characterization-vascular-morphology-neovascular-age-related-macular

Characterization of Vascular Morphology of Neovascular Age-Related Macular Degeneration by Indocyanine Green Angiography

Age-related macular degeneration (AMD) is a leading cause of blindness among older individuals, and its prevalence is rapidly increasing due to the aging ...

Baylor College of Medicine

Dystrophin proteomic regulation in muscular dystrophies (MDs) remains unclear. We report that a long noncoding RNA (lncRNA), H19, associates with dystrophin and inhibits E3-ligase-dependent polyubiquitination at Lys 3584 (referred to as Ub-DMD) and its subsequent protein degradation. In-frame deletions in BMD and a DMD non-silent mutation (C3340Y) resulted in defects in the ability of the protein to interact with H19, which caused elevated Ub-DMD levels and dystrophin degradation. Dmd C3333Y mice exhibited progressive MD, elevated serum creatine kinase, heart dilation, blood vessel irregularity and respiratory failure with concurrently reduced dystrophin and increased Ub-DMD status. H19 RNA oligonucleotides conjugated with agrin (AGR-H19) and nifenazone competed with or inhibited TRIM63. Dmd C3333Y animals, induced-pluripotent-stem-cell-derived skeletal muscle cells from patients with Becker MD and mdx mice subjected to exon skipping exhibited inhibited dystrophin degradation, preserved skeletal and cardiac muscle histology, and improved strength and heart function following AGR-H19 or nifenazone treatment. Our study paves the way for meaningful targeted therapeutics for Becker MD and for certain patients with Duchenne MD.

The lncRNA H19 alleviates muscular dystrophy by stabilizing dystrophin.

The molecular basis of the incomplete penetrance of monogenic disorders is unclear. We describe here eight related individuals with autosomal recessive TIRAP deficiency. Life-threatening staphylococcal disease occurred during childhood in the proband, but not in the other seven homozygotes. Responses to all Toll-like receptor 1/2 (TLR1/2), TLR2/6, and TLR4 agonists were impaired in the fibroblasts and leukocytes of all TIRAP-deficient individuals. However, the whole-blood response to the TLR2/6 agonist staphylococcal lipoteichoic acid (LTA) was abolished only in the index case individual, the only family member lacking LTA-specific antibodies (Abs). This defective response was reversed in the patient, but not in interleukin-1 receptor-associated kinase 4 (IRAK-4)-deficient individuals, by anti-LTA monoclonal antibody (mAb). Anti-LTA mAb also rescued the macrophage response in mice lacking TIRAP, but not TLR2 or MyD88. Thus, acquired anti-LTA Abs rescue TLR2-dependent immunity to staphylococcal LTA in individuals with inherited TIRAP deficiency, accounting for incomplete penetrance. Combined TIRAP and anti-LTA Ab deficiencies underlie staphylococcal disease in this patient.

Human Adaptive Immunity Rescues an Inborn Error of Innate Immunity.

Resistance to cancer treatment can be driven by epigenetic reprogramming of specific transcriptomes in favor of the refractory phenotypes. Here we discover that tamoxifen resistance in breast cancer is driven by a regulatory axis consisting of a master transcription factor, its cofactor, and an epigenetic regulator. The oncogenic histone methyltransferase EZH2 conferred tamoxifen resistance by silencing the expression of the estrogen receptor α (ERα) cofactor GREB1. In clinical specimens, induction of DNA methylation of a particular CpG-enriched region at the  promoter negatively correlated with  levels and cell sensitivity to endocrine agents. GREB1 also ensured proper cellular reactions to different ligands by recruiting distinct sets of ERα cofactors to -regulatory elements, which explains the contradictory biological effects of GREB1 on breast cancer cell growth in response to estrogen or antiestrogen. In refractory cells, EZH2-dependent repression of GREB1 triggered chromatin reallocation of ERα coregulators, converting the antiestrogen into an agonist. In clinical specimens from patients receiving adjuvant tamoxifen treatment, expression levels of EZH2 and GREB1 were correlated negatively, and taken together better predicted patient responses to endocrine therapy. Overall, our work suggests a new strategy to overcome endocrine resistance in metastatic breast cancer by targeting a particular epigenetic program. This study suggests a new strategy to overcome endocrine resistance in metastatic breast cancer by targeting a particular epigenetic program defined within. .

