CRISPRi-Mediated Treatment of Dominant Rhodopsin-Associated Retinitis Pigmentosa

Rhodopsin (RHO) mutations such as Pro23His are the leading cause of dominantly inherited retinitis pigmentosa in North America. As with other dominant retinal dystrophies, these mutations lead to production of a toxic protein product, and treatment will require knockdown of the mutant allele. The purpose of this study was to develop a CRISPR-Cas9-mediated transcriptional repression strategy using catalytically inactive Staphylococcus aureus Cas9 (dCas9) fused to the Krüppel-associated box (KRAB) transcriptional repressor domain. Using a reporter construct carrying green fluorescent protein (GFP) cloned downstream of the RHO promoter fragment (nucleotides -1403 to +73), we demonstrate a ∼74-84% reduction in RHO promoter activity in RHOpCRISPRi-treated versus plasmid-only controls. After subretinal transduction of human retinal explants and transgenic Pro23His mutant pigs, significant knockdown of rhodopsin protein was achieved. Suppression of mutant transgene in vivo was associated with a reduction in endoplasmic reticulum (ER) stress and apoptosis markers and preservation of photoreceptor cell layer thickness.

Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

High species diversity in Diaporthe associated with citrus diseases in China

Species in Diaporthe have broad host ranges and cosmopolitan geographic distributions, occurring as endophytes, saprobes and plant pathogens. Previous studies have indicated that many Diaporthe species are associated with Citrus. To further determine the diversity of Diaporthe species associated with citrus diseases in China, we conducted extensive surveys in major citrus-producing areas from 2017-2020. Diseased tissues were collected from leaves, fruits, twigs, branches and trunks showing a range of symptoms including melanose, dieback, gummosis, wood decay and canker. Based on phylogenetic comparisons of DNA sequences of the internal transcribed spacer regions (ITS), calmodulin (cal), histone H3 (his3), translation elongation factor 1-alpha (tef1) and beta-tubulin (tub2), 393 isolates from 10 provinces were identified as belonging to 36 species of Diaporthe, including 32 known species, namely D. apiculata, D. biconispora, D. biguttulata, D. caryae, D. citri, D. citriasiana, D. compacta, D. discoidispora, D. endophytica, D. eres, D. fusicola, D. fulvicolor, D. guangxiensis, D. hongkongensis, D. hubeiensis, D. limonicola, D. litchii, D. novem, D. passifloricola, D. penetriteum, D. pescicola, D. pometiae, D. sackstonii, D. sennicola, D. sojae, D. spinosa, D. subclavata, D. tectonae, D. tibetensis, D. unshiuensis, D. velutina and D. xishuangbanica, and four new species, namely D. gammata, D. jishouensis, D. ruiliensis and D. sexualispora. Among the 32 known species, 14 are reported for the first time on Citrus, and two are newly reported from China. Among the 36 species, D. citri was the dominant species as exemplified by its high frequency of isolation and virulence. Pathogenicity tests indicated that most Diaporthe species obtained in this study were weakly aggressive or non-pathogenic to the tested citrus varieties. Only D. citri produced the longest lesion lengths on citrus shoots and induced melanose on citrus leaves. These results further demonstrated that a rich diversity of Diaporthe species occupy Citrus, but only a few species are harmful and D. citri is the main pathogen for Citrus in China. The present study provides a basis from which targeted monitoring, prevention and control measures can be developed. Citation: Xiao XE, Liu YD, Zheng F, et al. 2023. High species diversity in Diaporthe associated with citrus diseases in China. Persoonia 51: 229-256. doi: 10.3767/persoonia.2023.51.06.

Early-life gut microbiota governs susceptibility to colitis via microbial-derived ether lipids

Localized intestine inflammation could induce short-term increases in colonic oxygenation and leads to increases in the aerobic bacteria population and reduction in the anaerobic bacteria population by changing the intestinal environment. However, the mechanisms involved and the associated functions of intestinal anaerobes in gut health still remain unclear. Here, we found that early-life depletion of gut microbiota exacerbated later colitis, while mid-life microbiota depletion showed partially reduced colitis. Notably, we observed that early-life gut microbiota depletion confers susceptibility to ferroptosis in colitis. In contrast, restitution of early-life microbiota conferred protection against colitis and inhibited ferroptosis triggered by gut microbiota dysbiosis. Similarly, colonization with anaerobic microbiota from young mice suppressed colitis. These results may attribute to high abundance of plasmalogen-positive (plasmalogen synthase [PlsA/R]-positive) anaerobes and plasmalogens (one of the common ether lipids) in young mice but reduced abundance in the development of inflammatory bowel disease. Early-life anaerobic bacteria elimination also resulted in the aggravation of colitis, while this aggravation phenotype was reverted by plasmalogen administration. Interestingly, plasmalogens inhibited ferroptosis triggered by microbiota dysbiosis. We further find that the alkenyl-ether group of plasmalogens was critical to colitis prevention and ferroptosis inhibition. These data point to one of the mechanisms by which the gut microbiota controls susceptibility to colitis and ferroptosis early in life via microbial-derived ether lipids.

Polysaccharide from Atractylodes macrocephala Koidz. ameliorates DSS-induced colitis in mice by regulating the Th17/Treg cell balance

Atractylodes macrocephala Koidz. is one of the most frequently used traditional Chinese medicines for the treatment of ulcerative colitis (UC). The beneficial effect of polysaccharide from Atractylodes macrocephala Koidz. (PAMK) on UC has been reported, while the underlying mechanism and target remain unclear. In this study, we systematically investigated the therapeutic effect and the underlying mechanism of PAMK in UC based on a mouse model of dextran sodium sulfate (DSS)-induced colitis. PAMK treatment (100 mg/kg, 200 mg/kg and 400 mg/kg) significantly ameliorated DSS-induced colitis, manifested as a reduction in weight loss, disease activity index (DAI), colon shortening, spleen index and histological score. Moreover, PAMK treatment inhibited inflammation and improved the integrity of the intestinal barrier in colitis mice. Mechanistically, microarray analysis determined the critical role of the immunoregulatory effect of PAMK in alleviating UC. Flow cytometry analysis further demonstrated that PAMK treatment regulated the balance between T helper (Th) 17 and regulatory T (Treg) cells in the mesenteric lymph nodes (MLN) and spleen in mice with colitis. In addition, PAMK treatment downregulated the expression of IL-6 and suppressed the phosphorylation of STAT3. Together, these data revealed that PAMK treatment alleviated DSS-induced colitis by regulating the Th17/Treg cell balance, which may be dependent on the inhibition of the IL-6/STAT3 signaling pathway. Our study is the first to elucidate that the underlying mechanism by which PAMK treatment alleviates DSS-induced colitis is associated with an improved the Th17/Treg cell balance. Collectively, the study provides evidence for the potential of PAMK to treat UC.

Shenling Baizhu San ameliorates ulcerative colitis by regulating the gut microbiota and its tryptophan metabolites: A complementary medicine to mesalamine

ETHNOPHARMACOLOGICAL RELEVANCE

Shenling Baizhu San (SBS) is commonly employed to improve gastrointestinal dysfunction in patients with ulcerative colitis (UC) in China. SBS combined with mesalamine has been demonstrated to result in improve its curative effects without increasing any adverse reactions, but the underlying mechanism remains unclarified.

