ArsenicSkinImageBD: A comprehensive image dataset to classify affected and healthy skin of arsenic-affected people.

Compared to other popular research domains, dermatology got less attention among machine learning researchers. One of the main concerns for this problem is an inadequate dataset since collecting samples from the human body is very sensitive. In recent years, arsenic has emerged as a significant issue for dermatologists. Arsenic is a highly toxic substance found in the earth's crust whose small amounts can be very injurious to the human body. People who are exposed to arsenic for a long time through water and food can get cancer and skin lesions. With a view to contributing to this aspect, this dataset has been organized with the help of which the researchers can understand the impact of this contamination and design a solution using artificial intelligence. To the best of our knowledge, this is the first standard, easy-to-use, and open dataset of arsenic diseases. The images were collected from four places in Bangladesh, under the Department of Public Health Engineering, Chapainawabganj, where they are working on arsenic contamination. The dataset has 8892 skin images, with half of them showing people with arsenic effects and the other half showing mixed skin images that are not affected by arsenic. This makes the dataset useful for treating people with arsenic-related conditions. Eventually, this dataset can attract the attention of not only the machine learning researchers, but also scientists, doctors, and other professionals in the associated research field.

The Correlation of the Neutrophil-to-Lymphocyte Ratio With Microvascular Complications in Patients With Diabetes Mellitus.

Background High neutrophil-to-lymphocyte ratio (NLR) may be used as a reliable measure of vascular complications and an indicator of poor outcomes in cases of diabetes mellitus (DM). Methods A prospective analytical cross-sectional observational study was conducted at the Rajendra Institute of Medical Sciences (RIMS), Ranchi, Jharkhand, India. A total of 100 patients with DM who met the inclusion and exclusion criteria were included in the study. A pre-tested and semi-structured questionnaire was given to the patients. IBM SPSS software version 26 (IBM Corp., Armonk, NY, USA) and MedCalc trial version 20.114 (MedCalc Software Ltd., Ostend, Belgium) were used for data analysis. Logistic regression analysis was performed to determine the association of the NLR with microvascular complications. Results In our study, the male-to-female ratio was 1.78:1 (male: 64 (n)%, female: 36 (n)%). The mean age of our study population was 56.28 ± 13.24 years. Of 58 patients with microvascular complications, 34 had a high NLR, and 24 patients had a normal NLR. Of 42 patients without microvascular complications, only 14 had a high NLR, and the remaining 28 patients had a normal NLR (p = 0.012). Logistic regression was performed to analyze the association between the NLR and microvascular complications, which demonstrated a significant association (odds ratio (OR): 2.833, 95% confidence interval (CI): 1.238-6.481; p = 0.013). Conclusions Our study demonstrated the higher odds of having microvascular complications among diabetics with a high NLR compared with non-diabetics. Therefore, the NLR may be used as a measure of microvascular complications in the diabetic population.

Effect of pH on the phase behavior of DMPC bilayers.

We have studied the effect of acidic pH on the phase behavior of the zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) using differential scanning calorimetry and x-ray scattering. Dispersions of DMPC in HCl solutions of pH = 4 and 3 behave identical to dispersions in water. The main transition temperature increases sharply and the pre-transition disappears at lower pH. An untilted gel phase is observed at pH = 2 and 1, in contrast to the tilted gel phase found at higher pH. The relatively large periodicity of the untilted gel phase, in comparison to that of the tilted gel phase occurring near neutral pH, clearly demonstrates the simultaneous charging and dehydration of the headgroups as the pH approaches the pK of the phosphate group. Headgroup dehydration at low pH also leads to the formation of DMPC crystallites and the inverted hexagonal phase at low and high temperatures, respectively, after a few days of incubation. These results show the significant effect of acidic pH on the phase behavior of zwitterionic lipids.

Alcohol-induced CYP2E1, mitochondrial dynamics and retrograde signaling in human hepatic 3D organoids.

