Biology subjects

Moshiri, A.

Publications and source records attributed to Moshiri, A..

12 recordsLinked to original sources

bioRxiv2026

SMYD3 protein degraders in HPV-negative head and neck squamous cell carcinoma.

Despite the advent of immunotherapy in the treatment of human-papilloma-virus (HPV)-negative head and neck squamous cell carcinoma, the overall prognosis still remains dismal. Novel therapeutic approaches are thus urgently needed. We recently reported that SET and MYND containing 3 (SMYD3), a protein methyltransferase that is known to activate the transcription of its target genes through H3K4me3, is overexpressed in ~60% of HPV-negative HNSCC tumors, it drives proliferation and invasion, and induces resistance to immunotherapy in HPV-negative HNSCC. These phenotypes are mediated partially through transcriptional regulation of cell cycle, EMT and immune-related target genes by SMYD3. Despite its enzymatic inhibitory potency in HPV-negative HNSC cell lines, the commercially available SMYD3 inhibitors EPZ031686 and BAY-6035 demonstrated no in vitro phenotypic efficacy in these cell lines, supporting that SMYD3 exerts its oncogenic functions predominantly through catalytically-independent mechanisms. Thus, to effectively target SMYD3, we designed a series of SMYD3 proteolysis targeting chimeras (PROTACs). Treatment of HPV-negative HNSCC cell lines with SMYD3 PROTACs at nanomolar concentrations degraded SMYD3 effectively and induced a drastic decrease in the proliferative and invasive potential of HPV-negative HNSCC cells. One of the designed compounds, IAP-08, showed a promising DC50 at ~177nM with Dmax of ~90%, and effectively induced the formation of ternary complexes with SMYD3 and the XIAP E3 ligase. Furthermore, IAP-08 showed a favorable pharmacokinetic profile in vivo, underscoring the feasibility for further clinical development of this compound. Mass spectrometry analysis of IAP-08 supported its high specificity towards SMYD3. SMYD3 depletion by IAP-08 in HNSCC cells revealed transcriptional regulation of cell cycle, EMT- and type I IFN response genes, in contrast to SMYD3 inhibition which had only a weak transcriptional effect. In summary, we show that inhibition of the enzymatic activity of SMYD3 is not sufficient to repress its oncogenic activity and provide evidence that depletion through PROTACs effectively targets the oncogenic functions of SMYD3 in HPV-negative HNSCC.

cancer biology↗

bioRxiv2026

A Translational Reference for Green Autofluorescence Imaging in the Rhesus Macaque Eye using the OcuMet Beacon

PurposeTo evaluate associations between green autofluorescence (GAF) and structural and functional measures relevant to retinal and optic neuropathies, and to establish normative GAF values across the optic nerve head (ONH), macula, and papillofoveal bundle (PFB) in rhesus macaques. MethodsEighty-two macaques with normal ONH morphology by spectral-domain optical coherence tomography (SD-OCT) were included with a mean {+/-} SD age of 12.76 {+/-} 7.18 (range 0.11-29.39) years. The GAF images were acquired in the ONH, macula and PFB with the OcuMet Beacon. In a subset of macaques (n=19), pattern electroretinogram (PERG) and photopic full-field ERG including the photopic negative response (PhNR) were recorded. ResultsThe GAF significantly increased with age in the ONH, macula and PFB. After adjusting by age, there were no sex differences, but IOP showed a positive association with macular GAF. At the ONH, higher GAF correlated with thinner retinal nerve fiber layer, inner and outer segment complex, and total retinal thickness. In the macula, inner nuclear layer thickness was positively associated with GAF, whereas outer plexiform layer and inner and outer segment complex were inversely associated. The PERG amplitudes inversely tracked ONH GAF. ConclusionsGAF rises with age and IOP, couples to retinal structure, and at the ONH, aligns with inner-retinal functional indices. This study provides a regional reference for GAF in rhesus macaques. Translational RelevanceNormative GAF data in healthy rhesus macaques provide a framework for interpreting this noninvasive signal in translational studies of retinal and optic nerve disease.

physiology↗

bioRxiv2026

Ocular Safety and Efficacy of AAV-mediated Tyrosinase Gene Augmentation in a Nonhuman Primate Model