AIM OF THE STUDY

Our study aimed to illuminate the potential therapeutic effects and mechanisms of SBS, which is a medicine complementary to mesalamine, in the treatment of UC.

MATERIALS AND METHODS

A prospective cohort study was conducted to evaluate the efficacy of SBS as a complementary medicine to mesalamine for patients with UC (n = 48). The patients in the control group (n = 24) were given mesalamine alone, whereas those in the experimental group were administered mesalamine combined with SBS. The therapeutic outcome was assessed at 8 weeks. The structures of the gut microbiota (GMB) were characterized by 16S rRNA sequencing, and the microbial tryptophan metabolites were analyzed by UPLC-MS/MS to investigate the mechanism through which SBS achieves its effects.

RESULTS

Our results showed that the combination of SBS and mesalamine could significantly improve the clinical signs of UC by achieving mucosal healing and relieving colon damage. Interestingly, the combination of SBS and mesalamine could alter the GMB structures and increase the microbial levels of tryptophan metabolites, including indole-3-propionic acid and indole-3-acetic acid.

CONCLUSION

SBS combined with mesalamine is effective in improving the clinical and endoscopic outcomes of patients with UC. SBS, as a complementary therapy to conventional treatment, alleviates UC via the GMB-tryptophan metabolite axis.

Resilience Factors Preventing Schizophrenia in Ultra-high Risk Patients: Lessons from Genetics

Over the past decades, researchers and psychiatrists in the field of psychosis have moved from a conception of a chronic presentation to a more dynamic paradigm. Accordingly, schizophrenia is now conceptualized as a progressive illness that typically emerges during late adolescence and follows different stages: early vulnerability, ultra-high risk state, first episode of psychosis, and chronic disease. Only one-quarter of the ultra-high risk patients will convert to a full-blown psychotic episode within 3 years while the others, called non-converters, will remain at-risk, develop other psychiatric disorders, or fully recover. The reasons for this differential outcome are not yet understood but this concept opens the way to scientific research to determine the protective factors involved in resilience for non-converters. Based on the Gene X Environment interaction model, schizophrenia results from genetic vulnerability and environmental aggressions which can have an impact on the epigenome and gene expression. Recent studies have shown that genetic variants play a role in the resilience of psychosis. Polygenic risk scores, computed as the addition of genetic polymorphisms, can modulate the effects of genetic at-risk deletions (i.e. del22q11) that predispose to psychosis and may also influence the cognitive symptoms of ultra-high risk patients. Resilience, defined as the ability to withstand adversity, is not only related to external skills or psychotherapeutic care but could also be explained by internal molecular factors. Identifying the genetic factors of resilience might help to stratify the risk and to develop precision medicine in psychiatry.

Biocompatibility of Human Induced Pluripotent Stem Cell-Derived Retinal Progenitor Cell Grafts in Immunocompromised Rats

Loss of photoreceptor cells is a primary feature of inherited retinal degenerative disorders including age-related macular degeneration and retinitis pigmentosa. To restore vision in affected patients, photoreceptor cell replacement will be required. The ideal donor cells for this application are induced pluripotent stem cells (iPSCs) because they can be derived from and transplanted into the same patient obviating the need for long-term immunosuppression. A major limitation for retinal cell replacement therapy is donor cell loss associated with simple methods of cell delivery such as subretinal injections of bolus cell suspensions. Transplantation with supportive biomaterials can help maintain cellular integrity, increase cell survival, and encourage proper cellular alignment and improve integration with the host retina. Using a pig model of retinal degeneration, we recently demonstrated that polycaprolactone (PCL) scaffolds fabricated with two photon lithography have excellent local and systemic tolerability. In this study, we describe rapid photopolymerization-mediated production of PCL-based bioabsorbable scaffolds, a technique for loading iPSC-derived retinal progenitor cells onto the scaffold, methods of surgical transplantation in an immunocompromised rat model and tolerability of the subretinal grafts at 1, 3, and 6 months of follow-up (n = 150). We observed no local or systemic toxicity, nor did we observe any tumor formation despite extensive clinical evaluation, clinical chemistry, hematology, gross tissue examination and detailed histopathology. Demonstrating the local and systemic compatibility of biodegradable scaffolds carrying human iPSC-derived retinal progenitor cells is an important step toward clinical safety trials of this approach in humans.

Species of Botryosphaeriaceae associated with citrus branch diseases in China

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of Botryosphaeriaceae are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of Botryosphaeriaceae species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (tef1), the β-tubulin gene (tub2) and the DNA-directed RNA polymerase II second largest subunit (rpb2), 111 isolates from nine provinces were identified as 18 species of Botryosphaeriaceae, including Botryosphaeria dothidea, B. fabicerciana, Diplodia seriata, Dothiorella alpina, Do. plurivora, Lasiodiplodia citricola, L. iraniensis, L. microconidia, L. pseudotheobromae, L. theobromae, Neodeightonia subglobosa, Neofusicoccum parvum, and six previously undescribed species, namely Do. citrimurcotticola, L. guilinensis, L. huangyanensis, L. linhaiensis, L. ponkanicola and Sphaeropsis linhaiensis spp. nov. Botryosphaeria dothidea (28.8 %) was the most abundant species, followed by L. pseudotheobromae (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of Botryosphaeriaceae obtained from diseased citrus tissues in this study were pathogenic to the tested Citrus reticulata shoots in vitro, while not all species are pathogenic to the tested Cocktail grapefruit (C. paradisi × C. reticulata) shoots in vivo. In addition, Lasiodiplodia was the most aggressive genus both in vitro and in vivo. This is the first study to identify Botryosphaeriaceae species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures. Citation: Xiao XE, Wang W, Crous PW, et al. 2021. Species of Botryosphaeriaceae associated with citrus branch diseases in China. Persoonia 47: 106-135. https://doi.org/10.3767/persoonia.2021.47.03.

A Pilot Study of Clinical Evaluation and Formation Mechanism of Irritable Bowel Syndrome-like Symptoms in Inflammatory Bowel Disease Patients in Remission

Background/Aims

Some inflammatory bowel disease (IBD) patients in remission suffer from irritable bowel syndrome (IBS)-like symptoms (IBD-IBS). The pathogenesis has not yet been elucidated. The study aim is to evaluate relationships among quality of life (QOL), psychological status, and visceral sensitivity, and explore the formation mechanism of IBD-IBS.

Methods

Forty-seven patients with Crohn’s disease in remission, 24 ulcerative colitis in remission, 26 IBS, and 20 healthy controls were included in the study. The abdominal pain, QOL, anxiety, and depression were evaluated through questionnaires. Visceral sensitivity was measured by rectal balloon distension. The serum levels of 5-hydroxytryptamine (5-HT) and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay. The expressions of tryptase, 5-HT, NGF, and related receptors in colonic tissues were detected by immunohistochemistry and western blot.

Results

Prevalence of IBS-like symptoms in Crohn’s disease and ulcerative colitis patients in clinical remission was 29.8% and 50.0%, respectively. The QOL was lower, the anxiety/depression scores were higher in IBD-IBS patients than those without IBS-like symptoms. Additionally, patients with IBD-IBS existed visceral hypersensitivity. Besides, abdominal pain was associated with poor QOL, visceral hypersensitivity, anxiety, and depression in IBD-IBS patients. The number of mast cells (MCs) and expressions of 5-HT, NGF, and related receptors were higher in IBD-IBS patients than those with no such symptoms. The serum levels of 5-HT and NGF positively correlated with abdominal pain and visceral hypersensitivity.