Alcohol toxicity is a significant health problem with ~3 million estimated deaths per year globally. Alcohol is metabolized to the toxic metabolite, acetaldehyde by alcohol dehydrogenase or CYP2E1 in the hepatic tissue, and also induces reactive oxygen species (ROS), which together play a pivotal role in cell and tissue damage. Our previous studies with COS-7 cells transduced with unique human CYP2E1 variants that mostly localize to either microsomes or mitochondria revealed that mitochondrially-localized CYP2E1 drives alcohol toxicity through the generation of higher levels of ROS, which has a consequent effect on cytochrome c oxidase (CcO) and mitochondrial oxidative function. Alcohol treatment of human hepatocyte cell line, HepaRG, in monolayer cultures increased ROS, affected CcO activity/stability, and induced mitophagy. Alcohol treatment of 3D organoids of HepaRG cells induced higher levels of CYP2E1 mRNA and activated mitochondrial stress-induced retrograde signaling, and also induced markers of hepatic steatosis. Knock down of CYP2E1 mRNA using specific shRNA, FK506, a Calcineurin inhibitor, and Mdivi-1, a DRP1 inhibitor, ameliorated alcohol-induced mitochondrial retrograde signaling, and hepatic steatosis. These results for the first time present a mechanistic link between CYP2E1 function and alcohol mediated mitochondrial dysfunction, retrograde signaling, and activation of hepatic steatosis in a 3D organoid system that closely recapitulates the in vivo liver response.

Dysregulation of RyR Calcium Channel Causes the Onset of Mitochondrial Retrograde Signaling.

This study shows that multiple modes of mitochondrial stress generated by partial mtDNA depletion or cytochrome c oxidase disruption cause ryanodine receptor channel (RyR) dysregulation, which instigates the release of Ca2+ in the cytoplasm of C2C12 myoblasts and HCT116 carcinoma cells. We also observed a reciprocal downregulation of IP3R channel activity and reduced mitochondrial uptake of Ca2+. Ryanodine, an RyR antagonist, abrogated the mitochondrial stress-mediated increase in [Ca2+]c and the entire downstream signaling cascades of mitochondrial retrograde signaling. Interestingly, ryanodine also inhibited mitochondrial stress-induced invasive behavior in mtDNA-depleted C2C12 cells and HCT116 carcinoma cells. In addition, co-immunoprecipitation shows reduced FKBP12 protein binding to RyR channel proteins, suggesting the altered function of the Ca2+ channel. These results document how the endoplasmic reticulum-associated RyR channels, in combination with inhibition of the mitochondrial uniporter system, modulate cellular Ca2+ homeostasis and signaling under mitochondrial stress conditions.

Mitochondria-targeted paraquat and metformin mediate ROS production to induce multiple pathways of retrograde signaling: A dose-dependent phenomenon.

The mitochondrial electron transport chain is a major source of reactive oxygen species (ROS) and is also a target of ROS, with an implied role in the stabilization of hypoxia-inducible factor (HIF) and induction of the AMPK pathway. Here we used varying doses of two agents, Mito-Paraquat and Mito-Metformin, that have been conjugated to cationic triphenylphosphonium (TPP+) moiety to selectively target them to the mitochondrial matrix compartment, thereby resulting in the site-specific generation of ROS within mitochondria. These agents primarily induce superoxide (O2•-) production by acting on complex I. In Raw264.7 macrophages, C2C12 skeletal myocytes, and HCT116 adenocarcinoma cells, we show that mitochondria-targeted oxidants can induce ROS (O2•- and H2O2). In all three cell lines tested, the mitochondria-targeted agents disrupted membrane potential and activated calcineurin and the Cn-dependent retrograde signaling pathway. Hypoxic culture conditions also induced Cn activation and HIF1α activation in a temporally regulated manner, with the former appearing at shorter exposure times. Together, our results indicate that mitochondrial oxidant-induced retrograde signaling is driven by disruption of membrane potential and activation of Ca2+/Cn pathway and is independent of ROS-induced HIF1α or AMPK pathways.

Hyaluronan-binding protein 1 (HABP1) overexpression triggers induction of senescence in fibroblasts cells.

