Efficacy of sulphasalazine on lung histopathology in a murine model of chronic asthma

Beneficial effects of ursodeoxycholic acid via inhibition of airway remodelling, apoptosis of airway epithelial cells, and Th2 immune response in murine model of chronic asthma

BACKGROUND AND AIMS

In previous studies, anti-inflammatory, anti-apoptotic and immunomodulatory effects of ursodeoxycholic acid (UDCA) on liver diseases have been shown. In this study, we aimed to investigate the effects of UDCA on airway remodelling, epithelial apoptosis, and T Helper (Th)-2 derived cytokine levels in a murine model of chronic asthma.

METHODS

Twenty-seven BALB/c mice were divided into five groups; PBS-Control, OVA-Placebo, OVA-50mg/kg UDCA, OVA-150mg/kg UDCA, OVA-Dexamethasone. Mice in groups OVA-50mg/kg UDCA, OVA-150mg/kg UDCA, OVA-Dexamethasone received the UDCA (50mg/kg), UDCA (150mg/kg), and dexamethasone, respectively. Epithelium thickness, sub-epithelial smooth muscle thickness, number of mast and goblet cells of samples isolated from the lung were measured. Immunohistochemical scorings of the lung tissue for matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEG-F), transforming growth factor-beta (TGF-β), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases (caspase)-3 were determined. IL-4, IL-5, IL-13, Nitric oxide, ovalbumin-specific immunoglobulin (Ig) E levels were quantified.

RESULTS

The dose of 150mg/kg UDCA treatment led to lower epithelial thickness, sub-epithelial smooth muscle thickness, goblet and mast cell numbers compared to placebo. Except for MMP-9 and TUNEL all immunohistochemical scores were similar in both UDCA treated groups and the placebo. All cytokine levels were significantly lower in group IV compared to the placebo.

CONCLUSIONS

These findings suggested that the dose of 150mg/kg UDCA improved all histopathological changes of airway remodelling and its beneficial effects might be related to modulating Th-2 derived cytokines and the inhibition of apoptosis of airway epithelial cells.

Molecular engineering of a dual emission near-infrared ratiometric fluorophore for the detection of pH at the organism level

A near-infrared ratiometric fluorophore (NIR-HBT) was rationally designed and constructed by expanding both the excitation and emission wavelength of the classical ratiometric fluorophore 2-(benzothiazol-2-yl)phenol (HBT) into the near-infrared region. The NIR-HBT was easily synthesized by incorporating the HBT module into the hemicyanine skeleton and showed evident NIR ratiometric fluorophore characteristics. Further application of the new fluorophore for pH detection demonstrated that NIR-HBT possesses superior overall analytical performance and NIR-HBT was successfully applied for detection of acidosis caused by inflammation in living animal tissue, which indicated the potential application value of NIR-HBT in biological imaging and sensing.

Pharmacological strategies in lung cancer-induced cachexia: effects on muscle proteolysis, autophagy, structure, and weakness

Cachexia is a relevant comorbid condition of chronic diseases including cancer. Inflammation, oxidative stress, autophagy, ubiquitin-proteasome system, nuclear factor (NF)-κB, and mitogen-activated protein kinases (MAPK) are involved in the pathophysiology of cancer cachexia. Currently available treatment is limited and data demonstrating effectiveness in in vivo models are lacking. Our objectives were to explore in respiratory and limb muscles of lung cancer (LC) cachectic mice whether proteasome, NF-κB, and MAPK inhibitors improve muscle mass and function loss through several molecular mechanisms. Body and muscle weights, limb muscle force, protein degradation and the ubiquitin-proteasome system, signaling pathways, oxidative stress and inflammation, autophagy, contractile and functional proteins, myostatin and myogenin, and muscle structure were evaluated in the diaphragm and gastrocnemius of LC (LP07 adenocarcinoma) bearing cachectic mice (BALB/c), with and without concomitant treatment with NF-κB (sulfasalazine), MAPK (U0126), and proteasome (bortezomib) inhibitors. Compared to control animals, in both respiratory and limb muscles of LC cachectic mice: muscle proteolysis, ubiquitinated proteins, autophagy, myostatin, protein oxidation, FoxO-1, NF-κB and MAPK signaling pathways, and muscle abnormalities were increased, while myosin, creatine kinase, myogenin, and slow- and fast-twitch muscle fiber size were decreased. Pharmacological inhibition of NF-κB and MAPK, but not the proteasome system, induced in cancer cachectic animals, a substantial restoration of muscle mass and force through a decrease in muscle protein oxidation and catabolism, myostatin, and autophagy, together with a greater content of myogenin, and contractile and functional proteins. Attenuation of MAPK and NF-κB signaling pathway effects on muscles is beneficial in cancer-induced cachexia.

