Alteration in serum miR126 expression in healthy adults observing Navratri fast.

Background: Fasting is practiced by various religions in the world. The previous studies show the effect of fasting on biochemical markers in healthy subjects; however, no study is available on its effect on gene expression or epigenetic markers. In the present study, miR126, a microRNA, was measured in serum samples of healthy adult subjects, and their correlation with biochemical profile was carried out during the short-term fasting of the Navratri festival. Methods: A total of 30 subjects who underwent fasting for 07 days during the Navratri festival were recruited for the study. The fasting blood samples were obtained at three different time points; day 1 of fasting, day 7 of fasting, and day 7 after completion of fasting period. The miR126 expression, fasting plasma glucose, and lipid profile were measured in all the three samples. Results: The miR126 levels showed a decreasing trend with a significant difference across the three time points (p-value = 0.006). Fasting plasma glucose increased continuously across three time points without showing any statistical significance. Serum total cholesterol (p = 0.001) and triglycerides (p = 0.001) levels were decreased initially and then increased after resuming normal diet. There was a medium-level negative correlation (-0.332) between baseline fasting glucose level and miR126 level (p = 0.068). Conclusion: The study revealed that serum levels of total cholesterol and triglyceride were more dynamic than the miR126 levels. A significant decrease in the miR126 expression across three time points is a promising outcome of this pilot study and indicates its role in short-term fasting. However, the fasting plasma glucose showed heterogeneous values without significant correlation with miR126 levels.

Correlation of CYP2R1 gene promoter methylation with circulating vitamin D levels among healthy adults.

Background & objectives: Despite being a tropical country, vitamin D deficiency is highly prevalent in India with studies indicating 40-99 per cent prevalence. Apart from calcium and phosphate metabolism, vitamin D is involved in cell cycle regulation, cardiovascular, hepatoprotection. The metabolism of vitamin D is regulated by vitamin D tool genes (CYP2R1/CYP27B1/CYP24A1/VDR). The promoter regions of some of these genes have CpG islands, making them prone to methylation induced gene silencing, which may cause a reduction in circulating vitamin D levels. Epigenetic basis of vitamin D deficiency is yet to be studied in India, and hence, this pilot study was aimed to analyze whether methylation levels of CYP2R1 gene were correlated with the levels of 25(OH)D in healthy, adult individuals in Indian population. Methods: In this cross-sectional study, healthy adults of 18-45 yr of age with no history of malabsorption, thyroidectomy, chronic illness or therapeutic vitamin D supplementation were recruited. DNA methylation analysis was carried out by methylation specific quantitative PCR. Serum calcium, phosphate and vitamin D levels were also quantified. Statistical analysis was done by R 4.0.5 software. Results: A total of 61 apparently healthy adults were analyzed. The serum vitamin D levels did not correlate with CYP2R1 methylation levels in our study population. Significant positive correlation was observed between age and serum vitamin D levels. Significant association of gender was found with CYP2R1 methylation levels. Interpretation & conclusions: This study found no significant correlation between levels of CYP2R1 methylation and circulating 25(OH)D deficiency. Further studies on the Indian population having a larger sample size including entire vitamin D tool genes, among different ethnic groups may be conducted to elucidate molecular etiology of circulating 25(OH)D deficiency. The high prevalence of normal serum calcium and phosphate levels among vitamin D deficient subjects in this study coupled with the strikingly high prevalence of the deficiency at the national level, may suggest the need to revise the cut-off criteria for vitamin D deficiency in the Indian population.

Machine learning-driven blood transcriptome-based discovery of SARS-CoV-2 specific severity biomarkers.

The Coronavirus disease 2019 (COVID-19) pandemic, caused by rapidly evolving variants of severe acute respiratory syndrome coronavirus (SARS-CoV-2), continues to be a global health threat. SARS-CoV-2 infection symptoms often intersect with other nonsevere respiratory infections, making early diagnosis challenging. There is an urgent need for early diagnostic and prognostic biomarkers to predict severity and reduce mortality when a sudden outbreak occurs. This study implemented a novel approach of integrating bioinformatics and machine learning algorithms over publicly available clinical COVID-19 transcriptome data sets. The robust 7-gene biomarker identified through this analysis can not only discriminate SARS-CoV-2 associated acute respiratory illness (ARI) from other types of ARIs but also can discriminate severe COVID-19 patients from nonsevere COVID-19 patients. Validation of the 7-gene biomarker in an independent blood transcriptome data set of longitudinal analysis of COVID-19 patients across various stages of the disease showed that the dysregulation of the identified biomarkers during severe disease is restored during recovery, showing their prognostic potential. The blood biomarkers identified in this study can serve as potential diagnostic candidates and help reduce COVID-19-associated mortality.

