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Biology subjects

Akram, S.

Publications and source records attributed to Akram, S..

8 recordsLinked to original sources

FiCOPS: Hardware/Software Co-Design of FPGA Computational Framework for Mass Spectrometry-Based Peptide Database Search

Improving the speed and efficiency of database search algorithms that deduce peptides from mass spectrometry (MS) data has been an active area of research for more than three decades. The significance of the need for faster database search methods has rapidly increased due to the growing interest in studying non-model organisms, meta-proteomics, and proteogenomic data, which are notorious for their enormous search space. Poor scalability of serial algorithms with the growing size of the database and increasing parameters of post-translational modifications is a widely recognized problem. While high-performance computing techniques can be used on supercomputing machines, the need for real-time, on-the-instrument solutions necessitates the development of an efficient sytem-on-chip that optimizes design constraints such as cost, performance, and power of the system. To show case that such a system can work, we present an FPGA-based computational framework called FiCOPS to accelerate database search using a hardware/software co-design methodology. First, we theoretically analyze the database-search algorithm (closed-search) to reveal opportunities for parallelism and uncover computational bottlenecks. We then design an FPGA-based architectural template to exploit parallelism inherent in the search workload. We also formulate an analytical performance model for the architecture template to perform rapid design space exploration and find a near-optimal accelerator configuration. Finally, we implement our design on the Intel Stratix 10 FPGA platform and evaluate it using real-world datasets. Our experiments demonstrate that FiCOPS achieves 3.5 x speed-up over existing CPU solutions and 3x and 5x reduction in power consumption compared to existing CPU and GPU solutions.

bioinformatics↗

Isotopic tracing in Mycobacterium tuberculosis-infected alveolar epithelial cells indicates metabolic specificity to their virulence and drug-resistance status

Mycobacterium tuberculosis (Mtb), the causative organism of tuberculosis (TB), infects different host cells; however, studies on its metabolic impact on the type 2 alveolar epithelial cells are limited. In this study, comparative metabolic insights of A549 cells infected with laboratory (H37RV, H37Ra) and clinical isolates (drug-resistant: S6, S11 and sensitive: S4, S5) were derived from read out of the 13C-based proteinogenic amino acid kinetics. Mtb H37Rv (virulent) exhibited higher growth kinetics within A549 cells compared to H37Ra (avirulent), whereas drug-resistant clinical isolate S6 showed the highest intracellular growth. The viability of H37Rv-infected A549 cells was significantly low. Interestingly, the drug-resistant clinical Mtb isolates maintained better cell viability over time. A [13C6] glucose tracer and mass isotopomer distributions revealed that A549 cells infected with virulent Mtb strains exhibited higher dependency on the central carbon metabolism like glycolysis, the pentose phosphate pathway and the tricarboxylic acid cycle for de novo amino acid biosynthesis. Drug-resistant Mtb isolates infected A549 cells showed robust 13C incorporation in the proteinogenic Threonine, Methionine and Lysine, derived from the tricarboxylic acid cycle. A549 cells infected with Mtb, irrespective of their drug resistance status, showed 13C incorporation in the essential amino acids (lysine, methionine, threonine, valine), underlining the dependencies of the pathogen on the de novo host metabolic precursors. These findings elucidate the importance of deciphering the strain-specific host-pathogen metabolic interactions to develop targeted therapies against drug-resistant Mtb infections.

biochemistry↗

Proximity labeling reveals differential interaction partners of the human mitochondrial import receptor proteins TOMM20 and TOMM70

Import of most mitochondrial proteins requires that their precursor proteins are bound by the (peripheral) receptor proteins TOM20, TOM22, and TOM70. For budding yeast TOM20 and TOM70, there is evidence of specific yet overlapping substrate recognition, but no such data is available for metazoan cells. Using APEX2-based proximity labeling, we thus created association profiles for human TOMM20 and TOMM70 in HeLa cells. We particularly focused on their interaction with RNA-binding proteins (RBPs) since there is evidence for RNA association with the mitochondrial outer membrane (MOM) and local translation at the mitochondrial surface, but these processes are poorly understood. Our results show a preferred association of several RBPs and translation factors with TOMM20 over TOMM70. These include SYNJBP2, a previously identified membrane-bound RBP that binds and protects mRNAs encoding mitochondrial proteins. Translational inhibition by puromycin resulted in an even increased association of these RBPs with TOMM20 compared to TOMM70, suggesting that TOMM20 but not TOMM70 might play a role in preserving cellular hemostasis during translation stress by retaining protective RBPs and translation-related proteins at the MOM.