Tamoxifen Resistance in Breast Cancer Is Regulated by the EZH2-ERα-GREB1 Transcriptional Axis.

Trichinellosis is a serious food-borne parasitic zoonosis worldwide. In the effort to develop vaccine against Trichinella infection, we have identified Trichinella spiralis Heat shock protein 70 (Ts-Hsp70) elicits partial protective immunity against T. spiralis infection via activating dendritic cells (DCs) in our previous study. This study aims to investigate whether DCs were activated by Ts-Hsp70 through TLR2 and/or TLR4 pathways.

Ts-Hsp70 induces protective immunity against Trichinella spiralis infection in mouse by activating dendritic cells through TLR2 and TLR4.

Human cancer cell lines are fundamental models for cancer research and therapeutic strategy development. However, there is no characterization of circular RNAs (circRNAs) in a large number of cancer cell lines.

Comprehensive characterization of circular RNAs in ~ 1000 human cancer cell lines.

Tumor hypoxia is a major contributor to resistance to anti-cancer therapies. Given that the results of hypoxia-targeted therapy trials have been disappointing, a more personalized approach may be needed. Here we characterize multi-OMIC molecular features associated with tumor hypoxia and identify molecular alterations that correlate with both drug-resistant and drug-sensitive responses to anti-cancer drugs. Based on a well-established hypoxia gene expression signature, we classify about 10,000 tumor samples into hypoxia score-high and score-low groups across different cancer types from The Cancer Genome Atlas and demonstrate their prognostic associations. We then identify various types of molecular features associated with hypoxia status that correlate with drug resistance but, in some cases, also with drug sensitivity, contrasting the conventional view that hypoxia confers drug resistance. We further show that 110 out of 121 (90.9%) clinically actionable genes can be affected by hypoxia status and experimentally validate the predicted effects of hypoxia on the response to several drugs in cultured cells. Our study provides a comprehensive molecular-level understanding of tumor hypoxia and may have practical implications for clinical cancer therapy.

Characterization of Hypoxia-associated Molecular Features to Aid Hypoxia-Targeted Therapy.

Acquired therapy resistance is a major problem for anticancer treatment, yet the underlying molecular mechanisms remain unclear. Using an established breast cancer cellular model, we show that endocrine resistance is associated with enhanced phenotypic plasticity, indicated by a general downregulation of luminal/epithelial differentiation markers and upregulation of basal/mesenchymal invasive markers. Consistently, similar gene expression changes are found in clinical breast tumours and patient-derived xenograft samples that are resistant to endocrine therapies. Mechanistically, the differential interactions between oestrogen receptor α and other oncogenic transcription factors, exemplified by GATA3 and AP1, drive global enhancer gain/loss reprogramming, profoundly altering breast cancer transcriptional programs. Our functional studies in multiple culture and xenograft models reveal a coordinated role of GATA3 and AP1 in re-organizing enhancer landscapes and regulating cancer phenotypes. Collectively, our study suggests that differential high-order assemblies of transcription factors on enhancers trigger genome-wide enhancer reprogramming, resulting in transcriptional transitions that promote tumour phenotypic plasticity and therapy resistance.

Enhancer reprogramming driven by high-order assemblies of transcription factors promotes phenotypic plasticity and breast cancer endocrine resistance.

Tamoxifen, a widely used modulator of the estrogen receptor (ER), targets ER-positive breast cancer preferentially. We used a powerful validation-based insertion mutagenesis method to find that expression of a dominant-negative, truncated form of the histone deacetylase ZIP led to resistance to tamoxifen. Consistently, increased expression of full-length ZIP gives the opposite phenotype, inhibiting the expression of genes whose products mediate resistance. An important example is  By binding to two specific sequences in the promoter, ZIP suppresses  expression. Increased expression and activation of JAK2 when ZIP is inhibited lead to increased STAT3 phosphorylation and increased resistance to tamoxifen, both in cell culture experiments and in a mouse xenograft model. Furthermore, data from human tumors are consistent with the conclusion that decreased expression of ZIP leads to resistance to tamoxifen in ER-positive breast cancer.