PurposeOculocutaneous albinism type 1 (OCA1) is an inherited disorder caused by tyrosinase (TYR) gene mutations. Affected individuals experience visual impairment and severe photosensitivity from ocular hypomelanosis, with no current treatments. We evaluated the safety and efficacy of a TYR-encoding adeno-associated virus (AAV) vector in healthy rhesus macaques as a potential OCA1 treatment. MethodsA novel AAV2-based capsid (ATX002) was packaged with the human VMD2 promoter and TYR (hTYR) fused with mGreenLantern (mGL). Two adult rhesus macaques were injected with ATX002-hVMD2-hTYR-mGL subretinally (OD) and intravitreally (OS). Safety and efficacy were assessed via comprehensive ophthalmic examination, fundus photography, spectral-domain optical coherence tomography (SD-OCT), and full-field electroretinography at baseline and defined timepoints up to 12 weeks post-injection, followed by post-mortem immunohistochemistry (IHC). ResultsBoth subretinal doses induced localized hypermelanosis by 3 weeks post-injection, which persisted through the study endpoint and was accompanied by measurable thickening of the retinal pigment epithelium (RPE) on SD-OCT. Histological IHC confirmed successful RPE transduction via robust mGL fluorescence, corroborating in vivo findings by revealing localized RPE hyperplasia and transgene-expressing cells adjacent to regions of de novo hypermelanosis. Intravitreal delivery did not induce any changes to the RPE. Transient uveitis was observed but successfully managed with anti-inflammatory treatment. ConclusionsSubretinal AAV-TYR delivery is a safe and effective approach with the potential to induce RPE pigmentation. These findings support the use of AAV-TYR gene therapy for OCA1, demonstrating efficacy and a manageable safety profile in a large-animal model, and provide a critical bridge toward human clinical translation.

bioengineering↗

bioRxiv2025

Oncogenic and immunomodulatory functions of SUV420H1 in HPV-negative head and neck squamous cell carcinoma.

Despite the advent of immunotherapy, human-papilloma-virus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) carries a high morbidity and mortality rate, thus novel therapies are urgently needed. Suppressor Of Variegation 4-20 Homolog 1 (SUV420H1) is a protein lysine methyltransferase that writes H4K20me3. Approximately 35% of HPV-negative HNSCC tumors carry gains/amplifications of SUV420H1. Gene Set Enrichment Analysis (GSEA) showed enrichment of proliferation-, epithelial-mesenchymal transition (EMT)- and immune-response pathways in SUV420H1-overexpressing HPV-negative HNSCC tumors. Depletion of SUV420H1 led to decreased proliferation, cell cycling and invasion in human HPV-negative HNSCC cell lines, while enzymatic inhibition decreased the invasive capacity but not the proliferation and cell cycling of HPV-negative HNSCC cell lines, supporting the presence of catalytically-independent and -dependent functions of SUV420H1. In a syngeneic mouse model of mouse oral carcinoma 1 tumors (MOC1), Suv420h1 knockout (KO) in MOC1 cancer cells halted tumor growth and synergized with anti-PD-1 therapy. In the tumor immune microenvironment (TIME) of Suv420h1 KO MOC1 tumors, a significant increase in the macrophage compartment with a concurrent decrease in the protumorigenic granulocytic myeloid derived suppressor cells (gMDSCs) was observed. Genome-wide mapping of SUV420H1-mediated H4K20me3 revealed enrichment of EMT-, IFN-response, and myeloid-attracting chemokines. This work provides rationale for the depletion/degradation of SUV420H1 as a novel therapeutic strategy to hinder proliferation and invasion, and to impart sensitization to anti-PD-1 immunotherapy for patients with HPV-negative HNSCC tumors with SUV420H1 gain/amplification.

cancer biology↗

bioRxiv2025

Super-resolution microscopy reveals a Rab6a-dependent trafficking hub for rhodopsin at the mammalian rod photoreceptor Golgi