biochemistry↗

Decoding contextual influences on auditory perception from primary auditory cortex

Perception can be highly dependent on stimulus context, but whether and how sensory areas encode the context remains uncertain. We used an ambiguous auditory stimulus - a tritone pair - to investigate the neural activity associated with a preceding contextual stimulus that strongly influenced the tritone pairs perception: either as an ascending or a descending step in pitch. We recorded single-unit responses from a population of auditory cortical cells in awake ferrets listening to the tritone pairs preceded by the contextual stimulus. We find that the responses adapt locally to the contextual stimulus, consistent with human MEG recordings from the auditory cortex under the same conditions. Decoding the population responses demonstrates that cells responding to pitch-class-changes are able to predict well the context-sensitive percept of the tritone pairs. Conversely, decoding the individual pitch-class representations and taking their distance in the circular Shepard tone space predicts the opposite of the percept. The various percepts can be readily captured and explained by a neural model of cortical activity based on populations of adapting, pitch-class and pitch-class-direction cells, aligned with the neurophysiological responses. Together, these decoding and model results suggest that contextual influences on perception may well be already encoded at the level of the primary sensory cortices, reflecting basic neural response properties commonly found in these areas.

neuroscience↗

Socio-demographic determinants of monkeypox virus preventive behavior: a cross-sectional study in Pakistan

BackgroundMonkeypox, a re-emerging zoonotic infectious disease, is striking the world with serious public health concerns, especially in non-endemic countries. The publics knowledge and attitude toward the monkeypox virus (MPXV) influence their adherence to preventive strategies. Therefore, we aimed to assess the general publics knowledge, attitudes, and perceptions (KAP) of MPXV in Pakistan. MethodsWe collected data for this cross-sectional study from 1040 participants via an online self-reported questionnaire from 5th July 2022 to 1stAugust 2022. The questionnaire consisted of a total of 29 items in four sections, assessing socio-demographics, knowledge, attitudes, and practices regarding MPXV. The data was analyzed using IBM SPSS V.25, and factors associated with MPXV knowledge, attitude, and practices were identified by using logistic regression analyses ResultsA total of1040participants were included. 61.4% were male and 57.2% had graduation level education. Only 34.4% had good knowledge about MPXV and 30% were aware of effectiveness of smallpox vaccine against MPXV. 41.7% had positive attitude with 48.6% agreed that it is a fatal disease and 44.6% were in favor of banning travelling from endemic to non-endemic regions.57.7% had good practices and 69.9% would use protective measures if MPXV become an epidemic. Binary logistic regression analysis revealed that gender and education significantly impacted knowledge (p<0.05). While monthly income status had a significant impact on attitudes (p<0.05). The practices were correlated positively with gender and education (p<0.05). ConclusionThe majority of study participants had inadequate levels of knowledge, and attitudes regarding MPXV. To prevent the emergence and spread of MPXV in Pakistan, a comprehensive strategic framework for public health education must be established and implemented.

microbiology↗

Kinetic isotope tracing of glycerol and de novo proteogenic amino acids in Human Lung Carcinoma cells using glucose