Loss of ZIP facilitates JAK2-STAT3 activation in tamoxifen-resistant breast cancer.

The function of enhancer RNAs (eRNAs) in transcriptional regulation remains obscure. By analyzing the genome-wide nascent transcript profiles in breast cancer cells, we identify a special group of eRNAs that are essential for estrogen-induced transcriptional repression. Using eRNAs of TM4SF1 and EFEMP1 as the paradigms, we find that these RNA molecules not only stabilize promoter-enhancer interactions but also recruit liganded estrogen receptor α (ERα) to particular enhancer regions, facilitate the formation of a functional transcriptional complex, and cause gene silencing. Interestingly, ERα is shown to directly bind with eRNAs by its DNA-binding domain. These eRNAs help with the formation of a specific ERα-centered transcriptional complex and promote the association of the histone demethylase KDM2A, which dismisses RNA polymerase II from designated enhancers and suppresses the transcription of target genes. Our work demonstrates a complete mechanism underlying the action of eRNAs in modulating and refining the locus-specific transcriptional program.

Enhancer RNAs Mediate Estrogen-Induced Decommissioning of Selective Enhancers by Recruiting ERα and Its Cofactor.

The rise of metabolic disorders in modern times is mainly attributed to the environment. However, heritable effects of environmental chemicals on mammalian offsprings' metabolic health are unclear. Inorganic arsenic (iAs) is the top chemical on the Agency for Toxic Substances and Disease Registry priority list of hazardous substances. Here, we assess cross-generational effects of iAs in an exclusive male-lineage transmission paradigm. The exposure of male mice to 250 ppb iAs causes glucose intolerance and hepatic insulin resistance in F1 females, but not males, without affecting body weight. Hepatic expression of glucose metabolic genes, glucose output, and insulin signaling are disrupted in F1 females. Inhibition of the glucose 6-phosphatase complex masks the intergenerational effect of iAs, demonstrating a causative role of hepatic glucose production. F2 offspring from grandpaternal iAs exposure show temporary growth retardation at an early age, which diminishes in adults. However, reduced adiposity persists into middle age and is associated with altered gut microbiome and increased brown adipose thermogenesis. In contrast, F3 offspring of the male-lineage iAs exposure show increased adiposity, especially on a high-calorie diet. These findings have unveiled sex- and generation-specific heritable effects of iAs on metabolic physiology, which has broad implications in understanding gene-environment interactions.

Inter- and Transgenerational Effects of Paternal Exposure to Inorganic Arsenic.

The functional role of long noncoding RNAs (lncRNAs) in inherited metabolic disorders, including phenylketonuria (PKU), is unknown. Here, we demonstrate that the mouse lncRNA  and human  associate with phenylalanine hydroxylase (PAH). -knockout mice exhibited excessive blood phenylalanine (Phe), musty odor, hypopigmentation, growth retardation, and progressive neurological symptoms including seizures, which faithfully models human PKU.  depletion led to reduced PAH enzymatic activities in human induced pluripotent stem cell-differentiated hepatocytes. Mechanistically,  modulated the enzymatic activities of PAH by facilitating PAH-substrate and PAH-cofactor interactions. To develop a therapeutic strategy for restoring liver lncRNAs, we designed GalNAc-tagged lncRNA mimics that exhibit liver enrichment. Treatment with GalNAc- mimics reduced excessive Phe in   and   mice and improved the Phe tolerance of these mice.

A noncoding RNA modulator potentiates phenylalanine metabolism in mice.

