Inhalation treatment of cystic fibrosis with lumacaftor and ivacaftor co-delivered by nanostructured lipid carriers

Cystic fibrosis (CF), a most deadly genetic disorder, is caused by mutations of CF transmembrane receptor (CFTR) - a chloride channel present at the surface of epithelial cells. In general, two steps have to be involved in treatment of the disease: correction of cellular defects and potentiation to further increase channel opening. Consequently, a combinatorial simultaneous treatment with two drugs with different mechanisms of action, lumacaftor and ivacaftor, has been recently proposed. While lumacaftor is used to correct p.Phe508del mutation (the loss of phenylalanine at position 508) and increase the amount of cell surface-localized CFTR protein, ivacaftor serves as a CFTR potentiator that increases the open probability of CFTR channels. Since the main organ that is affected by cystic fibrosis is the lung, the delivery of drugs directly to the lungs by inhalation has a potential to enhance the efficacy of the treatment of CF and limit adverse side effects upon healthy tissues and organs. Based on our extensive experience in inhalation delivering of drugs by different nanocarriers, we selected nanostructured lipid carriers (NLC) for the delivery both drugs directly to the lungs by inhalation and tested NLC loaded with drugs in vitro (normal and CF human bronchial epithelial cells) and in vivo (homozygote/homozygote bi-transgenic mice with CF). The results show that the designed NLCs demonstrated a high drug loading efficiency and were internalized in the cytoplasm of CF cells. It was found that NLC-loaded drugs were able to restore the expression and function of CFTR protein. As a result, the combination of lumacaftor and ivacaftor delivered by lipid nanoparticles directly into the lungs was highly effective in treating lung manifestations of cystic fibrosis.

Migraine in the Andes and Headache at Sea Level

In Cerro de Pasco (CP), Peru (altitude 4338 m) 24% of men have migraine with aura. We studied 30 men. Twenty CP natives, examined in CP, were rated using a chronic mountain sickness (CMS) score to separate controls (10) from those with CMS (10), a maladaptation syndrome in natives to altitude which includes severe, recurring headache. We collected white cells in CP and, from the same men, within 1 h of arrival in Lima (150 m above sea level). Ten normal US men volunteered white cells for comparison. After RNA extraction we assessed gene expression by reverse transcription-polymerase chain reaction. Low ATP1A1 subunit of the ATPase gene mRNA expression in CP was correlated with headache ( P = 0.002), acral paraesthesias ( P = 0.004) and CMS score ( P < 0.001). ATP1A1 subunit expression was increased in all Andeans in Lima ( P < 0.001). There were no differences between Andean controls in Lima and US controls. Manipulation of Na+/K+ATPase could offer relief for migraineurs at sea level.

Nanotechnology approaches for personalized treatment of multidrug resistant cancers

The efficacy of chemotherapy is substantially limited by the resistance of cancer cells to anticancer drugs that fluctuates significantly in different patients. Under identical chemotherapeutic protocols, some patients may receive relatively ineffective doses of anticancer agents while other individuals obtain excessive amounts of drugs that induce severe adverse side effects on healthy tissues. The current review is focused on an individualized selection of drugs and targets to suppress multidrug resistance. Such selection is based on the molecular characteristics of a tumor from an individual patient that can potentially improve the treatment outcome and bring us closer to an era of personalized medicine.

Chronic hypoxia in Andeans; are there lessons for neurology at sea level?

Hypoxia is implicated in aging and neurodegenerative diseases. We posited that changes in gene expression induced by ambient hypoxia at altitude may be neuroprotective to natives of these regions. We studied 30 men. Twenty natives of Cerro de Pasco (CP), altitude 4,338 m were examined in CP; then transported within 6 h to Lima (150 m-sea level) and examined 1 h after arrival. They were assessed by a Chronic Mountain Sickness-score (CMS-sc) in CP, 10 were normal Andeans and 10 had chronic mountain sickness (CMS), a sudden inexplicable loss of adaptation to their native environment. RNA was extracted from venous blood white cells. The Andeans were compared to 10 normal US men living at 1500 m using RT-PCR. We focused on the cyto-neuro-protective genes, Ataxia telangiectasia mutated (ATM), heme-oxygenase-1 (HMOX 1), heat shock protein-70 (HSP-70), heat shock protein-90 (HSP-90), and the neuroprotective enzyme, nicotinamide mononucleotide adenylyl transferase 1 (Nnmat 1). CMS patients had significantly higher levels of gene expression (HMOX-1, HSP-70, ATM) than Andean controls in CP. HSP-90 and Nmnat 1, however, were higher in Andean controls in all locations. Significant reductions of all gene products, within an hour of arriving in normoxia in Lima, were found. In Andean controls, the gene products in Lima fell to levels approaching US controls. Correlation and regression methods showed men with high expression of all gene products had an average CMS-sc=19.8; those with low expression a normal score (9.4, P=0.02). ATM expression was related to age (P<0.001). The natural experiment that unfolds in the mountainous regions of the world provides opportunities to study neuroprotection in intact humans.

