Phylotranscriptomics of Swertiinae (Gentianaceae) reveals that key floral traits are not phylogenetically correlated.

Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth. Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups. The subtribe Swertiinae (Gentianaceae) comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries. Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu, representing the range of floral diversity, using data from the nuclear and plastid genomes. Extensive topological conflicts were present between the nuclear and plastome trees. Three of the 15 genera represented by multiple species are polyphyletic in both trees. Key floral traits including corolla type, absence or presence of lobe scales, nectary type, nectary position, and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation. We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits. These results highlight the complex evolutionary history of this subtribe. The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.

Intergeneric Relationships within the Family Salicaceae s.l. based on Plastid Phylogenomics.

Many Salicaceae s.l. plants are recognized for their important role in the production of products such as wood, oils, and medicines, and as a model organism in life studies. However, the difference in plastid sequence, phylogenetic relationships, and lineage diversification of the family Salicaceae s.l. remain poorly understood. In this study, we compare 24 species representing 18 genera of the family. Simple sequence repeats (SSRs) are considered effective molecular markers for plant species identification and population genetics. Among them, a total of 1798 SSRs were identified, among which mononucleotide repeat was the most common with 1455 accounts representing 80.92% of the total. Most of the SSRs are located in the non-coding region. We also identified five other types of repeats, including 1750 tandems, 434 forward, 407 palindromic, 86 reverse, and 30 complementary repeats. The species in Salicaceae s.l. have a conserved plastid genome. Each plastome presented a typical quadripartite structure and varied in size due to the expansion and contraction of the inverted repeat (IR) boundary, lacking major structural variations, but we identified six divergence hotspot regions. We obtained phylogenetic relationships of 18 genera in Salicaceae s.l. and the 24 species formed a highly supported lineage. Casearia was identified as the basal clade. The divergence time between Salicaceae s.l. and the outgroup was estimated as ~93 Mya; Salix, and Populus diverged around 34 Mya, consistent with the previously reported time. Our research will contribute to a better understanding of the phylogenetic relationships among the members of the Salicaceae s.l.

PCBP2 Modulates Neural Apoptosis and Astrocyte Proliferation After Spinal Cord Injury.

PCBP2, a member of the poly(C)-binding protein (PCBP) family, plays a pivotal role in posttranscriptional and translational regulation by interacting with single-stranded poly(C) motifs in target mRNAs. It is reported that several PCBP family members are involved in human malignancies. However, the distribution and function of PCBP2 in the central nervous system (CNS) remain unclear. In this study, we performed an acute spinal cord injury (SCI) model in adult rats and investigated the dynamic changes of PCBP2 expression in the spinal cord. Western blot and immunohistochemistry analysis revealed that PCBP2 presented in normal spinal cord. It gradually increased, reached a peak at 3 day, and then declined to basal levels at 14 days after SCI. We observed that the expression of PCBP2 was enhanced in the gray and white matter. Immunofluorescence indicated that PCBP2 was located in the neurons and astrocytes. Moreover, colocalization of PCBP2/active caspase-3 was detected in neurons, and colocalization of PCBP2/proliferating cell nuclear antigen was detected in astrocytes after SCI. These results indicated that PCBP2 might play an important role in neuronal apoptosis and astrocyte proliferation. In vitro, PCBP2-specific siRNA-transfected neuron showed significantly decrease of neuronal apoptosis and expression of cell cycle related proteins following glutamate stimulation. Meanwhile, PCBP2 knockdown also reduced primary astrocytes proliferation. All above indicated that PCBP2 might play a crucial role in cell proliferation and apoptosis. Collectively, our data suggested that PCBP2 might play important roles in CNS pathophysiology after SCI.

O-GlcNAc glycosylation of p27(kip1) promotes astrocyte migration and functional recovery after spinal cord contusion.

