Non-canonical RNA-binding protein ANXA11 regulates microRNA resorting into small extracellular vesicles to mediate cisplatin resistance.

The sensitivity of laryngeal squamous cell carcinoma (LSCC) to chemotherapy shows large heterogeneity. The role of miRNA in small extracellular vesicles (sEV) in chemotherapy resistance is under investigation. However, the regulation and sorting mechanism of sEV miRNAs remains unclear. In this study, small RNA sequencing was used to explore miRNA expression profiles in sEV of LSCC after cisplatin stimulation; RNA pull-down, mass spectrometry, and EMSA were used to clarify the binding of candidate RNA-binding protein (RBP) and candidate miRNA. Immunostaining and microRNA fluorescence in situ hybridization were performed to identify how candidate RBP affects miRNA stability and nuclear/cytoplasmic distribution. In vivo experiments were performed to verify the biological functions and response to cisplatin of candidate RBP. We found that cisplatin stimulation induced increased expression of miR-148a-3p and sEV sorting. ANXA11 binds to miR-148a-3p in a sequence-specific manner. ANXA11 inhibits tumor cell proliferation and drug resistance by binding to and retaining miR-148a-3p. Cisplatin stimulation reduced ANXA11 expression and promoted miR-148a-3p efflux through sEV pathways. ANXA11 overexpression reduced in vivo tumor proliferation and cisplatin-resistance. Taken together, ANXA11 mediates cisplatin resistance through sEV miRNA resorting. Mechanically, ANXA11 binds to miR-148a-3p in a sequence-specific manner to regulate its resorting and thus influences tumor proliferation and chemoresistance.

An ANXA11 P93S variant dysregulates TDP-43 and causes corticobasal syndrome.

INTRODUCTION: Variants of uncertain significance (VUS) surged with affordable genetic testing, posing challenges for determining pathogenicity. We examine the pathogenicity of a novel VUS P93S in Annexin A11 (ANXA11) - an amyotrophic lateral sclerosis/frontotemporal dementia-associated gene - in a corticobasal syndrome kindred. Established ANXA11 mutations cause ANXA11 aggregation, altered lysosomal-RNA granule co-trafficking, and transactive response DNA binding protein of 43 kDa (TDP-43) mis-localization. METHODS: We described the clinical presentation and explored the phenotypic diversity of ANXA11 variants. P93S's effect on ANXA11 function and TDP-43 biology was characterized in induced pluripotent stem cell-derived neurons alongside multiomic neuronal and microglial profiling. RESULTS: ANXA11 mutations were linked to corticobasal syndrome cases. P93S led to decreased lysosome colocalization, neuritic RNA, and nuclear TDP-43 with cryptic exon expression. Multiomic microglial signatures implicated immune dysregulation and interferon signaling pathways. DISCUSSION: This study establishes ANXA11 P93S pathogenicity, broadens the phenotypic spectrum of ANXA11 mutations, underscores neuronal and microglial dysfunction in ANXA11 pathophysiology, and demonstrates the potential of cellular models to determine variant pathogenicity. HIGHLIGHTS: ANXA11 P93S is a pathogenic variant. Corticobasal syndrome is part of the ANXA11 phenotypic spectrum. Hybridization chain reaction fluorescence in situ hybridization (HCR FISH) is a new tool for the detection of cryptic exons due to TDP-43-related loss of splicing regulation. Microglial ANXA11 and related immune pathways are important drivers of disease. Cellular models are powerful tools for adjudicating variants of uncertain significance.

