Biology subjects

Fazelinia, H.

Publications and source records attributed to Fazelinia, H..

13 recordsLinked to original sources

bioRxiv2026

Gut-derived serine protease reduces sleep but extends lifespan

Sleep has historically been viewed through a brain-centric lens with little known about the contribution of the periphery. Through a targeted screen of secreted peptides from the fat body, gut, and body wall muscle in Drosophila, we identified CG11037, a trypsin-like serine endopeptidase secreted from midgut enterocytes, as a previously unrecognized regulator of sleep. Loss of CG11037 reduces daily sleep, as well as sleep following injury/infection, although recovery is enhanced suggesting reduced need for sleep during sickness. Proteomic analysis of flies with reduced CG11037 revealed altered oxidative stress response pathways including cytochrome P450-related proteins. Indeed, gut-specific knockdown of Cyp6a2 or Cyp28d1 phenocopies CG11037 sleep defects, and loss of CG11037 or P450 elevates reactive oxygen species (ROS) selectively in the gut without affecting brain ROS. Rescue of sleep by antioxidant treatment demonstrates that peripheral ROS accumulation drives the behavioral phenotype. Strikingly, despite physiological dysfunction and reduced sleep, CG11037 or Cytochrome P450 knockdown extends lifespan in a ROS-dependent manner, suggesting that stress adaptation of these knockdowns allows them to live longer. Together, these findings uncover a mechanism for the unexpected association of reduced sleep and extended lifespan.

genetics↗

bioRxiv2026

Short-Term Combined Tat-Beclin1 and Endurance Training Improves Age-Related Decline in Physical Function in Male Mice

Autophagy is a hallmark of aging, but autophagy-related proteins have not been exclusively targeted to attenuate the progressive decline in physical function associated with aging. Here, we combined Tat-Beclin1, an autophagy agonist, and endurance training to determine whether Tat-Beclin1 enhances exercise adaptation in old male mice. Tat-Beclin1 was administered intraperitoneally (TB group, 15 mg/kg, 2x/week) as a standalone therapy, or in combination with endurance training (TB+Exe group, 70% of maximal running speed 3x/week) for 1 month in 23-month-old male C57BL/6J mice. Control groups were age-matched cage controls and exercise-only groups. Animals were assessed for grip strength, endurance capacity on a treadmill, and balance and coordination on a rotarod. Gastrocnemius/plantaris (G/P) and tibialis anterior muscles were harvested for western blotting, myofiber typing, and proteomic profiling (G/P only). TB+Exe led to significant increases in grip strength, endurance capacity, and balance and coordination performance beyond those observed in the TB and Exe groups alone. Autophagy markers, including Beclin1, the LC3B-II/I ratio, and p62, did not differ among groups. A proteomic analysis of the G/P muscle revealed that TB upregulated biological processes involved in muscle contraction and adaptation, whereas TB+Exe increased mitochondrial bioenergetic processes and, surprisingly, upregulated acute inflammatory responses, including proteins such as haptoglobin and orosomucoid-1. We conclude that combining Tat-Beclin1 and endurance training may represent a new approach to attenuate aging-related decline in physical function. New & NoteworthyWe show evidence that combining Tat-Beclin1 and endurance training (TB+Exe) resulted in greater improvements in physical function in 24-month-old male mice than either standalone therapy. We also show that TB+Exe upregulates traditional exercise-like biological processes and unexpectedly upregulates acute-inflammatory proteins (e.g., orosomucoid-1), which are thought to improve physical function in preclinical studies. Our study suggests that TB may be a new drug enhancing physical function, especially when combined with endurance training in old male mice.

physiology↗

bioRxiv2026

SPTBN2 promotes an immunosuppressive tumor microenvironment and cross-resistance to anti-cancer therapies