Cardiovascular autonomic function and baroreflex sensitivity in drug-resistant temporal lobe epilepsy.

OBJECTIVE: Temporal lobe epilepsy (TLE) is often associated with autonomic manifestations. Sudden unexpected death in epilepsy (SUDEP) is a leading cause of mortality in epilepsy. Cardiac disturbances and autonomic dysfunction are the potential mechanisms behind SUDEP. Though heart rate variability (HRV) and autonomic function tests are well studied in drug-resistant temporal lobe epilepsy, there is a paucity of data on baroreflex sensitivity (BRS), a better marker of cardiac mortality in this population. We aimed to study the interictal cardiac autonomic function and BRS in people living with drug-resistant temporal lobe epilepsy compared to healthy controls. MATERIALS AND METHODS: Thirty drug-resistant temporal lobe epilepsy (TLE) individuals and thirty healthy volunteers were recruited. Heart rate variability at rest, heart rate and blood pressure (BP) at rest, during deep breathing, postural change, BP response to isometric handgrip exercise, and baroreflex sensitivity were recorded in all study participants. The results were analyzed and compared between the two groups. RESULTS: Compared to controls, the resting heart rate, HRV, parasympathetic reactivity test, and BRS significantly differed in people living with drug-resistant TLE. Time-domain indices including SDNN (p < 0.001), RMSSD (p < 0.001), NN50 (p < 0.001), and pNN50 (p < 0.001) were significantly reduced in the patients compared to controls. In frequency-domain indices, the total power was reduced (p < 0.001) in drug-resistant TLE. The parasympathetic reactivity such as changes in heart rate during deep breathing (E: I) (p < 0.02) and postural change (30:15) (p < 0.005) were significantly reduced in the patients. Baroreflex sensitivity was also significantly reduced in the drug-resistant TLE group (p < 0.001). CONCLUSION: The present study findings are suggestive of parasympathetic dysfunction in drug-resistant TLE. Reduced HRV and BRS may increase the risk of SUDEP in people living with epilepsy.

Effect of intermolecular anionic interactions on spin crossover of two triple-stranded dinuclear Fe(II) complexes showing above room temperature spin transition.

Two new Fe(II)-based dinuclear triple helicates having the formula {[Fe2(L)3]·(CF3SO3)4·6.5H2O·CH3OH} (complex 1) and {[Fe2(L)3]·(ClO4)4·7H2O·1.35CH3OH} (complex 2), displaying near room temperature spin transition have been synthesized and the effect of intermolecular interactions and co-operativity between metal centers on the spin crossover (SCO) has been studied. Picolinimidamide-based ligand system is chosen to provide maximum intermolecular interactions. Variable-temperature single crystal X-ray diffraction (SCXRD), magnetic study, and Hirshfeld analysis reveal that complex 1 shows a multistep spin transition, whereas, complex 2 shows an abrupt spin transition from [LS-LS] ↔ [HS-HS]. In complex 2 the presence of perchlorate anion induces high intermolecular O-H interaction that enhances the cooperativity resulting in high T1/2 of 330 K. This study accentuates the interplay between anion effect, crystal packing, and supramolecular interactions in tuning the magnetic properties of SCO compounds.

Host and viral non-coding RNAs in dengue pathogenesis.

Dengue virus (DENV) is a mosquito-borne flavivirus that causes frequent outbreaks in tropical countries. Due to the four different serotypes and ever-mutating RNA genome, it is challenging to develop efficient therapeutics. Early diagnosis is crucial to prevent the severe form of dengue, leading to mortality. In the past decade, rapid advancement in the high throughput sequencing technologies has shed light on the crucial regulating role of non-coding RNAs (ncRNAs), also known as the "dark matter" of the genome, in various pathological processes. In addition to the human host ncRNAs like microRNAs and circular RNAs, DENV also produces ncRNAs such as subgenomic flaviviral RNAs that can modulate the virus life cycle and regulate disease outcomes. This review outlines the advances in understanding the interplay between the human host and DENV ncRNAs, their regulation of the innate immune system of the host, and the prospects of the ncRNAs in clinical applications such as dengue diagnosis and promising therapeutics.