Genetic and in silico analysis of Indian sporadic young onset patient with amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is an old onset devastating neurodegenerative disorder. Young-onset ALS cases especially sporadic ones who are between 25 and 45 years are rarely affected by the disease. Despite the identification of numerous candidate genes associated with ALS, the etiology of the disease remains elusive due to extreme genetic and phenotypic variability. The advent of affordable whole exome sequencing (WES) has opened new avenues for unraveling the disease's pathophysiology better. METHODS AND RESULTS: We aimed to determine the genetic basis of an Indian-origin, young onset sporadic ALS patient with very rapid deterioration of the disease course without any cognitive decline who was screened for mutations in major ALS candidate genes by WES. Variants detected were reconfirmed by Sanger sequencing. The clinicopathological features were investigated and two heterozygous missense variants were identified: R452W, not previously associated with ALS, present in one of the four conserved C terminal domains in ANXA11 and R208W in SIGMAR1, respectively. Both of these variants were predicted to be damaging by pathogenicity prediction tools and various in silico methods. CONCLUSION: Our study revealed two potentially pathogenic variants in two ALS candidate genes. The genetic makeup of ALS patients from India has been the subject of a few prior studies, but none of them examined ANXA11 and SIGMAR1 genes so far. These results establish the framework for additional research into the pathogenic processes behind these variations that result in sporadic ALS disease and further our understanding of the genetic makeup of Indian ALS patients.

An ANXA11 P93S variant dysregulates TDP-43 and causes corticobasal syndrome.

As genetic testing has become more accessible and affordable, variants of uncertain significance (VUS) are increasingly identified, and determining whether these variants play causal roles in disease is a major challenge. The known disease-associated Annexin A11 (ANXA11) mutations result in ANXA11 aggregation, alterations in lysosomal-RNA granule co-trafficking, and TDP-43 mis-localization and present as amyotrophic lateral sclerosis or frontotemporal dementia. We identified a novel VUS in ANXA11 (P93S) in a kindred with corticobasal syndrome and unique radiographic features that segregated with disease. We then queried neurodegenerative disorder clinic databases to identify the phenotypic spread of ANXA11 mutations. Multi-modal computational analysis of this variant was performed and the effect of this VUS on ANXA11 function and TDP-43 biology was characterized in iPSC-derived neurons. Single-cell sequencing and proteomic analysis of iPSC-derived neurons and microglia were used to determine the multiomic signature of this VUS. Mutations in ANXA11 were found in association with clinically diagnosed corticobasal syndrome, thereby establishing corticobasal syndrome as part of ANXA11 clinical spectrum. In iPSC-derived neurons expressing mutant ANXA11, we found decreased colocalization of lysosomes and decreased neuritic RNA as well as decreased nuclear TDP-43 and increased formation of cryptic exons compared to controls. Multiomic assessment of the P93S variant in iPSC-derived neurons and microglia indicates that the pathogenic omic signature in neurons is modest compared to microglia. Additionally, omic studies reveal that immune dysregulation and interferon signaling pathways in microglia are central to disease. Collectively, these findings identify a new pathogenic variant in ANXA11, expand the range of clinical syndromes caused by ANXA11 mutations, and implicate both neuronal and microglia dysfunction in ANXA11 pathophysiology. This work illustrates the potential for iPSC-derived cellular models to revolutionize the variant annotation process and provides a generalizable approach to determining causality of novel variants across genes.

An atypical ALS with PSP-like symptoms caused by ANXA11 p.D40G mutation: A case report and literature review.

Background: ANXA11 mutations were first reported to be associated with amyotrophic lateral sclerosis (ALS) in 2017. Several studies have investigated the prevalence of ANXA11 mutations in different populations, while less is known about the spectrum of phenotypes and the genotype-phenotype correlation with this gene mutation. Case presentation: Here, we report a 74-year-old man who was initially diagnosed with progressive supranuclear palsy (PSP) because of repeated falls, slight upward gaze palsy, and mild cognitive dysfunction at the onset. He finally turned out to be ALS with more and more prominent limb weakness and atrophy, together with the evidence of chronic neurogenic change and ongoing denervation on electromyography. Brain magnetic resonance imaging showed extensive cortical atrophy. A missense mutation c.119A > G (p.D40G) on the ANXA11 gene was identified using whole-exome sequencing, which confirmed the diagnosis of ALS. We performed a systematic review of the literature about ALS-relevant cases with ANXA11 mutations and identified 68 affected subjects and 29 variants with the ANXA11 gene. We summarized the phenotypes of ANXA11 mutations and the clinical characteristics of nine patients harboring the ANXA11 p.D40G variant including our case. Conclusions: The phenotype of ANXA11-related cases is heterogeneous, and most cases showed typical ALS, while some could also have the characteristics of frontotemporal dementia (FTD) and PSP, even inclusion body myopathies (hIBM) occurred in familial ALS (FALS). Our patient presented with ALS with a co-morbid PSP-like symptom (ALS-PSP) phenotype, which has not been reported. Except for our patient, the remaining eight patients with the ANXA11 p.D40G variant presented with a classical ALS phenotype without cognitive impairment.

