Reactive oxygen species (ROS) are continuously generated within living systems and the inability to manage ROS load leads to elevated oxidative stress and cell damage. Oxidative stress is coupled to the oxidative degradation of lipid membranes, also known as lipid peroxidation. This process generates over 200 types of aldehydes, many of which are highly reactive and toxic. Aldehyde dehydrogenases (ALDHs) metabolize endogenous and exogenous aldehydes and thereby mitigate oxidative/electrophilic stress in prokaryotic and eukaryotic organisms. ALDHs are found throughout the evolutionary gamut, from single celled organisms to complex multicellular species. Not surprisingly, many ALDHs in evolutionarily distant, and seemingly unrelated, species perform similar functions, including protection against a variety of environmental stressors like dehydration and ultraviolet radiation. The ability to act as an ‘aldehyde scavenger’ during lipid peroxidation is another ostensibly universal ALDH function found across species. Up-regulation of ALDHs is a stress response in bacteria (environmental and chemical stress), plants (dehydration, salinity and oxidative stress), yeast (ethanol exposure and oxidative stress), Caenorhabditis elegans (lipid peroxidation) and mammals (oxidative stress and lipid peroxidation). Recent studies have also identified ALDH activity as an important feature of cancer stem cells. In these cells, ALDH expression helps abrogate oxidative stress and imparts resistance against chemotherapeutic agents such as oxazaphosphorine, taxane and platinum drugs. The ALDH superfamily represents a fundamentally important class of enzymes that significantly contributes to the management of electrophilic/oxidative stress within living systems. Mutations in various ALDHs are associated with a variety of pathological conditions in humans, underscoring the fundamental importance of these enzymes in physiological and pathological processes.

We have combined the drug release and delivery potential of nanoparticle (NP) systems with the ease of flow, processing, and aerosolization potential of large porous particle (LPP) systems by spray drying solutions of polymeric and nonpolymeric NPs into extremely thin-walled macroscale structures. These hybrid LPPs exhibit much better flow and aerosolization properties than the NPs; yet, unlike the LPPs, which dissolve in physiological conditions to produce molecular constituents, the hybrid LPPs dissolve to produce NPs, with the drug release and delivery advantages associated with NP delivery systems. Formation of the large porous NP (LPNP) aggregates occurs via a spray-drying process that ensures the drying time of the sprayed droplet is sufficiently shorter than the characteristic time for redistribution of NPs by diffusion within the drying droplet, implying a local Peclet number much greater than unity. Additional control over LPNPs physical characteristics is achieved by adding other components to the spray-dried solutions, including sugars, lipids, polymers, and proteins. The ability to produce LPNPs appears to be largely independent of molecular component type as well as the size or chemical nature of the NPs. L arge porous particles (LPPs), characterized by geometric sizes larger than 5 m and mass densities around 0.1 g͞cm 3 or less, have achieved recent popularity as carriers of drugs to the lungs for local and systemic applications (1, 2). A principal advantage of LPPs relative to conventional inhaled therapeutic aerosol particles is their aerosolization efficiency (3, 4); in addition, LPPs possess the potential for avoidance of alveolar macrophage clearance (5-7), enabling sustained drug release in the lungs (8).Particles with geometric diameters less than a few hundred nanometers (9) represent an even more tenacious resident of the lungs. Once deposited, nanoparticles (NPs) or ''ultrafine'' particles often remain in the lung lining fluid until dissolution (assuming they are soluble), escaping both phagocytic and mucociliary clearance mechanisms (5-8). Thus, deposition of drug-bearing NPs in the lungs may offer the potential for sustained drug action and release throughout the lumen of the lungs, not only in the deep lung or alveolar region, where macrophage clearance occurs. However, the utility of NPs for drug release is severely limited because of their low inertia, which causes them to be predominantly exhaled from the lungs after inspiration (10, 11). Moreover, their small size leads to particleparticle aggregation, making physical handling of NPs difficult in liquid and dry powder forms; this is a common practical problem that must be overcome before using NPs for oral drug delivery (12, 13). As a result of these limitations, NPs are not presently being explored commercially or clinically as vehicles for drug delivery in the lungs.We have developed a form of particle for drug delivery that combines the advantages of LPPs and NPs while avoiding their limitations. We use spray drying (14) to form...

Members of the aldehyde dehydrogenase gene (ALDH) superfamily play an important role in the enzymic detoxification of endogenous and exogenous aldehydes and in the formation of molecules that are important in cellular processes, like retinoic acid, betaine and gamma-aminobutyric acid. ALDHs exhibit additional, non-enzymic functions, including the capacity to bind to some hormones and other small molecules and to diminish the effects of ultraviolet irradiation in the cornea. Mutations in ALDH genes leading to defective aldehyde metabolism are the molecular basis of several diseases, including gamma-hydroxybutyric aciduria, pyridoxine-dependent seizures, Sjögren–Larsson syndrome and type II hyperprolinaemia. Interestingly, several ALDH enzymes appear to be markers for normal and cancer stem cells. The superfamily is evolutionarily ancient and is represented within Archaea, Eubacteria and Eukarya taxa. Recent improvements in DNA and protein sequencing have led to the identification of many new ALDH family members. To date, the human genome contains 19 known ALDH genes, as well as many pseudogenes. Whole-genome sequencing allows for comparison of the entire complement of ALDH family members among organisms. This paper provides an update of ALDH genes in several recently sequenced vertebrates and aims to clarify the associated records found in the National Center for Biotechnology Information (NCBI) gene database. It also highlights where and when likely gene-duplication and gene-loss events have occurred. This information should be useful to future studies that might wish to compare the role of ALDH members among species and how the gene superfamily as a whole has changed throughout evolution.