Can We Really Trust the Findings of the COVID-19 Research? Quality Assessment of Randomized Controlled Trials Published on COVID-19

ObjectiveTo evaluate the quality of randomized controlled trials (RCTs) published on Coronavirus Disease-19 (COVID-19) and to investigate the reasons behind compromising the quality, if found. MethodsA systematic literature search was performed in PubMed, Google Scholar, and Cochrane CENTRAL to identify the Randomized Controlled Trails published on Coronavirus Disease-19 between 1st Dec 2019 to 31st Aug 2021. Research articles met with study criteria were included in the study. Assessment of quality of randomized controlled trials was done using modified Jadad scale. Results21,259 records of randomized controlled trials were identified through database searching, out of which 90 randomized controlled trials were included in the study and, 34 (37.8%) were of high-quality, 46 (51.1%) were of moderate quality, and 10 (11.1 %) were of low-quality studies. There were 40 (44.4%), 38 (42.2%), and 12 (13.3%) randomized controlled trials published in the early, middle, and late terms with Jadad score 5.12{+/-}1.67, 5.34{+/-}1.32, and 5.68{+/-}1.50 respectively (P=0.52). When comparing the blinding status, appropriate blinding, and methods to evaluate adverse events in randomized controlled trials with modified Jadad score, a significant difference was observed (P<0.001). A significant moderate positive correlation was found between the impact factor of the journal and the modified Jadad scale score (R2= 0.48, P<0.001). ConclusionFindings from our study indicate that accelerated publication of Coronavirus Disease-19 researches along with the fast-track review process has resulted in lowering study quality scores. With the emergence of stronger evidence, Coronavirus Disease-19 clinical studies with lower methodological quality should be revisited. Impacts on practiceO_LIThere have been numerous sacrifices and tragedies in the clinical response to covid-19. Revising the quality of randomized controlled trials published on COVID-19 as we enter the third wave of the pandemic and beyond, will improve the evidence-based practice of medications for clinical pharmacy services. C_LIO_LICOVID-19 Patients will benefit from evidence-based pharmaceutical care through reduced drug-related problems. C_LI

Innate immune sensing of influenza A viral RNA through IFI16 promotes pyroptotic cell death.

Programmed cell death pathways are triggered by various stresses or stimuli, including viral infections. The mechanism underlying the regulation of these pathways upon Influenza A virus (IAV) infection is not well characterized. We report that a cytosolic DNA sensor IFI16 is essential for the activation of programmed cell death pathways in IAV infected cells. We have identified that IFI16 functions as an RNA sensor for the influenza A virus by interacting with genomic RNA. The activation of IFI16 triggers the production of type I, III interferons, and also pro-inflammatory cytokines via the STING-TBK1 and Pro-caspase-1 signaling axis, thereby promoting cell death (apoptosis and pyroptosis in IAV infected cells). On the contrary, IFI16 knockdown cells showed reduced inflammatory responses and also prevented cell mortality during IAV infection. Collectively, these results demonstrate the pivotal role of IFI16-mediated IAV sensing and its essential role in activating programmed cell death pathways.

Thermoplastic starch nanocomposites using cellulose-rich Chrysopogon zizanioides nanofibers.

Green thermoplastic starch (TPS) nanocomposite films aided by cellulose nanofibers (CNFs) from Chrysopogon zizanioides roots were developed and characterized. When compared to other lignocellulosic fibers, Chrysopogon zizanioides roots revealed exceptionally high cellulose content (~48%). CNFs were separated using an environmentally friendly acid isolation technique that included three stages: (i) alkali treatment; (ii) bleaching; and (iii) mild acid hydrolysis using oxalic acid in an autoclave. Following that, green nanocomposite films were made from potato starch using the solution casting process, by which we used glycerol (30 wt%) to make thermoplastic starch. Then, cellulose nanofibers in different concentrations (0, 1, 2, 3, 4 wt%) were added to the thermoplastic starch matrix. The isolated CNFs had diameters in the range of 17-27 nm. Besides, these nanostructures presented a very high crystallinity index (~65%), thereby enhanced the thermal stability. TPS/CNF green nanocomposites containing 3 wt% CNFs had exceptional tensile strength (~161%), tensile modulus (~167%), thermal stability, and crystallinity. As a result, nanocomposite films made of starch and cellulose nanofibers (3 wt%) extracted from Chrysopogon zizanioides roots would be alternatives for sustainable packaging. It can be concluded that Chrysopogon zizanioides roots have high potential for polymer industry.