CircSOD2 Contributes to Tumor Progression, Immune Evasion and Anti-PD-1 Resistance in Hepatocellular Carcinoma by Targeting miR-497-5p/ANXA11 Axis.

Circular RNAs (circRNAs) can function as functional molecules in hepatocellular carcinoma (HCC). Herein, circRNA superoxide dismutase 2 (circSOD2) was researched in HCC progression and immune system. The real-time polymerase chain reaction (qRT-PCR) was used for quantification of circSOD2, microRNA-497-5p (miR-497-5p) and Annexin A11 (ANXA11). Cell assays were performed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and colony formation assays for proliferation, flow cytometry for apoptosis and cell cycle, wound healing assay for migration and transwell assay for migration/invasion. ANXA11 and metastatic protein levels were measured by western blot. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to analyze target binding. CD8+ T cell immunity was assessed by Immunohistochemistry (IHC) assay, and the effect of circSOD2 on programmed cell death 1 (PD-1) immune checkpoint inhibitors (anti-PD-1) therapy was evaluated by mice xenograft assay. CircSOD2 was upregulated in HCC tissues and cells. Knockdown of circSOD2 resulted in HCC cell growth inhibition, apoptosis promotion, cell cycle arrest and metastasis suppression. Mechanically, circSOD2 promoted HCC development by acting as a miR-497-5p sponge and miR-497-5p played a tumor-inhibitory role in HCC cells by targeting ANXA11. Moreover, circSOD2 induced upregulation of ANXA11 expression by interacting with miR-497-5p. Also, the promoting effects of circSOD2 on immune evasion and anti-PD-1 resistance were related to miR-497-5p/ANXA11 axis. This study elucidated the pivotal function of circSOD2 in HCC progression and immunosuppression by mediating miR-497-6p/ANXA11 axis. CircSOD2/miR-497-5p/ANXA11 axis was a novel view of circRNA research in HCC.

Clinical and genetic characteristics of amyotrophic lateral sclerosis patients with ANXA11 variants.

Increasing genetic evidence supports the hypothesis that variants in the annexin A11 gene (ANXA11) contribute to amyotrophic lateral sclerosis pathogenesis. Therefore, we studied the clinical aspects of sporadic amyotrophic lateral sclerosis patients carrying ANXA11 variants. We also implemented functional experiments to verify the pathogenicity of the hotspot variants associated with amyotrophic lateral sclerosis-frontotemporal dementia. Korean patients diagnosed with amyotrophic lateral sclerosis (n = 882) underwent genetic evaluations through next-generation sequencing, which identified 16 ANXA11 variants in 26 patients. We analysed their clinical features, such as the age of onset, progression rate, initial symptoms and cognitive status. To evaluate the functional significance of the ANXA11 variants in amyotrophic lateral sclerosis-frontotemporal dementia pathology, we additionally utilized patient fibroblasts carrying frontotemporal dementia-linked ANXA11 variants (p.P36R and p.D40G) to perform a series of in vitro studies, including calcium imaging, stress granule dynamics and protein translation. The frequency of the pathogenic or likely pathogenic variants of ANXA11 was 0.3% and the frequency of variants classified as variants of unknown significance was 2.6%. The patients with variants in the low-complexity domain presented unique clinical features, including late-onset, a high prevalence of amyotrophic lateral sclerosis-frontotemporal dementia, a fast initial progression rate and a high tendency for bulbar-onset compared with patients carrying variants in the C-terminal repeated annexin homology domains. In addition, functional studies using amyotrophic lateral sclerosis-frontotemporal dementia patient fibroblasts revealed that the ANXA11 variants p.P36R and p.D40G impaired intracellular calcium homeostasis, stress granule disassembly and protein translation. This study suggests that the clinical manifestations of amyotrophic lateral sclerosis and amyotrophic lateral sclerosis-frontotemporal dementia spectrum patients with ANXA11 variants could be distinctively characterized depending upon the location of the variant.