Immunosuppressive tumor microenvironment (TME) inactivates CD8+ cytotoxic lymphocytes (CTLs). Here, we identify SPTBN2 spectrin as a key immunosuppressive regulator induced in CTLs in response to nutritional deficit. In human pancreatic and colorectal cancers, SPTBN2 expression negatively correlated with CTL infiltration and patients survival. In TME of mouse pancreatic and colorectal adenocarcinomas, SPTBN2 inactivated intratumoral CTLs, stimulated tumor growth and conferred cross-resistance to anti-cancer therapies. SPTBN2 knockout protected CAR T-cells from trogocytosis and increased their memory state. SPTBN2 maintained levels of cell surface proteins such as BTLA that undermine CAR T-cell cytotoxicity and promote exhaustion. Re-expression of BTLA largely reversed phenotypes in SPTBN2-deficient CAR T-cells. In manufactured CAR T cells, SPTBN2 was associated with their clinical failure in pediatric patients with leukemia. Accordingly, ablation of SPTBN2 in CAR T-cells increased their cytotoxicity, in vivo persistence and therapeutic effects indicating that SPTBN2 can be targeted to increase the efficacy of anti-cancer therapies.

cancer biology↗

bioRxiv2026

Multi-omic profiling of early pregnancy small and large plasma extracellular vesicles reveals placental, metabolic, and structural adaptation signatures

Early human pregnancy is a critical period characterized by rapid growth and extensive maternal-fetal communication that influence maternal and fetal outcomes. Circulating extracellular vesicles (EVs) have the capacity to capture cargo that reflect these processes in real-time; however, signatures of EV subtypes during early pregnancy are poorly defined. Here we quantified mitochondrial DNA (mtDNA) and performed transcriptomic and proteomic profiling of small ([~]100 nm) and large ([~]200 nm) plasma EVs from n=10 normal pregnancies (11-15 weeks) to define subtype-specific molecular signatures. mtDNA and mitochondrial protein content were more abundant in large EVs (lEVs). lEVs also contained a more complex set of long RNAs enriched for placental, immune, and mitochondrial-related transcripts compared with small EVs (sEVs). Proteomic profiling showed enrichment of canonical EV markers and extracellular matrix proteins in sEVs, whereas lEVs were preferentially associated with pregnancy-specific proteins, including proteins related to placental hormone production. MicroRNAs (miRNAs) accounted for [~]25% of small RNAs in both EV subtypes with miR-223 and miR-16 enriched in lEVs and miR-639 enriched in sEVs. These data together, support a model where small and large plasma EVs have distinct, yet complementary signatures reporting systemic adaptations during the critical 11-15 week transition period. This work establishes a foundational framework for future studies linking EV signatures to placental dysfunction and adverse outcomes.

physiology↗

bioRxiv2026

Hypoxic stress granules trigger immunogenic dormancy in lung cancer

Induction of the MHC class I antigen processing and presentation pathway (C1APP) is a critical part of the IFN-{gamma} response necessary for effective cytotoxic immunity against tumors of epithelial origin1,2. Loss of this response is associated with worse disease outcomes and renders patients refractory to immunotherapies3-6. Without C1APP induction, tumor cells cannot optimally process and present immunopeptides from tumor-associated antigens (TAA) and neoantigens to effector cytotoxic T cells7-9. Here, we show that physiologic levels of hypoxia block induction of the immunoproteasome (IP) and other C1APP components in cancer cells, including human non-small cell lung cancer (NSCLC). In A549 cells, this leads to impaired presentation of more than 73% of detectable immunopeptides, including TAA and neoantigen-derived immunopeptides. This effect is independent of HIF-1 or HIF-2 signaling, protein degradation, autophagy, or stimulus type. Instead, hypoxia induces translational arrest of C1APP mRNAs prior to complete monosome loading, along with sequestration into hypoxia-associated stress granules. This phenomenon is reversible with the epitranscriptomic compound 5-azacytidine. Consistent with these findings, IP expression is excluded from hypoxic regions in most human NSCLC tumors. Together, these results link tumor hypoxia to a state of "immunogenic dormancy" and identify stress granules as a previously unrecognized mechanism of immune escape.

cancer biology↗

bioRxiv2025

Determination of α-Synuclein Protein Interactions by μMap Photo-proximity Labeling