Glial scar formation derived from astrocyte proliferation and migration influences the functional recovery after spinal cord injury. Cyclin-dependent kinase inhibitor p27(kip1), whose activity is closely related to its phosphorylation state, reportedly regulates astrocyte proliferation and migration. In this study, we reported that p27(Kip1) undergoes O-GlcNAc modification at Ser 2, Ser 110 and Thr 197. Inhibiting O-GlcNAcylation on Ser 2 by gene mutation (S2A) attenuated the phosphorylation of Ser 10, and vice versa. Interestingly, compared with wild type p27(Kip1), S2A p27(Kip1) displayed a decreased interaction with CRM1 and reduced nuclear export following serum starvation and release. In addition, the interaction between stathmin and S2A p27(Kip1) was also decreased. Cytoskeletal proteins microtubules appeared high density in astrocytes transfected with S2A p27(Kip1) especially at the leading edge of the scratch wound. Accordingly, scratch-wound assay revealed that the motility of astrocytes transfected with S2A p27(Kip1) was faster than that of control. Finally, we injected lentiviral vectors immediately after spinal cord contusion, and found the lesion volume of the rat injected with S2A p27(Kip1) was smaller than that of rat injected with wild type p27(Kip1). Besides, the BBB and CBS behavioral tests showed greater functional recovery in S2A p27(Kip1) treated rats. Taken together, our findings revealed a novel function of O-GlcNAc modification of p27(Kip1) in mediating astrocytes migration and functional recovery after spinal cord contusion.

Spatiotemporal Expression of EAPP Modulates Neuronal Apoptosis and Reactive Astrogliosis After Spinal Cord Injury.

E2F-associated phosphoprotein (EAPP) is a novel E2F binding protein that interacts with the activating members of the E2F transcription factors family and involved in various biological processes. However, the expression and function of EAPP in central nervous system (CNS) are still unknown. In this study, we performed an acute spinal cord injury (SCI) model in adult rats, we found that EAPP protein levels were significantly increased and reached a peak at day 3, and then gradually returned to normal level at day 14 after spinal cord injury and we observed that the expression of EAPP is enhanced in the gray and white matter. Spatially, increased levels of EAPP were striking in neurons and astrocytes. Moreover, colocalization of EAPP/active caspase-3 was detected in neurons, and colocalization of EAPP/proliferating cell nuclear antigen (PCNA) was detected in astrocytes after spinal cord injury. These results indicated that EAPP might play an important role in neuronal apoptosis and reactive astrogliosis. Furthermore in vitro, EAPP depletion by siRNA inhibited astrocyte proliferation, migration and CDK4/cyclinD1 expression. Meanwhile, EAPP knockdown also reduce neuronal apoptosis and cell cycle related proteins. Which indicated that EAPP might integrate cell cycle progression and play a crucial role in cell proliferation and apoptosis. Taken together, we speculated that EAPP was involved in biochemical and physiological responses after SCI.

Up-Regulation of CCT8 Related to Neuronal Apoptosis after Traumatic Brain Injury in Adult Rats.

Traumatic brain injury (TBI) initiates a series of neurochemical and signaling changes that could eventually lead to neuronal apoptosis. Recent studies indicated that mature neurons cell cycle re-enter played a crucial role in neuronal apoptosis. In this study, we identified that the chaperonin containing TCP-1, subunit 8 (CCT8), as a member of class II chaperonins, was significantly upregulated following TBI. Moreover, double immunofluorescence staining revealed that CCT8 was co-expressed with neuronal nuclei (NeuN). Besides, co-localization of CCT8/active caspase 3 was detected in NeuN. We also examined the expression profiles of active caspase 3 whose changes were correlated with the expression of CCT8. All our findings suggested that CCT8 might be involved in the pathophysiology of brain after TBI.

Up-regulation of HDAC4 is associated with Schwann cell proliferation after sciatic nerve crush.