ANXA11 mutations are associated with amyotrophic lateral sclerosis-frontotemporal dementia.

Background: The Annexin A11 (ANXA11) gene has been newly identified as a causative gene of amyotrophic lateral sclerosis (ALS) with or without frontotemporal dementia (FTD). The current study aimed to investigate the ANXA11 mutations in a Chinese ALS-FTD or FTD cohort. Methods: We included ten probands/patients with suspected ALS-FTD or FTD. Mutational analysis of ANXA11 was performed through Next Generation Sequencing (NGS) and Sanger sequencing. We collected and reviewed clinical presentation, neuropsychology test results, brain-imaging findings, and electrophysiological examination findings. Results: In total, six probands presented with ALS-FTD, and four with behavior variant FTD (bv-FTD). We identified a non-synonymous heterozygous mutation (c.119A>G, p.D40G) of ANXA11 in proband 1, which is associated with ALS. However, this is the first report of the mutation causing ALS-FTD. Proband 1 started with abnormal behavior and progressed to classic upper motor nervous disease. Magnetic resonance imaging (MRI) showed significant bilateral temporal lobe atrophy and bilateral hyperintensities along the corticospinal tracts.18F-AV45-PET imaging showed negative amyloid deposits. Conclusion: ANXA11-related diseases have high clinical and genetic heterogeneity. Our study confirmed the contribution of ANXA11 mutations to ALS-FTD. The ANXA11 mutations established a complex genotype-phenotype correlation in ALS-FTD. Our research further elucidated the genetic mechanism of ALS-FTD and contributed to setting the foundation of future targeted therapy.

Genetic analysis of and clinical characteristics associated with ANXA11 variants in a Chinese cohort with amyotrophic lateral sclerosis.

BACKGROUND: Variants in the annexin A11 gene (ANXA11) have been reported to be associated with amyotrophic lateral sclerosis (ALS). These variants may be involved in the pathogenesis of ALS by causing defects in intracellular protein trafficking. However, the genetic spectrum and clinical characteristics of ALS patients with ANXA11 variants are largely unknown. METHODS: Genetic analysis was performed on 1587 Chinese patients with ALS. Eight software packages were used to predict the deleteriousness of missense variants. In addition, we searched PubMed, Embase, and Web of Science for relevant literature and meta-analysed variant frequencies. RESULTS: In our ALS cohort, we identified 20 non-synonymous variants in 29 ALS patients, including one stop-gain, one frameshift, and 18 rare missense variants with seven predicted pathogenic variants. In a literature review of 11 reported studies that included 69 patients, 37 ANXA11 variants were reported, with a frequency of 1.7%, which was similar to that in our cohort (1.8%). Both our cohort and previous reports showed that ANXA11 carriers were more commonly males than females (12/17 vs. 19/31). Patients carrying ANXA11 variants affecting the C-terminal of the protein had earlier disease onset and shorter survival times than those carrying variants affecting the N-terminal. We found a relatively longer median survival time than that previously reported (53.6 months vs. 46.0 months). Additionally, Caucasian ANXA11 carriers were more likely to have cognitive impairment, typically frontotemporal dementia (FTD) than their Asian counterparts (20.0% vs. 14.3%). While more than half of the patients in our cohort had cognitive impairment, none had FTD. CONCLUSION: In our and previously published cases, ALS-associated ANXA11 variants predominantly affected the N- and C-terminal conserved domains. ANXA11 variant carriers are typically male and cognitively impaired. Our study extends the genotypic and phenotypic spectra of ALS patients with ANXA11 variants. Further expansion of the sample size is needed to analyse the clinical and non-motor symptom characteristics of patients and to deepen the understanding of the pathogenesis of ANXA11-associated ALS.