Association of Dental Neglect Scale and Severity of Dental Caries among Nursing Students: A Cross-Sectional Study.

AIMS: The aim of this study is to assess the utilization of available dental services and home dental care practices in a sample of nursing students and to seek out the correlation if any, between the Dental Neglect Scale (DNS) scores and severity of dental caries. SUBJECTS AND METHODS: The study was conducted among 630 nursing students aged 18-21 years from the area of South Bangalore. The study was cross-sectional in design and a convenience sampling method was adopted to get the desired sample size. A prestructured questionnaire was administered to the students in their classrooms. Following this, a brief oral examination was conducted using mouth mirror and light for the detection of any visible carious lesions. RESULTS: The dental attendance variable was found to be significantly associated with the DNS scores (P < 0.001). The DNS scores were significantly higher (P < 0.001) among those who had visible caries than those who do not. A very good correlation was obtained between scores of DNS and the caries severity (P < 0.001, r = 0.773). CONCLUSIONS: The DNS can be a very good predictor of the dental attendance pattern as well as clinically assessed severity of carious lesions.

Preparation and characterization of iron-chelating peptides from whey protein: An alternative approach for chemical iron fortification.

Iron fortification of staple food is a strategy utilized worldwide to address the concern of dietary iron deficiency. However, traditional salt-based fortification methods have limitations with gastrointestinal stability and bioavailability. Iron chelating peptides from easily available and scalable proteins such as whey protein have been proposed as promising candidates to circumvent the above mentioned limitations by enhancing iron absorption and bioavailability. In this study, we report methods to produce whey protein derived iron-chelating peptides and describe their physicochemical characteristics. Peptides derived from whey proteins prepared by ultrafiltration of whey followed by hydrolysation were iron chelated to produce peptide-iron complexes. These complexes had a size of 422.9 ± 3.41 nm, chelated iron content of 36.42 µg/ mg protein, and a low zeta potential (-10.80 mV) compared to whey peptides. Spectra analysis using ultraviolet-visible absorption and Fourier transform infrared spectroscopy showed structural transformation indicating iron chelation. Mass spectrometric analysis using LC-MS/MS confirmed the presence of both hydrophilic and hydrophobic peptides in the complexes with sizes ranging from 275 Da to 1916 Da. Furthermore, reduction in the antioxidant property of peptides following iron complexing indicates iron chelation. Our results suggest that whey protein derived peptide-iron complexes can be used as a potential alternative for chemical iron fortificants for food products and also as iron supplements.

Comparative transcriptome analysis of SARS-CoV, MERS-CoV, and SARS-CoV-2 to identify potential pathways for drug repurposing.

The ongoing COVID-19 pandemic caused by the coronavirus, SARS-CoV-2, has already caused in excess of 1.25 million deaths worldwide, and the number is increasing. Knowledge of the host transcriptional response against this virus and how the pathways are activated or suppressed compared to other human coronaviruses (SARS-CoV, MERS-CoV) that caused outbreaks previously can help in the identification of potential drugs for the treatment of COVID-19. Hence, we used time point meta-analysis to investigate available SARS-CoV and MERS-CoV in-vitro transcriptome datasets in order to identify the significant genes and pathways that are dysregulated at each time point. The subsequent over-representation analysis (ORA) revealed that several pathways are significantly dysregulated at each time point after both SARS-CoV and MERS-CoV infection. We also performed gene set enrichment analyses of SARS-CoV and MERS-CoV with that of SARS-CoV-2 at the same time point and cell line, the results of which revealed that common pathways are activated and suppressed in all three coronaviruses. Furthermore, an analysis of an in-vivo transcriptomic dataset of COVID-19 patients showed that similar pathways are enriched to those identified in the earlier analyses. Based on these findings, a drug repurposing analysis was performed to identify potential drug candidates for combating COVID-19.

Dextran stabilized fullerene soot induced toxicity on alveolar epithelial cells (A549 cells).