Rhodopsin and cone opsins are essential for light detection in vertebrate rods and cones, respectively. It is well established that rhodopsin is required for rod phototransduction, outer segment disk morphogenesis, and rod viability. However, the roles of cone opsins are less well understood. In this study, we adopted a loss-of-function approach to investigate the physiological roles of cone opsins in mice. We showed that cones lacking cone opsins do not form normal outer segments due to the lack of disk morphogenesis. Surprisingly, cone opsin-deficient cones survive for at least 12 mo, which is in stark contrast to the rapid rod degeneration observed in rhodopsin-deficient mice, suggesting that cone opsins are dispensable for cone viability. Although the mutant cones do not respond to light directly, they maintain a normal dark current and continue to mediate visual signaling by relaying the rod signal through rod-cone gap junctions. Our work reveals a striking difference between the role of rhodopsin and cone opsins in photoreceptor viability.

Visual pigment-deficient cones survive and mediate visual signaling despite the lack of outer segments.

Anti-VEGF resistance represents a major unmet clinical need in the management of choroidal neovascularization (CNV). We have previously reported that a combination of AIBP, apoA-I, and an anti-VEGF antibody overcomes anti-VEGF resistance in laser-induced CNV in old mice in prevention experiments. The purpose of this work is to conduct a more clinically relevant study to assess the efficacy of the combination of AIBP, apoA-I, and aflibercept in the treatment of anti-VEGF resistance of experimental CNV at different time points after laser photocoagulation.

Combination of AIBP, apoA-I, and Aflibercept Overcomes Anti-VEGF Resistance in Neovascular AMD by Inhibiting Arteriolar Choroidal Neovascularization.

One of the major obstacles to treating pancreatic ductal adenocarcinoma (PDAC) is its immunoresistant microenvironment. The functional importance and molecular mechanisms of Schwann cells in PDAC remains largely elusive. We characterized the gene signature of tumor-associated nonmyelinating Schwann cells (TASc) in PDAC and indicated that the abundance of TASc was correlated with immune suppressive tumor microenvironment and the unfavorable outcome of patients with PDAC. Depletion of pancreatic-specific TASc promoted the tumorigenesis of PDAC tumors. TASc-expressed long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 () was triggered by the tumor cell-produced interleukin-6. Mechanistically,  modulated RAF proto-oncogene serine/threonine protein kinase-mediated phosphorylation of tryptophan 2,3-dioxygenase in TASc, facilitating its enzymatic activities in catalysis of tryptophan to kynurenine. Depletion of TASc-expressed  suppressed PDAC tumor growth. Furthermore, depletion of TASc using a small-molecule inhibitor effectively sensitized PDAC to immunotherapy, signifying the important roles of TASc in PDAC immune resistance.

Tumor-associated nonmyelinating Schwann cell-expressed  promotes pancreatic cancer kynurenine pathway and tumor immune exclusion.

Obesity, in which the functional importance of small nucleolar RNAs (snoRNAs) remains elusive, correlates with risk for many cancer types. Here, we identify that the serum copies of adipocyte-expressed SNORD46 correlate with body mass index (BMI), and serum SNORD46 antagonizes interleukin-15 (IL-15) signaling. Mechanically, SNORD46 binds IL-15 via G11, and G11A (a mutation that significantly enhances binding affinity) knockin drives obesity in mice. Functionally, SNORD46 blocks IL-15-induced, FER kinase-dependent phosphorylation of platelet glycoprotein 4 (CD36) and monoglyceride lipase (MGLL) in adipocytes, leading to inhibited lipolysis and browning. In natural killer (NK) cells, SNORD46 suppresses the IL-15-dependent autophagy, leading to reduced viability of obese NK. SNORD46 power inhibitors exhibit anti-obesity effects, concurring with improved viability of obese NK and anti-tumor immunity of CAR-NK cell therapy. Hence, our findings demonstrate the functional importance of snoRNAs in obesity and the utility of snoRNA power inhibitors for antagonizing obesity-associated immune resistance.

Zhao Zhang

Cullen Eye Institute

Baylor College of Medicine

Characterization of Vascular Morphology of Neovascular Age-Related Macular Degeneration by Indocyanine Green Angiography

Zhao Zhang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Cullen Eye Institute

Baylor College of Medicine

Characterization of Vascular Morphology of Neovascular Age-Related Macular Degeneration by Indocyanine Green Angiography

Cullen Eye Institute