Semantic variant primary progressive aphasia with a pathogenic variant p.Asp40Gly in the ANXA11 gene.

We report a patient with right-predominant semantic variant primary progressive aphsia linked with p.Asp40Gly variant of ANXA11, which is the first description of frontotemporal dementia without clinical and electrophysiological evidences of amyotrophic lateral sclerosis associated with a known pathogenic variant of ANXA11.

ANXA11 rs1049550 Associates with Löfgren's Syndrome and Chronic Sarcoidosis Patients.

Sarcoidosis is an immune mediated granulomatous disease commonly affecting the lungs. Genome wide association studies identified many genomic regions that are shared among multiple immune mediated diseases. However, ANXA11 gene polymorphism rs1049550 is exclusively associated with sarcoidosis, making it a key gene of interest for sarcoidosis disease pathogenesis. However, sarcoidosis is a heterogeneous disease and contradictory findings for ANXA11 have been reported for disease phenotypes. We performed a case-control association study to investigate if ANXA11 associates with benign (Löfgren's syndrome (LS)) or chronic sarcoidosis and performed a meta-analysis on previously reported findings. A total of 262 sarcoidosis patients, of which 149 had LS and 113 chronic sarcoidosis, and 363 controls were genotyped for rs1049550. Meta-analysis included allele findings for rs1049550 from 6 additional studies. We found a significantly lower T allele frequency in sarcoidosis patients than in healthy controls (0.30 vs. 0.41, respectively, odds ratio (OR) 0.61, 95% confidence interval (CI) 0.48-0.77, p = 3 × 10-5). In LS the T allele frequency of 0.33, and in chronic sarcoidosis the T allele frequency of 0.26 were significantly lower than in healthy controls (OR 0.69, 95% CI 0.52-0.92, p = 0.01 and OR 0.51, 95% CI 0.36-0.70, p = 4 × 10-5, respectively). Meta-analysis including previously published European, African American and Asian cohorts confirmed the association of rs1049550 with sarcoidosis and resulted in a pooled OR of 0.70 (CI 0.66-0.75, p = 3.58 × 10-29). Presence of the T allele of rs1049550 in ANXA11 is protective for sarcoidosis, including benign and chronic phenotypes of the disease.

Circular RNA_0061587 is associated with the tumorigenesis of neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a kind of common neurogenetic disorder associated with various developmental deficits. Circular RNAs (circRNAs) have been frequently verified to be crucial modulators in human diseases. However, the functions of circRNAs on the occurrence of NF1 remain largely obscure. In our study, RT-qPCR was applied to analyze circ_0061,587 expression and we noticed that circ_0061,587 expression was overtly elevated in human NF1-associated malignant peripheral nerve sheath tumor (MPNST) cell lines. Meanwhile, the results of loss-of-function assays revealed that silencing of circ_0061,587 hampered the proliferation, migration, and invasion but stimulated the apoptosis of human NF1-associated MPNST cells. In addition, mechanism assays were implemented to unveil the possible regulatory mechanism behind circ_0061,587. As a result, circ_0061,587 sequestered microRNA-485-5p (miR-485-5p) to modulate the expression of RUNX family transcription factor 1 (RUNX1) and annexin A11 (ANXA11). Finally, rescue experiments confirmed that circ_0061,587 boosted the malignant behaviors of human NF1-associated MPNST cells through up-regulating RUNX1 and ANXA11. In conclusion, circ_0061,587 functioned as an oncogene in NF1-associated MPNST cells and this study might provide novel insights for the diagnosis and treatment of NF1.