Beneficial effects of arginase inhibition and inhaled L-arginine administration on airway histology in a murine model of chronic asthma

BACKGROUND

Increased arginase activity in the airways induces reduced bioavailability of L-arginine and cause deficiency of bronchodilatating and anti-inflammatory nitric oxide (NO). Therefore, arginine and arginase inhibitors may have therapeutic potential in the treatment of asthma. Using a murine model of asthma, we aimed to investigate the effects of inhaled L-arginine and arginase inhibitor Nω-hydroxy-nor-L-arginine (nor-NOHA) and co-treatment on airway histology of asthmatic lung tissue.

METHODS

Forty-two BALB/c mice were divided into six groups: I (control), II (placebo), III, IV, V and VI. All mice except for control group were sensitised by an intraperitoneal injection of ovalbumin with alum adjuvant and then challenged with an aerosol of ovalbumin on three days of the week for eight weeks beginning from the 21st day of the study. Lung histology and bronchoalveolar lavage cell (BAL) counts were evaluated after treatment with inhaled L-arginine, nor-NOHA, l-arginine-nor-NOHA combination, budesonide and placebo. Interleukin(IL)-4 and IL-5 levels are determined in lung homogenates with ELISA.

RESULTS

L-Arginine group was similar to budesonide group in lowering all histological parameters. Results of groups treated with nor-NOHA were also similar to budesonide group except for epithelial thickness. The number of eosinophils in BAL decreased significantly in groups receiving study drugs. Decrease was only noted in IL-4 levels in group receiving nor-NOHA.

CONCLUSION

We demonstrated that inhaled l-arginine administration alleviated all histological parameters similar to budesonide and treatment with arginase inhibitor improved not all but some of the pathological changes in chronic asthma. Combination therapy had no additive effect on either treatment.

Real-time noninvasive monitoring of in vivo inflammatory responses using a pH ratiometric fluorescence imaging probe

It is often difficult to continuously monitor and quantify inflammatory responses in vivo. These dynamic responses however are often accompanied by specific pH changes. A new ratiometric optical pH probe is developed by combining pH-sensitive (CypHer5E) and pH-insensitive (Oyster800) fluorescent dyes into nanoparticles for in vivo optical imaging. By taking the ratio of fluorescence intensities at different wavelengths, these nanosized sensors provide excellent measurement capabilities, and unique mapping, of the continuous in vivo pH changes for three different inflammation models. In each model a strong positive correlation is found between ratiometric pH changes and the corresponding inflammatory response measured by histological analyses. These results indicate that ratiometric imaging can provide a noninvasive, rapid, and highly sensitive optical readout for the pH-ratio changes in vivo. Furthermore this technique may be used to monitor the real-time dynamics of inflammatory processes.

Mitochondrial dysfunction and therapeutic approaches in respiratory and limb muscles of cancer cachectic mice

