Sustained Release Formulation of Hydroxypropyl-ß-cyclodextrin Eye Drops Using Xanthan Gum.

Bietti's crystalline dystrophy (BCD) is an autosomal recessive chorioretinal degeneration caused by mutations in the CYP4V2 gene. It is characterized by cholesterol accumulation and crystal-like deposits in the retinas. Hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) exerts therapeutic effects against BCD by reducing lysosomal dysfunction and inhibiting cytotoxicity in induced pluripotent stem cell (iPSC)-RPE cells established from patient-derived iPS cells. However, the ocular retention of HP-ß-CyD is low and needs to be improved. Therefore, this study used a viscous agent to develop a sustained-release ophthalmic formulation containing HP-ß-CyD. Our results suggest that HP-ß-CyD-containing xanthan gum has a considerably higher sustained release capacity than other viscous agents, such as methylcellulose and sodium alginate. In addition, the HP-ß-CyD-containing xanthan gum exhibited pseudoplastic behavior. It was less cytotoxic to human retinal pigment epithelial cells compared with HP-ß-CyD alone. Furthermore, the slow release of HP-ß-CyD from xanthan gum caused a sustained decrease in free intracellular cholesterol. These results suggest that xanthan gum is a useful substrate for the sustained release formulation of HP-ß-CyD, and that HP-ß-CyD-containing xanthan gum has potential as an eye drop for BCD treatment.

Folate-Appended Hydroxypropyl-ß-Cyclodextrin Induces Autophagic Cell Death in Acute Myeloid Leukemia Cells.

Acute myeloid leukemia (AML) is a heterogenous myeloid neoplasm that remains challenging to treat. Because intensive conventional chemotherapy reduces survival rates in elderly patients, drugs with lower toxicity and fewer side effects are needed urgently. 2-Hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) is used clinically as a pharmaceutical excipient for poorly water-soluble drugs. Previously, we showed that HP-ß-CyD exerts antitumor activity by disrupting cholesterol homeostasis. Recently, we developed folate-conjugated HP-ß-CyD (FA-HP-ß-CyD) and demonstrated its potential as a new antitumor agent that induces not only apoptosis, but also autophagic cell death; however, we do not know whether FA-HP-ß-CyD exerts these effects against AML. Here, we investigated the effects of FA-HP-ß-CyD on folate receptor (FR)-expressing AML cells. We found that the cytotoxic activity of FA-HP-ß-CyD against AML cells was stronger than that of HP-ß-CyD. Also, FA-HP-CyD induced the formation of autophagosomes in AML cell lines. FA-HP-ß-CyD increased the inhibitory effects of cytarabine and a BCL-2-selective inhibitor, Venetoclax, which are commonly used treat elderly AML patients. Notably, FA-HP-ß-CyD suppressed the proliferation of AML cells in BALB/c nude recombinase-activating gene-2 (Rag-2)/Janus kinase 3 (Jak3) double-deficient mice with AML. These results suggest that FA-HP-ß-CyD acts as a potent anticancer agent for AML chemotherapy by regulating autophagy.

Different solubilizing ability of cyclodextrin derivatives for cholesterol in Niemann-Pick disease type C treatment.