Genetic screening of ANXA11 revealed novel mutations linked to amyotrophic lateral sclerosis.

ANXA11 mutations have previously been discovered in amyotrophic lateral sclerosis (ALS) motor neuron disease. To confirm the contribution of ANXA11 mutations to ALS, a large exome data set obtained from 330 French patients, including 150 familial ALS index cases and 180 sporadic ALS cases, was analyzed, leading to the identification of 3 rare ANXA11 variants in 5 patients. The novel p.L254V variant was associated with early onset sporadic ALS. The novel p.D40Y mutation and the p.G38R variant concerned patients with predominant pyramidal tract involvement and cognitive decline. Neuropathologic findings in a p.G38R carrier associated the presence of ALS typical inclusions within the spinal cord, massive degeneration of the lateral tracts, and type A frontotemporal lobar degeneration. This mutant form of annexin A11 accumulated in various brain regions and in spinal cord motor neurons, although its stability was decreased in patients' lymphoblasts. Because most ANXA11 inclusions were not colocalized with transactive response DNA-binding protein 43 or p62 deposits, ANXA11 aggregation does not seem mandatory to trigger neurodegeneration with additional participants/partner proteins that could intervene.

EIF3J-AS1 promotes glioma cell growth via up-regulating ANXA11 through sponging miR-1343-3p.

BACKGROUND: Glioma is one prevalent malignant tumor originates from the central nervous system. Dysregulation of long non-coding RNAs (lncRNAs) has been found to be a molecular signature behind the pathology of a variety of cancers, including glioma. EIF3J antisense RNA 1 (EIF3J-AS1) is a novel lncRNA, whose performance in carcinogenesis has been unfolded. Nevertheless, the role of EIF3J-AS1 has never been investigated in glioma. METHODS: qRT-PCR analysis was adopted to evaluate the relative levels of RNAs. In vitro functional assays, including colony formation, EdU, TUNEL and caspase-3/8/9 activity assays were conducted to study the impacts of EIF3J-AS1 on glioma. Dual-luciferase activity assays, RNA pull down assay and RIP assay were performed to elucidate molecular interplay among genes. RESULTS: EIF3J-AS1 was overexpressed in glioma cell lines. Knockdown of EIF3J-AS1 hampered glioma malignant phenotypes. MiR-1343-3p could bind to EIF3J-AS1. Moreover, miR-1343-3p targeted Annexin A11 (ANXA11) in its 3'UTR region. Mechanistically, EIF3J-AS1 relieved ANXA11 from miR-1343-3p silencing in the EIF3J-AS1/miR-1343-3p/ANXA11 RNA induced silencing complex (RISC), thus eliciting promoting effects on glioma progression. MiR-1343-3p inhibitor and ANXA11 overexpression offset the inhibitory impacts of EIF3J-AS1 silencing on glioma development. CONCLUSION: EIF3J-AS1/miR-1343-3p/ANXA11 axis significantly affected biological behaviors in glioma, suggesting new therapeutic target for glioma treatment.

Association of TGF-ß3 and ANXA11 with pulmonary sarcoidosis in Greek population.

BACKGROUND: In sarcoidosis, the direction and intensity of immunological reactions involved in disease pathophysiology is affected by variation in the genes coding for effector and regulatory molecules with immune functions. This study, therefore, investigates polymorphic variants in genes involved in inflammation, immune reactions, and granuloma formation in context of their plausible association with sarcoidosis, with specific focus on Greek population. METHODS: A total of 18 single-nucleotide polymorphisms (SNPs) were genotyped in Greek patients with pulmonary sarcoidosis (n = 103) and in healthy Greek control subjects (n = 100) using multiplexed MassARRAY (MassARRAY ®) iPLEX assay based on MALDI-TOF mass spectrometry. RESULTS: TGF-ß3 rs3917200*G variant was associated with sarcoidosis (OR: 3.04 [95% CI: 1.98-4.69], p = 2.76*10-7). Further, ANXA11 rs1049550*A variant was associated with sarcoidosis (OR: 0.59 [0.39-0.89], p = 0.01). CONCLUSIONS: This first study of genetic variation of immune-related genes in Greek patients with sarcoidosis brings to attention a novel disease 'susceptibility' factor: TGF-ß3 rs3917200*G allele. It also confirms previously reported 'protective' association between sarcoidosis and functional variant ANXA11 rs1049550*A. Further work is required to validate these findings and to expand investigation of their plausible relationship with clinical course of the disease.