Rod photoreceptor stability is critical for retinal health and lifelong vision. The proper intracellular trafficking of the photopigment receptor rhodopsin (Rho) is essential for normal rod homeostasis, as Rho mislocalization precedes rod cell death in inherited retinal disorders such as retinitis pigmentosa. Despite its importance, the molecular mechanisms of Rho trafficking in mammalian rods remain largely undefined. In this study, we combined multiple Rho-labeling strategies with super-resolution microscopy to investigate the subcellular organization of Rho in the Golgi complex of mammalian rods. Using stochastic optical reconstruction microscopy (STORM) and structured illumination microscopy (SIM) super-resolution imaging modalities, we mapped the localization of Golgi proteins with Rho in mouse and macaque rods and found that Rho specifically colocalizes with Rab6a in the trans-Golgi. To test the functional significance of this interaction, we utilized a dominant-negative Rab6a mutant in both HEK293T cells and mouse rods. We demonstrated that the dominant negative Rab6a significantly inhibits Rho secretion in cell culture, causing intracellular retention. In mouse rods, we found that this mutant similarly causes significant Rho retention in the trans-Golgi. However, surprisingly, a majority of Rho protein still escaped the Golgi and reached the outer segment. Together, these findings uncover critical new subcellular details about Rho organization at the Golgi and establish a role for Rab6a as a regulator of Rho protein release from the trans-Golgi in mammalian rods. Our results provide critical insight into the protein trafficking mechanisms that must be sustained and regulated in mammalian rods for long-term retinal health.

cell biology↗

bioRxiv2024

Stimulating the regenerative capacity of the human retina with proneural transcription factors in 3D cultures

Retinal diseases often lead to degeneration of specific retinal cell types with currently limited therapeutic options to replace the lost neurons. Previous studies have reported that overexpression of ASCL1 or combinations of proneural factors in Muller glia (MG) induces regeneration of functional neurons in the adult mouse retina. Recently, we applied the same strategy in dissociated cultures of fetal human MG and although we stimulated neurogenesis from MG, our effect in 2D cultures was modest and our analysis of newborn neurons was limited. In this study, we aimed to improve our MG reprogramming strategy in a more intact retinal environment. For this purpose, we used an in vitro culture system of human fetal retinal tissue and adult human postmortem retina. To stimulate reprogramming, we used lentiviral vectors to deliver constructs with a glial-specific promoter (HES1) driving ASCL1 alone or in combination with additional developmental transcription factors such as ATOH1 and NEUROD1. Combining IHC, scRNA-seq and electrophysiology, we show for the first time that human MG can generate new neurons even in adults. This work constitutes a key step towards a future clinical application of this regenerative medicine approach for retinal degenerative disorders.

developmental biology↗

bioRxiv2022

Silicone Oil-Induced Glaucomatous Neurodegeneration in Rhesus Macaques

Previously, we developed a simple procedure of intracameral injection of silicone oil (SO) into mouse eyes and established the mouse SOHU (SO-induced ocular hypertension under-detected) glaucoma model with reversible intraocular pressure (IOP) elevation and significant glaucomatous neurodegeneration. Because the anatomy of the non-human primate (NHP) visual system closely resembles that of humans, it is the most likely to predict human responses to diseases and therapies. Here we replicated the SOHU glaucoma model in rhesus macaque monkeys. All six animals that we tested showed significant retinal ganglion cell (RGC) death, optic nerve (ON) degeneration, and visual functional deficits at both 3 and 6 months. In contrast to the mouse SOHU model, IOP changed dynamically in these animals, probably due to individual differences in ciliary body tolerance capability. This acute NHP glaucoma model closely recapitulates the major features of glaucomatous neurodegeneration in humans, and is therefore suitable for studying the pathology of primate RGC/ON, assessing experimental therapies for neuroprotection and regeneration, and therefore for translating relevant findings into novel and effective treatments for patients with glaucoma and other neurodegenerations.