BACKGROUND: Niemann-Pick disease type C (NPC) is a fatal neurodegenerative disorder caused by abnormal intracellular cholesterol trafficking. Cyclodextrins (CDs), the most promising therapeutic candidates for NPC, but with concerns about ototoxicity, are cyclic oligosaccharides with dual functions of unesterified cholesterol (UC) shuttle and sink that catalytically enhance the bidirectional flux and net efflux of UC, respectively, between the cell membrane and the extracellular acceptors. However, the properties of CDs that regulate these functions and how they could be used to improve treatments for NPC are unclear. METHODS: We estimated CD-UC complexation for nine CD derivatives derived from native α-, ß-, and γ-CD with different cavity sizes, using solubility and molecular docking analyses. The stoichiometry and complexation ability of the resulting complexes were investigated in relation to the therapeutic effectiveness and toxicity of each CD derivative in NPC experimental models. FINDINGS: We found that shuttle and sink activities of CDs are dependent on cavity size-dependent stoichiometry and substituent-associated stability of CD-UC complexation. The ability of CD derivatives to form 1:1 and 2:1 complexes with UC were correlated with their ability to normalize intracellular cholesterol trafficking serving as shuttle and with their cytotoxicity associated with cellular UC efflux acting as sink, respectively, in NPC model cells. Notably, the ability of CD derivatives to form an inclusion complex with UC was responsible for not only efficacy but ototoxicity, while a representative derivative without this ability negligibly affected auditory function, underscoring its preventability. CONCLUSIONS: Our findings highlight the importance of strategies for optimizing the molecular structure of CDs to overcome this functional dilemma in the treatment of NPC.

Versatile delivery platform for nucleic acids, negatively charged protein drugs, and genome-editing ribonucleoproteins using a multi-step transformable polyrotaxane.

Various biopharmaceuticals, such as nucleic acids, proteins, and genome-editing molecules, have been developed. Generally, carriers are prepared for each biopharmaceutical to deliver it intracellularly; thus, the applications of individual carriers are limited. Moreover, the development of carriers is laborious and expensive. Therefore, in the present study, versatile and universal delivery carriers were developed for various biopharmaceuticals using aminated polyrotaxane libraries. Step-by-step and logical screening revealed that aminated polyrotaxane, including the carbamate bond between the axile molecule and endcap, is suitable as a backbone polymer. Movable and flexible properties of the amino groups modified on polyrotaxane facilitated efficient complexation with various biopharmaceuticals, such as small interfering RNA, antisense oligonucleotides, messenger RNA, ß-galactosidase, and genome-editing ribonucleoproteins. Diethylenetriamine and cystamine modifications of polyrotaxane provided endosomal-escape abilities and drug-release properties in the cytosol, allowing higher delivery efficacies than commercially available high-standard carriers without cytotoxicity. Thus, the resulting polyrotaxane might serve as a versatile and universal delivery platform for various biopharmaceuticals.

Tannic acid-based sustained-release system for protein drugs.

In recent years, protein drug development has gained momentum, and simple and facile controlled-release systems without loss of activity are required. Herein, we developed a sustained-release system for protein drugs by exploiting the "astringency" mechanism, namely insoluble precipitate formation by interacting with tannic acid. Tannic acid formed insoluble precipitates with various protein drugs, such as nisin, insulin, lysozyme, ovalbumin, hyaluronidase, and human immunoglobulin G, through hydrophobic interactions and hydrogen bonds. The lysozyme/tannic acid complex retained in vitro lytic activity. Precipitates of the insulin/tannic acid complex prolonged hypoglycemic effects without loss of activity after subcutaneous administration. The ovalbumin/tannic acid complex enhanced anti-ovalbumin antibody production induced by ovalbumin, which may be attributed to its sustained-release profile. Accordingly, tannic acid is useful as a simple and user-friendly drug delivery system for protein drugs.

Mannose-methyl-ß-cyclodextrin suppresses tumor growth by targeting both colon cancer cells and tumor-associated macrophages.

Methylated ß-cyclodextrin (MßCD) can extract cholesterol from lipid rafts and induce apoptosis in cancer cells by inhibiting activation of the PI3K-Akt-Bad pathway. In this study, we modified MßCD with mannose (Man-MßCD) and assessed its in vitro and in vivo potential for targeting colon cancer cells expressing the mannose receptor (MR) and tumor-associated macrophages (TAM). Man-MßCD showed a significantly greater level of cellular association with colon-26 cells and M2 macrophages, and much more prominent anticancer activity than that of MßCD against MR-positive colon-26 cells. These results revealed that autophagy was the main mechanism of cell death associated with Man-MßCD. Furthermore, compared with MßCD, Man-MßCD significantly reduced tumor development following intravenous delivery to tumor-bearing mice, with no apparent side effects. Thus, Man-MßCD has the potential to be a novel anticancer drug.

