Chinese Guideline on the Management of Polypoidal Choroidal Vasculopathy (2022).

Background In mainland China, patients with neovascular age-related macular degeneration (nAMD) have approximately an 40% prevalence of polypoidal choroidal vasculopathy (PCV). This disease leads to recurrent retinal pigment epithelium detachment (PED), extensive subretinal or vitreous hemorrhages, and severe vision loss. China has introduced various treatment modalities in the past years and gained comprehensive experience in treating PCV.Methods A total of 14 retinal specialists nationwide with expertise in PCV were empaneled to prioritize six questions and address their corresponding outcomes, regarding opinions on inactive PCV, choices of anti-vascular endothelial growth factor (anti-VEGF) monotherapy, photodynamic therapy (PDT) monotherapy or combined therapy, patients with persistent subretinal fluid (SRF) or intraretinal fluid (IRF) after loading dose anti-VEGF, and patients with massive subretinal hemorrhage. An evidence synthesis team conducted systematic reviews, which informed the recommendations that address these questions. This guideline used the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach to assess the certainty of evidence and grade the strengths of recommendations. Results The panel proposed the following six conditional recommendations regarding treatment choices. (1) For patients with inactive PCV, we suggest observation over treatment. (2) For treatment-na?ve PCV patients, we suggest either anti-VEGF monotherapy or combined anti-VEGF and PDT rather than PDT monotherapy. (3) For patients with PCV who plan to initiate combined anti-VEGF and PDT treatment, we suggest later/rescue PDT over initiate PDT. (4) For PCV patients who plan to initiate anti-VEGF monotherapy, we suggest the treat and extend (T&E) regimen rather than the pro re nata (PRN) regimen following three monthly loading doses. (5) For patients with persistent SRF or IRF on optical coherence tomography (OCT) after three monthly anti-VEGF treatments, we suggest proceeding with anti-VEGF treatment rather than observation. (6) For PCV patients with massive subretinal hemorrhage (equal to or more than four optic disc areas) involving the central macula, we suggest surgery (vitrectomy in combination with tissue-plasminogen activator (tPA) intraocular injection and gas tamponade) rather than anti-VEGF monotherapy. Conclusions Six evidence-based recommendations support optimal care for PCV patients' management.

Identification of the human mature B cell miRNome.

The full set of microRNAs (miRNAs) in the human genome is not known. Because presently known miRNAs have been identified by virtue of their abundant expression in a few cell types, many tissue-specific miRNAs remain unrevealed. To understand the role of miRNAs in B cell function and lymphomagenesis, we generated short-RNA libraries from normal human B cells at different stages of development (naive, germinal center, memory) and from a Burkitt lymphoma cell line. A combination of cloning and computational analysis identified 178 miRNAs (miRNome) expressed in normal and/or transformed B cell libraries. Most notably, the B cell miRNome included 75 miRNAs which to our knowledge have not been previously reported and of which 66 have been validated by RNA blot and/or RT-PCR analyses. Numerous miRNAs were expressed in a stage- or transformation-specific fashion in B cells, suggesting specific functional or pathologic roles. These results provide a resource for studying the role of miRNAs in B cell development, immune function, and lymphomagenesis.

microRNAs regulate cell-to-cell variability of endogenous target gene expression in developing mouse thymocytes.

The development and homeostasis of multicellular organisms relies on gene regulation within individual constituent cells. Gene regulatory circuits that increase the robustness of gene expression frequently incorporate microRNAs as post-transcriptional regulators. Computational approaches, synthetic gene circuits and observations in model organisms predict that the co-regulation of microRNAs and their target mRNAs can reduce cell-to-cell variability in the expression of target genes. However, whether microRNAs directly regulate variability of endogenous gene expression remains to be tested in mammalian cells. Here we use quantitative flow cytometry to show that microRNAs impact on cell-to-cell variability of protein expression in developing mouse thymocytes. We find two distinct mechanisms that control variation in the activation-induced expression of the microRNA target CD69. First, the expression of miR-17 and miR-20a, two members of the miR-17-92 cluster, is co-regulated with the target mRNA Cd69 to form an activation-induced incoherent feed-forward loop. Another microRNA, miR-181a, acts at least in part upstream of the target mRNA Cd69 to modulate cellular responses to activation. The ability of microRNAs to render gene expression more uniform across mammalian cell populations may be important for normal development and for disease.

mir-181a-1/b-1 Modulates Tolerance through Opposing Activities in Selection and Peripheral T Cell Function.