Histone deacetylase 4 (HDAC4), a member of the class IIa HDACs subfamily, has emerged as a critical regulator of cell growth, differentiation, and migration in various cell types. It was reported that HDAC4 stimulated colon cell proliferation via repression of p21. Also, HDAC4 contributes to platelet-derived growth factor-BB-induced proliferation and migration of vascular smooth muscle cells. Furthermore, HDAC4 may play an important role in the regulation of neuronal differentiation and survival. However, the role of HDAC4 in the process of peripheral nervous system regeneration after injury remains virtually unknown. Herein, we investigated the spatiotemporal expression of HDAC4 in a rat sciatic nerve crush model. We found that sciatic nerve crush induced up-regulated expression of HDAC4 in Schwann cells. Moreover, the expression of the proliferation marker Ki-67 exhibited a similar tendency with that of HDAC4. In cell cultures, we observed increased expression of HDAC4 during the process of TNF-α-induced Schwann cell proliferation, whereas the protein level of p21 was down-regulated. Interference of HDAC4 led to enhanced expression of p21 and impaired proliferation of Schwan cells. Taken together, our findings implicated that HDAC4 was up-regulated in the sciatic nerve after crush, which was associated with proliferation of Schwann cells.

IGF2BP2 regulates the inflammation of fibroblast-like synoviocytes via GSTM5 in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease with an unknown etiology. RA cannot be fully cured and requires lengthy treatment, imposing a significant burden on both individuals and society. Due to the lack of specific drugs available for treating RA, exploring a key new therapeutic target for RA is currently an important task. Activated fibroblast-like synoviocytes (FLSs) play a crucial role in the progression of RA, which release interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α resulting in abnormal inflammatory reaction in the synovium. A previous study has highlighted the correlation of m6A reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) with inflammation-related diseases in human. However, the role of IGF2BP2 in the inflammatory reaction of FLSs during RA progression has not been assessed. In this study, IGF2BP2 expression was decreased in the synovial tissues of RA patients and collagen-induced arthritis (CIA) rats. Intra-articular injection of an adeno-associated virus (AAV) vector overexpressing IGF2BP2 relieved paw swelling, synovial hyperplasia and cartilage destruction in CIA rats. IGF2BP2 overexpression also inhibited lipopolysaccharide (LPS)-mediated RA fibroblast-like synoviocytes (RA-FLSs) migration and invasion accompanied by a decreased level of inflammatory factors in vitro. Conversely, IGF2BP2 suppression promoted RA-FLSs migration and invasion with an elevated level of inflammatory factors in vitro. The sequencing result showed that glutathione S-transferase Mu 5 (GSTM5), a key antioxidant gene, was the target mRNA of IGF2BP2. Further experiments demonstrated that IGF2BP2 strengthened the stability of GSTM5 mRNA, leading to weakened inflammatory reaction and reduced expression of matrix metalloproteinase 9 and 13 (MMP9, MMP13). Therefore, IGF2BP2-GSTM5 axis may represent a potential therapeutic target for RA treatment.

Acute primary angle closure during the Omicron outbreak.

AIM: To investigate Omicron's impact on clinical presentation of acute primary angle closure (APAC) in China. METHODS: A consecutive case series with historical controls was conducted at Shenzhen Eye Hospital, the largest specialized hospital in Shenzhen, China. Medical records from a two-month period during the Omicron pandemic (December 1, 2022, to January 31, 2023) were compared with records from two control groups (12/2018-1/2019 and 12/2021-1/2022) before pandemic. Patients with APAC were included, and the prevalence of APAC and demographic characteristics in Omicron-infected and non-infected patients were compared. RESULTS: Seventy-one (23.43%) out of 303 patients were diagnosed with APAC in the pandemic cohort, which was 2.98 and 2.61 times higher than that in control cohorts (7.87% in 2019, 8.96% in 2022, P<0.001). The pandemic cohort has significantly higher Omicron-infected rate (78.87% vs 0 vs 0; P<0.001), lower proportion of glaucoma history (16.90% vs 42.86% vs 41.67%, P=0.005), higher surgical rate (95.77% vs 83.33% vs 78.57%, P=0.024), higher total medical costs and larger pupil diameter (5.63±0.15 vs 4.68±0.15 vs 4.69±0.22 mm, P<0.01). In 83% Omicron-infected patients, ocular symptoms appeared within 3d after systemic symptoms onset. In multivariate analysis, Omicron infection (P<0.001) was the only independent predictor of pupil diameter. CONCLUSION: In the Omicron epidemic in China, there is an increase of prevalence and severity of APAC, particularly focusing on the first 3d following infection.