Nanoparticles of folic acid-methyl-ß-cyclodextrin (FA-MßCD)/adamantane-albumin exhibit enhanced antitumor activity compared with FA-MßCD alone.

Supramolecular drug carriers are a promising approach for delivering anticancer drugs with high blood retention after administration. We previously synthesized folic acid-modified methyl-ß-cyclodextrin (FA-MßCD) as an anticancer drug. FA-MßCD has a selective autophagy-mediated antitumor effect on folic acid receptor (FR)-expressing cancer cells. Here, we enhanced the antitumor effect and safety of FA-MßCD by preparing a supramolecular nanoparticle formulation of FA-MßCD via host-guest interactions using an adamantane conjugate with human serum albumin (Ad-HSA). The Ad-HSA/FA-MßCD supramolecular complex prolonged the blood retention of FA-MßCD and improved its antitumor effect and safety after intravenous administration in tumor-bearing mice xenografted with FR-expressing cancer cells. These results suggest that the supramolecular technique using Ad-HSA is a promising approach for the delivery of CD-based anticancer drugs.

Feasibility Study of Dendrimer-Based TTR-CRISPR pDNA Polyplex for Ocular Amyloidosis in Vitro.

Hereditary amyloidgenic transthyretin (ATTR) amyloidosis is caused by a genetic point-mutated transthyretin such as TTR Val30Met (TTR V30M), since it forms protein aggregates called amyloid resulting in the tissue accumulation and functional disorders. In particular, ATTR produced by retinal pigment epithelial cells often causes ATTR ocular amyloidosis, which elicits deterioration of ocular function and ultimately blindness. Therefore, development of novel therapeutic agents is urgently needed. Genome-editing technology using Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated proteins (CRISPR-Cas9) system is expected to be a therapeutic approach to treat genetic diseases, such as ATTR amyloidosis caused by a point mutation in TTR gene. Previously, we reported that glucuronylglucosyl-ß-cyclodextrin conjugated with a polyamidoamine dendrimer (CDE) had excellent gene transfer ability and that underlying dendrimer inhibited TTR aggregation. Conversely, folate receptors are known to be highly expressed in retina; thus, folate has potential as a retinal target ligand. In this study, we prepared a novel folate-modified CDE (FP-CDE) and investigated its potential as a carrier for the retinal delivery of TTR-CRISPR plasmid DNA (pDNA). The results suggested that FP-CDE/TTR-CRISPR pDNA could be taken up by retinal pigment epithelial cells via folate receptors, exhibited TTR V30M amyloid inhibitory effect, and suppressed TTR production via the genome editing effect (knockout of TTR gene). Thus, FP-CDE may be useful as a novel therapeutic TTR-CRISPR pDNA carrier in the treatment of ATTR ocular amyloidosis.

Antigen stabilizing hydrogels based on cyclodextrins and polyethylene glycol act as type-2 adjuvants with suppressed local irritation.

Recent viral pandemics have increased global demand for vaccines. However, the supply of effective and safe vaccine not only to developed countries but also developing countries with inadequate storage equipment is still challenging due to the lack of robust systems which improve the efficacy and the stability of vaccines with few side effects. In our previous study, polypseudorotaxane (PPRX) hydrogels based on cyclodextrin (CyD) and polyethylene glycol (PEG) significantly improved the stability of antibody preparations and showed no serious adverse effects after subcutaneous injection, suggesting the possibility as safe vaccine formulations to stabilize an antigen protein. Moreover, recent studies have reported that one of the CyD derivatives, hydroxypropyl-ß-CyD (HP-ß-CyD), acts as an adjuvant to enhance protective type-2 immune responses. However, it is still unknown that CyD PPRX hydrogels enhance not only the stability of an antigen protein but also its immunogenicity with tolerable side effects. Here, we demonstrate that α- and γ-CyD PPRX hydrogels containing an antigen protein significantly induce antigen-specific type-2 immune responses. Moreover, α- and γ-CyD PPRX hydrogels showed negligible local irritation at the injection site, although subcutaneous injection of α-CyD alone induced skin lesion. Finally, shaking stability of the antigen protein at room temperature was significantly improved by being included in α- and γ-CyD PPRX hydrogels. These results propose the possibility of α- and γ-CyD PPRX hydrogels as novel vaccine formulations which improve both the immunogenicity and stability of an antigen protein with suppressed local irritation.