Understanding the consequences of tuning TCR signaling on selection, peripheral T cell function, and tolerance in the context of native TCR repertoires may provide insight into the physiological control of tolerance. In this study, we show that genetic ablation of a natural tuner of TCR signaling, mir-181a-1/b-1, in double-positive thymocytes dampened TCR and Erk signaling and increased the threshold of positive selection. Whereas mir-181a-1/b-1 deletion in mice resulted in an increase in the intrinsic reactivity of naive T cells to self-antigens, it did not cause spontaneous autoimmunity. Loss of mir-181a-1/b-1 dampened the induction of experimental autoimmune encephalomyelitis and reduced basal TCR signaling in peripheral T cells and their migration from lymph nodes to pathogenic sites. Taken together, these results demonstrate that tolerance can be modulated by microRNA gene products through the control of opposing activities in T cell selection and peripheral T cell function.

Regulation of immune responses and tolerance: the microRNA perspective.

Much has been learned about the molecular and cellular components critical for the control of immune responses and tolerance. It remains a challenge, however, to control the immune response and tolerance at the system level without causing significant toxicity to normal tissues. Recent studies suggest that microRNA (miRNA) genes, an abundant class of non-coding RNA genes that produce characteristic approximately 22 nucleotides small RNAs, play important roles in immune cells. In this article, we discuss emerging knowledge regarding the functions of miRNA genes in the immune system. We delve into the roles of miRNAs in regulating signaling strength and threshold, homeostasis, and the dynamics of the immune response and tolerance during normal and pathogenic immunological conditions. We also present observations based on analyzes of miR-181 family genes that indicate the potential functions of primary and/or precursor miRNAs in target recognition and explore the impact of these findings on target identification. Finally, we illustrate that despite the subtle effects of miRNAs on gene expression, miRNAs have the potential to influence the outcomes of normal and pathogenic immune responses by controlling the quantitative and dynamic aspects of immune responses. Tuning miRNA functions in immune cells, through gain- and loss-of-function approaches in mice, may reveal novel approach to restore immune equilibrium from pathogenic conditions, such as autoimmune disease and leukemia, without significant toxicity.

Modulating the strength and threshold of NOTCH oncogenic signals by mir-181a-1/b-1.

Oncogenes, which are essential for tumor initiation, development, and maintenance, are valuable targets for cancer therapy. However, it remains a challenge to effectively inhibit oncogene activity by targeting their downstream pathways without causing significant toxicity to normal tissues. Here we show that deletion of mir-181a-1/b-1 expression inhibits the development of Notch1 oncogene-induced T cell acute lymphoblastic leukemia (T-ALL). mir-181a-1/b-1 controls the strength and threshold of Notch activity in tumorigenesis in part by dampening multiple negative feedback regulators downstream of NOTCH and pre-T cell receptor (TCR) signaling pathways. Importantly, although Notch oncogenes utilize normal thymic progenitor cell genetic programs for tumor transformation, comparative analyses of mir-181a-1/b-1 function in normal thymocyte and tumor development demonstrate that mir-181a-1/b-1 can be specifically targeted to inhibit tumor development with little toxicity to normal development. Finally, we demonstrate that mir-181a-1/b-1, but not mir-181a-2b-2 and mir-181-c/d, controls the development of normal thymic T cells and leukemia cells. Together, these results illustrate that NOTCH oncogene activity in tumor development can be selectively inhibited by targeting the molecular networks controlled by mir-181a-1/b-1.

The potential functions of primary microRNAs in target recognition and repression.

Major RNA products of a microRNA (miRNA) gene--the long primary transcript (pri-miRNA), the ∼70-nucleotide (nt) precursor miRNA (pre-miRNA), and the ∼21-nt mature miRNA--all contain the same sequence required for target gene recognition. Thus, it is intrinsically difficult to discern the contribution of individual RNA species or to rule out a function of miRNA precursor species in target repression. Here, we describe a novel approach to dissect the functional contribution of pri-miRNA without compromising important cellular pathways. We show that pri-let-7 has a direct function in target repression in the absence of properly processed mature let-7. Moreover, we show that loop nucleotides provide regulatory controls of the activity of pri-let-7 by modulating interactions between pri-let-7 and target RNAs in vitro and in vivo. Finally, we show that human let-7a-3 pri-miRNA can directly interact with target mRNAs. These findings illustrate that the regulatory information encoded in structured pri-miRNAs may be translated into function through direct interactions with target mRNAs.