neuroscience↗

bioRxiv2022

Zfp503/Nlz2 is Required for RPE Differentiation and Optic Fissure Closure

PurposeUveal coloboma is a congenital eye malformation caused by failure of the optic fissure to close in early human development. Despite significant progress in identifying genes whose regulation is important for executing this closure, mutations are detected in a minority of cases using known gene panels, implying additional genetic complexity. We have previously shown knock down of znf503 (the ortholog of mouse Zfp503) in zebrafish causes coloboma. Here we characterize Zfp503 knock out (KO) mice and evaluate transcriptomic profiling of mutant vs. wild-type (WT) retinal pigment epithelium (RPE)/Choroid. MethodsZfp503 KO mice were generated by gene targeting using homologous recombination. Embryos were characterized grossly and histologically. Patterns and level of developmentally relevant proteins/genes were examined with immunostaining/in situ hybridization. The transcriptomic profile of E11.5 KO RPE/choroid was compared to that of WT. ResultsZfp503 is dynamically expressed in developing mouse eyes and that loss of its expression results in uveal coloboma. KO embryos exhibit altered mRNA levels and expression patterns of several key transcription factors involved in eye development, including Otx2, Mitf, Pax6, Pax2, Vax1 and Vax2, resulting in reduced melanin pigmentation in the presumptive RPE and its differentiation into neural-retina-like lineages. Comparison of RNA-Seq data from wild type and KO E11.5 embryos demonstrated reduced expression of melanin-related genes and significant overlap with genes known to be dynamically regulated at the optic fissure. ConclusionsThese results demonstrate a critical role of Zfp503 in RPE differentiation and in optic fissure closure.

developmental biology↗

bioRxiv2021

Arap1 Loss Causes RPE Phagocytic Dysfunction and Subsequent Photoreceptor Death

PurposeArap1 is an Arf-directed GTPase-activating protein (GAP) shown to modulate actin cytoskeletal dynamics by regulating Arf and Rho family members. We have previously shown that Arap1-/- mice develop photoreceptor degeneration similar to the human condition retinitis pigmentosa (RP), corroborated by fundus examination, histopathology, and ERG analysis. However, Arap1 expression was not detected in photoreceptors, but in Muller Glia and retinal pigment epithelium (RPE), suggesting a non-cell-autonomous mechanism for degeneration. The aim of this study was to elucidate the role of retinal Arap1 in photoreceptor maintenance. MethodsAlbino Arap1-/- mice were generated via breeding pigmented Arap1-/- mice onto a Tyr-/- C57BL/6J background. Conditional knockout (cKO) mice were generated for Muller Glia/RPE, Muller Glia, and RPE via targeting Cralbp, Glast, and Vmd2 promoters, respectively, to drive Cre recombinase expression to knock out Arap1. Mice were analyzed by fundus photography, optical coherence tomography (OCT), histology, and immunohistochemistry. Arap1 binding partners were assayed by affinity purification mass spectrometry. ResultsVmd2-Cre Arap1tm1c/tm1c and Cralbp-Cre Arap1tm1c/tm1c mice, but not Glast-Cre Arap1tm1c/tm1c mice, recapitulated the photoreceptor degeneration phenotype originally observed in germline Arap1-/- mice. These findings were corroborated by fundus exam, OCT, and histological analysis. Mass spectrometry analysis of ARAP1 co-immunoprecipitation identified putative binding partners of ARAP1, revealing numerous interactants involved in phagocytosis, cytoskeletal composition, intracellular trafficking, and endocytosis. Quantification of rod outer segment (OS) phagocytosis in vivo demonstrated a clear phagocytic defect in Arap1-/- mice compared to Arap1+/+ littermate controls while cone phagocytosis was preserved. ConclusionsArap1 expression, specifically in RPE, is necessary for photoreceptor survival due to its indispensable function in RPE phagocytosis. We propose a model in which Arap1 regulates G-protein function for nonmuscle myosin II targeting during phagocytosis. This novel role of Arap1 is important for further understanding of both the diversity of its functions and the complex molecular regulation of RPE phagocytosis.

molecular biology↗

bioRxiv2021

Age-Related Changes in the Rhesus Macaque Eye

PurposeTo assess age-related changes in the rhesus macaque eye and evaluate them to corresponding human age-related eye disease. MethodsData from eye exams and imaging tests including intraocular pressure (IOP), lens thickness, axial length, and retinal optical coherence tomography (OCT) images were evaluated from 142 individuals and statistically analyzed for age-related changes. Quantitative autofluorescence (qAF) was measured as was the presence of macular lesions as related to age. ResultsAges of the 142 rhesus macaques ranged from 0.7 to 29 years (mean=16.4 years, stdev=7.5 years). Anterior segment measurements such as IOP, lens thickness, and axial length were acquired. Advanced retinal imaging in the form of optical coherence tomography and qAF were obtained. Quantitative assessments were made and variations by age groups were analyzed to compare with established age-related changes in human eyes. Quantitative analysis of data revealed age-related increase in intraocular pressure, ocular biometry (lens thickness and axial length), and presence of macular lesions. Age-related changes in thicknesses of retinal layers on OCT were observed and quantified. Age was correlated with increased qAF. ConclusionsThe rhesus macaque has age-related ocular changes similar to humans. IOP increases with age while retinal ganglion cell layer thickness decreases. Macular lesions develop in some aged animals. Our findings support the concept that rhesus macaques may be useful for the study of important age-related diseases such as glaucoma, macular diseases, and cone disorders, and for development of therapies for these diseases.