Fullerene comprises the major allotrope of carbon holding several fruitful potentials to be applied in various industrial and biomedical scenarios. Scientists have acquired large number of data on fullerene research using its derivatives like C60, C70 etc. Nevertheless, a precise focus on fullerene soot nanopaticles and its toxic impacts in living tissue is still behind mainstay even if it represents the crude parent form of all other derivatives. Present study addresses an acute toxicity profiling of fullerene soot nanoparticles in alveolar epithelial cells (A549) as a paradigm of pulmonary exposure. Surface functionalization was given for fullerene soot nanoparticles using dextran polymer as a mean to establish a stable homogenous dispersion (denoted as dFSNPs hereafter). Following functionalization, dFSNPs were characterized for various parameters including size, surface charge, morphology and functional groups using DLS, Zeta potential analysis, TEM and FT-IR measurements respectively. Effective dextran functionalization was evident from the characteristic peaks in FTIR spectra. Cell viability assessed using MTT and NRU assays; both of which showed a dose dependent cytotoxic response. Thymidine incorporation also confirmed similar trend in viability rate. In accordance with literatures, DCFHDA assay confirmed free radical scavenging activity of fullerene nanoparticles. An altered cellular morphology was observed under fluorescent microscope. Sub-cellular functionalities including lysosomal integrity and mitochondrial stability were found to be compromised at highest tested concentration of dFSNPs (160 µg/ml) without any genotoxic impacts within nuclear premises. FACS analysis following Annexin-PI staining confirmed apoptotic cell death. Hence the overall study substantiated dose dependent toxicity of dFSNPs which is likely to occur during pulmonary exposure.

Cellulose Nanofibers Isolated from the Cuscuta Reflexa Plant as a Green Reinforcement of Natural Rubber.

In the present work, we used the steam explosion method for the isolation of cellulose nanofiber (CNF) from Cuscuta reflexa, a parasitic plant commonly seen in Kerala and we evaluated its reinforcing efficiency in natural rubber (NR). Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA) techniques indicated that type I cellulose nanofibers, with diameter: 10-30 nm and a 67% crystallinity index were obtained by the proposed method. The results showed that application of CNF in NR based nanocomposites resulted in significant improvement of their processing and performance properties. It was observed that the tensile strength and tear strength of NR/CNF nanocomposites are found to be a maximum at 2 phr CNF loading, which corresponds with the studies of equilibrium swelling behavior. Dynamic mechanical analysis, thermogravimetric analysis, and morphological studies of tensile fractured samples also confirm that CNF isolated from Cuscuta reflexa plant can be considered as a promising green reinforcement for rubbers.

Zinc oxide nanoparticle induced neurotoxic potential upon interaction with primary astrocytes.

As obvious from the basic prerequisite of any particle in nanoscale, Zinc oxide nanoparticles (ZnO NPs) possess numerous tunable properties distinct from their bulk formulations. Emerging innovations in various sectors of nanotechnology are exploiting ZnO NPs largely. This inturn picks up the occasions of human exposure irrespective of the application fields. Although the platform of nanotoxicology has been garnished with nano-bio interaction studies using different cell lines, a few are existing so far comprising primary cells which symbolize realistic in vivo environment. The present study addresses the neurotoxic potential of ZnO NPs using primary astrocytes isolated from post-natal 0-2 day old rat pups. Cells were cultured and maintained in DMEM F12 followed by purification. ZnO NPs generated by wet chemical method was then characterized both physico chemically and biologically. All of the techniques confirmed homogenous distribution of NPs and ensured enough colloidal stability. Bio-nano interaction studies commence on cell viability assays (MTT and NRU) and both of which confirmed dose and time dependent cytotoxicity. Alterations within cellular morphology, cytoskeletal arrangement, lysosomal stability, mitochondrial membrane potential (MMP) and caspase activation were evaluated by standardized techniques. All of the assays substantiated significant toxic consequences in astrocytes with characteristic hall marks. Apoptotic cell death was noted without any deformations of nuclear material. A comparative toxicity study using ZnO NPs, ZnCl2 and ZnO bulk form was performed which confirmed nanospecific toxicity of ZnO NPs. Overall study evidently provide cautious information that ZnO NPs is capable of eliciting serious neuronal tissue damages which can turn out to be fatal during prolonged exposure.