Stabilization and Movable Ligand-Modification by Folate-Appended Polyrotaxanes for Systemic Delivery of siRNA Polyplex.

To achieve a systemic targeted delivery of siRNA using polymeric carriers, there is a dilemma between ligand modification and stabilization of the polyplex. Namely, ligand modification often leads to destabilization of the polyplex in the blood circulation. In fact, we previously developed cyclodextrin (CD)/polyamidoamine dendrimer conjugates (CDE) as siRNA carriers, and the interaction of CDE/siRNA was decreased by the conjugation with folate-polyethylene glycol, leading to the destabilization. To overcome this dilemma, in this study, folate-appended polyrotaxanes (Fol-PRX) were developed. Fol-PRX stabilized CDE/siRNA polyplex by intermolecularly connecting CDE molecules through a host-guest interaction between adamantane at the terminals of Fol-PRX and ß-CD in the polyplex. Moreover, the intermolecular connection of the polyplex with Fol-PRX provided movable folate moieties on the surface. As a result, Fol-PRXs enhanced the in vivo antitumor activity of the polyplex after intravenous administration, suggesting their utility as the dual-functional materials for systemic delivery of siRNA polyplexes.

Fine-tuned cholesterol solubilizer, mono-6-O-α-D-maltosyl-γ-cyclodextrin, ameliorates experimental Niemann-Pick disease type C without hearing loss.

Niemann-Pick disease type C (NPC) is a fatal disorder with abnormal intracellular cholesterol trafficking resulting in neurodegeneration and hepatosplenomegaly. A cyclic heptasaccharide with different degrees of substitution of 2-hydroxypropyl groups, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), acts as a strong cholesterol solubilizer and is under investigation for treating this disease in clinical trials, but its physicochemical properties and ototoxicity remain a concern. Here, we evaluated the potential of mono-6-O-α-maltosyl-γ-CD (G2-γ-CD), a single-maltose-branched cyclic octasaccharide with a larger cavity than HP-ß-CD, for treating NPC. We identified that G2-γ-CD ameliorated NPC manifestations in model mice and showed lower ototoxicity in mice than HP-ß-CD. To investigate the molecular mechanisms of action behind the differential ototoxicity of these CDs, we performed cholesterol solubility analysis, proton nuclear magnetic resonance spectroscopy, and molecular modeling, and estimated that the cholesterol inclusion mode of G2-γ-CD maintained solely the 1:1 inclusion complex, whereas that of HP-ß-CD shifted to the highly-soluble 2:1 complex at higher concentrations. We predicted the associations of these differential complexations of CDs with cholesterol with the profile of disease attenuation and of the auditory cell toxicity using specific cell models. We proposed that G2-γ-CD can serve as a fine-tuned cholesterol solubilizer for treating NPC, being highly biocompatible and physicochemically suitable for clinical application.

Multifunctional Therapeutic Cyclodextrin-Appended Dendrimer Complex for Treatment of Systemic and Localized Amyloidosis.