SMAD2 inhibits pyroptosis of fibroblast-like synoviocytes and secretion of inflammatory factors via the TGF-ß pathway in rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease. Over-activation of fibroblast-like synoviocytes is responsible for the hyperplasia of synovium and destruction of cartilage and bone and pyroptosis of FLS plays a key role in those pathological processes during RA. This study investigated the detailed mechanisms that SMAD2 regulates the pyroptosis of FLS and secretion of inflammatory factors in rheumatoid arthritis. METHODS: We collected synovial tissues of RA patients and FLS-RA and cultured FLS for detection of expression of SMAD2. ASC, NLRP3, cleaved-caspase-1, and GSDMD-N were detected by Western blot after overexpression of SMAD2. Besides, flow cytometry, electron microscope, ELISA, HE staining, and Safranin O staining were performed to further demonstrate that SMAD2 can affect the pyroptosis of FLS-RA. RESULTS: The expression of SMAD2 was down-regulated in synovial tissues of RA patients and FLS-RA. Overexpression of SMAD2 can inhibit the expression of ASC, NLRP3, cleaved-caspase-1, and GSDMD-N. Flow cytometry and electron microscope further demonstrated that SMAD2 attenuated pyroptosis of FLS-RA. In addition, overexpression of SMAD2 also inhibited inflammatory factors such as IL-1ß, IL-18, IL-6, and IL-8 secretion and release of LDH. Besides, overexpression of SMAD2 can reverse the decrease of p-SMAD2 and TGF-TGF-ß induced by nigericin. In vivo experiments on CIA rats further demonstrated that overexpression of SMAD2 by local intra-articular injection of LV-SMAD2 can effectively alleviate joint redness, swelling, and destruction of cartilage and bones. CONCLUSION: SMAD2 inhibited FLS-RA pyroptosis by down-regulating of NLRP3 inflammasomes (NLRP3, ASC, and caspase-1 complex) and eased the secretion of inflammatory factors via the TGF-ß signaling pathway, thereby improving the symptom of RA. We hope that this study may provide a new research idea for RA and a potential target for the treatment of RA.

Inhibition of Cdc37 Ameliorates Arthritis in Collagen-Induced Arthritis Rats by Inhibiting Synoviocyte Proliferation and Migration Through the ERK Pathway.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to synovial inflammation, pannus formation, cartilage damage, bone destruction, and ultimate disability. Fibroblast-like synoviocytes (FLS) are involved in the pathogenetic mechanism of RA. Cdc37 (cell division cycle protein 37) is regarded as a molecular chaperone involved in various physiological processes such as cell cycle progression, cell proliferation, cell signal transduction, tumorigenesis, and progression. However, the precise role of Cdc37 in the pathogenesis of rheumatoid arthritis (RA) remains uncertain. In our study, we found that Cdc37 expression was upregulated in human rheumatoid synovia in contrast with the normal group. Interestingly, Cdc37 activated the ERK pathway to promote RA-FLS proliferation and migration in vitro. Ultimately, in vivo experiments revealed that silencing of Cdc37 alleviated ankle swelling and cartilage destruction and validated the ERK signaling pathways in vitro findings. Collectively, we demonstrate that Cdc37 promotes the proliferation and migration of RA-FLS by activation of ERK signaling pathways and finally aggravates the progression of RA. These data indicated that Cdc37 may be a novel target for the treatment of RA.

Surgical Outcomes of Myopic Foveoschisis According to the ATN Classification System.