Gene expression, autonomic function and chronic hypoxia:lessons from the Andes

Autonomic function is altered by altitude in sojourners and natives. We hypothesized that these physiologic responses are modulated by changes in gene expression. We compared gene product levels in 20 natives of Cerro de Pasco (CP), (4338 m), 10 of which had chronic mountain sickness (CMS) established by a CMS-scoring system, with gene products in the same men after 1 h at sea level. We further compared the results with those obtained from 10 US men residing at 1500 m. We measured gene products in white cells by reverse transcription polymerase chain reaction (RT-PCR). We focused on genes important in vascular autonomic physiology, and/or activated by hypoxia; hypoxia inducible factor 1-alpha (HIF 1-alpha), 2 splicing variants of vascular endothelial growth factor (VEGF); VEGF-121, VEGF-165, and phosphoglycerate kinase 1 (PGK 1). Normal CP natives showed high expression of all genes in CP, compared to US controls. Within 1 h of arrival at sea level, they had comparable levels to US residents. In CMS, the gene products were higher in CP. Although gene products decreased in Lima in this group, they never reached US values. VEGF 121 and 165 were correlated (P<0.001). VEGF 165 was higher in CMS in CP (P=0.006), and was positively correlated with CMS-score (R=0.86, P<0.001), and negatively correlated with arterial saturation (R=-0.79, P<0.001). Our findings underscore the changes in gene expression levels in intact humans in response to environmental stress. These changes may support the physiologic alterations induced by the ambient hypoxia at altitude and impact organism survival. They also suggest therapeutic strategies for autonomic and neurodegenerative diseases at sea level.

Remediation of Cellular Hypoxic Damage by Pharmacological Agents

Many known pathological conditions lead to decreases in oxygen supply to various cells. When secondary cellular hypoxia becomes severe, it causes additional cellular damage, aggravating the primary disorder and leading to cell death. Therefore, remediation of secondary hypoxic damage should significantly increase the efficacy of the treatment of primary disease and prevent extensive cellular damage. Analysis of the literature and our experimental data show that the main mechanisms of secondary hypoxic cellular damage include lactate acidosis (lactic acidosis), the boost in free radical processes and the activation of apoptosis and necrosis. These factors result in damage to cellular membranes which in turn further limits oxygen supply leading to augmented hypoxic cellular damage. Therefore, to effectively break this vicious cycle of cellular hypoxia, antihypoxic therapy should simultaneously: (1) mitigate existing cellular hypoxic damage; (2) increase cellular ability to utilize available oxygen; (3) amplify the power of cellular antioxidant defense and (4) prevent hypoxic activation of apoptosis and necrosis. It is clear that such complex task cannot be fulfilled by a single pharmacological agent. Therefore, a complex multi component antihypoxic drug delivery system should be designed to address all the four desiderata indicated above. This review will examine existing pharmaceutical antihypoxic preparations and evaluate the new methods for the pharmacological remediation of cellular hypoxic damage and propose future directions for the design of the needed drug delivery systems.

Bimodal effect of hypoxia in cancer: role of hypoxia inducible factor in apoptosis

The effects of the separate and combined application of hypoxia and antisense oligonucleotides (ASO) against hypoxia inducible factor 1alpha (HIF1A) on cancer cells were examined. Experiments were carried out on human ovarian carcinoma cells in four series: (1) control [Normoxia (5% CO2 in air), no treatment], (2) hypoxia (1% O2, 5% CO2, and 94% N2 for 48 h), (3) treatment with ASO targeted to HIF1A (48 h), and (4) combined action of hypoxia and ASO. After treatment, the following processes and factors were monitored: apoptosis, cellular metabolism and viability, expression of genes encoding HIF1A, von Hippel-Lindau tumor suppressor protein (VHL), and genes responsible for cell death induction and antiapoptotic defense (P53, BCL2, BAX, and caspases 9 and 3). Expression of caspase 9 and HIF1A protein was confirmed by Western blotting. Liposomes were used as a delivery system of HIF1A ASO. It was found that hypoxia alone significantly disturbed cellular metabolism, reducing the level of respiration by 50% when compared with control. Hypoxia induced apoptosis by upregulating the P53-, BAX-, and caspase-dependent cell death pathways, while activating cellular antiapoptotic defense by the overexpression of BCL2 protein. Both opposing effects were dependent on the overexpression of hypoxia inducible factor. We conclude that hypoxia induces a bimodal effect, simultaneously promoting cell death and activating cellular resistance. The downregulation of HIF1A promoted cell death induction and prevented activation of cellular defense by hypoxia. This suggests that HIF1A is a potential candidate for anticancer therapeutic targeting.