Hyaluronan-binding protein 1 (HABP1), a multi-compartmental, multi-functional protein has a wide range of functions, which can be attributed to its ability to associate with a variety of cellular ligands. Earlier we have reported that HABP1 overexpression in rat normal fibroblasts (F-HABP07) shows chronic generation of reactive oxygen species (ROS), induction of autophagy, and apoptosis. However, a significant proportion of cells remained viable after the majority went through apoptosis from 60 to 72 h. In this study, an attempt has been made to delineate the cellular events in the declined population of surviving cells. It has been elucidated here that, these cells at later time points of growth, that is, 72 and 84 h, not only appeared to shrink but also are devoid of autophagic vacuoles and displayed polyploidy. F-HABP07 cells exhibited an altered cytoskeletal structure from their parental cell line F111, assumed to be caused upon inhibition of actin polymerization and decrease in IQ motif-containing GTPase activating protein 1 (IQGAP1), a key protein associated with maintenance of cytoskeletal integrity. Enhanced expression and nuclear localization of AKT observed in F-HABP07 cells appears to be contributing toward the maintenance of high ROS levels in these cells and also potentially modulating the IQGAP1 activity. These observations, in fact have been considered to result in sustained DNA damage, which then leads to increased expression of p53 and activation of p21 and carry out the cellular events responsible for senescence. Subsequent assessment of the presence of positive ß-gal staining and enhanced expression of p16INK4a in F-HABP07, confirmed that HABP1 overexpressing fibroblasts undergo senescence.

Effect of adsorbed polyelectrolytes on the interactions and elasticity of charged surfactant bilayers.

We present studies on the structure of complexes of the cationic, bilayer-forming surfactant, didodecyldimethylammonium bromide (DDAB), and the anionic polyelectrolyte sodium polyacrylate (PAANa). In the presence of uncomplexed polyelectrolyte in the coexisting aqueous solution, these complexes are found to exhibit a swelling transition followed by a deswelling transition on increasing the salt concentration. Lamellar structures with low periodicities occur at both low and high salt concentrations, which are stabilized by polymer bridging and van der Waals attraction, respectively. The swollen complex found at intermediate salt concentrations forms the sponge phase. Our results reveal that polyelectrolyte adsorption on bilayers has a profound effect on inter-bilayer interactions. The polymer-induced interaction changes from being attractive to repulsive as the surface coverage increases on increasing the salt concentration. Our results also confirm that polymer adsorption alters the elastic moduli of the bilayer, in agreement with earlier theoretical predictions.

Mitochondrially targeted cytochrome P450 2D6 is involved in monomethylamine-induced neuronal damage in mouse models.

Parkinson's disease (PD) is a major human disease associated with degeneration of the central nervous system. Evidence suggests that several endogenously formed 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mimicking chemicals that are metabolic conversion products, especially ß-carbolines and isoquinolines, act as neurotoxins that induce PD or enhance progression of the disease. We have demonstrated previously that mitochondrially targeted human cytochrome P450 2D6 (CYP2D6), supported by mitochondrial adrenodoxin and adrenodoxin reductase, can efficiently catalyze the conversion of MPTP to the toxic 1-methyl-4-phenylpyridinium ion. In this study, we show that the mitochondrially targeted CYP2D6 can efficiently catalyze MPTP-mimicking compounds, i.e. 2-methyl-1,2,3,4-tetrahydroisoquinoline, 2-methyl-1,2,3,4-tetrahydro-ß-carboline, and 9-methyl-norharmon, suspected to induce PD in humans. Our results reveal that activity and respiration in mouse brain mitochondrial complex I are significantly affected by these toxins in WT mice but remain unchanged in Cyp2d6 locus knockout mice, indicating a possible role of CYP2D6 in the metabolism of these compounds both in vivo and in vitro These metabolic effects were minimized in the presence of two CYP2D6 inhibitors, quinidine and ajmalicine. Neuro-2a cells stably expressing predominantly mitochondrially targeted CYP2D6 were more sensitive to toxin-mediated respiratory dysfunction and complex I inhibition than cells expressing predominantly endoplasmic reticulum-targeted CYP2D6. Exposure to these toxins also induced the autophagic marker Parkin and the mitochondrial fission marker Dynamin-related protein 1 (Drp1) in differentiated neurons expressing mitochondrial CYP2D6. Our results show that monomethylamines are converted to their toxic cationic form by mitochondrially directed CYP2D6 and result in neuronal degradation in mice.