The serpin family comprises a structurally similar, yet functionally diverse, set of proteins. Named originally for their function as serine proteinase inhibitors, many of its members are not inhibitors but rather chaperones, involved in storage, transport, and other roles. Serpins are found in genomes of all kingdoms, with 36 human protein-coding genes and five pseudogenes. The mouse has 60 Serpin functional genes, many of which are orthologous to human SERPIN genes and some of which have expanded into multiple paralogous genes. Serpins are found in tissues throughout the body; whereas most are extracellular, there is a class of intracellular serpins. Serpins appear to have roles in inflammation, immune function, tumorigenesis, blood clotting, dementia, and cancer metastasis. Further characterization of these proteins will likely reveal potential biomarkers and therapeutic targets for disease.

ABSTRACT:Ethanol-induced damage is largely attributed to its toxic metabolite, acetaldehyde. Clearance of acetaldehyde is achieved by its oxidation, primarily catalyzed by the mitochondrial class II aldehyde dehydrogenase (ALDH2). ALDH1B1 is another mitochondrial aldehyde dehydrogenase (ALDH) that shares 75% peptide sequence homology with ALDH2. Recent population studies in whites suggest a role for ALDH1B1 in ethanol metabolism. However, to date, no formal documentation of the biochemical properties of ALDH1B1 has been forthcoming. In this current study, we cloned and expressed human recombinant ALDH1B1 in Sf9 insect cells. The resultant enzyme was purified by affinity chromatography to homogeneity. The kinetic properties of purified human ALDH1B1 were assessed using a wide range of aldehyde substrates. Human ALDH1B1 had an exclusive preference for NAD ؉ as the cofactor and was catalytically active toward short-and medium-chain aliphatic aldehydes, aromatic aldehydes, and the products of lipid peroxidation, 4-hydroxynonenal and malondialdehyde. Most importantly, human ALDH1B1 exhibited an apparent K m of 55 M for acetaldehyde, making it the second low K m ALDH for metabolism of this substrate. The dehydrogenase activity of ALDH1B1 was sensitive to disulfiram inhibition, a feature also shared with ALDH2. The tissue distribution of ALDH1B1 in C57BL/6J mice and humans was examined by quantitative polymerase chain reaction, Western blotting, and immunohistochemical analysis. The highest expression occurred in the liver, followed by the intestinal tract, implying a potential physiological role for ALDH1B1 in these tissues. The current study is the first report on the expression, purification, and biochemical characterization of human ALDH1B1 protein.

The forkhead box (FOX) proteins are transcription factors that play complex and important roles in processes from development and organogenesis to regulation of metabolism and the immune system. There are 50 FOX genes in the human genome and 44 in the mouse, divided into 19 subfamilies. All human FOX genes have close mouse orthologues, with one exception: the mouse has a single Foxd4 , whereas the human gene has undergone a recent duplication to a total of seven ( FOXD4 and FOXD4L1 → FOXD4L6 ). Evolutionarily ancient family members can be found as far back as the fungi and metazoans. The DNA-binding domain, the forkhead domain, is an example of the winged-helix domain, and is very well conserved across the FOX family and across species, with a few notable exceptions in which divergence has created new functionality. Mutations in FOX genes have been implicated in at least four familial human diseases, and differential expression may play a role in a number of other pathologies -- ranging from metabolic disorders to autoimmunity. Furthermore, FOX genes are differentially expressed in a large number of cancers; their role can be either as an oncogene or tumour suppressor, depending on the family member and cell type. Although some drugs that target FOX gene expression or activity, notably proteasome inhibitors, appear to work well, much more basic research is needed to unlock the complex interplay of upstream and downstream interactions with FOX family transcription factors.

Background: We have an incomplete understanding of the differences between cancer stem cells (CSCs) in human papillomavirus-positive (HPV-positive) and -negative (HPV-negative) head and neck squamous cell cancer (HNSCC). The PI3K pathway has the most frequent activating genetic events in HNSCC (especially HPV-positive driven), but the differential signaling between CSCs and non-CSCs is also unknown. Methods: We addressed these unresolved questions using CSCs identified from 10 HNSCC patient-derived xenografts (PDXs). Sored populations were serially passaged in nude mice to evaluate tumorigenicity and tumor recapitulation. The transcription profile of HNSCC CSCs was characterized by mRNA sequencing, and the susceptibility of CSCs to therapy was investigated using an in vivo model. SOX2 transcriptional activity was used to follow the asymmetric division of PDX-derived CSCs. All statistical tests were two-sided. Results: CSCs were enriched by high aldehyde dehydrogenase (ALDH) activity and CD44 expression and were similar between HPV-positive and HPV-negative cases (percent tumor formation injecting 1x10 3 cells: ALDH þ CD44 high ¼ 65.8%,

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