Conclusion

IBD-IBS patients may have low QOL and psychological abnormalities, as wells as visceral hypersensitivity which may be related to increased 5-HT and NGF levels released from activated mast cells.

Faecalibacterium prausnitzii Attenuates DSS-Induced Colitis by Inhibiting the Colonization and Pathogenicity of Candida albicans

SCOPE

Intestinal commensal microbiota interactions play critical roles in the inflammatory bowel disease (IBD) development. Candida albicans (CA) can aggravate intestinal inflammation; however, whether Faecalibacterium prausnitzii (FP) can antagonize CA is unknown.

METHODS AND RESULTS

CA are co-cultured with bacteria (FP and Escherichia coli (EC)), bacterial supernatant, and bacterial medium, respectively. Then, the CA hyphae-specific genes' expression and CA cells' morphology are investigated. The Nod-like receptor pyrin-containing protein 6 (NLRP6) inflammasome, inflammatory cytokines, and antimicrobial peptides (AMPs) production are evaluated in intestinal epithelial cells pre-treated with bacteria, bacterial med, and bacterial supernatant and exposed without or with CA. Both bacteria significantly prohibit CA numbers, while only FP and FP supernatant prohibit the transformation and virulence factors (extracellular phospholipase, secreted aspartyl proteinase, and hemolysin) secretion of CA in a co-culture system compared with media controls. Further, FP and FP supernatant promote the production of the NLRP6 inflammasome, interleukin (IL)-1β, IL-18, and antibacterial peptides (β-defensin (BD)-2 and BD-3) and inhibit in vitro and in vivo CA growth and pathogenicity, and alleviate DSS-colitis in mice, while EC do not show the similar effect.

CONCLUSION

FP improve intestinal inflammation by inhibiting CA reproduction, colonization, and pathogenicity and inducing AMP secretion in the gut. This study uncovers new relationships between intestinal microbes and fungi in IBD patients.

Species of Botryosphaeriaceae associated with citrus branch diseases in China

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of Botryosphaeriaceae are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of Botryosphaeriaceae species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (tef1), the β-tubulin gene (tub2) and the DNA-directed RNA polymerase II second largest subunit (rpb2), 111 isolates from nine provinces were identified as 18 species of Botryosphaeriaceae, including Botryosphaeria dothidea, B. fabicerciana, Diplodia seriata, Dothiorella alpina, Do. plurivora, Lasiodiplodia citricola, L. iraniensis, L. microconidia, L. pseudotheobromae, L. theobromae, Neodeightonia subglobosa, Neofusicoccum parvum, and six previously undescribed species, namely Do. citrimurcotticola, L. guilinensis, L. huangyanensis, L. linhaiensis, L. ponkanicola and Sphaeropsis linhaiensis spp. nov. Botryosphaeria dothidea (28.8 %) was the most abundant species, followed by L. pseudotheobromae (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of Botryosphaeriaceae obtained from diseased citrus tissues in this study were pathogenic to the tested Citrus reticulata shoots in vitro, while not all species are pathogenic to the tested Cocktail grapefruit (C. paradisi × C. reticulata) shoots in vivo. In addition, Lasiodiplodia was the most aggressive genus both in vitro and in vivo. This is the first study to identify Botryosphaeriaceae species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures. Citation: Xiao XE, Wang W, Crous PW, et al. 2021. Species of Botryosphaeriaceae associated with citrus branch diseases in China. Persoonia 47: 106-135. https://doi.org/10.3767/persoonia.2021.47.03.

Cell-Matrix Interactions in the Eye: From Cornea to Choroid

The extracellular matrix (ECM) plays a crucial role in all parts of the eye, from maintaining clarity and hydration of the cornea and vitreous to regulating angiogenesis, intraocular pressure maintenance, and vascular signaling. This review focuses on the interactions of the ECM for homeostasis of normal physiologic functions of the cornea, vitreous, retina, retinal pigment epithelium, Bruch's membrane, and choroid as well as trabecular meshwork, optic nerve, conjunctiva and tenon's layer as it relates to glaucoma. A variety of pathways and key factors related to ECM in the eye are discussed, including but not limited to those related to transforming growth factor-β, vascular endothelial growth factor, basic-fibroblastic growth factor, connective tissue growth factor, matrix metalloproteinases (including MMP-2 and MMP-9, and MMP-14), collagen IV, fibronectin, elastin, canonical signaling, integrins, and endothelial morphogenesis consistent of cellular activation-tubulogenesis and cellular differentiation-stabilization. Alterations contributing to disease states such as wound healing, diabetes-related complications, Fuchs endothelial corneal dystrophy, angiogenesis, fibrosis, age-related macular degeneration, retinal detachment, and posteriorly inserted vitreous base are also reviewed.

Characterization of fungal and bacterial dysbiosis in young adult Chinese patients with Crohn's disease

Intestinal microbiota dysbiosis has been described in inflammatory bowel disease (IBD), but data from China are limited. In this study, we performed molecular analysis of the fecal microbial community from 20 healthy Chinese subjects and 25 patients with Crohn's disease (CD), and evaluated associations with bacterial and fungal compositions. Decreased richness and diversity of bacterial composition was observed in the CD group compared with healthy (H) subjects. Significant structural differences in bacterial (but not fungal) composition among healthy controls and CD patients were found. A reduction in Firmicutes and Actinobacteria abundance, and overrepresentation of Proteobacteria were observed in the CD patients compared with the H group. The Escherichia-Shigella genus was overrepresented in the CD group, whereas Faecalibacterium, Gemmiger, Bifidobacterium, Romboutsia, Ruminococcus, Roseburia, and Fusicatenibacter abundance were decreased in the CD group compared with H subjects. Differences in fungal microbiota between the H and CD groups were observed at the genus rather than at the phylum level. The Candida genus was overrepresented in the CD (active disease) group compared with the H group, whereas no difference between CD (remission) and H groups was observed. Aspergillus, unclassified_Sordariomycetes, and Penicillium genera had greater representation in the H subjects compared with the CD group. Bacterial and fungal intra- and inter-kingdom correlations were observed between the H and CD groups. Therefore, fecal bacterial and fungal microbiome communities differed considerably between H and CD patients, and between Chinese and Western populations. The role of gut microbiota in homeostasis and in gastrointestinal disorders should be investigated further.

Prophylaxis of implant-related infections by local release of vancomycin from a hydrogel in rabbits

Local prophylaxis with antibiotic-loaded bone cement is a successful method to prevent post-operative infections in patients receiving orthopaedic implants. No comparable method is available for uncemented implants. Therefore, a hydrogel consisting of hyaluronic and polylactic acids was evaluated in a rabbit model for delivery of antimicrobial agents to prevent post-operative infections. In a pilot study, the suitability of the in vivo model was assessed by testing the hydrogel as carrier material for antimicrobial agents.In the main study, the antimicrobial-agent-loaded hydrogel was evaluated for infection prophylaxis. Rabbits received a titanium rod intramedullary in the tibia after contamination with Staphylococcus aureus. The rods were coated with unloaded hydrogel (Gel), hydrogel loaded with 2 % (Van2) or 5 % vancomycin (Van5), bioactive glass (BAG) or N-acetyl-L-cysteine (NAC). To analyse the infection severity after 28 d, histopathological, bacteriological, micro-computed tomographic and haematological analyses were performed. In the pilot study, the Van5 group had less infection (0/6 infected) as compared to the Gel group (5/5, p = 0.000) and the in vivo model was deemed suitable. In the main study, in the Van2 and Van5 groups, the number of infected animals was lower [1/6 (p = 0.006) and 2/6 (p = 0.044) infected, respectively]. In contrast, BAG and NAC groups showed no infection reduction (5/6 both groups, p = 0.997). The hydrogel can be used as a local carrier of vancomycin for prophylaxis of implant-related infections.The present study showed promising results for local delivery of antibacterial agents by hydrogel to prevent implant-related infections.