MicroRNA programs in normal and aberrant stem and progenitor cells.

Emerging evidence suggests that microRNAs (miRNAs), an abundant class of ∼22-nucleotide small regulatory RNAs, play key roles in controlling the post-transcriptional genetic programs in stem and progenitor cells. Here we systematically examined miRNA expression profiles in various adult tissue-specific stem cells and their differentiated counterparts. These analyses revealed miRNA programs that are common or unique to blood, muscle, and neural stem cell populations and miRNA signatures that mark the transitions from self-renewing and quiescent stem cells to proliferative and differentiating progenitor cells. Moreover, we identified a stem/progenitor transition miRNA (SPT-miRNA) signature that predicts the effects of genetic perturbations, such as loss of PTEN and the Rb family, AML1-ETO9a expression, and MLL-AF10 transformation, on self-renewal and proliferation potentials of mutant stem/progenitor cells. We showed that some of the SPT-miRNAs control the self-renewal of embryonic stem cells and the reconstitution potential of hematopoietic stem cells (HSCs). Finally, we demonstrated that SPT-miRNAs coordinately regulate genes that are known to play roles in controlling HSC self-renewal, such as Hoxb6 and Hoxa4. Together, these analyses reveal the miRNA programs that may control key processes in normal and aberrant stem and progenitor cells, setting the foundations for dissecting post-transcriptional regulatory networks in stem cells.

Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children.

AIM: To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure (PHOMS) in myopic children and to investigate factors associated with PHOMS. METHODS: This retrospective observational study included 101 eyes of 101 children (age ≤17y) with myopia. All included patients underwent comprehensive clinical examination. Optic nerve canal parameters, including disc diameter, optic nerve head (ONH) tilt angle, and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT). Based on the optic disc drusen consortium's definition of PHOMS, eyes were classified as PHOMS group and non-PHOMS group. PHOMS was categorized according to height. RESULTS: Sixty-seven (66.3%) eyes were found with PHOMS. Small PHOMS could only be detected by optical coherence tomography (OCT). Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT. The most frequent location of PHOMS was at the nasosuperior (91%, 61 of 67 eyes) to ONH disc. The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group (both P<0.001). ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group [8.90 (7.16-10.54) vs 3.93 (3.09-5.25), P<0.001]. Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group [29.70 (20.90-43.81) vs 45.62 (35.18-60.45), P<0.001]. In the multivariable analysis, spherical equivalent (OR=3.246, 95%CI=1.209-8.718, P=0.019) and ONH tilt angle (OR=3.275, 95%CI=1.422-7.542, P=0.005) were significantly correlated with PHOMS. There was no disc diameter associated with PHOMS. In the linear regression analysis, border tissue angle was negatively associated with PHOMS height (ß=-2.227, P<0.001). CONCLUSION: PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia. Disc diameter is not a risk factor for PHOMS. The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS.

Photoreceptor changes in Leber hereditary optic neuropathy with m.G11778A mutation.

AIM: To evaluate the functional and structural changes of photoreceptors in patients and asymptomatic carriers with Leber hereditary optic neuropathy (LHON) using full-field electroretinography (FERG) and optical coherence tomography (OCT). METHODS: Individuals diagnosed with LHON at the Renmin Hospital of Wuhan University and their family members were included in this cross-sectional observational study. The FERG a-wave amplitude of affected patients and asymptomatic carriers was analyzed. The thickness of the outer nuclear layer (ONL), inner and outer segment (IS/OS) and total photoreceptors in the macular fovea and parafovea were measured. RESULTS: This study included 14 LHON patients (mean age: 20.00±9.37y), 12 asymptomatic carriers (mean age: 39.83±6.48y), and 14 normal subjects (mean age: 24.20±1.52y). The FERG results showed that the dark-adapted 3.0 electroretinography and light-adapted 3.0 electroretinography a-wave amplitudes of patients and carriers were significantly decreased (P<0.001). The ONL and photoreceptors layers were slightly thicker in patients than in normal subjects (P<0.05), whereas they were thinner in carriers (P<0.05). There were no differences in IS/OS thickness among the groups (P>0.05). CONCLUSION: Photoreceptors function is significantly impaired in LHON-affected patients and asymptomatic carriers. Meanwhile, photoreceptors morphology is slightly altered, mainly manifesting as a change in ONL thickness.