Inherited and Sporadic Amyotrophic Lateral Sclerosis and Fronto-Temporal Lobar Degenerations arising from Pathological Condensates of Phase Separating Proteins.

Recent work on the biophysics of proteins with low complexity, intrinsically disordered domains that have the capacity to form biological condensates has profoundly altered the concepts about the pathogenesis of inherited and sporadic neurodegenerative disorders associated with pathological accumulation of these proteins. In the present review, we use the FUS, TDP-43 and A11 proteins as examples to illustrate how missense mutations and aberrant post-translational modifications of these proteins cause amyotrophic lateral sclerosis (ALS) and fronto-temporal lobar degeneration (FTLD).

RNA Granules Hitchhike on Lysosomes for Long-Distance Transport, Using Annexin A11 as a Molecular Tether.

Long-distance RNA transport enables local protein synthesis at metabolically-active sites distant from the nucleus. This process ensures an appropriate spatial organization of proteins, vital to polarized cells such as neurons. Here, we present a mechanism for RNA transport in which RNA granules "hitchhike" on moving lysosomes. In vitro biophysical modeling, live-cell microscopy, and unbiased proximity labeling proteomics reveal that annexin A11 (ANXA11), an RNA granule-associated phosphoinositide-binding protein, acts as a molecular tether between RNA granules and lysosomes. ANXA11 possesses an N-terminal low complexity domain, facilitating its phase separation into membraneless RNA granules, and a C-terminal membrane binding domain, enabling interactions with lysosomes. RNA granule transport requires ANXA11, and amyotrophic lateral sclerosis (ALS)-associated mutations in ANXA11 impair RNA granule transport by disrupting their interactions with lysosomes. Thus, ANXA11 mediates neuronal RNA transport by tethering RNA granules to actively-transported lysosomes, performing a critical cellular function that is disrupted in ALS.

Long non-coding RNA AGAP2-AS1, functioning as a competitive endogenous RNA, upregulates ANXA11 expression by sponging miR-16-5p and promotes proliferation and metastasis in hepatocellular carcinoma.

BACKGROUND: Accumulating evidence has highlighted the potential role of long non-coding RNAs (lncRNAs) in the biological behaviors of hepatocellular carcinoma (HCC). Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA-AGAP2-AS1 on the biological behaviors of HCC. METHODS: EdU, Transwell and flow cytometry were used to determine proliferation, migration, invasion and apoptosis of HCC cells in vitro. The subcutaneous tumor model and lung metastasis mouse model in nude mice was established to detect tumor growth and metastasis of HCC in vivo. The direct binding of miR-16-5p to 3'UTR of ANXA11 was confirmed by luciferase reporter assay. The expression of AGAP2-AS1 and miR-16-5p in HCC specimens and cell lines were detected by real-time PCR. The correlation among AGAP2-AS1 and miR-16-5p were disclosed by a dual-luciferase reporter assay, RIP assay and biotin pull-down assay. RESULTS: Here, we demonstrated that AGAP2-AS1 expression was up-regulated in HCC tissues and cell lines, especially in metastatic and recurrent cases. Gain- and loss-of-function experiments indicated that AGAP2-AS1 promoted cell proliferation, migration, invasion, EMT progression and inhibited apoptosis of HCC cells in vitro and in vivo. Further studies demonstrated that AGAP2-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-16-5p in HCC cells. Functionally, gain- and loss-of-function studies showed that miR-16-5p promoted HCC progression and alteration of miR-16-5p abolished the promotive effects of AGAP2-AS1 on HCC cells. Moreover, ANXA11 was identified as direct downstream targets of miR-16-5p in HCC cells, and mediated the functional effects of miR-16-5p and AGAP2-AS1 in HCC, resulting in AKT signaling activation. Clinically, AGAP2-AS1 and miR-16-5p expression were markedly correlated with adverse clinical features and poor prognosis of HCC patients. We showed that hypoxia was responsible for the overexpression of AGAP2-AS1 in HCC. And the promoting effects of hypoxia on metastasis and EMT of HCC cells were reversed by AGAP2-AS1 knockdown. CONCLUSIONS: Taken together, this research supports the first evidence that AGAP2-AS1 plays an oncogenic role in HCC via AGAP2-AS1/miR-16-5p/ANXA11/AKT axis pathway and represents a promising therapeutic strategy for HCC patients.