Visualization of Mouse Choroidal and Retinal Vasculature Using Fluorescent Tomato Lectin Perfusion

Purpose

To develop a reliable and simplified method to assess choroid and retinal vasculature on whole mount and cross sections in mice using tomato lectin (TL; Lycopersicon esculentum).

Methods

Albino mice (n = 27) received 1 mg/mL of TL (conjugated to Dylight-594) intravascularly through the tail vein, jugular vein, or cardiac left ventricle. Whole mounts of the retina and choroid were evaluated using fluorescence microscopy. Perfusion with GSL-IB4 conjugated to Dylight-594 and fluorescein isothiocyanate was performed to compare against labeling with TL. Co-labeling of choroidal endothelial cells with perfused TL on cross-sections with antibodies directed against the choriocapillaris-restricted endothelial cell marker CA4 was performed. The percentage of perfused choroidal and retinal vessels was assessed semiquantitatively. One mouse was subjected to thermal laser damage before perfusion to cause retinal and choroidal vasculature ablation.

Results

Intravascular injection of TL led to consistent, robust labeling of retinal and choroidal vascular walls. On cross-sections, choriocapillaris was co-labeled with CA4 and TL. On flat mount, TL perfusion resulted in better labeling of choroidal vessels using tail/jugular vein injection compared with cardiac perfusion (P < .01). More consistent labeling of the choroidal and retinal vascular trees was observed with TL than with GSL-IB4. Vascular damage caused by laser ablation was detected readily using this method.

Conclusions

TL injection intravascularly can reliably label normal and ablated choroid and retinal vasculature in mouse in a quick, simple manner.

Translational Relevance

These data will help to facilitate modeling in rodents for diseases such as age-related macular degeneration, diabetes, and other ischemic/angiogenic processes that can also be used for treatment evaluation.

Candida albicans SC5314 inhibits NLRP3/NLRP6 inflammasome expression and dampens human intestinal barrier activity in Caco-2 cell monolayer model

Candida albicans is an opportunistic fungal pathogen that colonizes human gastro-intestinal mucosal tissues. Its effect on the immune response in intestinal epithelial cells and on the intestinal mucosal barrier are not yet fully understood. In this study, we investigated Caco-2 cells, a monolayer model of intestinal epithelial cells, with or without treatment with C. albicans SC5314 (CA) or heat-inactivated CA (CA-inact). RNA sequencing was conducted, and the mRNA and protein levels of NOD-like receptor pyrin domain-containing protein 3 (NLRP3) or NLRP6/ASC/caspase-1 inflammasome signaling pathway components, inflammatory cytokines (interleukin-18 [IL-18] and IL-1β), anti-microbial peptides (AMPs; β-defensin-2 [BD-2], BD-3, and LL-37), and tight junction proteins (occludin and zona occludens-1 [ZO-1]) were examined by real-time PCR, western blotting, and/or immunofluorescence microscopy. Lactase dehydrogenase (LDH) activity in the Caco-2 cell supernatant were measured by enzyme kinetics analysis. Our results showed that the NOD-like receptor signaling pathway participates in the CA- and CA-inact-infected Caco-2 cells, as shown by microarray analysis of total mRNA expression. The expression of NLRP3, NLRP6, ASC, BD-2, BD-3, occludin, and ZO-1 were significantly decreased in Caco-2 cells infected with CA and CA-inact compared to that in the untreated control. IL-1β expression was decreased in the Caco-2 cells in both the CA- and CA-inact-infected groups compared to that in the control. Caspase-1 and IL-18 levels were not markedly affected by CA or CA-inact in Caco-2 cells. Our findings indicate that CA can inhibit the NLRP3 and NLRP6 pathways and dampen human intestinal mucosal barrier activity by decreasing the production of AMPs and tight junction proteins, independent of CA activity.

Two-photon polymerized poly(caprolactone) retinal cell delivery scaffolds and their systemic and retinal biocompatibility

Cell replacement therapies are often enhanced by utilizing polymer scaffolds to improve retention or direct cell orientation and migration. Obstacles to refinement of such polymer scaffolds often include challenges in controlling the microstructure of biocompatible molecules in three dimensions at cellular scales. Two-photon polymerization of acrylated poly(caprolactone) (PCL) could offer a means of achieving precise microstructural control of a material in a biocompatible platform. In this work, we studied the effect of various formulation and two-photon polymerization parameters on minimum laser power needed to achieve polymerization, resolution, and fidelity to a target 3D model designed to be used for retinal cell replacement. Overall, we found that increasing the concentration of crosslink-able groups decreased polymerization threshold and the size of resolvable features while increasing fidelity of the scaffold to the 3D model. In general, this improvement was achieved by increasing the number of acrylate groups per prepolymer molecule, increasing the acrylated PCL concentration, or decreasing its molecular weight. Resulting two-photon polymerized PCL scaffolds successfully supported human iPSC derived retinal progenitor cells in vitro. Sub-retinal implantation of cell free scaffolds in a porcine model of retinitis pigmentosa did not cause inflammation, infection or local or systemic toxicity after one month. In addition, comprehensive ISO 10993 testing of photopolymerized scaffolds revealed a favorable biocompatibility profile. These results represent an important step towards understanding how two-photon polymerization can be applied to a wide range of biologically compatible chemistries for various biomedical applications. STATEMENT OF SIGNIFICANCE: Inherited retinal degenerative blindness results from the death of light sensing photoreceptor cells. To restore high-acuity vision a photoreceptor cell replacement strategy will likely be necessary. Unfortunately, single cell injection typically results in poor cell survival and integration post-transplantation. Polymeric biomaterial cell delivery scaffolds can be used to promote donor cell viability, control cellular polarity and increase packing density. A challenge faced in this endeavor has been developing methods suitable for generating scaffolds that can be used to deliver stem cell derived photoreceptors in an ordered columnar orientation (i.e., similar to that of the native retina). In this study we combined the biomaterial poly(caprolactone) with two-photon lithography to generate a biocompatible, clinically relevant scaffold suitable for retina cell delivery.

[Mid-to-long term outcomes and influence factors of postoperative concurrent chronic ankle instability and posterior ankle impingement]

OBJECTIVE

To investigate the mid-to-long-term efficacy of patients with chronic ankle instability combined with posterior impingement syndrome after 3-9 years of follow-up, and to analyze the influencing factors.