Fibrillar aggregates of the natively disordered protein -synuclein (S) are hallmarks of Parkinsons disease and related neurodegenerative disorders termed synucleinopathies. Here, we used micromap ({micro}Map) photo-proximity labeling to determine the interactomes of S monomers and fibrils in mouse brain lysate to better understand both the loss of healthy function and gain of toxic function aspects of synucleinopathies. Several S variants were synthesized and characterized, showing that the small size (1 kDa) of the Ir catalyst attached through a Cys-maleimide linkage makes it minimally-perturbing to S, with a narrow labeling radius that allows one to identify interactome differences between different regions of S. Monomer and fibril interactomes were compared to each other and to previous proximity labeling data sets for validation and several examples of further investigations are demonstrated, including Western blotting, super-resolution microscopy, and {micro}Map in primary neurons.

biochemistry↗

bioRxiv2025

Biosynthetic plasticity enables CD8+ T cell functional resilience under nutrient stress

Summary / AbstractTo maintain lineage-specific functions, cells must acquire and allocate nutrients across diverse cellular processes, even in metabolically-dysregulated environments. The mechanisms allowing CD8+ T cells to maintain immune function in perturbed environments are poorly understood. We find that CD8+ T cells adapt to nutrient stresses over time, reconfiguring gene-regulatory and metabolic networks to license functional recovery. Under acute stress, T cells reorient translational programming, limiting nutrient demand while prioritizing stress-sensitive metabolic and transcriptional responses. Within these responses, the transcription factors ATF4 and CEBPG jointly establish an adaptive metabolic program, promoting amino acid synthesis and uptake while maintaining mitochondrial anaplerosis. Despite diminished energetic capacity under environmental stress, this program prevents failure of central carbon metabolism, mitigating stress amplification and cellular dysfunction to potentiate anti-tumor immunity. Altogether, we demonstrate that biosynthetic plasticity via translational and metabolic reprioritization confers functional resilience to immune cells in unfavorable environments, offering novel strategies to enhance immunotherapies.

immunology↗

bioRxiv2023

An exploration of mechanisms underlying Desemzia incerta colonization resistance to methicillin-resistant Staphylococcus aureus on the skin

Colonization of human skin and nares by methicillin-resistant Staphylococcus aureus (MRSA) leads to community spread of MRSA. This spread is exacerbated by transfer of MRSA between humans and livestock, particularly swine. Here we capitalized on the shared features between human and porcine skin, including shared MRSA colonization, to study novel bacterial mediators of MRSA colonization resistance. We focused on the poorly studied bacterial species Desemzia incerta, which we found to exert antimicrobial activity through a secreted product and exhibited colonization resistance against MRSA in an in vivo murine skin model. Using parallel genomic and biochemical investigation, we discovered that D. incerta secretes an antimicrobial protein. Sequential protein purification and proteomics analysis identified 24 candidate inhibitory proteins, including a promising peptidoglycan hydrolase candidate. Aided by transcriptional analysis of D. incerta and MRSA cocultures, we found that exposure to D. incerta leads to decreased MRSA biofilm production. These results emphasize the value in exploring microbial communities across a spectrum of hosts, which can lead to novel therapeutic agents as well as increased understanding of microbial competition. IMPORTANCEMethicillin-resistant Staphylococcus aureus causes significant healthcare burden and can be spread to the human population via livestock transmission. Members of the skin microbiome can prevent MRSA colonization via a poorly-understood phenomenon known as colonization resistance. Here, we studied colonization resistance of S. aureus by bacterial inhibitors previously identified from a porcine skin model. We identify a pig skin commensal, Desemzia incerta, that reduced MRSA colonization in a murine model. We employ a combination of genomic, proteomic, and transcriptomic analyses to explore the mechanisms of inhibition between D. incerta and S. aureus. We identify 24 candidate antimicrobial proteins secreted by D. incerta that could be responsible for its antimicrobial activity. We also find that exposure to D. incerta leads to decreased S. aureus biofilm formation. These findings show that the livestock transmission of MRSA can be exploited to uncover novel mechanisms of MRSA colonization resistance.

