Efficacy and Safety of Advanced Therapies in Moderately-to-Severely Active Ulcerative Colitis: a Systematic Review and Network Meta-analysis.

INTRODUCTION: This study aimed to compare the efficacy and safety of biologics and small molecules for treatment of adults with moderately-to-severely active ulcerative colitis (UC). METHODS: A systematic literature review was conducted to identify randomised controlled trials evaluating approved and emerging targeted therapies for patients with UC. A Bayesian network meta-analysis (NMA) approach was applied. Outcomes assessed included clinical response and remission, endoscopic mucosal healing, and safety. RESULTS: Thirty studies were included in the NMA following a feasibility assessment comparing approved induction dosing regimens and 22 studies comparing approved maintenance dosing regimens. In the biologic/Janus kinase inhibitor (JAKi)-naïve population, induction studies showed similar clinical response and remission rates across most interventions, with upadacitinib demonstrating significant improvements versus most other interventions. For maintenance studies, mirikizumab demonstrated significant improvements in clinical response and remission versus most other interventions. In the biologic/JAKi-experienced population, no significant differences were observed between most interventions in induction studies, except for significantly improved clinical response and remission for mirikizumab versus adalimumab, and upadacitinib demonstrated significant improvement versus all other interventions. Few differences between active treatments were observed in maintenance studies. In both populations, all active interventions had similar efficacy in terms of endoscopic mucosal healing in both induction and maintenance studies. Regardless of prior treatment exposure, similar rates of serious adverse events were seen across all active interventions in the induction period. CONCLUSION: Among the available interventions, owing to its favourable efficacy and safety profile, mirikizumab has a relevant role in the long-term treatment of UC.

Burden of Bowel Urgency in Patients With Ulcerative Colitis and Crohn's Disease: A Real-World Global Study.

Background: Bowel urgency is a highly disruptive and bothersome symptom experienced by patients with inflammatory bowel diseases (IBD), (ulcerative colitis [UC], and Crohn's disease [CD]). However, the burden of bowel urgency among patients with varying experiences in targeted treatment has not been consistently assessed. This real-world study explored the clinical and health-related quality of life burden of bowel urgency among patients with IBD with differing treatment experiences. Methods: This cross-sectional survey included gastroenterologists and their patients with IBD across France, Germany, Italy, Spain, the United Kingdom, and the United States treated for over 3 months. Physicians provided patient demographics, clinical characteristics, and treatment history. Patients reported their health-related quality of life and work productivity. Patients with UC and CD were analyzed separately and stratified into 3 groups: Targeted therapy naïve, those receiving their first-line targeted therapy, and targeted therapy experienced. Results: This study found that 17%-26% of UC and 13%-17% of CD patients experienced persistent bowel urgency, irrespective of receiving conventional or targeted therapy. Moreover, patients with bowel urgency experienced an increased clinical and health-related quality of life burden compared to patients without bowel urgency, which physicians most commonly regarded as one of the most difficult symptoms to treat, with the burden remaining substantial irrespective of their treatment experience. Conclusions: Despite several current treatment options, new therapeutic strategies are necessary to provide relief from bowel urgency, one of the most challenging symptoms for people living with IBD.

Early and Sustained Symptom Control with Mirikizumab in Patients with Ulcerative Colitis in the Phase 3 LUCENT Programme.

BACKGROUND AND AIMS: Ulcerative colitis [UC], a chronic inflammatory bowel disease, may manifest with symptoms of increased stool frequency [SF], rectal bleeding [RB], bowel urgency [BU], abdominal pain [AP], and fatigue. Mirikizumab, an anti-IL-23p19 antibody, demonstrated efficacy and safety in patients with moderately to severely active UC in the LUCENT Phase 3 trials. We evaluated mirikizumab's efficacy in achieving symptom control and time to symptom improvement during induction, maintenance of sustained symptom control, 'comprehensive symptom control', defined according to a combination of individual patient-reported outcomes, and prognostic baseline indicators of early symptomatic remission at Week 4. METHODS: The results of LUCENT-1/-2 have previously been reported. Treatment differences for symptomatic endpoints were compared over 52 weeks versus placebo [PBO] and comprehensive symptomatic endpoints at 12 and 52 weeks of continuous treatment. Subgroup analyses were conducted for prior biologic or tofacitinib treatment failure. Prognostic analyses were run using regression analysis. RESULTS: By Week [W] 2, mirikizumab-treated patients achieved greater reductions in SF, RB, BU, and fatigue versus PBO. At W4, there was a higher rate of AP improvement. At W12, a greater proportion of mirikizumab-treated patients achieved symptomatic remission, RB remission, SF remission, and BU remission/clinically meaningful improvement. Mirikizumab-treated patients sustained symptom control versus placebo patients in maintenance until W52. This treatment effect was shown in patients regardless of prior biologic or tofacitinib failure. Additionally, mirikizumab achieved comprehensive symptom control versus PBO at W12 and W52. CONCLUSIONS: Mirikizumab demonstrated efficacy in achieving and sustaining symptom control and comprehensive symptom control over 52 weeks [NCT03518086; NCT03524092].