METHODS

From February 2010 to December 2015, 46 patients underwent concurrent lateral ankle ligament repair with posterior ankle arthroscopic surgery at the Institute of Sports Medicine, Peking University Third Hospital. The patient was first placed in a prone position and underwent arthroscopic debridement for the posterior impingement. After finishing the posterior arthroscopy, the surgeon and assistants first translated the patient to the affected side, then turned to the healthy side, and changed the position to the supine position. During the turning over, another assistant held the arthroscope and the instrument to ensure that it was sterile and could be used without replacement. The anterior ankle arthroscopy was operated if necessary and the lateral ankle ligament repair was anatomic repaired with anchors. The 42 patients were followed up, including 26 males and 16 females. The average age was (28.9±10.0) years. The patient's clinical symptoms, joint stability, mobility and motor function were compared by questionnaire and physical examination. The preoperative and postoperative visual analogue scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Tegner scores were compared, and the clinical scores and the patient age, gender, height and weight were compared. The correlations between body mass index (BMI), preoperative duration, surgery duration, and cartilage injury were analyzed.

RESULTS

The mean follow-up time was (71.8±22.8) months. The postoperative VAS scores (1.0 vs. 5.0, P<0.001), AOFAS scores (92 vs. 80, P<0.001), and Tegner scores (6.5 vs. 2, P<0.001) were significantly superior to the preoperative levels. The excellent and good rate was 97.6%. The postoperative VAS score (t=2.719, P=0.10), AOFAS score (t=-2.853, P=0.10), Tegner score (t=-3.443, P=0.001) and time to return exercise (t=2.814, P=0.008) were negatively correlated with the patient age, and the postoperative VAS score was negatively correlated with cartilage injury (Z=-2.195, P=0.028).

CONCLUSION

The mid-to-long-term clinical outcomes of the chronic ankle ligament instability combined with the posterior impingement were good. The age of the patients was negatively correlated with the clinical outcome. The combined cartilage injury could aggravate the postoperative pain.

Optimizing Donor Cellular Dissociation and Subretinal Injection Parameters for Stem Cell-Based Treatments

Subretinal delivery of stem cell‐derived retinal cells as a strategy to treat retinal degenerative blindness holds great promise. Currently, two clinical trials are underway in which human fetal retinal progenitor cells (RPCs) are being delivered to patients by intravitreal or subretinal injection to preserve or restore vision, respectively. With the advent of the induced pluripotent stem cell (iPSC), and in turn three‐dimensional derivation of retinal tissue, it is now possible to generate autologous RPCs for cell replacement. The purpose of this study was to evaluate the effect of commonly used cell isolation and surgical manipulation strategies on donor cell viability. iPSC‐RPCs were subjected to various conditions, including different dissociation and isolation methods, injection cannula sizes, and preinjection storage temperatures and times. The effects of commonly used surgical techniques on both host and donor cell viability were evaluated in Yucatan mini‐pigs (n = 61 eyes). We found a significant increase in cell viability when papain was used for RPC isolation. In addition, a significant decrease in cell viability was detected when using the 41G cannula compared with 31G and at storage times of 4 hours compared with 30 minutes. Although 96.4% of all eyes demonstrated spontaneous retinal reattachment following injection, retinal pigment epithelium (RPE) abnormalities were seen more frequently in eyes receiving injections via a 31G cannula; interestingly, eyes that received cell suspensions were relatively protected against such RPE changes. These findings indicate that optimization of donor cell isolation and delivery parameters should be considered when developing a subretinal cell replacement strategy. stem cells translational medicine2019;8:797&809

[Retrospective analysis of modified Karlsson surgery for chronic calcaneofibular ligament injury]

Objective: To retrospectively evaluate the therapeutic effect and influencing factors of the modified Karlsson operation (anchor method) in treating chronic rupture of the calcaneofibular ligament (CFL). Methods: From August 2010 to May 2014, the data of 24 patients with calcaneofibular ligament rupture treated in Institute of Sports Medicine, Third Hospital of Peking University were retrospectively analyzed. All cases were repaired with modified Karlsson operation (anchor method). There were 14 males and 10 females, with an average age of (30±9) years, and the average body mass index (BMI) was (25±5) kg/m(2). Visual analogue pain score (VAS), American Foot and Ankle Surgery Association score (AOFAS), Tegner knee motion score, ankle stability and mobility were followed up and analyzed. The paired t test was used to compare the normal distribution data before and after the operation. Results: The average follow-up time was (41±13) months. Compared with pre-operation, VAS score decreased significantly at the last follow-up [0(0,7) vs 5(0,8), Z=4.13,P=0.000], AOFAS score increased significantly (94±10 vs 70±14, t=8.94, P<0.05), Tegner score increased significantly (4.7±1.5 vs 2.8±1.3, t=6.87, P<0.05), all improved significantly. AOFAS score was excellent in 19 cases, good in 4 cases and moderate in 1 case, the excellent and good rate was 95.8%. Among them, 20 cases (83.3%) were satisfied with the recovery effect after the operation. Postoperative sprain occurred in 5 cases (20.8%) and ankle mobility was limited in 3 cases (12.5%). Conclusions: The modified Karlsson operation (anchor method) can restore the stability of the ankle joint by treating the chronic rupture of CFL. It is an effective therapy for lateral ankle instability.

[Reconstruction of neglected Achilles tendon rupture: flexor hallucis longus transfer versus gastrocnemius turn-down flaps]

Objective: To compare the outcome of either flexor hallucis longus transfer or turn-down of proximal Achilles tendon tissue repair in treating chronic Achilles tendon rupture. Methods: The clinical data of 21 patients who underwent repair of Myerson type Ⅲ chronic Achilles tendon rupture at Peking University Sports Medicine Research Institute from May 2012 to March 2015 were retrospectively analyzed. Among them, 11 cases were treated with flexor hallucis longus (FHL) transfer, and 10 cases were treated with gastrocnemius turn-down flaps repair. The American Orthopedic Foot & Ankle Society (AOFOS) hindfoot score and Tegner motor function score before and after surgery were recorded and compared between the two groups. Data comparison between groups was performed with t test. Results: The patients in the both group were followed up for an average of (21±7) months. The postoperative AOFOS hindfoot score in the long flexor and gastrocnemius groups were both significantly higher than those before surgery, and the differences were statistically significant (97.7±2.6 vs 72.0±8.1 and 96.0±5.5 vs 78.5±6.4, t=10.70, 6.42, both P<0.05).The postoperative Tegner scores of the two groups were also significantly higher than those before surgery (4.2±1.4 vs 0.7±0.4 and 4.1±0.8 vs 0.6±0.5,t=7.29, 9.35, both P<0.05). There were no significant differences in postoperative AOFOS hindfoot scores and Tegner motor function scores between the two groups (both P>0.05). Conclusion: The flexor hallucis longus transfer and turn-down of proximal Achilles tendon tissue repair can both get satisfactory results in treating chronic Achilles tendon rupture.

Correlation of Optical Coherence Tomography and Retinal Histology in Normal and Pro23His Retinal Degeneration Pig

Purpose

We correlate optical coherence tomography (OCT) retinal layer thickness measurements with histology in wild-type and retinal degenerative pigs.

Methods

OCT scans were obtained using the Bioptigen Envisu R2200. In normal pigs, three eyes were imaged in vivo, and three eyes were imaged after enucleation. In the Pro23His retinal degeneration pigs (P23H), one eye was imaged in vivo and four eyes were imaged after enucleation. All eyes were fixed in 4% paraformaldehyde and processed for histology. Corresponding retinal locations on OCT and histology were identified using anatomic landmarks (optic nerve, retinal vessels, visual streak). Individual retinal layer thicknesses were measured by two independent, masked graders, and intraclass correlation coefficients were used to determine agreement. OCT and histologic retinal thickness measurements were averaged and compared.