systems biology↗

bioRxiv2021

Retinal organoids derived from rhesus macaque iPSCs undergo accelerated differentiation compared to human stem cells

PurposeTo compare the timing and efficiency of the development of non-human primate (NHP) derived retinal organoids in comparison to those derived from human embryonic stem cells. MethodsHuman embryonic stem cells (hESCs) and induced-pluripotent stem cells (rhiPSCs) derived from non-human primates (Macaca mulatta) were differentiated into retinal organoids by using an established differentiation protocol. Briefly, embryoid bodies were formed from pluripotent stem cells and induced into a neural lineage with neural induction media with the addition of BMP4. Thereafter, self-formation of optic vesicles was allowed to form in a 2D culture in retinal differentiation media (RDM). Optic vesicles were then manually harvested and cultured in suspension in 3D-RDM media until analysis. Differences in the timing of differentiation and efficiency of retinal organoid development were assessed by light microscopy, electron microscopy, immunocytochemistry, and single-cell transcriptomics. ResultsGeneration of retinal organoids was achieved from both human and several NHP pluripotent stem cells lines. All rhiPSC lines resulted in retinal differentiation with the formation of optic vesicle-like structures similar to what has been observed in hESC retinal organoids. NHP retinal organoids had laminated structure and were composed of mature retinal cell types including cone and rod photoreceptors. Single cell RNA sequencing was conducted at two time points, which allowed identification of cell types and characterization of developmental trajectory in the developing organoid. Important differences between rhesus and human cells were measured regarding the timing and efficiency of retinal organoid differentiation. While the culture of NHP-derived iPSCs is relatively difficult compared to human stem cells, the generation of retinal organoids is feasible and may be less time consuming due to an intrinsically faster timing of retinal differentiation. ConclusionsRetinal organoids produced from iPSCs derived from Rhesus monkey using established protocols differentiate through the stages of organoid development faster than those derived from human stem cells. The production of NHP retinal organoids may be advantageous to reduce experimental time and cost for basic biology studies in retinogenesis as well as for preclinical trials in NHPs studying retinal allograft transplantation.

cell biology↗

bioRxiv2020

Advanced Retinal Imaging and Ocular Parameters of the Rhesus Macaque Eye

PurposeTo determine the normal ocular biometric and perform advanced retinal imaging and functional assessment of a non-human primate used commonly in scientific research, the rhesus macaque. MethodsWe performed ocular phenotyping on rhesus macaques at the California National Primate Research Center. This consisted of anterior and posterior segment eye examination by ophthalmologists, advanced retinal imaging, and functional retinal electrophysiology. ResultsFull eye exams were performed on 142 animals consisting of pupillary light reflex, tonometry, external exam and photography, anterior slit lamp examination, and posterior segment examination by indirect ophthalmoscopy. Ages of the rhesus macaques ranged from 0.7 to 29 years (mean=16.4 years, stdev=7.5 years). Anterior segment measurements such as intraocular pressure (n=142), corneal thickness (n=84), lens thickness (n=114), and axial length (n=114) were acquired. Advanced retinal imaging in the form of fundus photography (n=78), optical coherence tomography (n=60), and quantitative autofluorescence (n=44) were obtained. Electroretinography (n=75) was used to assay retinal function. Quantitative analyses of macular structure, retinal layer segmentation, and rod and cone photoreceptor electrical responses are reported. Quantitative assessments were made and variations between genders and age groups were analyzed to compare with established sex and age-related changes in human eyes. ConclusionsThe rhesus macaque has ocular structure and function very similar to that of the human eye. Age-related ocular changes between rhesus and humans are similar. In particular, macular structure and function are very similar to humans making this species particularly useful for the study of macular biology and development of therapies for inherited and age-related macular degenerations as well as cone photoreceptor disorders.

physiology↗