Enhancement of the efficacy of chemotherapy for lung cancer by simultaneous suppression of multidrug resistance and antiapoptotic cellular defense: novel multicomponent delivery system

The efficacy of chemotherapy of lung cancer is limited by the development of resistance in cancer cells during treatment. In most lung cancers, this resistance is associated with the overexpression of (a) multidrug resistance-associated protein (MRP) responsible for drug efflux from the cancer cells (pump resistance) and (b) BCL2 protein that activates antiapoptotic cellular defense (nonpump resistance). A novel liposomal proapoptotic anticancer drug delivery system was developed to enhance anticancer efficacy of the well-established drug doxorubicin (DOX). This multicomponent drug delivery system was tested on multidrug-sensitive and -resistant human small-cell lung cancer cells. The drug delivery system includes four components: (a) liposome as a carrier, (b) DOX as an inductor of apoptosis, (c) antisense oligonucleotides (ASOs) targeted to MRP1 mRNA as a suppressor of pump resistance, and (d) ASOs targeted to BCL2 mRNA as a suppressor of nonpump resistance. Intracellular internalization of ASOs and DOX; the influence of the proposed system on the expression of genes and proteins involved in the multidrug resistance, cytotoxicity, and apoptosis induction and antiapoptotic defense; and the activity of caspases were studied. It was found that the proposed liposomal delivery system successfully delivered ASOs and DOX to cell nuclei, inhibited MRP1 and BCL2 protein synthesis, and substantially increased the anticancer action of DOX by stimulating the caspase-dependent pathway of apoptosis in multidrug-resistant human lung cancer cells.

Gene expression in the Andes; relevance to neurology at sea level

Chronic mountain sickness (CMS), a maladaptation syndrome to chronic hypoxia, occurs in the Andes. Gene expression differences in Andeans could explain adaptation and maladaptation to hypoxia, both of which are relevant to neurology at sea level. Expression of genes responsive to cellular oxygen concentration, hypoxia-inducible factor-1alpha (HIF-1alpha), three splicing variants of vascular endothelial growth factor (VEGF) and von Hippel-Lindau protein (pVHL) was measured by reverse transcription polymerase chain reaction (RT-PCR) in 12 Cerro de Pasco (CP) (altitude 4338 m) natives and 15 CMS patients in CP. Thirteen high altitude natives living in Lima and five Lima natives were sea level controls. A CMS score (CMS-sc) was assigned clinically. Expression was related to the clinical assessment. High expression of HIF-1alpha and VEGF-121 was found in CMS (P<0.001). Samples from CP had higher expression than those from Lima (P<0.001). Expression of HIF-1alpha and VEGF-121 was related to age (P<0.001); adjusting for age did not abolish the group effect. Higher CMS-sc was related to expression independent of age (P<0.001). VEGF-165 and -189 were expressed only in CMS. Birth altitude had no effect on gene expression. pVHL was not quantifiable.HIF-1alpha and VEGF-121 participate in adaptation to hypoxia. The high levels may explain blood vessel proliferation in Andeans and hold lessons for patients at sea level. VEGF-165 expression suggests that it contributes to preservation of neuronal function in human chronic hypoxia. VHL mutations may mark those destined to develop neural crest tumors which are common in the Andes.

Selected contribution: Lung hypoxia: antioxidant and antiapoptotic effects of liposomal alpha-tocopherol

The aim of this study is to examine the antioxidant and antiapoptotic activity of liposomal alpha-tocopherol (LAT) in anesthetized rats exposed to severe hypoxia. It was shown that intratracheal application of LAT normalized lung phospholipid composition and inhibited lipid peroxidation in lung tissues, which in turn decreased lung edema and damage and improved breathing pattern, oxygen diffusion, and lung gas exchange. LAT also limited the overexpression of genes encoding hypoxia inducible factor-1alpha and both studied forms of phospholipase A(2), and it increased the power of cellular antioxidant and antiapoptotic defense by overexpressing genes encoding Mn- and Cu-Zn-cofactored superoxide dismutases, Bcl-2, and heat shock 70 proteins. The overexpression of studied caspases and their activity were downregulated, which significantly (1.6-2 times) limited apoptosis in lung cells. Finally, all these positive changes decreased mortality during hypoxia from approximately 60% in untreated animals to approximately 30% in the group of rats treated with LAT. The data obtained indicate that LAT may be useful for the correction of hypoxic lung injury.