INTRODUCTION: This study compared the surgical outcomes in eyes with myopic foveoschisis (MF) according to the recently developed ATN classification system. METHODS: This was an observational case series of 64 consecutive eyes that underwent vitrectomy for MF. Eyes were classified into severe myopic maculopathy (MM) (n = 43) and non-severe MM (n = 21) groups according to the ATN classification system. The primary outcome measures constituted best-corrected visual acuity (BCVA) and anatomical changes. RESULTS: In total, BCVA improved from 0.97 to 0.53 (P < 0.001) after surgery. The ATN score was significantly lower in the eyes with vision improvement than those without vision improvement (P < 0.001). In the subgroup, BCVA improved from 0.79 to 0.28 in the non-severe MM group (P < 0.001), and improved from 1.05 to 0.65 in the severe MM group (P = 0.001) after surgery. The non-severe MM group achieved better postoperative BCVA (P = 0.001) and were more likely to gain vision improvement (P < 0.001) after surgery compared with the severe MM group. Anatomical success was achieved in 62 of the 64 eyes (96.88%). Two eyes with anatomical failure developed full-thickness macular holes postoperatively; both were in the severe MM group. CONCLUSIONS: For patients with MF, different severity of MM based on ATN classification could lead to a significantly different prognosis after surgery. For patients with high ATN scores, the operative decision should be made cautiously for the worse anatomical and visual prognosis. ATN system is instructive in making operative proposals for MF.

On the basis of the newly developed ATN classification system, we found significant differences in postoperative visual acuity, the rate of vision improvement, and the rate of primary retinal reattachment after vitrectomy between the severe and non-severe myopic maculopathy groups in patients with myopic foveoschisis.

Genome Editing of Pik3cd Impedes Abnormal Retinal Angiogenesis.

Abnormal angiogenesis is associated with myriad human diseases, including proliferative diabetic retinopathy (PDR). Signaling transduction through phosphoinositide 3-kinases (PI3Ks) plays a critical role in angiogenesis. Herein, we showed that p110δ, the catalytic subunit of PI3Kδ, was highly expressed in pathological retinal vascular endothelial cells (ECs) in a mouse model of oxygen-induced retinopathy (OIR) and in fibrovascular membranes from patients with PDR. To explore novel intervention with PI3Kδ expression, we developed a recombinant dual adeno-associated viral (rAAV) system for delivering CRISPR/Cas9 in which Streptococcus pyogenes (Sp) Cas9 expression was driven by an endothelial specific promoter of the intercellular adhesion molecule 2 (pICAM2) to edit genomic Pik3cd, the gene encoding p110δ. We then demonstrated that infection of cultured mouse vascular ECs with the dual rAAV1s of rAAV1-pICAM2-SpCas9 and rAAV1-SpGuide targeting genomic Pik3cd resulted in 80% DNA insertion/deletion in the locus of genomic Pik3cd and 70% depletion of p110δ expression. Furthermore, we showed that in the mouse model of OIR editing retinal Pik3cd with the dual rAAV1s resulted in not only a significant decrease in p110δ expression, and Akt activation, but also a dramatic reduction in pathological retinal angiogenesis. These findings reveal that Pik3cd editing is a novel approach to treating abnormal retinal angiogenesis.

4-Iodo-6-phenylpyrimidine (4-IPP) suppresses fibroblast-like synoviocyte- mediated inflammation and joint destruction associated with rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic immune-mediated inflammatory disease that significantly impacts patients' quality of life. Fibroblast-like synovial cells (FLSs) within the synovial intima exhibit "tumor-like" properties such as increased proliferation, migration, and invasion. Activation of FLSs and secretion of pro-inflammation factors result in pannus formation and cartilage destruction. As an inhibitor of the cytokine, macrophage migration inhibitory factor (MIF), 4-Iodo-6-phenylpyrimidine (4-IPP) has been shown to reduce cell proliferation, migration, invasion, and the secretion of pro-inflammatory mediators in a variety of diseases. However, the usefulness of 4-IPP for RA treatment has not been assessed and was the purpose of this study. In vitro, 4-IPP was demonstrated to inhibit proliferation, migration, and invasion of RA FLSs, as well as the expression of pro-inflammatory cytokines. 4-IPP was also shown to inhibit MIF-induced phosphorylation of ERK, JNK, and p38, as well as reduce expression of COX2 and PGE2. In order to efficiently deliver 4-IPP to anatomical RA sites, we developed lactic-co-glycolic acid (PLGA) nanospheres, which not only protected 4-IPP from degradation but also controlled the release of 4-IPP. 4-IPP/PLGA nanospheres had potent anti-inflammatory activity and a high degree of biosafety. Results showed that local 4-IPP concentration was increased by nanosphere delivery, effectively reducing the inflammatory microenvironment as well as synovial inflammation, joint swelling, and cartilage destruction in a collagen-induced rheumatoid arthritis (CIA) rat model. Therefore, 4-IPP nanospheres are a sustained-release delivery system that may be an effective therapeutic strategy for RA treatment.