Loop nucleotides control primary and mature miRNA function in target recognition and repression.

MicroRNA (miRNA) genes produce three major RNA products; primary (pri-), precursor (pre-), and mature miRNAs. Each product includes sequences complementary to cognate targets, thus they all can in principle interact with the targets. In a recent study we showed that pri-miRNAs play a direct role in target recognition and repression in the absence of functional mature miRNAs. Here we examined the functional contribution of pri-miRNAs in target regulation when full-length functional miRNAs are present. We found that pri-let-7 loop nucleotides control the production of the 5' end of mature miRNAs and modulate the activity of the miRNA gene. This insight enabled us to modulate biogenesis of functional mature miRNAs and dissect the causal relationships between mature miRNA biogenesis and target repression. We demonstrate that both pri- and mature miRNAs can contribute to target repression and that their contributions can be distinguished by the differences between the pri- and mature miRNAs' sensitivity to bind to the first seed nucleotide. Our results demonstrate that the regulatory information encoded in the pri-/pre-miRNA loop nucleotides controls the activities of pri-miRNAs and mature let-7 by influencing pri-miRNA and target complex formation and the fidelity of mature miRNA seed generation.

Sweep pattern visual evoked potential acuity in children during their periods of visual development.

PURPOSE: To study the clinical usage of sweep pattern visual evoked potential (SPVEP) acuity in children's visual development periods and compare the amplitude-spatial frequency (A-SP) function regression method with the amplitude-logarithm of the visual angle (A-logVA) function regression method in evaluating the SPVEP acuity of children, especially those who have poor visual acuities. METHODS: Twenty-six eyes of 26 amblyopic children (ages ranged from 3 to 12 years; mean age±standard deviation 6.69±1.74 years) and 31 eyes of normal children whose ages were matched with the amblyopic group were involved in this study. SPVEP acuity was recorded with GT-2000 NV (Guote Medical Apparatus Ltd., China) using sinusoidally modulated horizontal gratings with 10 different spatial frequencies from 0.99 to 12.89 cycles per degree to stimulate the retina. The averaging responses were displayed with the discrete Fourier transformation method. SPVEP acuity was assessed by both the A-SP function regression method and the A-logVA function regression method. The logarithm of minimal angle of resolution (logMAR) chart was used to obtain logMAR visual acuity. RESULTS: In the normal group, logMAR acuity calculated by both the A-SP and A-logVA function regression methods had a significant correlation with SPVEP acuity. The average value of SPVEP acuity (by A-logVA) was closer to logMAR acuity. The difference of mean values between logMAR acuity and SPVEP acuity was significant in both regression methods. In the amblyopic group, it was SPVEP acuity (by A-logVA) that had a significant correlation with logMAR acuity, whereas the result was not significant when calculated by the A-SP function regression method (p=0.515). The average value of SPVEP acuity (A-SP) was closer to logMAR acuity. The difference of mean values between logMAR acuity and SPVEP acuity (A-logVA) was significant; however, when compared with SPVEP acuity (A-SP), it was not significant (p=0.174). In addition, SPVEP acuity may be overestimated or underestimated when it is compared with different logMAR visual acuities. CONCLUSION: SPVEP could be used to evaluate the visual acuity for normal children or those with poor visual acuity. Moreover, the A-logVA function regression method was more accurate than the A-SP function regression method in evaluating SPVEP acuity.

Quantitative analysis of retinal vasculature in normal eyes using ultra-widefield fluorescein angiography.

AIM: To quantify the area and density of retinal vascularity by ultra-widefield fluorescein angiography (UWFA). METHODS: In a retrospective study, UWFA images were obtained using an ultra-widefield imaging device in 42 normal eyes of 42 patients. Central and peripheral steered images were used to define the edge of retinal vasculature by a certified grader. The length from the center of the optic disc to the edge of retinal vascularity (RVL) in each quadrant and the total retinal vascular perfusion area (RVPA) were determined by the grader using OptosAdvance software. The density of retinal vascularity (RVD) was quantified in different zones of central-steered images using Image J software. RESULTS: Among 42 healthy eyes, the values for mean RVL in each quadrant were 19.007±0.781 mm (superior), 18.467±0.869 mm (inferior), 17.738±0.622 mm (nasal) and 24.241±1.336 mm (temporal). The mean RVPA was 1140.117±73.825 mm2. The mean RVD of the total retina was 4.850%±0.638%. RVD varied significantly between different retina zones (P<0.001), and significant differences existed in the RVD values for total retinal area in patients over 50 years old compared to those under 50 years old (P=0.033). No gender difference was found. CONCLUSION: The UWFA device can be a promising tool for analyzing the overall retinal vasculature and may provide a better understanding of retinal vascular morphology in normal eyes. Aging may be related to lower RVD.