Results

OCT and histologic measurements correlated highly in normal and diseased eyes (R² = 0.91 and 0.92, respectively), and scans performed in vivo and ex vivo did not differ significantly. Despite good overall correlation, certain individual retinal layers (e.g., retinal nerve fiber layer [NFL], inner [INL] and outer [ONL] nuclear layers) appeared thicker on OCT compared to histology, while other layers (e.g., retinal pigment epithelium) appeared thinner. No statistically significant difference was found between OCT and histology for any retinal layer thickness measurement.

Conclusions

Retinal layer thickness measurements correlate well with histology in pig eyes, but differences in individual retinal layers may be seen.

Translational Relevance

OCT may be used in pigs to measure retinal thicknesses with good overall correlation to histologic measurements.

Effect of Molecular Weight and Functionality on Acrylated Poly(caprolactone) for Stereolithography and Biomedical Applications

Degradable polymers are integral components in many biomedical polymer applications. The ability of these materials to decompose in situ has become a critical component for tissue engineering, allowing scaffolds to guide cell and tissue growth while facilitating gradual regeneration of native tissue. The objective of this work is to understand the role of prepolymer molecular weight and functionality of photocurable poly(caprolactone) (PCL) in determining reaction kinetics, mechanical properties, polymer degradation, biocompatibility, and suitability for stereolithography. PCL, a degradable polymer used in a number of biomedical applications, was functionalized with acrylate groups to enable photopolymerization and three-dimensional printing via stereolithography. PCL prepolymers with different molecular weights and functionalities were studied to understand the role of molecular structure in reaction kinetics, mechanical properties, and degradation rates. The mechanical properties of photocured PCL were dependent on cross-link density and directly related to the molecular weight and functionality of the prepolymers. High-molecular weight, low-functionality PCLDA prepolymers exhibited a lower modulus and a higher strain at break, while low-molecular weight, high-functionality PCLTA prepolymers exhibited a lower strain at break and a higher modulus. Additionally, degradation profiles of cross-linked PCL followed a similar trend, with low cross-link density leading to degradation times up to 2.5 times shorter than those of more highly cross-linked polymers. Furthermore, photopolymerized PCL showed biocompatibility both in vitro and in vivo, causing no observed detrimental effects on seeded murine-induced pluripotent stem cells or when implanted into pig retinas. Finally, the ability to create three-dimensional PCL structures is shown by fabrication of simple structures using digital light projection stereolithography. Low-molecular weight, high-functionality PCLTA prepolymers printed objects with feature sizes near the hardware resolution limit of 50 μm. This work lays the foundation for future work in fabricating microscale PCL structures for a wide range of tissue regeneration applications.

Assessment of Adeno-Associated Virus Serotype Tropism in Human Retinal Explants

Advances in the discovery of the causes of monogenic retinal disorders, combined with technologies for the delivery of DNA to the retina, offer enormous opportunities for the treatment of previously untreatable blinding diseases. However, for gene augmentation to be most effective, vectors that have the correct cell-type specificity are needed. While animal models are very useful, they often exhibit differences in retinal cell surface receptors compared to the human retina. This study evaluated the use of an ex vivo organotypic explant system to test the transduction efficiency and tropism of seven different adeno-associated virus type 2 (AAV2) serotypes in the human retina and retinal pigment epithelium-choroid-AAV2/1, AAV2/2, AAV2/4, AAV2/5, AAV2/6, AAV2/8, and AAV2/9-all driving expression of GFP under control of the cytomegalovirus promoter. After 7 days in culture, it was found that AAV2/4 and AAV2/5 were particularly efficient at transducing photoreceptor cells and that AAV2/5 was highly specific to the outer nuclear layer, whereas AAV2/8 displayed consistently low transduction of photoreceptors. To validate the authenticity of the organotypic culture system, the transduction of the same set of AAVs was also compared in a pig model, in which sub-retinal injections in vivo were compared to cultured and transduced organotypic cultures ex vivo. This study shows how different AAV serotypes behave in the human retina and provides insight for further investigation of each of these serotypes for gene augmentation-based treatment of inherited retinal degeneration.

Alterations in the mucosa-associated fungal microbiota in patients with ulcerative colitis

Background

Fungi colonize the human gut and might play a key role in the pathogenesis of ulcerative colitis (UC). However, studies on the fungal composition in the gut (especially adhering to the intestinal mucosa) of UC patients is limited.

Results

The number of fungi decreased significantly in inflamed mucosa compared with that in HS mucosa. Fifteen major genera were examined, among which Wickerhamomyces, unidentified genus of Saccharomycetales, Aspergillus, Sterigmatomyces, and Candida showed increasing trends, whereas Exophiala, Alternaria, Emericella, Epicoccum, Acremonium, Trametes, and Penicillium showed decreasing trends in UC patients compared to the HS. The pro-inflammatory cytokines (IL-Iβ, TNF-α, INF-γ, IL-6, IL-17A, and IL-23) were up-regulated in the UC group. The genera Wickerhamomyces, Nigrospora, and Penicillium were positively correlated, while Sporobolomyces and Trametes were negatively correlated with the expression of several colonic pro-inflammatory cytokines and the Baron and/or Mayo score.

Conclusions

Our study confirms the alteration of the colonic fungal microbiota in the UC patients, which might be associated with mucosal inflammation and pathogenesis of UC. Further studies need to identify the roles of different intestinal fungi in detail, and to determine the mechanism of the host-fungal interaction underlying the development of UC.

Methods

Mucosal samples of inflamed descending colon from 14 active UC patients and 15 healthy subjects (HS) were analyzed by high-throughput sequencing to compare the fungal microbiota. The expressions of pro-inflammatory cytokines (IL-Iβ, TNF-α, INF-γ, IL-6, IL-17A, and IL-23) in intestinal mucosal tissues were examined. The Baron and Mayo scores of UC patients were evaluated, and the correlation between intestinal fungal composition and intestinal inflammatory status was analyzed.

iTRAQ-Based Quantitative Proteomic Analyses of High Grade Esophageal Squamous Intraepithelial Neoplasia

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide and is the fourth most lethal cancer in China. Little is known about the proteome of high grade esophageal squamous intraepithelial neoplasia (HGN), which is a premalignant lesion of ESCC. A quantitative proteomic analysis using an isobaric tag for relative and absolute quantification (iTRAQ) approach is used to characterize the protein expression profiles in HGN. Among the 3156 identified proteins, a total of 236 proteins are discovered to be differentially expressed. Compared with paired normal esophageal epithelial tissues, 138 proteins are upregulated and 98 proteins are downregulated in HGN. Bioinformatics analyses are performed according to gene ontology, clusters of orthologous groups, and kyoto encyclopedia of genes and genomes enrichment analyses. Six differentially expressed proteins are chosen and validated by Western blotting. The results of the study increase our understanding of early tumorigenesis during ESCC, and provide insights into the proteome at the initial stages of the disease that can be used to identify potential biomarkers for early diagnosis and for therapeutic targets.