NEW FINDINGS

What is the central question of this study? We explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles,and whether signalling pathways, proteasome and oxidative stress influence that process. What is the main finding and what is its importance? In cancer cachectic mice, MRC complexes and oxygen consumption were decreased in the diaphragm and gastrocnemius. Blockade of nuclear factor-κB and mitogen-activated protein kinase actions partly restored the muscle mass and force and corrected the MRC dysfunction,while concomitantly reducing tumour burden. Antioxidants improved mitochondrial oxygen consumption without eliciting effects on the loss of muscle mass and force or the tumour size,whereas bortezomib reduced tumour burden without influencing muscle mass and strength or MRC function. Abnormalities in mitochondrial content, morphology and function have been reported in several muscle-wasting conditions. We specifically explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles, and whether signalling pathways, proteasomes and oxidative stress may influence that process. We evaluated complex I, II and IV enzyme activities (specific activity assays) and MRC oxygen consumption (polarographic measurements) in diaphragm and gastrocnemius of cachectic mice bearing the LP07 lung tumour, with and without treatment with N-acetylcysteine, bortezomib and nuclear factor-κB (sulfasalazine) and mitogen-activated protein kinases (MAPK, U0126) inhibitors (n = 10 per group for all groups). Whole-body and muscle weights and limb muscle force were also assessed in all rodents at baseline and after 1 month. Compared with control animals, cancer cachectic mice showed a significant reduction in body weight gain, smaller sizes of the diaphragm and gastrocnemius, lower muscle strength, decreased activity of complexes I, II and IV and decreased oxygen consumption in both muscles. Blockade of nuclear factor-κB and MAPK actions restored muscle mass and force and corrected the MRC dysfunction in both muscles, while partly reducing tumour burden. Antioxidants improved mitochondrial oxygen uptake without eliciting significant effects on the loss of muscle mass and force or tumour size, whereas the proteasome inhibitor reduced tumour burden without significantly influencing muscle mass and strength or mitochondrial function. In conclusion, nuclear factor-κB and MAPK signalling pathways modulate muscle mass and performance and MRC function of respiratory and limb muscles in this model of experimental cancer cachexia, thus offering targets for therapeutic intervention.

Anti-inflammatory effects of curcumin in a murine model of chronic asthma

BACKGROUND

Curcumin, a dietary pigment responsible for the yellow colour of curry, has been used for the treatment of inflammatory diseases and exhibits a variety of pharmacological effects.

METHODS

Forty-two BALB/c mice were divided into six groups: I, II, III, IV, V, and control group. All groups except the controls were sensitised and challenged with ovalbumin. Group I received nebulised saline in challenge period. Mice in groups II, III, IV, and V were administered curcumin at a dose of 10 mg/kg, curcumin 20 mg/kg, dexamethasone 1 mg/kg, and dimethyl sulfoxide 1 mg/kg, respectively, intraperitoneally once a day for the final 5 days of the challenge period. Animals were sacrificed 24 h after the last drug administration and the airway samples were evaluated histologically by light microscopy.

RESULTS

All histological parameters in Group III improved similar to Group IV when compared to Group I. In Group II, only thickness of epithelium was significantly lower compared with regard to Group I. All variables except epithelium thicknesses were found to be significantly better in Group III compared to Group II.

CONCLUSIONS

In our study, we demonstrated that curcumin administration alleviates the pathological changes of chronic asthma. Curcumin might be a promising therapy for asthma in the future.

Beneficial effects of erythropoietin on airway histology in a murine model of chronic asthma

BACKGROUND

Erythropoietin (EPO) is originally defined as a haematopoietic growth factor, but also has anti-inflammatory effects through cytokine modulation. This anti-inflammatory and cytokine modulating effect has not been investigated for the treatment of asthma. We aimed to determine the beneficial effects of erythropoietin on lung histology of murine model of chronic asthma.

METHODS

Thirty-five BALB/c mice were divided into five groups: I; II; III; IV; and control group. All groups except control group were sensitised and challenged with ovalbumin. Mice with experimentally induced asthma in Group I received saline; Group II EPO 500IU/kg; Group III EPO 1000IU/kg; and Group IV dexamethasone 1mg/kg intraperitoneally once a day in the last five days of the challenge period. Animals were sacrificed 24h after the last administration of study drugs. Histological findings of airways were evaluated by light and electron microscopic examination.