microbiology↗

bioRxiv2023

Quantitative label free mass spectrometry reveals content and signaling differences between neonatal and adult platelets

Background and ObjectiveRecent clinical studies have shown that transfusions of adult platelets increase morbidity and mortality in preterm infants. Neonatal platelets are hyporesponsive to agonist stimulation, and emerging evidence suggests developmental differences in platelet immune functions. This study was designed to compare the proteome and phosphoproteome of resting adult and neonatal platelets. MethodsWe isolated resting umbilical cord blood-derived platelets from healthy full term neonates (n=9) and resting blood platelets from healthy adults (n=7), and compared protein and phosphoprotein contents using data independent acquisition mass spectrometry. ResultsWe identified 4745 platelet proteins with high confidence across all samples. Adult and neonatal platelets clustered separately by principal component analysis. Adult platelets were significantly enriched for immunomodulatory proteins, including {beta}2 microglobulin and CXCL12, whereas neonatal platelets were enriched for ribosomal components and proteins involved in metabolic activities. Adult platelets were enriched for phosphorylated GTPase regulatory enzymes and proteins participating in trafficking, which may help prime them for activation and degranulation. Neonatal platelets were enriched for phosphorylated proteins involved in insulin growth factor signaling. ConclusionsUsing state-of-the-art mass spectrometry, our findings expanded the known neonatal platelet proteome and identified important differences in protein content and phosphorylation compared with adult platelets. These developmental differences suggested enhanced immune functions for adult platelets and presence of a molecular machinery related to platelet activation. These findings are important to understanding mechanisms underlying key platelet functions as well as the harmful effects of adult platelet transfusions given to preterm infants.

cell biology↗

bioRxiv2022

A Coxiella burnetii effector interacts with the host PAF1 complex and suppresses the innate immune response

Intracellular bacteria such as the pathogen Coxiella burnetii inject effector proteins into the host cell that promote productive infection. One common strategy of pathogen effectors is to suppress host immune responses to enable pathogen replication. The C. burnetii type IV secretion system translocates a large number of effectors into host cells that collectively promote intracellular bacterial replication, but the individual functions of most of these effectors are poorly understood. In this study, we describe a C. burnetii effector, CBU1314, that localizes to the nucleus and inhibits NF-{kappa}B-, MAPK-, and type I IFN-dependent gene expression. Mechanistically, we find that CBU1314 interacts with the PAF1 complex (PAF1C), a central host transcriptional complex that regulates expression of inflammatory genes in innate immune cells. Notably, we find that PAF1 promotes immune gene expression in response to various immune agonists and C. burnetii infection. Moreover, we find that PAF1 is critical for restricting intracellular C. burnetii replication. Overall, our findings uncover PAF1C as a host target of a C. burnetii effector and reveal new insight into how intracellular bacterial pathogens subvert cell- intrinsic innate defenses. SignificanceIntracellular bacteria often employ secreted effector proteins to modulate cellular processes and survive intracellularly. The study of these effectors can provide valuable insight into microbial pathogenesis and host biology. Here, we describe a Coxiella burnetii effector that inhibits multiple host signaling pathways and modulates the innate immune response. This effector interacts with the host PAF1 complex (PAF1C), a central regulator of transcription. Furthermore, we show that PAF1 is necessary for maximal gene expression downstream of various innate immune receptors and restricts bacterial replication during infection. Overall, our study elucidates the function of a C. burnetii effector in evading the immune response and provides insight into the role of PAF1C in cell-intrinsic defense against bacterial pathogens.

microbiology↗

bioRxiv2022

FBXW7β isoform drives transcriptional activation of a proinflammatory TNF cluster in normal and malignant pro-B cells