Cigarette Smoke Toxins-Induced Mitochondrial Dysfunction and Pancreatitis Involves Aryl Hydrocarbon Receptor Mediated Cyp1 Gene Expression: Protective Effects of Resveratrol.

We previously reported that mitochondrial CYP1 enzymes participate in the metabolism of polycyclic aromatic hydrocarbons and other carcinogens leading to mitochondrial dysfunction. In this study, using Cyp1b1-/-, Cyp1a1/1a2-/-, and Cyp1a1/1a2/1b1-/- mice, we observed that cigarette and environmental toxins, namely benzo[a]pyrene (BaP) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induce pancreatic mitochondrial respiratory dysfunction and pancreatitis. Our results suggest that aryl hydrocarbon receptor (AhR) activation and resultant mitochondrial dysfunction are associated with pancreatic pathology. BaP treatment markedly inhibits pancreatic mitochondrial oxygen consumption rate (OCR), ADP-dependent OCR, and also maximal respiration, in wild-type mice but not in Cyp1a1/1a2-/- and Cyp1a1/1a2/1b1-/- mice. In addition, both BaP and TCDD treatment markedly affected mitochondrial complex IV activity, in addition to causing marked reduction in mitochondrial DNA content. Interestingly, the AhR antagonist resveratrol, attenuated BaP-induced mitochondrial respiratory defects in the pancreas, and reversed pancreatitis, both histologically and biochemically in wild-type mice. These results reveal a novel role for AhR- and AhR-regulated CYP1 enzymes in eliciting mitochondrial dysfunction and cigarette toxin-mediated pancreatic pathology. We propose that increased mitochondrial respiratory dysfunction and oxidative stress are involved in polycyclic aromatic hydrocarbon associated pancreatitis. Resveratrol, a chemo preventive agent and AhR antagonist, and CH-223191, a potent and specific AhR inhibitor, confer protection against BaP-induced mitochondrial dysfunction and pancreatic pathology.

ß-Naphthoflavone-Induced Mitochondrial Respiratory Damage in Cyp1 Knockout Mouse and in Cell Culture Systems: Attenuation by Resveratrol Treatment.

A number of xenobiotic-inducible cytochrome P450s (CYPs) are now known to be localized in the mitochondrial compartment, though their pharmacological or toxicological roles remain unclear. Here, we show that BNF treatment markedly inhibits liver mitochondrial O2 consumption rate (OCR), ADP-dependent OCR, and also reserve OCR, in wild-type mice but not in Cyp1a1/1a2(-/-) double knockout mice. BNF treatment markedly affected mitochondrial complex I and complex IV activities and also attenuated mitochondrial gene expression. Furthermore, under in vitro conditions, BNF treatment induced cellular ROS production, which was inhibited by mitochondria-targeted antioxidant Mito-CP and CYP inhibitor proadefin, suggesting that most of the ROS production was intramitochondrial and probably involved the catalytic activity of mitochondrial CYP1 enzymes. Interestingly, our results also show that the AHR antagonist resveratrol, markedly attenuated BNF-induced liver mitochondrial defects in wild-type mice, confirming the role of AHR and AHR-regulated CYP1 genes in eliciting mitochondrial dysfunction. These results are consistent with reduced BNF-induced mitochondrial toxicity in Cyp1a1/1a2(-/-) mice and elevated ROS production in COS cells stably expressing CYP1A1. We propose that increased mitochondrial ROS production and respiratory dysfunction are part of xenobiotic toxicity. Resveratrol, a chemopreventive agent, renders protection against BNF-induced toxicity.

Strand-biased gene distribution, purine assymetry and environmental factors influence protein evolution in Bacillus.

A strong purine asymmetry, along with strand-biased gene distribution and the presence of PolC, prevails in Bacillus and some other members of Firmicutes, Fusobacteria and Tenericutes. The analysis of protein features in 21 Bacillus species of diverse metabolic, virulence and ecological traits revealed that purine asymmetry in conjunction with lineage/niche specific constraints significantly influences protein evolution in Bacillus. All Bacillus species, except for Se-respiring Bacillus selenitireducens, display distinct strand-specific biases in amino acid usage, which may affect the isoelectric point or surface charge distribution of proteins with prevalence of acidic and basic residues in the leading and lagging strand proteins, respectively.