Towards precision medicine based on a continuous deep learning optimization and ensemble approach.

We developed a continuous learning system (CLS) based on deep learning and optimization and ensemble approach, and conducted a retrospective data simulated prospective study using ultrasound images of breast masses for precise diagnoses. We extracted 629 breast masses and 2235 images from 561 cases in the institution to train the model in six stages to diagnose benign and malignant tumors, pathological types, and diseases. We randomly selected 180 out of 3098 cases from two external institutions. The CLS was tested with seven independent datasets and compared with 21 physicians, and the system's diagnostic ability exceeded 20 physicians by training stage six. The optimal integrated method we developed is expected accurately diagnose breast masses. This method can also be extended to the intelligent diagnosis of masses in other organs. Overall, our findings have potential value in further promoting the application of AI diagnosis in precision medicine.

Complete chloroplast genome of Lamiophlomis rotata: comparative genome analysis and phylogenetic analysis.

Lamiophlomis rotata, the only species within the genus Lamiophlomis (family Labiatae), exhibits a broad geographical distribution in elevated highland areas in Qinghai-Tibetan Plateau and possesses significant therapeutic properties. Numerous chemical compositions and putative phylogenetic affiliations of this species have been documented in prior research. Nevertheless, there is a scarcity of accessible publications regarding the genomic data of L. rotata, particularly its chloroplast genome. This dearth of knowledge hampers the comprehensive investigation of its phylogenetic placement within the Labiatae family. In this study, we present a comprehensive analysis of the plastid genome of L. rotata. The plastid genome has a length of 151,837 base pairs (bp) and a GC content of 38.5%. Within this genome, a total of 135 genes were identified, including 90 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. By employing phylogenetic analysis, the taxonomic position of L. rotata within the family Labiatae is elucidated, highlighting a close relationship between the genus Lamiophlomis and the genus Phlomis. Notably, extensive genetic variations were uncovered between L. rotata and other Phlomis species. This study could provide significant insights for understanding the phylogenetic relationships of taxa within Labiatae.

Research on the function of the Cend1 regulatory mechanism on p75NTR signaling in spinal cord injury.

How to use NSC repair mechanisms, minimize the loss of neurons, and recover the damaged spinal cord functions are hotspots and difficulties in spinal cord injury research. Studies have shown that Cend1 signaling is involved in regulating the NSC differentiation, that p75NTR signaling is involved in the regulation of mature neuronal apoptosis and that NSC differentiation decreases mature neuron apoptosis. Our research group found an interaction between Cend1 and p75NTR, and there was a correlation with spinal cord injury. Therefore, we speculate that Cend1 regulates p75NTR signals and promotes the differentiation of NSCs, and inhibits neuronal apoptosis. Therefore, this study first analyzed the expression of p75NTR and Cend1 in spinal cord injury and its relationship with NSCs and neurons and then analyzed the regulatory mechanism and the mechanism of survival on neuronal apoptosis and differentiation of NSCs. Finally, we analyzed the effect of p75NTR and the regulation of Cend1 damage on functional recovery of the spinal cord with overall intervention. The completion of the subject will minimize the loss of neurons, innovative use of NSC repair mechanisms, and open up a new perspective for the treatment of spinal cord injury.

A Novel Role of IL13Rα2 in the Pathogenesis of Proliferative Vitreoretinopathy.