Amyloidosis pathologically proceeds via production of amyloidogenic proteins by organs, formation of protein aggregates through structural changes, and their deposition on tissues. A growing body of evidence demonstrates that amyloidosis generally develops through three critical pathological steps: (1) production of amyloid precursor proteins, (2) amyloid formation, and (3) amyloid deposition. However, no clinically effective therapy that is capable of targeting each pathological step of amyloidosis independently is currently available. Here, we combined therapeutic effects and developed a short hairpin RNA expression vector (shRNA) complex with a cyclodextrin-appended cationic dendrimer (CDE) as a novel multitarget therapeutic drug that is capable of simultaneously suppressing these three steps. We evaluated its therapeutic effects on systemic transthyretin (ATTR) amyloidosis and Alzheimer's disease (AD) as localized amyloidosis, by targeting TTR and amyloid ß, respectively. CDE/shRNA exhibited RNAi effects to suppress amyloid protein production and also achieved both inhibition of amyloid formation and disruption of existing amyloid fibrils. The multitarget therapeutic effects of CDE/shRNA were confirmed by evaluating TTR deposition reduction in early- and late-onset human ATTR amyloidosis model rats and amyloid ß deposition reduction in AppNL-G-F/NL-G-F AD model mice. Thus, the CDE/shRNA complex exhibits multifunctional therapeutic efficacy and may reveal novel strategies for establishing curative treatments for both systemic and localized amyloidosis.

The Effects of Sacran, a Sulfated Polysaccharide, on Gut Microbiota Using Chronic Kidney Disease Model Rats.

The aim of this study was to investigate the beneficial effects of sacran, a sulfated polysaccharide, on renal damage and intestinal microflora, in 5/6 nephrectomy rats as a model for chronic kidney disease (CKD). 5/6 Nephrectomy rats were divided into sacran treated and non-treated groups and examined for lethality after 4 weeks. The 5/6 nephrectomy rats were also divided into three groups: sacran treated, non-treated and AST-120 treated groups, and treated orally in a concentration-dependent manner for 4 weeks. Renal function was estimated by biochemical and histopathological analyses. Metagenomic analysis of feces from each group after 4 weeks was also performed and changes in intestinal microflora were compared. The administration of sacran to CKD rats at ≥19 mg/d increased their survival. In addition, the sacran-treated group improved CKD-related parameters in a concentration-dependent manner, and the inhibitory effect of 40 mg/d of sacran was comparable to that of AST-120. The changes in the intestinal microflora of the sacran treated group were positively correlated with an increase in the number of Lactobacillus species, which are known to be rich in beneficial bacteria, and the increment of this beneficial bacteria was negatively correlated with the concentration of indoxyl sulfate, a uremic toxin, in plasma. These results strongly suggest that the oral administration of sacran could contribute to the stabilization of intestinal microflora in CKD rats and to the reduction of oxidative stress as well as the inhibition of progression of CKD.

Lactose-Appended Hydroxypropyl-ß-Cyclodextrin Lowers Cholesterol Accumulation and Alleviates Motor Dysfunction in Niemann-Pick Type C Disease Model Mice.

Niemann-Pick disease type C (NPC) is characterized by the accumulation of glycolipids such as free cholesterol, sphingomyelin, and gangliosides in late endosomes/lysosomes (endolysosomes) due to abnormalities in the membrane proteins NPC1 or NPC2. The main symptoms of NPC caused by free cholesterol accumulation in various tissues vary depending on the time of onset, but hepatosplenomegaly and neurological symptoms accompanied by decreased motor, cognitive, and mental functions are observed in all age groups. However, the efficacy of NPC treatment remains limited. Herein, we have fabricated lactose-appended hydroxypropyl-ß-cyclodextrin (Lac-HPßCD) and evaluated its lowering effects on cholesterol accumulation in NPC model mice. We reveal that Lac-HPßCD lowers cholesterol accumulation in the liver and spleen by reducing the amount of free cholesterol. Moreover, Lac-HPßCD reduces the amount of free cholesterol in the cerebrum and slightly alleviates motor dysfunction. These results suggest that Lac-HPßCD has potential for the treatment of NPC.

"Human and Mouse Cross-Reactive" Albumin-Binding Helix-Loop-Helix Peptide Tag for Prolonged Bioactivity of Therapeutic Proteins.