Using CRISPR-Cas9 to Generate Gene-Corrected Autologous iPSCs for the Treatment of Inherited Retinal Degeneration

Patient-derived induced pluripotent stem cells (iPSCs) hold great promise for autologous cell replacement. However, for many inherited diseases, treatment will likely require genetic repair pre-transplantation. Genome editing technologies are useful for this application. The purpose of this study was to develop CRISPR-Cas9-mediated genome editing strategies to target and correct the three most common types of disease-causing variants in patient-derived iPSCs: (1) exonic, (2) deep intronic, and (3) dominant gain of function. We developed a homology-directed repair strategy targeting a homozygous Alu insertion in exon 9 of male germ cell-associated kinase (MAK) and demonstrated restoration of the retinal transcript and protein in patient cells. We generated a CRISPR-Cas9-mediated non-homologous end joining (NHEJ) approach to excise a major contributor to Leber congenital amaurosis, the IVS26 cryptic-splice mutation in CEP290, and demonstrated correction of the transcript and protein in patient iPSCs. Lastly, we designed allele-specific CRISPR guides that selectively target the mutant Pro23His rhodopsin (RHO) allele, which, following delivery to both patient iPSCs in vitro and pig retina in vivo, created a frameshift and premature stop that would prevent transcription of the disease-causing variant. The strategies developed in this study will prove useful for correcting a wide range of genetic variants in genes that cause inherited retinal degeneration.

IGF2BP3 as a potential tissue marker for the diagnosis of esophageal high-grade intraepithelial neoplasia

Background

The clinical significance of insulin-like growth factor-II mRNA-binding protein-3 (IGF2BP3) in esophageal high-grade intraepithelial neoplasia (HGIN) is not clear. This study was designed to characterize the expression of IGF2BP3 in HGIN.

Patients and methods

IGF2BP3 expression was evaluated by Western blot analyses in 12 cases and by immunohistochemistry (IHC) in 112 cases. The associations between IGF2BP3 expression in HGIN and the clinicopathological parameters were examined.

Results

Moderate to strong IGF2BP3 expression was present in HGIN samples. Using IHC, it was found that IGF2BP3 was positive in 68 (60.71%) cases. Intense IHC of IGF2BP3 in HGIN was associated with a deeper lesion depth, and the lesion depth was the only predictor of the positive expression of IGF2BP3.

Conclusion

Our results suggested that IGF2BP3 may be a supplementary tissue marker for preoperative diagnosis of HGIN.

[Segmented biodegradable esophageal stents in a porcine model: preclinical evaluation of degradation, complications and tissue reactions]

Objective: To evaluate the feasibility of two types of segmented biodegradable esophageal stents in treatment of refractory benign esophagus strictures. Methods: Uncovered biodegradable segmented stent and fully-covered biodegradable segmented stent were implanted into the porcine esophagus (6 for each). Data on biodegradation, complications, and tissue reactions were compared between two groups. Results: All animals kept good general conditions; no death, decreased food intake, weight loss and malnutrition were observed. No perforation, ulcer, hemorrhage, stent migration and severe complications occurred. Stents degradation commenced at week 3. Stents structure breakage and complete stents absorption occurred at week 7-8 and week 9-10 in uncovered stents. While in fully-covered stents, stents structure breakage and complete stents absorption occurred at week 8-9 and week 10-11. Hyperplasia was prominent at week 1-3 and ameliorated at week 6 after stent implantation. A longer degradation period was present in fully-covered stents than in uncovered stents, while fully-covered stents induced tissue reactions at early stage were mild. Conclusions: The application of biodegradable esophageal stents with a segmented trunk in refractory benign esophagus strictures worth further investigation. The fully-covered stent has longer degradation period, which may be more suitable for clinical use.

Gut microbial composition can differentially regulate bile acid synthesis in humanized mice

We previously reported that alcohol drinkers with and without cirrhosis showed a significant increase in fecal bile acid secretion compared to nondrinkers. We hypothesized this may be due to activation by alcohol of hepatic cyclic adenosine monophosphate responsive element-binding protein 3-like protein 3 (CREBH), which induces cholesterol 7α-hydroxylase (Cyp7a1). Alternatively, the gut microbiota composition in the absence of alcohol might increase bile acid synthesis by up-regulating Cyp7a1. To test this hypothesis, we humanized germ-free (GF) mice with stool from healthy human subjects (Ctrl-Hum), human subjects with cirrhosis (Cirr-Hum), and human subjects with cirrhosis and active alcoholism (Alc-Hum). All animals were fed a normal chow diet, and none demonstrated cirrhosis. Both hepatic Cyp7a1 and sterol 12α-hydroxylase (Cyp8b1) messenger RNA (mRNA) levels were significantly induced in the Alc-Hum and Ctrl-Hum mice but not in the Cirr-Hum mice or GF mice. Liver bile acid concentration was correspondingly increased in the Alc-Hum mice despite fibroblast growth factor 15, fibroblast growth receptor 4, and small heterodimer partner mRNA levels being significantly induced in the large bowel and liver of the Ctrl-Hum mice and Alc-Hum mice but not in the Cirr-Hum mice or GF mice. This suggests that the normal pathways of Cyp7a1 repression were activated in the Alc-Hum mice and Ctrl-Hum mice. CREBH mRNA was significantly induced only in the Ctrl-Hum mice and Alc-Hum mice, possibly indicating that the gut microbiota up-regulate CREBH and induce bile acid synthesis genes. Analysis of stool bile acids showed that the microbiota of the Cirr-Hum and Alc-Hum mice had a greater ability to deconjugate and 7α-dehydroxylate primary bile acids compared to the microbiota of the Cirr-Hum mice. 16S ribosomal RNA gene sequencing of the gut microbiota showed that the relative abundance of taxa that 7-α dehydroxylate primary bile acids was higher in the Ctrl-Hum and Alc-Hum groups. Conclusion: The composition of gut microbiota influences the regulation of the rate-limiting enzymes in bile acid synthesis in the liver. (Hepatology Communications 2017;1:61-70).

Gut microbiota drive the development of neuroinflammatory response in cirrhosis in mice

The mechanisms behind the development of hepatic encephalopathy (HE) are unclear, although hyperammonemia and systemic inflammation through gut dysbiosis have been proposed. The aim of this work was to define the individual contribution of hyperammonemia and systemic inflammation on neuroinflammation in cirrhosis using germ-free (GF) and conventional mice. GF and conventional C57BL/6 mice were made cirrhotic using CCl4 gavage. These were compared to their noncirrhotic counterparts. Intestinal microbiota, systemic and neuroinflammation (including microglial and glial activation), serum ammonia, intestinal glutaminase activity, and cecal glutamine content were compared between groups. GF cirrhotic mice developed similar cirrhotic changes to conventional mice after 4 extra weeks (16 vs. 12 weeks) of CCl4 gavage. GF cirrhotic mice exhibited higher ammonia, compared to GF controls, but this was not associated with systemic or neuroinflammation. Ammonia was generated through increased small intestinal glutaminase activity with concomitantly reduced intestinal glutamine levels. However, conventional cirrhotic mice had intestinal dysbiosis as well as systemic inflammation, associated with increased serum ammonia, compared to conventional controls. This was associated with neuroinflammation and glial/microglial activation. Correlation network analysis in conventional mice showed significant linkages between systemic/neuroinflammation, intestinal microbiota, and ammonia. Specifically beneficial, autochthonous taxa were negatively linked with brain and systemic inflammation, ammonia, and with Staphylococcaceae, Lactobacillaceae, and Streptococcaceae. Enterobacteriaceae were positively linked with serum inflammatory cytokines.

CONCLUSION

Gut microbiota changes drive development of neuroinflammatory and systemic inflammatory responses in cirrhotic animals. (Hepatology 2016;64:1232-1248).