13C based Isotopic tracers of the media components can be used to kinetically track their contribution in the cell systems. A tracer ([U-13C6] glucose) was used to monitor its contribution into the central carbon metabolic pathways of human lung carcinoma (A549) cells by Gas chromatography-mass spectrometry (GC-MS) based mass isotopomer analysis. Calculated average 13C of methanolic extracts (glycerol: 5.46{+/-}3.53 % and lactate: 74.4{+/-}2.65 %), protein acid hydrolysates (serine: 4.51{+/-}0.21 %, glycine: 2.44{+/-}0.31 %, alanine: 24.56{+/-}0.59 %, glutamate: 8.81{+/-}0.85 %, proline: 6.96{+/-}0.53 % and aspartate: 10.72{+/-}0.95 %) and the culture filtrate (glycerol: 43.14{+/-}1.45 % and lactate: 81.67{+/-}0.91 %), showed significant contribution of 13C glucose. We observed the Warburg effect with higher levels of 13C lactate in the culture filtrate. 13C glycerol levels in culture supernatant showed significant increase with time and amino acids of glucogenic origin also contributed cellular protein biomass. The workflow adopted in this study for 13C analysis could be useful for the metabolic phenotyping of other mammalian cell systems under normal and perturbed (cancer and infection) conditions.

biochemistry↗

Anti-inflammatory Role of Curcumin in LPS Treated A549 cells at Global Proteome level and on Mycobacterial infection.

A diet derived agent Curcumin (Diferuloylmethane), demonstrated its clinical application in inflammation, infection and cancer conditions. Nevertheless, its impact on the proteome of epithelial cells of non-small cell lung carcinoma (NSCLC) is yet to be explored. We employed a stable isotope labeling method for cell culture (SILAC) based relative quantitative proteomics and informatics analysis to comprehend global proteome change in A549 cells treated with curcumin and/or Lipopolysaccharide (LPS). Pretreated A549 cells were infected with Mycobacterium tuberculosis H37Rv strain to monitor bacterial load. With exposure to curcumin and LPS, out of the 1492 identified proteins, 305 and 346 proteins showed deregulation respectively. The expression of BID and AIFM1 mitochondrial proteins which play critical role in apoptotic pathway were deregulated in curcumin treated cells. Higher mitochondria intensity was observed in curcumin treated A549 cells than LPS treatment. Simultaneous treatment of curcumin and LPS neutralized the effect of LPS. Curcumin and/or LPS pretreated A549 cells infected with H37Rv, showed successful bacterial internalization. LPS treated A549 cells after infection showed increased bacterial load than curcumin compared to non-treated infected cells. However, simultaneous treatment of curcumin and LPS neutralized the effect of LPS. This study generated molecular evidence to deepen our understanding of the anti-inflammatory role of curcumin and may be useful to identify molecular targets for drug discovery.

biochemistry↗

Real-Time Tracking of Selective Auditory Attention from M/EEG: A Bayesian Filtering Approach

Humans are able to identify and track a target speaker amid a cacophony of acoustic interference, which is often referred to as the cocktail party phenomenon. Results from several decades of studying this phenomenon have culminated in recent years in various promising attempts to decode the attentional state of a listener in a competing-speaker environment from non-invasive neuroimaging recordings such as magnetoencephalography (MEG) and electroencephalography (EEG). To this end, most existing approaches compute correlation-based measures by either regressing the features of each speech stream to the M/EEG channels (the decoding approach) or vice versa (the encoding approach). These procedures operate in an offline fashion, i.e., require the entire duration of the experiment and multiple trials to provide robust results. Therefore, they cannot be used in emerging applications such as smart hearing aid devices, where a single trial must be used in real-time to decode the attentional state. In this paper, we close this gap by developing an algorithmic pipeline for real-time decoding of the attentional state. Our proposed framework consists of three main modules: 1) Real-time and robust estimation of encoding or decoding coefficients, achieved by sparse adaptive filtering, 2) Extracting reliable markers of the attentional state, and thereby generalizing the widely-used correlation-based measures thereof, and 3) Devising a near real-time state-space estimator that translates the noisy and variable attention markers to robust and reliable estimates of the attentional state with minimal delay. Our proposed algorithms integrate various techniques including forgetting factor-based adaptive filtering, {ell}1-regularization, forward-backward splitting algorithms, fixed-lag smoothing, and Expectation Maximization. We validate the performance of our proposed framework using comprehensive simulations as well as application to experimentally acquired M/EEG data. Our results reveal that the proposed real-time algorithms perform nearly as accurate as the existing state-of-the-art offline techniques, while providing a significant degree of adaptivity, statistical robustness, and computational savings.

neuroscience↗