Quantitative proteomic profiling of extracellular matrix and site-specific collagen post-translational modifications in an in vitro model of lung fibrosis.

Lung fibrosis is characterized by excessive deposition of extracellular matrix (ECM), in particular collagens, by fibroblasts in the interstitium. Transforming growth factor-ß1 (TGF-ß1) alters the expression of many extracellular matrix (ECM) components produced by fibroblasts, but such changes in ECM composition as well as modulation of collagen post-translational modification (PTM) levels have not been comprehensively investigated. Here, we performed mass spectrometry (MS)-based proteomics analyses to assess changes in the ECM deposited by cultured lung fibroblasts from idiopathic pulmonary fibrosis (IPF) patients upon stimulation with transforming growth factor ß1 (TGF-ß1). In addition to the ECM changes commonly associated with lung fibrosis, MS-based label-free quantification revealed profound effects on enzymes involved in ECM crosslinking and turnover as well as multiple positive and negative feedback mechanisms of TGF-ß1 signaling. Notably, the ECM changes observed in this in vitro model correlated significantly with ECM changes observed in patient samples. Because collagens are subject to multiple PTMs with major implications in disease, we implemented a new bioinformatic platform to analyze MS data that allows for the comprehensive mapping and site-specific quantitation of collagen PTMs in crude ECM preparations. These analyses yielded a comprehensive map of prolyl and lysyl hydroxylations as well as lysyl glycosylations for 15 collagen chains. In addition, site-specific PTM analysis revealed novel sites of prolyl-3-hydroxylation and lysyl glycosylation in type I collagen. Interestingly, the results show, for the first time, that TGF-ß1 can modulate prolyl-3-hydroxylation and glycosylation in a site-specific manner. Taken together, this proof of concept study not only reveals unanticipated TGF-ß1 mediated regulation of collagen PTMs and other ECM components but also lays the foundation for dissecting their key roles in health and disease. The proteomic data has been deposited to the ProteomeXchange Consortium via the MassIVE partner repository with the data set identifier MSV000082958.

Two rare variants of the ANXA11 gene identified in Chinese patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. A recent study has identified mutations in the ANXA11 gene (encoding the calcium-binding protein annexin A11) associated with ALS. Mutation screening of ANXA11 protein-coding exons was performed in a Chinese cohort of 434 patients with sporadic ALS and 50 index patients with familial ALS. Polymerase chain reaction and Sanger sequencing were used for mutation detection. We failed to discover an N-terminal mutation, which was common in the Caucasian cohort. We revealed two rare heterozygous missense variants, c.878C>T (p.A293V) and c.921C>G (p.I307M), which are absent from the population databases and non-neurological controls. They are both located in the conserved annexin domain. The carriers of the mutation exhibited the classical ALS phenotype without cognitive impairment. Our results suggested that further functional studies for these variants are required to support the pathogenicity.