Proliferative vitreoretinopathy (PVR), an inflammatory and fibrotic blinding disease, is still a therapeutic challenge. Retinal pigment epithelial (RPE) cells dislodged in the vitreous play a central role in the PVR pathogenesis. To identify potential novel contributors to the pathogenesis of PVR, we investigated a profile of vitreous-induced changes in ARPE-19 cells by RNA sequencing. Bioinformatics analysis of the sequencing data showed that there were 258 genes up-regulated and 835 genes down-regulated in the ARPE-19 cells treated with human vitreous. Among these genes, there were three genes related to eye disease with more than threefold changes. In particular, quantitative PCR and western blot results showed that interleukin 13 receptor (IL13R)α2 that is over-expressed in a variety of cancers was up-regulated more than three times in the vitreous-treated ARPE-19 cells. Immunofluorescence analysis indicated that interleukin-13 receptor subunit α2 (IL13Rα2) was highly expressed in ARPE-19 cells within epiretinal membranes from patients with PVR. Importantly, blocking IL13Rα2 with its neutralizing antibody significantly inhibited vitreous-induced contraction of ARPE-19 cells, suggesting a novel role of IL13Rα2 in the PVR pathogenesis. These findings will improve our understanding of the molecular mechanisms by which PVR develops and provides potential targets for PVR therapeutics.

Molecular signatures of parallel adaptive divergence causing reproductive isolation and speciation across two genera.

Parallel evolution of reproductive isolation (PERI) provides strong evidence for natural selection playing a fundamental role in the origin of species. However, PERI has been rarely demonstrated for well established species drawn from different genera. In particular, parallel molecular signatures for the same genes in response to similar habitat divergence in such different lineages is lacking. Here, based on whole-genome sequencing data, we first explore the speciation process in two sister species of Carpinus (Betulaceae) in response to divergence for temperature and soil-iron concentration in habitats they occupy in northern and southwestern China, respectively. We then determine whether parallel molecular mutations occur during speciation in this pair of species and also in another sister-species pair of the related genus, Ostryopsis, which occupy similarly divergent habitats in China. We show that gene flow occurred during the origin of both pairs of sister species since approximately 9.8 or approximately 2 million years ago, implying strong natural selection during divergence. Also, in both species pairs we detected concurrent positive selection in a gene (LHY) for flowering time and in two paralogous genes (FRO4 and FRO7) of a gene family known to be important for iron tolerance. These changes were in addition to changes in other major genes related to these two traits. The different alleles of these particular candidate genes possessed by the sister species of Carpinus were functionally tested and indicated likely to alter flowering time and iron tolerance as previously demonstrated in the pair of Ostryopsis sister species. Allelic changes in these genes may have effectively resulted in high levels of prezygotic reproductive isolation to evolve between sister species of each pair. Our results show that PERI can occur in different genera at different timescales and involve similar signatures of molecular evolution at genes or paralogues of the same gene family, causing reproductive isolation as a consequence of adaptation to similarly divergent habitats.

Pervasive hybridization during evolutionary radiation of Rhododendron subgenus Hymenanthes in mountains of southwest China.

Radiations are especially important for generating species biodiversity in mountainous ecosystems. The contribution of hybridization to such radiations has rarely been examined. Here, we use extensive genomic data to test whether hybridization was involved in evolutionary radiation within Rhododendron subgenus Hymenanthes, whose members show strong geographic isolation in the mountains of southwest China. We sequenced genomes for 143 species of this subgenus and 93 species of four other subgenera, and found that Hymenanthes was monophyletic and radiated during the late Oligocene to middle Miocene. Widespread hybridization events were inferred within and between the identified clades and subclades. This suggests that hybridization occurred both early and late during diversification of subgenus Hymenanthes, although the extent to which hybridization, speciation through mixing-isolation-mixing or hybrid speciation, accelerated the diversification needs further exploration. Cycles of isolation and contact in such and other montane ecosystems may have together promoted species radiation through hybridization between diverging populations and species. Similar radiation processes may apply to other montane floras in this region and elsewhere.