Rifaximin Exerts Beneficial Effects Independent of its Ability to Alter Microbiota Composition

OBJECTIVES

Rifaximin has clinical benefits in minimal hepatic encephalopathy (MHE) but the mechanism of action is unclear. The antibiotic-dependent and -independent effects of rifaximin need to be elucidated in the setting of MHE-associated microbiota. To assess the action of rifaximin on intestinal barrier, inflammatory milieu and ammonia generation independent of microbiota using rifaximin.

METHODS

Four germ-free (GF) mice groups were used (1) GF, (2) GF+rifaximin, (3) Humanized with stools from an MHE patient, and (4) Humanized+rifaximin. Mice were followed for 30 days while rifaximin was administered in chow at 100 mg/kg from days 16-30. We tested for ammonia generation (small-intestinal glutaminase, serum ammonia, and cecal glutamine/amino-acid moieties), systemic inflammation (serum IL-1β, IL-6), intestinal barrier (FITC-dextran, large-/small-intestinal expression of IL-1β, IL-6, MCP-1, e-cadherin and zonulin) along with microbiota composition (colonic and fecal multi-tagged sequencing) and function (endotoxemia, fecal bile acid deconjugation and de-hydroxylation).

RESULTS

All mice survived until day 30. In the GF setting, rifaximin decreased intestinal ammonia generation (lower serum ammonia, increased small-intestinal glutaminase, and cecal glutamine content) without changing inflammation or intestinal barrier function. Humanized microbiota increased systemic/intestinal inflammation and endotoxemia without hyperammonemia. Rifaximin therapy significantly ameliorated these inflammatory cytokines. Rifaximin also favorably impacted microbiota function (reduced endotoxin and decreased deconjugation and formation of potentially toxic secondary bile acids), but not microbial composition in humanized mice.

CONCLUSIONS

Rifaximin beneficially alters intestinal ammonia generation by regulating intestinal glutaminase expression independent of gut microbiota. MHE-associated fecal colonization results in intestinal and systemic inflammation in GF mice, which is also ameliorated with rifaximin.

Evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects

The high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. The genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid Acyrthosiphon pisum: sucrase 1 (SUC1), a sucrase in glycoside hydrolase family 13 (GH13), and aquaporin 1 (AQP1), a member of the Drosophila integral protein (DRIP) family of aquaporins. Here, we describe molecular analysis of GH13 and AQP genes in phloem-feeding representatives of the four phloem-feeding groups: aphids (Myzus persicae), coccids (Planococcus citri), psyllids (Diaphorina citri, Bactericera cockerelli) and whiteflies (Bemisia tabaci MEAM1 and MED). A single candidate GH13-SUC gene and DRIP-AQP gene were identified in the genome/transcriptome of most insects tested by the criteria of sequence motif and gene expression in the gut. Exceptionally, the psyllid Ba. cockerelli transcriptome included a gut-expressed Pyrocoelia rufa integral protein (PRIP)-AQP, but has no DRIP-AQP transcripts, suggesting that PRIP-AQP is recruited for osmoregulatory function in this insect. This study indicates that phylogenetically related SUC and AQP genes may generally mediate osmoregulatory functions in these diverse phloem-feeding insects, and provides candidate genes for empirical validation and development as targets for osmotic disruption of pest species.

Allogenic iPSC-derived RPE cell transplants induce immune response in pigs: a pilot study

Stem cell strategies focused on replacement of RPE cells for the treatment of geographic atrophy are under intense investigation. Although the eye has long been considered immune privileged, there is limited information about the immune response to transplanted cells in the subretinal space of large animals. The purpose of this study was to evaluate the survival of allogenic induced pluripotent stem cell-derived RPE cells (iPSC-RPE) delivered to the subretinal space of the pig as well as determine whether these cells induce an immune response in non-diseased eyes. GFP positive iPSC-RPE, generated from outbred domestic swine, were injected into the subretinal space of vitrectomized miniature swine. Control eyes received vehicle only. GFP positive iPSC-RPE cells were identified in the subretinal space 3 weeks after injection in 5 of 6 eyes. Accompanying GFP-negative cells positive for IgG, CD45 and macrophage markers were also identified in close proximity to the injected iPSC-RPE cells. All subretinal cells were negative for GFAP as well as cell cycle markers. We found that subretinal injection of allogenic iPSC-RPE cells into wild-type mini-pigs can induce the innate immune response. These findings suggest that immunologically matched or autologous donor cells should be considered for clinical RPE cell replacement.

Expression of a GDP-L-galactose phosphorylase-like gene in a Chinese wild Vitis species induces responses to Erysiphe necator and defense signaling molecules

Using rapid amplification of cDNA ends, a full-length cDNA sequence of a GDP-L-galactose phosphorylase-like gene was isolated from leaves infected by Erysiphe necator in the Chinese wild (Vitis pseudoreticulata) clone, 'Baihe-35-1', an E. necator-resistant genotype. The full-length cDNA, designated as VpVTC, comprised 1943 bp and putatively encodes a 453-amino acid polypeptide containing an HIT motif. The deduced amino acid sequence showed high similarity with that of VTC genes from other plants. The expression of VpVTC, determined by reverse transcriptase-polymerase chain reaction, was induced by E. necator and defense signaling molecules, including salicylic acid, methyl jasmonate, and ethephon, in 'Baihe-35-1', the V. quinquangularis genotype 'Shang-24', and the E. necator-susceptible V. pseudoreticulata genotype, 'Hunan-1'. Transcript levels of VpVTC correlated well with the degree of disease resistance in the 3 genotypes. Maximum induction of VpVTC by E. necator (>7-fold at 96 h post-inoculation) occurred in 'Baihe-35-1', which also showed the fastest response to signaling molecules. Upregulating the expression of VpVTC in 'Baihe-35-1' resulted in a gradual increase in the ascorbic acid concentration of leaves inoculated with E. necator. Furthermore, VpVTC was expressed in leaves, stems, inflorescence, tendrils, and fruit at all developmental stages, with the highest level occurring in fruit 35 days after flowering.

Lin- cells mediate tissue repair by regulating MCP-1/CCL-2

Exogenous bone marrow-derived cells (BMDCs) are promising therapeutic agents for the treatment of tissue ischemia and traumatic injury. However, until we identify the molecular mechanisms that underlie their actions, there can be no rational basis for the design of therapeutic strategies using BMDCs. The pro-healing effects of BMDCs are apparent very shortly after treatment, which suggests that they may exert their effects by the modulation of acute inflammation. We investigated this hypothesis by taking advantage of the fact that BMDCs from healthy, young, but not obese, diabetic mice stimulate vascular growth. By comparing both in vitro secretion and in vivo local induction of acute phase inflammatory cytokines by these cells, we identified monocyte chemoattractant factor 1 and tumor necrosis factor α as potential mediators of BMDC-induced tissue repair. In vivo analysis of BMDC-treated ischemic limbs and cutaneous wounds revealed that the production of monocyte chemoattractant factor 1 by exogenous and endogenous BMDCs is essential for BMDC-mediated vascular growth and tissue healing, while the inability of BMDCs to produce tumor necrosis factor α appears to play a lesser but still meaningful role. Thus, measurements of the secretion of cytokines by BMDCs may allow us to identify a priori individuals who would or would not be good candidates for BMDC-based therapies.