The effectiveness of protein and peptide pharmaceuticals depends essentially on their intrinsic pharmacokinetics. Small-sized pharmaceuticals in particular often suffer from short serum half-lives due to rapid renal clearance. To improve the pharmacokinetics by association with serum albumin (SA) in vivo, we generated an SA-binding tag of a helix-loop-helix (HLH) peptide to be linked with protein pharmaceuticals. For use in future preclinical studies, screening of yeast-displayed HLH peptide libraries against human SA (HSA) and mouse SA (MSA) was alternately repeated to give the SA-binding peptide AY-VE, which exhibited cross-binding activities to HSA and MSA with KD of 65 and 20 nM, respectively. As a proof of concept, we site-specifically conjugated peptide AY-VE with insulin to examine its bioactivity in vivo. In mouse bioassay monitoring the blood glucose level, the AY-VE conjugate was found to have a prolonged hypoglycemic effect for 12 h. The HLH peptide tag is a general platform for extending the bioactivity of therapeutic peptides or proteins.

Polyrotaxane-Based Supramolecular Material for Improvement of Pharmaceutical Properties of Protein Drugs.

Pharmaceutical excipients, such as surfactants, amino acids, and polymers, have often been used to improve the physicochemical properties of protein drugs. However, the effects of these additives are limited because of factors such as their weak interactions with protein drugs. In the present study, we evaluated the application of a supramolecular polymer, aminated polyrotaxane (NH2-PRX), which can strongly interact with protein drugs via its dynamic and transformable properties, as a new pharmaceutical excipient for these agents. As a conventional control polymer with low mobility and average complexation ability, aminated dextran (NH2-DEX) was also prepared. NH2-PRX significantly reduced the aggregation of antibodies induced by shaking, compared with NH2-DEX. The adsorption of insulin onto glass and polypropylene containers was also reduced by the addition of NH2-PRX. In addition, the in vivo bioactivity of insulin was completely retained in the presence of NH2-PRX. Moreover, severe adverse effects were not observed following the administration of NH2-PRX. These findings indicate the potential use of NH2-PRX as a transformable pharmaceutical excipient for protein drugs.

Folic Acid-Appended Hydroxypropyl-ß-Cyclodextrin Exhibits Potent Antitumor Activity in Chronic Myeloid Leukemia Cells via Autophagic Cell Death.

2-Hydroxypropyl-ß-cyclodextrin (HP-ß-CyD) is widely used as an enabling excipient in pharmaceutical formulations. We previously demonstrated that HP-ß-CyD disrupted cholesterol homeostasis, and inhibited the proliferation of leukemia cells by inducing apoptosis and cell-cycle arrest. Recently developed drug delivery systems using folic acid (FA) and folic acid receptors (FR) are currently being used in cancer treatment. To confer tumor cell-selectivity to HP-ß-CyD, we synthesized folate-appended HP-ß-CyD (FA-HP-ß-CyD) and evaluated the potential of FA-HP-ß-CyD as an anticancer agent using chronic myeloid leukemia (CML) cells in vitro and in vivo. FA-HP-ß-CyD inhibited the growth of FR-expressing cells but not that of FR-negative cells. FA-HP-ß-CyD had stronger anti-leukemia and cell-binding activities than HP-ß-CyD in CML cells. Unlike HP-ß-CyD, FA-HP-ß-CyD entered CML cells through endocytosis and induced both apoptosis and autophagy via mitophagy. FA-HP-ß-CyD increased the inhibitory effects of the ABL tyrosine kinase inhibitors imatinib mesylate and ponatinib, which are commonly used in CML. In vivo experiments in a BCR-ABL leukemia mouse model showed that FA-HP-ß-CyD was more effective than HP-ß-CyD at a ten-fold lower dose. These results indicate that FA-HP-ß-CyD may be a novel tumor-targeting agent for the treatment of leukemia.

Supramolecular polymer-based transformable material for reversible PEGylation of protein drugs.