Integrin-alpha5 mediates epidermal growth factor-induced retinal pigment epithelial cell proliferation and migration.

Proliferation and migration of retinal pigment epithelial (RPE) cells play a crucial role in proliferative vitreoretinopathy (PVR)-related pathology. Cytokines, including EGF, can result in RPE cell activation and cause PVR. In this study, integrin-alpha(5) expression was first studied in PVR membranes by immunofluorescence. Then the effect of EGF on integrin-alpha(5) expression was determined by flow cytometry, Western blot analysis and the reverse-transcription polymerase chain reaction (RT-PCR) in the ARPE-19 cell line. Proliferation and migration of ARPE-19 cells were measured by the methylthiazolyldiphenyl-tetrazolium bromide and Boyden chamber assays. We found that a higher level integrin-alpha(5) was present at the RPE cell surface in PVR compared with normal retina. EGF could dose dependently increase integrin-alpha(5) mRNA and protein levels in vitro. EGF promoted ARPE-19 cell proliferation and migration. Neutralizing integrin-alpha(5) by specific anti-integrin-alpha(5) antibody abolished most of the effects of EGF. The study provided evidence that EGF might influence PVR by promoting integrin-alpha(5) expression and subsequent proliferation and migration of RPE.

Prevalence and correlates of depressive symptoms among Chinese patients with cataracts treated in tertiary general hospitals.

BACKGROUND: Previous studies recruited unrepresentative samples of Chinese patients with cataract and reported a wide range of prevalence of depressive symptoms in this patient population (18.0-89.7%). The present study determined the prevalence and correlates of depressive symptoms among a consecutive sample of Chinese patients with cataract treated in tertiary general hospitals. METHODS: A total of 339 patients with cataract were consecutively selected from ophthalmology departments of two large general hospitals in Wuhan, China. Depressive symptoms were assessed with the Chinese Hospital Anxiety and Depression Scale. Logistic regression was used to identify factors that were associated with depression. RESULTS: The prevalence of depressive symptoms was 23.9% (95% CI [19.4-28.4]%) among patients with cataract. Correlates for depressive symptoms include an education level of primary school and below (OR = 1.93, P = 0.038), marital status of "others" (OR =3.15, P < 0.001), poor family economic status (OR = 2.26, P = 0.010), nuclear cataract (OR =4.32, P < 0.001), and mixed cataract (OR = 2.76, P = 0.017). CONCLUSIONS: Depressive symptoms are common among Chinese patients with cataract treated in large general hospitals. Patients who are poorly educated, have a marital status other than "married", have poor family economic status, and suffer from nuclear and mixed cataracts are at greater risk for depressive symptoms.

The Mir181ab1 cluster promotes KRAS-driven oncogenesis and progression in lung and pancreas.

Few therapies are currently available for patients with KRAS-driven cancers, highlighting the need to identify new molecular targets that modulate central downstream effector pathways. Here we found that the microRNA (miRNA) cluster including miR181ab1 is a key modulator of KRAS-driven oncogenesis. Ablation of Mir181ab1 in genetically engineered mouse models of Kras-driven lung and pancreatic cancer was deleterious to tumor initiation and progression. Expression of both resident miRNAs in the Mir181ab1 cluster, miR181a1 and miR181b1, was necessary to rescue the Mir181ab1-loss phenotype, underscoring their nonredundant role. In human cancer cells, depletion of miR181ab1 impaired proliferation and 3D growth, whereas overexpression provided a proliferative advantage. Lastly, we unveiled miR181ab1-regulated genes responsible for this phenotype. These studies identified what we believe to be a previously unknown role for miR181ab1 as a potential therapeutic target in 2 highly aggressive and difficult to treat KRAS-mutated cancers.

[Evaluation of visual function after congenital cataract extraction].