RESULTS

All histological parameters of asthma in the group treated with a high dose of EPO (Group III) were significantly ameliorated when compared with the group treated with saline (Group I). In comparison to the group treated with low dose of EPO (Group II) and the group treated with saline (Group I), basement membrane thicknesses and number of mast cells were significantly lower in the group treated with low dose of EPO (Group II). All histological parameters were similar between the group treated with high dose of EPO (Group III) and the group treated with dexamethasone (Group IV) except higher number of mast cells in the group treated with high dose of EPO (Group III). Additionally, the results of all histological parameters in the group treated with high dose of EPO (Group III) were significantly better when compared with the group treated with low dose of EPO (Group II).

CONCLUSIONS

We found that EPO ameliorated histological changes of chronic murine model of asthma. Further studies are needed to evaluate the efficacy of EPO in the treatment of asthma.

A plasminogen activator inhibitor-1 inhibitor reduces airway remodeling in a murine model of chronic asthma

We previously reported that plasminogen activator inhibitor (PAI)-1 deficiency prevents collagen deposition in the airways of ovalbumin (OVA)-challenged mice. In this study, we explored the therapeutic utility of blocking PAI-1 in preventing airway remodeling, using a specific PAI-1 inhibitor, tiplaxtinin. C57BL/6J mice were immunized with intraperitoneal injections of OVA on Days 0, 3, and 6. Starting on Day 11, mice were challenged with phosphate-buffered saline or OVA by nebulization three times per week for 4 weeks. Tiplaxtinin was mixed with chow and administered orally from 1 day before the phosphate-buffered saline or OVA challenge. Lung tissues were harvested after challenge and characterized histologically for infiltrating inflammatory cells, mucus-secreting goblet cells, and collagen deposition. Airway hyperresponsiveness was measured using whole-body plethysmography. Tiplaxtinin treatment significantly decreased levels of PAI-1 activity in bronchoalveolar lavage fluids, which indicates successful blockage of PAI-1 activity in the airways. The number of infiltrated inflammatory cells was reduced by tiplaxtinin treatment in the lungs of the OVA-challenged mice. Furthermore, oral administration of tiplaxtinin significantly attenuated the degree of goblet cell hyperplasia and collagen deposition in the airways of the OVA-challenged mice, and methacholine-induced airway hyperresponsiveness was effectively reduced by tiplaxtinin in these animals. This study supports our previous findings that PAI-1 promotes airway remodeling in a murine model of chronic asthma, and suggests that PAI-1 may be a novel target of treatment of airway remodeling in asthma.

Effects of curcumin on lung histopathology and fungal burden in a mouse model of chronic asthma and oropharyngeal candidiasis

BACKGROUND AND AIMS

Oropharyngeal candidiasis (OPC) is one of the most common local side effects of current therapy in chronic asthma. New therapeutic options with fewer side effects and reverse chronic changes are needed. Curcumin, as a promising antiinflammatory and antifungal agent, could be a candidate of alternative therapy in asthma. This study aimed to determine the efficacy of orally administrated curcumin on lung histopathology, serum nitric oxide levels and fungal burden in a murine model of asthma and OPC.

METHODS

Thirty five BALB/c mice were divided into five groups: I, II, III, IV (placebo) and V (control). All groups except the control were sensitized and challenged with ovalbumin. OPC model was established after the model of chronic asthma. Lung histology, serum nitric oxide levels and fungal burden were evaluated after 5 days of treatment with curcumin, dexamethasone, curcumin-dexamethasone combination and placebo. Evaluation of lung histology included subepithelial smooth muscle and epithelial thickness and number of goblet and mast cells by using light microscopy.

RESULTS

All histological parameters improved in curcumin group similar to dexamethasone group. Curcumin and dexamethasone-curcumin combination were also as effective as dexamethasone on decreasing nitric oxide levels. Oral fungal burden was significantly lower in curcumin-treated group than dexamethasone.

CONCLUSIONS

In our study we demonstrated that curcumin administration alleviates the pathological changes in asthma and decreases the fungal burden. Curcumin may have a potential effect on treating chronic asthma and decreasing the frequency of the OPC.