Mitochondrial targeting of cytochrome P450 (CYP) 1B1 and its role in polycyclic aromatic hydrocarbon-induced mitochondrial dysfunction.

We report that polycyclic aromatic hydrocarbon (PAH)-inducible CYP1B1 is targeted to mitochondria by sequence-specific cleavage at the N terminus by a cytosolic Ser protease (polyserase 1) to activate the cryptic internal signal. Site-directed mutagenesis, COS-7 cell transfection, and in vitro import studies in isolated mitochondria showed that a positively charged domain at residues 41-48 of human CYP1B1 is part of the mitochondrial (mt) import signal. Ala scanning mutations showed that the Ser protease cleavage site resides between residues 37 and 41 of human CYP1B1. Benzo[a]pyrene (BaP) treatment induced oxidative stress, mitochondrial respiratory defects, and mtDNA damage that was attenuated by a CYP1B1-specific inhibitor, 2,3,4,5-tetramethoxystilbene. In support, the mitochondrial CYP1B1 supported by mitochondrial ferredoxin (adrenodoxin) and ferredoxin reductase showed high aryl hydrocarbon hydroxylase activity. Administration of benzo[a]pyrene or 2,3,7,8-tetrachlorodibenzodioxin induced similar mitochondrial functional abnormalities and oxidative stress in the lungs of wild-type mice and Cyp1a1/1a2-null mice, but the effects were markedly blunted in Cyp1b1-null mice. These results confirm a role for CYP1B1 in inducing PAH-mediated mitochondrial dysfunction. The role of mitochondrial CYP1B1 was assessed using A549 lung epithelial cells stably expressing shRNA against NADPH-cytochrome P450 oxidoreductase or mitochondrial adrenodoxin. Our results not only show conservation of the endoprotease cleavage mechanism for mitochondrial import of family 1 CYPs but also reveal a direct role for mitochondrial CYP1B1 in PAH-mediated oxidative and chemical damage to mitochondria.

Autophagic vacuolation induced by excess ROS generation in HABP1/p32/gC1qR overexpressing fibroblasts and its reversal by polymeric hyaluronan.

The ubiquitous hyaladherin, hyaluronan-binding protein 1 (HABP1/p32/gC1qR) upon stable overexpression in normal fibroblasts (F-HABP07) has been reported to induce mitochondrial dysfunction, growth retardation and apoptosis after 72 h of growth. HABP1 has been observed to accumulate in the mitochondria resulting in generation of excess Reactive Oxygen Species (ROS), mitochondrial Ca(++) efflux and drop in mitochondrial membrane potential. In the present study, autophagic vacuolation was detected with monodansylcadaverin (MDC) staining from 36 h to 60 h of culture period along with elevated level of ROS in F-HABP07 cells. Increased expression of autophagic markers like MAP-LC3-II, Beclin 1 and autophagic modulator, DRAM confirmed the occurrence of the phenomenon. Reduced vacuole formation was observed upon treatment with 3-MA, a known PI3 kinase inhibitor, only at 32 h and was ineffective if treated later, as high ROS level was already attained. Treatment of F111 and F-HABP07 cells with bafilomycin A1 further indicated an increase in autophagosome formation along with autophagic degradation in HABP1 overexpressed fibroblasts. Comparison between normal fibroblast (F111) and F-HABP07 cells indicate reduced level of polymeric HA, its depolymerization and perturbed HA-HABP1 interaction in F-HABP07. Interestingly, supplementation of polymeric HA, an endogenous ROS scavenger, in the culture medium prompted reduction in number of vacuoles in F-HABP07 along with drop in ROS level, implying that excess ROS generation triggers initiation of autophagic vacuole formation prior to apoptosis due to overexpression of HABP1. Thus, the phenomenon of autophagy takes place prior to apoptosis induction in the HABP1 overexpressing cell line, F-HABP07.

A pursuit of lineage-specific and niche-specific proteome features in the world of archaea.