Bio-interactions and risks of engineered nanoparticles.

Nano technological research offered uncountable opportunities for engineered nanoparticles (ENPs) in the field of biomedical, pharmaceutical, agricultural, cosmetics, textiles, automobiles and electronic industry. Large scale commercial production and use of nanoparticles with smaller size and characteristic physico-chemical properties enhance the possibility of amenable toxicity to the environment. Primary important species of the ecosystem like bacteria, algae, fishes and plants are at high risk with nanoparticle (NP) toxicity. ENP distributed in air, water and soil can directly affect the livelihood or even the existence of smaller organisms. In day-today life, human beings are getting exposed to thousands of NPs via dermal contact, inhalation or ingestion. Topical application of sunscreens and cosmetics containing ENPs has the potential to induce photo toxicity under ultra violet irradiation. ENP intentionally or non-intentionally enter into the body will affect the entire organ system and execute their toxicity even in reproduction and fetal developmental stages. Unfortunately the existing researches to evaluate the in vivo and in vitro toxic effects of ENPs are inefficient to give the exact nature and depth of toxicity. Hence an effort was made to discuss on the characteristics, classification, synthesis, applications and toxic potentials of various classes of commercially relevant ENPs along with a detailed review on currently available literatures.

Pyrogens, a polypeptide produces fever by metabolic changes in hypothalamus: Mechanisms and detections.

Fever is one of the cardinal symptoms of onset of an infection or inflammation and is the common clinical indicator for medical consultation in mammalian host worldwide. Simply, fever manifested with elevation of body temperature from normal physiological range represents adaptive response of immune system on challenge with an infectious and non-infectious circumstance. Fever usually initiated in the periphery as a result of interaction of immune cells with exogenous or endogenous pyrogens. Peripheral pyrogenic signals gain access to the central nervous system via humoral and neural route. Humoral pathway was initiated with production of pyrogenic cytokines and prostaglandins from immune cells of blood as well as liver, transmitted directly to pre-optic area of hypothalamus through the circumventricular organ of brain. On the other hand an alternative pathway was initiated by the same cytokines indirectly via stimulating the vagal sensory neurons result in pyrogenic fever; so-called neuronal pathway. If the magnitude of pyrogens associated fever is very high, it will lead to severe illness ranging from septic shock to death. So it is necessary to evaluate the presence of pyrogens in implants, medical devices, drugs and biological materials to ensure safety in biomedical applications and therapeutics. Classification, route of administration, mechanism of action and detection of pyrogens and associated products are the major subject of this review.

Distal airway microbiome is associated with immunoregulatory myeloid cell responses in lung transplant recipients.

BACKGROUND: Long-term survival of lung transplant recipients (LTRs) is limited by the occurrence of bronchiolitis obliterans syndrome (BOS). Recent evidence suggests a role for microbiome alterations in the occurrence of BOS, although the precise mechanisms are unclear. In this study we evaluated the relationship between the airway microbiome and distinct subsets of immunoregulatory myeloid-derived suppressor cells (MDSCs) in LTRs. METHODS: Bronchoalveolar lavage (BAL) and simultaneous oral wash and nasal swab samples were collected from adult LTRs. Microbial genomic DNA was isolated, 16S rRNA genes amplified using V4 primers, and polymerase chain reaction (PCR) products sequenced and analyzed. BAL MDSC subsets were enumerated using flow cytometry. RESULTS: The oral microbiome signature differs from that of the nasal, proximal and distal airway microbiomes, whereas the nasal microbiome is closer to the airway microbiome. Proximal and distal airway microbiome signatures of individual subjects are distinct. We identified phenotypic subsets of MDSCs in BAL, with a higher proportion of immunosuppressive MDSCs in the proximal airways, in contrast to a preponderance of pro-inflammatory MDSCs in distal airways. Relative abundance of distinct bacterial phyla in proximal and distal airways correlated with particular airway MDSCs. Expression of CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP), an endoplasmic (ER) stress sensor, was increased in immunosuppressive MDSCs when compared with pro-inflammatory MDSCs. CONCLUSIONS: The nasal microbiome closely resembles the microbiome of the proximal and distal airways in LTRs. The association of distinct microbial communities with airway MDSCs suggests a functional relationship between the local microbiome and MDSC phenotype, which may contribute to the pathogenesis of BOS.