Non-canonical exon usage plays many important roles in cellular phenotypes, but its contribution to human B-cell development remains sketchily understood. To fill this gap, we collected various B-cell fractions from bone marrow and tonsil donors, performed RNA-seq, and examined transcript variants. We identified 150 genes that harbor local splicing variations in all pairwise comparisons. One of them encodes FBXW7, an E3 ubiquitin ligase implicated as a cancer driver in several blood cancers. Surprisingly, we discovered that in normal human pro-B cells, the predominant transcript utilized an alternative first exon to produce the poorly characterized FBXW7{beta} isoform, previously thought to be restricted to neural tissues. The FBXW7{beta} transcript was also abundant in cell lines and primary samples of pediatric B-cell acute lymphoblastic leukemia (B-ALL), which originates in the bone marrow. When overexpressed in a heterologous cell system, this transcript yielded the expected protein product, as judged by anti-FLAG immunoblotting and mass spectrometry. Furthermore, in REH B-ALL cells, FBXW7{beta} mRNA was the only FBXW7 isoform enriched in the polyribosome fraction. To shed light on possible functions of FBXW7{beta}, we utilized gain- and loss-of-function approaches and identified an FBXW7{beta}-dependent inflammatory gene signature, apparent in a subset of B-ALL with high FBXW7{beta} expression. This signature contained several members of the TNF superfamily, including those comprising the HLA Class III cluster (LTB, LST1, NCR3, LTA, and NFKBIL1). Our findings suggest that FBXW7{beta} expression drives proinflammatory responses, which could contribute to normal B-cell development, leukemogenesis and responses to anti-cancer therapies. Key pointsO_LIPreviously thought to be restricted to neural tissues, FBXW7{beta} is the predominant FBXW7 isoform in normal and malignant human pro-B cells. C_LIO_LIFBXW7{beta} promotes transcriptional activation of a proinflammatory gene cluster that contains TNF superfamily members. C_LI

cell biology↗

bioRxiv2022

Targeted Down Regulation Of Core Mitochondrial Genes During SARS-CoV-2 Infection

Defects in mitochondrial oxidative phosphorylation (OXPHOS) have been reported in COVID-19 patients, but the timing and organs affected vary among reports. Here, we reveal the dynamics of COVID-19 through transcription profiles in nasopharyngeal and autopsy samples from patients and infected rodent models. While mitochondrial bioenergetics is repressed in the viral nasopharyngeal portal of entry, it is up regulated in autopsy lung tissues from deceased patients. In most disease stages and organs, discrete OXPHOS functions are blocked by the virus, and this is countered by the host broadly up regulating unblocked OXPHOS functions. No such rebound is seen in autopsy heart, results in severe repression of genes across all OXPHOS modules. Hence, targeted enhancement of mitochondrial gene expression may mitigate the pathogenesis of COVID-19. One-Sentence SummaryCovid-19 is associated with targeted inhibition of mitochondrial gene transcription.

molecular biology↗

bioRxiv2020

The connector between the kinase and RNase domains of IRE1α transmits the conformational change that underlies ER stress-induced activation.

The unfolded protein response (UPR) plays an evolutionarily conserved role in homeostasis, and its dysregulation often leads to human disease, including diabetes and cancer. IRE1 is a major transducer that conveys endoplasmic reticulum (ER) stress to biochemical signals, yet major gaps persist in our understanding of how the detection of stress is converted to one of several molecular outcomes. It is known that upon sensing unfolded proteins via its ER luminal domain, IRE1 dimerizes and oligomerizes (often visualized as clustering), and then trans-autophosphorylates. The IRE1 kinase activity is required for activation of its RNase effector domain and for clustering of IRE1. It is not yet clear if IRE1 clustering is a platform for the RNase activity, or if the two represent distinct biological functions. Here, we uncover a previously unrecognized role for helix K between IRE1 kinase and RNase domains in conveying critical conformational changes. Using mutants within this inter-domain helix, we show for the first time that: 1) distinct substitutions (specifically, of Leu827) selectively affect oligomerization, RNase activity, and, unexpectedly, the kinase activity of IRE1; 2) RNase activation can be uncoupled from IRE1 oligomerization, and phosphorylation of S729 marks the former but not the latter; 3) The nature of residue 827 determines the conformation that the IRE1 protein adopts, leading to different patterns of biochemical activities. In summary, this work reveals a previously unappreciated role for the inter-domain helix as a pivotal conduit for attaining the stress-responsive conformation of IRE1.

biochemistry↗