OBJECTIVE: To evaluate visual development after extraction of congenital cataract in young patients. METHODS: This was a retrospective clinical study. Forty one congenital cataract patients (62 eyes) at 0-3 years old were divided into 4 groups: <0.5 year old, > or =0.5 and <1 year old, > or =1 and <2 years old and > or =2 years old. Capsulectomy and cataract aspiration combined with anterior vitrectomy were performed in all cases. After the operation, patients were treated with optical correction by spectacles and visual training with occlusion therapy. Flash visual evoked potential (F-VEP)was examined by using Mini stimulator 3 days and 12 weeks after surgery. VISTON visual plasticity system was used to assess visual acuity 1 week and 12 weeks after surgery. RESULTS: VEP examination revealed that P100 latent time was reduced by visual training 3 months after surgery as compared with that of 3 days after surgery. Both P100 amplitude and visual acuity were increased. The younger patients obtained the better improvement. The group for lower than 0. 5 year old recovered best. CONCLUSION: Congenital cataract patients should be operated as early as possible and wear suitable spectacles for optical correction and undertake visual training after surgery, these procedures play a significant role for visual development and improvement in these patients.

Dissecting microRNA-mediated gene regulation and function in T-cell development.

MicroRNAs (miRNAs) are abundant approximately 22-nucleotide regulatory RNAs encoded in animal genomes. They are thought to exhibit diverse biological functions in animals by targeting messenger RNAs (mRNAs) for degradation or translational repression. Here we use T-cell development as a model to illustrate methods and strategies for dissecting the post transcriptional gene regulatory networks controlled by miRNAs and their roles in the differentiation of T-cell precursors. The process involves the identification of miRNA genes in rare T-cell progenitors, determining miRNA expression during T-cell development, characterizing miRNA function in T-cell development using an in vitro assay, and identifying functionally relevant gene(s) regulated by miRNAs.

Inhibition of cell proliferation, migration and apoptosis in blue-light illuminated human retinal pigment epithelium cells by down-regulation of HtrA1.

AIM: To investigate the effect of HtrA1 on the proliferation, migration and apoptosis of human retinal pigment epithelium (RPE) cells in the light injured model, as well as the expression of the apoptosis related molecules. METHODS: The human RPE cell line ARPE-19 was exposed to blue light to establish the light injured model. The cells were transfected with HtrA1 siRNA to knockdown HtrA1 expression. Subsequent expression of HtrA1 was determined by real-time polymerase chain reaction (RT-PCR) and Western blot, respectively. Changes in cell proliferation, migration and apoptosis were assessed by cell counting kit-8 (CCK-8), Transwell assay and flow cytometry respectively, as well as changes in the mRNA and protein levels of Bax, Caspase-3 and Bcl-2 expression. RESULTS: HtrA1 was highly expressed in ARPE-19 cells after blue light irradiation. Knockdown of HtrA1 expression inhibited the proliferation, migration and apoptosis of the blue-light-irradiated ARPE-19 cells (P<0.05). Bax and Caspase-3 expression were significantly reduced both at mRNA and protein levels (P<0.05) after siRNA treatment. Bcl-2 expression significantly increased in blue-light-irradiated ARPE-19 cells after siRNA interference (P<0.05). CONCLUSION: Silence of HtrA1 may inhibit the proliferation, migration and apoptosis of ARPE-19 cells in light injured model. Moreover, HtrA1 suppression in blue-light-irradiated ARPE-19 cells may ameliorate cell apoptosis through down-regulation of Bax and Caspase-3, and up-regulation of Bcl-2 expression.

Methods for analyzing microRNA expression and function during hematopoietic lineage differentiation.

MicroRNAs (miRNAs), an abundant class of approx 22-nucleotide (nt) small RNAs that control gene expression at the posttranscriptional level, may play important roles during normal hematopoiesis and leukemogenesis. This chapter focuses on the methods and strategies for dissecting miRNA function during hematopoietic lineage differentiation. We describe a modified miRNA cloning method and expression analysis approach for determining miRNA expression during hematopoietic lineage differentiation. We illustrate a retroviral vector and a general strategy for the ectopic expression of miRNAs in hemato-poietic stem/progenitor cells. We discuss in vitro and in vivo functional assays that can be used to examine the roles of miRNAs during hematopoietic lineage differentiation. The methods and principles described here should also be applicable to study the roles of miRNAs in the differentiation and function of nonhematopoietic cell types.