BACKGROUND: Archaea evoke interest among researchers for two enigmatic characteristics -a combination of bacterial and eukaryotic components in their molecular architectures and an enormous diversity in their life-style and metabolic capabilities. Despite considerable research efforts, lineage- specific/niche-specific molecular features of the whole archaeal world are yet to be fully unveiled. The study offers the first large-scale in silico proteome analysis of all archaeal species of known genome sequences with a special emphasis on methanogenic and sulphur-metabolising archaea. RESULTS: Overall amino acid usage in archaea is dominated by GC-bias. But the environmental factors like oxygen requirement or thermal adaptation seem to play important roles in selection of residues with no GC-bias at the codon level. All methanogens, irrespective of their thermal/salt adaptation, show higher usage of Cys and have relatively acidic proteomes, while the proteomes of sulphur-metabolisers have higher aromaticity and more positive charges. Despite of exhibiting thermophilic life-style, korarchaeota possesses an acidic proteome. Among the distinct trends prevailing in COGs (Cluster of Orthologous Groups of proteins) distribution profiles, crenarchaeal organisms display higher intra-order variations in COGs repertoire, especially in the metabolic ones, as compared to euryarchaea. All methanogens are characterised by a presence of 22 exclusive COGs. CONCLUSIONS: Divergences in amino acid usage, aromaticity/charge profiles and COG repertoire among methanogens and sulphur-metabolisers, aerobic and anaerobic archaea or korarchaeota and nanoarchaeota, as elucidated in the present study, point towards the presence of distinct molecular strategies for niche specialization in the archaeal world.

Silencing of IkBß mRNA causes disruption of mitochondrial retrograde signaling and suppression of tumor growth in vivo.

A number of studies show that mitochondrial DNA (mtDNA) depletion and attendant activation of retrograde signaling induces tumor progression. We have reported previously that activation of a novel nuclear factor-Kappa B pathway is critical for the propagation of mitochondrial retrograde signaling, which induces both phenotypic and morphological changes in C2C12 myoblasts and A549 lung carcinoma cells. In this study, we investigated the role of stress-induced nuclear factor-Kappa B in tumor progression in xenotransplanted mice. We used a retroviral system for the inducible expression of small interfering RNA against IkBα and IkBß mRNAs. Expression of small interfering RNA against IkBß markedly impaired tumor growth and invasive ability of mtDNA-depleted C2C12 myoblasts and also thwarted anchorage-independent growth of the cells. Knockdown of IkBα mRNA, however, did not have any modulatory effect in this cell system. Moreover, expression of small interfering RNA against IkBß reduced the expression of marker genes for retrograde signaling and tumor growth in xenografts of mtDNA-depleted cells. Our findings demonstrate that IkBß is a master regulator of mitochondrial retrograde signaling pathway and that the retrograde signaling plays a role in tumor growth in vivo. In this regard, IkBß supports the tumorigenic potential of mtDNA-depleted C2C12 cells.

Additive effects of mitochondrion-targeted cytochrome CYP2E1 and alcohol toxicity on cytochrome c oxidase function and stability of respirosome complexes.

Alcohol treatment induces oxidative stress by a combination of increased production of partially reduced oxygen species and decreased cellular antioxidant pool, including GSH. Recently, we showed that mitochondrion-targeted CYP2E1 augments alcohol-mediated toxicity, causing an increase in reactive oxygen species production and oxidative stress. Here, we show that cytochrome c oxidase (CcO), the terminal oxidase of the mitochondrial respiratory chain, is a critical target of CYP2E1-mediated alcohol toxicity. COS-7 and Hep G2 cell lines expressing predominantly mitochondrion-targeted (Mt(++)) CYP2E1 and livers from alcohol-treated rats showed loss of CcO activity and increased protein carbonylation, which was accompanied by a decline in the steady state levels of subunits I, IVI1, and Vb of the CcO complex. This was also accompanied by reduced mitochondrial DNA content and reduced mitochondrial mRNA. These changes were more prominent in Mt(++) cells in comparison with wild type (WT) CYP2E1-expressing or ER(+) (mostly microsome-targeted) cells. In addition, mitochondrion-specific antioxidants, ubiquinol conjugated to triphenyl phosphonium, triphenylphosphonium conjugated carboxyl proxyl, and the CYP2E1 inhibitor diallyl sulfide prevented the loss of CcO activity and the CcO subunits, most likely through reduced oxidative damage to the enzyme complex. Our results suggest that damage to CcO and dissociation of respirosome complexes are critical factors in alcohol-induced toxicity, which is augmented by mitochondrion-targeted CYP2E1. We propose that CcO is one of the direct and immediate targets of alcohol-induced toxicity causing respiratory dysfunction.