We herein developed a transformable mixing-type material for reversible PEGylation of protein drugs using a supramolecular backbone polymer, that is, polyrotaxane possessing both amino groups and PEG chains (PEG-NH2-PRX). We expected that PEG-NH2-PRX provides amino groups to interact with protein drugs on demand because the mobility of amino groups in PEG-NH2-PRX was high. In fact, PEG-NH2-PRX formed complexes with protein drugs efficiently compared to PEGylated amino-dextran (PEG-NH2-DEX), a control material fabricated with a macromolecular backbone polymer. Moreover, PEG-NH2-PRX markedly improved the stability of antibodies and prolonged the hypoglycemic effects of insulin without loss of bioactivity, compared to PEG-NH2-DEX. These findings suggest that the supramolecular material, PEG-NH2-PRX, is a promising reversible PEGylation material for protein drugs compared to macromolecular materials.

Fasting impairs type 2 helper T cell infiltration in the lung of an eosinophilic asthma mouse model.

Eosinophilic asthma is a form of bronchial asthma that is caused by the pulmonary infiltration of eosinophils and accounts for approximately half of the patients with severe asthma. Several cell types of the immune system in synergy with the epithelial cells of the lung provoke an inflammatory response in patients with asthma. Recently, the effect of fasting on immune cells and inflammation has attracted considerable attention. Therefore, we examined whether fasting may serve as novel preventive strategy in patients with asthma. In our study, we employed a previously established mouse model of eosinophilic asthma. C57BL/6 mice were inoculated intranasally with interleukin-33 and ovalbumin (OVA) in order to induce eosinophil infiltration in the lung and subjected to a 48-h long fasting period directly after or 7 days postinoculation. We used flow cytometry to characterise infiltrated immune cells in the lung and measured the quantity of inflammatory cytokines as well as antigen-specific immunoglobins (Ig) by ELISA. Our results indicated that fasting lowered the number of eosinophilic pulmonary infiltrates in the eosinophilic asthma model mice. Furthermore, fasting suppressed anti-OVA IgG1 production. Fasting suppressed Th2 cytokine production by impairing Th2 accumulation in the lung. The findings suggest that fasting may be a novel preventive strategy for eosinophilic asthma.

Differential mode of cholesterol inclusion with 2-hydroxypropyl-cyclodextrins increases safety margin in treatment of Niemann-Pick disease type C.

BACKGROUND AND PURPOSE: Niemann-Pick disease type C (NPC) is a lysosomal storage disorder with disrupted intracellular cholesterol trafficking. A cyclic heptasaccharide, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), is a cholesterol solubilizer that is being developed to treat NPC, but its ototoxicity and pulmonary toxicity remain important issues. We have characterized 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD), a cyclic octasaccharide with a larger cavity than HP-ß-CD, as a candidate drug to treat NPC. However, the molecular target of HP-γ-CD with respect to NPC and its potential for clinical application are still unclear. EXPERIMENTAL APPROACH: We investigated the mode of interaction between HP-γ-CD and cholesterol by phase-solubility analysis, proton NMR spectroscopy and molecular dynamics simulations. We then evaluated the therapeutic effects of HP-γ-CD compared with HP-ß-CD using cellular and murine NPC models. Mouse auditory and pulmonary function tests were also conducted. KEY RESULTS: HP-γ-CD solely formed a 1:1 inclusion complex with cholesterol with an affinity similar to that of HP-ß-CD. In vitro, HP-γ-CD and HP-ß-CD amelioration of NPC-related manifestations was almost equivalent at lower concentrations. However, at higher concentrations, the cholesterol inclusion mode of HP-ß-CD shifted to the highly soluble 2:1 complex whereas that of HP-γ-CD maintained solely the 1:1 complex. The constant lower cholesterol solubilizing ability of HP-γ-CD conferred it with significantly reduced toxicity compared with HP-ß-CD, but equal efficacy in treating a mouse model of NPC. CONCLUSIONS AND IMPLICATIONS: HP-γ-CD can serve as a fine-tuned cholesterol solubilizer for the treatment of NPC with a wider safety margin than HP-ß-CD in terms of ototoxicity and pulmonary toxicity.