 restores insulin sensitivity but induces aberrant bone microstructure in obese insulin-resistant rats.

Fibroblast growth factor (FGF)-21 is a potent endocrine factor that improves insulin resistance and obesity-associated metabolic disorders. However, concomitant activation of peroxisome proliferator-activated receptor-γ by FGF-21 makes bone susceptible to osteopenia and fragility fracture. Since an increase in body weight often induced adaptive change in bone by making it resistant to fracture, it was unclear whether FGF-21 would still induce bone defects in overweight rats. Therefore, the present study aimed to investigate bone microstructure and its mechanical properties in high fat diet (HF)-fed rats treated with 0.1 mg/kg/day FGF-21. Eighteen male rats were divided into two groups to receive either a normal diet or HF for 12 weeks. HF rats were then divided into two subgroups to receive either vehicle or FGF-21 for 4 weeks. The results showed that HF led to obesity, dyslipidemia and insulin resistance, as indicated by hyperinsulinemia with euglycemia. In HF rats, there was an increase in tibial yield displacement (an indicator of ability to be deformed without losing toughness, as determined by 3-point bending) without changes in tibial trabecular volumetric bone mineral density (vBMD) or cortical bone parameters, e.g., cortical thickness and bone area. FGF-21 treatment strongly improved the metabolic parameters and increased insulin sensitivity in HF rats. However, FGF-21-treated HF rats showed lower yield displacement, trabecular vBMD, trabecular bone volume, trabecular thickness, and osteoblast surface compared with vehicle-treated HF rats. These findings suggest that, despite being a potent antagonist of insulin resistance and visceral fat accumulation, FGF-21 is associated with bone defects in HF rats.

Na+/H+ exchanger 3 inhibitor diminishes the amino-acid-enhanced transepithelial calcium transport across the rat duodenum.

Na+/H+ exchanger (NHE)-3 is important for intestinal absorption of nutrients and minerals, including calcium. The previous investigations have shown that the intestinal calcium absorption is also dependent on luminal nutrients, but whether aliphatic amino acids and glucose, which are abundant in the luminal fluid during a meal, similarly enhance calcium transport remains elusive. Herein, we used the in vitro Ussing chamber technique to determine epithelial electrical parameters, i.e., potential difference (PD), short-circuit current (Isc), and transepithelial resistance, as well as 45Ca flux in the rat duodenum directly exposed on the mucosal side to glucose or various amino acids. We found that mucosal glucose exposure led to the enhanced calcium transport, PD, and Isc, all of which were insensitive to NHE3 inhibitor (100 nM tenapanor). In the absence of mucosal glucose, several amino acids (12 mM in the mucosal side), i.e., alanine, isoleucine, leucine, proline, and hydroxyproline, markedly increased the duodenal calcium transport. An inhibitor for NHE3 exposure on the mucosal side completely abolished proline- and leucine-enhanced calcium transport, but not transepithelial transport of both amino acids themselves. In conclusion, glucose and certain amino acids in the mucosal side were potent stimulators of the duodenal calcium absorption, but only amino-acid-enhanced calcium transport was NHE3-dependent.