Evidence for Serpentine as a novel antioxidant by a redox sensitive HABP1 overexpressing cell line by inhibiting its nuclear translocation of NF-κB.

Herbal antioxidants are gradually gaining importance as dietary supplements considering the growing implications of oxidative stress in most degenerative diseases and aging. Thus, continuous attempts are made to search for novel herbal molecules with antioxidative properties, using chemical methods predominantly with the need arising for cell based assays. We have generated a stable cell line F-HABP07, by constitutively overexpressing human Hyaluronan Binding Protein1 (HABP1) in murine fibroblasts which accumulates in the mitochondria leading to excess ROS generation without any external stimuli. In the present study, we demonstrated the nuclear translocation of p65 subunit of NF-κB in F-HABP07 cells, an important signature of ROS induced signalling cascade providing us an opportunity to use it as a screening system for ROS scavengers. Using known antioxidants on our designer cell line, we have demonstrated a dose dependant reduction in ROS generation and observed inhibition of p65 subunit of NF-κB nuclear translocation, increase in glutathione content and down-regulation of apoptotic marker Bax establishing its antioxidant biosensing capacity. With the help of this cell line, we for the first time demonstrated serpentine, one of the active components from the roots of Rauwolfia serpentina (a traditional medicinal plant), to be a novel non-cytotoxic antioxidant. The authenticity of this cell line screening system based discovery was validated using standard chemical assays thus, opening up new therapeutic avenues for this herbal compound and the use of this designer cell line.

Excessive reactive oxygen species induces apoptosis in fibroblasts: role of mitochondrially accumulated hyaluronic acid binding protein 1 (HABP1/p32/gC1qR).

Constitutively expressed HABP1 in normal murine fibroblast cell line induces growth perturbation, morphological abnormalities along with initiation of apoptosis. Here, we demonstrate that though HABP1 accumulation started in mitochondria from 48 hr of growth, induction of apoptosis with the release of cytochrome c and apoptosome complex formation occurred only after 60 hr. This mitochondrial dysfunction was due to gradual increase in ROS generation in HABP1 overexpressing cells. Along with ROS generation, increased Ca 2+ influx in mitochondria leading to drop in membrane potential was evident. Interestingly, upon expression of HABP1, the respiratory chain complex I was shown to be significantly inhibited. Electronmicrograph confirmed defective mitochondrial ultrastructure. The reduction in oxidant generation and drop in apoptotic cell population accomplished by disruption of HABP1 expression, corroborating the fact that excess ROS generation in HABP1 overexpressing cells leading to apoptosis was due to mitochondrial HABP1 accumulation.

Differential expression of Hyaluronic Acid Binding Protein 1 (HABP1)/P32/C1QBP during progression of epidermal carcinoma.

Our laboratory has characterized a novel cell surface glycoprotein, Hyaluronic Acid Binding Protein 1 (HABP1), interacting specifically with hyaluronan (HA) and regulating HA-mediated cellular event. The involvement of HA in different stages of carcinoma is well documented. In the present communication, the expression profile of HABP1 was investigated from initiation to progression of epidermal carcinoma in mice, induced by benzo[a]pyrene (B[a]P) exposure. During tumor initiation, HABP1 accumulated in inflammatory subsquamous tissue and with progression, the protein, was also seen to overexpress in papillomatic and acanthotic tissue. With the onset of metastasis, HABP1 overexpression was confined to metastatic islands, while it disappeared gradually from the surrounding mass. Such expression profiles in metastasized tissue were supported by decreased levels of HABP1, both at protein and transcript levels. These observations taken together suggest that the changes in HABP1 level coincide with specific stages of tumor progression, that lead to disruption of its interaction with HA, implying a role in the regulation of tumor metastasis.