Mast cells and COPD

The pathogenesis of chronic obstructive pulmonary disease (COPD) is based on the innate and adaptive inflammatory immune response to the inhalation of toxic particles and gases. Although tobacco smoking is the primary cause of this inhalation injury, many other environmental and occupational exposures contribute to the pathology of COPD. The immune inflammatory changes associated with COPD are linked to a tissue-repair and -remodeling process that increases mucus production and causes emphysematous destruction of the gas-exchanging surface of the lung. The common form of emphysema observed in smokers begins in the respiratory bronchioles near the thickened and narrowed small bronchioles that become the major site of obstruction in COPD. The inflamed airways of COPD patients contain several inflammatory cells including neutrophils, macrophages, T lymphocytes, and dendritic cells. The relative contribution of mast cells to airway injury and remodeling is not well documented. In this review, an overview is given on the possible role of mast cells and their mediators in the pathogenesis of COPD. Activation of mast cells and mast cell signaling in response to exposure to cigarette smoke is further discussed.

Mesenchymal stem cells ameliorate the histopathological changes in a murine model of chronic asthma

Asthma therapies are effective in reducing inflammation but airway remodeling is poorly responsive to these agents. New therapeutic options that have fewer side effects and reverse chronic changes in the lungs are essential. Mesenchymal stem cells (MSCs) are promising for the development of novel therapies in regenerative medicine. This study aimed to examine the efficacy of MSCs on lung histopathology in a murine model of chronic asthma. BALB/c mice were divided into four groups: Group 1 (control group, n=6), Group 2 (ovalbumin induced asthma only, n=10), Group 3 (ovalbumin induced asthma + MSCs, n=10), and Group 4 (MSCs only, n=10). Histological findings (basement membrane, epithelium, subepithelial smooth muscle thickness, numbers of goblet and mast cells) of the airways and MSC migration were evaluated by light, electron, and confocal microscopes. In Group 3, all early histopathological changes except epithelial thickness and all of the chronic changes were significantly ameliorated when compared with Group 2. Evaluation with confocal microscopy showed that no noteworthy amount of MSCs were present in the lung tissues of Group 4 while significant amount of MSCs was detected in Group 3. Serum NO levels in Group 3, were significantly lower than Group 2. The results of this study revealed that MSCs migrated to lung tissue and ameliorated bronchial asthma in murine model. Further studies are needed to evaluate the efficacy of MSCs for the treatment of asthma.

Effects of NAT2 polymorphism on SASP pharmacokinetics in Chinese population

BACKGROUND

Sulfasalazine (SASP) pharmacologic actions are widely applied in clinical therapy. The role of N-Acetyltransferase 2 (NAT2) in the pharmacokinetics of SASP and its metabolites has not been clarified. We investigated the effects of genetic polymorphism of NAT2 on pharmacokinetic profiles of SASP and its two metabolites, sulfapyridine (SP) and N-acetylsufapyridine (AcSP).

METHODS

Eighteen subjects were recruited and divided into 3 groups by NAT2 genotype: wild type (w/w), heterozygous variant (w/m), homozygous variant (m/m). After taking 1000mg SASP tablets, the plasma concentrations of SASP, SP and AcSP were measured with HPLC method and pharmacokinetic parameters were calculated by using the computing program 3P97.

RESULTS

The AUC(0)(-)(72) and Cmax of SP in m/m subjects were significantly higher than those in w/m and w/w subjects, with the values of 172.57+/-49.42, 103.38+/-39.85, 71.37+/-17.52mg h/l, and 9.65+/-2.34, 6.10+/-1.79, 4.55+/-1.38mg/l, respectively. In contrast, the AUC(0)(-)(72) of AcSP was significantly lower in m/m subjects. The Cmax of AcSP in w/w, w/m and m/m subjects was 12.67+/-3.32, 9.07+/-2.29 and 4.22+/-0.93mg/l, respectively, with significant differences among groups. However, there was no significant difference in any pharmacokinetic parameter of SASP among groups.

CONCLUSION

Different NAT2 genotypes, leading to functional heterogeneity of NAT2, may affect pharmacokinetics of SP and AcSP. Therefore, genotyping NAT2 gene before administration would be important in SASP therapy.