The influence of cytotoxicity of macromolecules and of VEGF gene modulated vascular permeability on the enhanced permeability and retention effect in resistant solid tumors

PURPOSE

To study the influence of cytotoxicity of macromolecules, VEGF gene expression, and vascular permeability on the enhanced permeability and retention (EPR) effect.

METHODS

Mice bearing xenografts of A2780 multidrug resistant human ovarian carcinoma were treated by free doxorubicin (DOX) and N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bound DOX (P(GFLG)-DOX), Texas Red (P-TR), and FITC (P-FITC). Antitumor activity, drug distribution in tumor, vascular permeability, VEGF gene expression, and DNA fragmentation were studied.

RESULTS

The accumulation of free DOX led to the VEGF gene overexpression and increased the vascular permeability, which in turn enhanced the drug accumulation in the same location. This positive feedback loop led to a highly inhomogeneous distribution of the drug within the tumor. In contrast, P(GFLG)-DOX down-regulated the VEGF gene and decreased vascular permeability. This negative feedback seemed to prevent additional drug accumulation in dead necrotic tissue, resulting in a more uniform drug distribution and enhanced the antitumor activity P(GFLG)-DOX.

CONCLUSIONS

The EPR effect significantly differed for macromolecules containing DOX when compared to macromolecules without drug. The cytotoxicity of P(GFLG)-DOX amplified the EPR effect, led to a more homogenous distribution of the drug, increased the average drug concentration in tumor and augmented its efficacy.

Familial hypercholesterolemia kindred in Utah with novel C54S mutations of the LDL receptor gene

In the course of investigations of coronary artery disease in Utah, we identified a family whose proband showed elevated plasma levels of LDL cholesterol. To determine the genetic etiology of the lipoprotein abnormalities, we screened DNA samples for mutations in all 18 exons and the exon- intron boundaries of the low-density lipoprotein (LDL) receptor gene. Novel point mutations were identified in the proband: a T-to-A transversion at nucleotide position 223, causing substitution of Ser for Cys at codon 54 in exon 3 of the receptor gene. This amino acid replacement would disrupt one of the disulfide bonds necessary for maintenance of the secondary structure of the repeat at the N-terminal of the receptor, prevent correct folding of the receptor, and result in defective intracellular transport of the receptor.

HPMA copolymer bound adriamycin overcomes MDR1 gene encoded resistance in a human ovarian carcinoma cell line

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer-adriamycin (ADR) conjugate containing lysosomally degradable oligopeptide (GFLG) side chains terminated in ADR was synthesized. The effect of free and HPMA copolymer-bound ADR on the viability of A2780 sensitive and A2780/AD multidrug resistant human ovarian carcinoma cells was studied in vitro. As expected, the IC50 dose for the HPMA copolymer-ADR conjugate was higher than for free ADR reflecting the difference in the mechanism of cell entry. The resistant A2780/AD cells demonstrated about 40-times higher resistance to free ADR than the sensitive A2780 cells. On the contrary, there was only a small difference in cytotoxicity of the HPMA copolymer-ADR conjugate toward sensitive A2780 or MDR resistant A2780/AD cells. The IC50 value for A2780/AD was only about 20% higher than the value for sensitive A2780 cells. These data seem to indicate that the HPMA copolymer-ADR conjugate may, at least partially, avoid the ATP driven P-glycoprotein (Pgp) efflux pump. The analysis of the expression of the MDR1 gene which encodes the Pgp, has shown that free ADR in high doses stimulated MDR1 gene expression in sensitive A2780 cells. At the same time both free and HPMA copolymer-ADR conjugate partially inhibited the expression of the MDR1 and beta 2 m genes in multidrug resistant A2780/AD cells.

Superresistance against hypoxia after preliminary adaptation to repeated stress

The study investigated the influence of adaptation to stress on resistance to hypoxia. After rats were adaptated to moderate restraint stress, they were anesthetized and exposed to 6% O2. Adaptation increased tidal volume by 2.6-fold, lung and alveolar ventilation by 1.6- and 1.8-fold, respectively, and O2 consumption by 1.6-fold; limited lactate accumulation in the liver by 2-fold, in the heart by 34%, in the lung by 36%, and in the blood by 36%; and elevated pH. At the same time, preliminary adaptation to stress inhibited the hypoxic activation of lipolysis and peroxidation in all tissues. The concentration of lipid peroxides decreased after adaptation by 1.3- to 1.5-fold in different organs, whereas the content of free fatty acids diminished by 1.7- to 2.3-fold. Finally, after adaptation, mortality decreased under severe hypoxia by 6.5-fold. Thus, the data suggest that the cross-protective effect of adaptation was achieved by the economization of respiration and circulation, by marked augmentation in the ability of tissue to utilize blood O2, and by the limitation of processes that are able to damage tissue membranes, namely, acidosis, lipolysis, and lipid peroxidation.