Real-World Treatment Patterns and Healthcare Resource Use for Ulcerative Colitis and Crohn's Disease in Italy.

INTRODUCTION: Real-world data are used to inform decision-makers and optimise therapeutic management for patients with ulcerative colitis (UC) and Crohn's disease (CD). We analysed data on the epidemiology (by using proxies of prevalence and incidence), patient characteristics, treatment patterns and associated healthcare direct costs for the management of patients with UC and patients with CD in Italy. METHODS: This retrospective observational study used administrative databases from eight Local Health Units geographically distributed across Italy. Adult patients with a hospitalisation and/or an exemption for UC or CD were included. Study outcomes were summarised descriptively, and limited statistical tests were performed. RESULTS: At baseline, 9255 adults with UC and 4747 adults with CD were included. Mean (standard deviation) age at inclusion was 54.0 (18.4)/48.6 (18.1) years, for UC/CD. The estimated average incidence of UC and CD for the period 2013-2020 was 36.5 and 18.7 per 100,000, respectively. The most frequently prescribed drug category for patients with UC/CD was conventional treatment [mesalazine and topical corticosteroids (67.4%/61.1%), immunomodulators and systemic corticosteroids (43.2%/47.7%)], followed by biologic treatments (2.1%/5.1%). The mean annual total direct cost per patient was 7678 euro (€), for UC and €6925 for CD. CONCLUSION: This analysis, carried-out in an Italian clinical setting, may help to optimise therapy for patients with UC and CD and provide relevant clinical practice data to inform decision-makers.

Data from clinical practice can be used to guide healthcare decisions and optimise treatment for patients with ulcerative colitis and Crohn's disease. This study used anonymised patient information from almost four million individuals across Italy to describe the epidemiology, patient characteristics, treatment patterns and healthcare costs of patients with ulcerative colitis and Crohn's disease. Adults with an Italian National Health System code in their records associated with the diagnosis of ulcerative colitis or Crohn's disease were included. Baseline characteristics were balanced between groups and rates of perceived incidence were numerically similar to the results reported in similar Italian studies. This study found that patients with ulcerative colitis and Crohn's disease were most often prescribed conventional treatments, and biological treatments were least-commonly prescribed. More than half of patients with ulcerative colitis and nearly half of those with Crohn's disease were persistent with first (index) treatment of mesalazine and topical corticosteroids and with biologic index treatment during the follow-up period. Switch occurred in up to approximately a quarter of patients with ulcerative colitis and Crohn's disease. The main factors that predicted switch were index biologic for ulcerative colitis and baseline comorbidities for Crohn's disease. The average direct cost per patient in 1 year was 7678 euro (€) for ulcerative colitis and €6925 for Crohn's disease. The results of this analysis may help to optimise therapy for patients with ulcerative colitis and Crohn's disease, and to inform decision-makers in healthcare systems on which treatment options provide value for money and benefit patients.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials.

INTRODUCTION: Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer. AREAS COVERED: This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission. EXPERT OPINION: Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

Ulcerative colitis (UC) is the most common inflammatory bowel disease and often results in bloody diarrhea, frequent bowel movements, and bowel urgency. Patients with UC are at greater risk for hospitalization, surgery, and colorectal cancer. To reduce these risks, the goals of UC treatment are changing from mainly addressing symptoms to reducing inflammation at a deeper histologic, or microscopic, level. The inflammation in UC causes distinct microscopic changes in the colon, which can be assessed after collecting biopsies or tissue samples. This review provides an overview of histologic remission (when no signs of inflammation are seen in tissue samples viewed under a microscope) as a treatment goal in UC.Histologic remission has been shown to be associated with lower rates of relapse, hospitalization, surgical removal of the colon, and colorectal cancer. However, using histologic remission as a treatment target can be difficult due to varying definitions and the many different scoring assessments available to healthcare providers. Updated guidance from regulatory agencies and academic organizations has helped align definitions of histologic remission and how to assess histologic healing in clinical trials.The introduction of targeted advanced therapies has allowed for deeper healing with the potential for histologic resolution. This enables clinicians and researchers to aim for treatment targets that are harder to achieve but have a greater impact for patients in the course of their disease. New technologies such as artificial intelligence, high-resolution endoscopy, and digital pathology have also led to targets beyond histologic healing, aiming to restore the function of the colon's mucosal barrier and disease clearance.

REPRODUCTIVE CYCLE STAGE ASSESSMENT IN THE TWO-TOED SLOTH (CHOLOEPUS HOFFMANNI), PRELIMINARY RESULTS.

The number of two-toed sloths (Choloepus hoffmanni) has significantly decreased in the last years. Deepening the knowledge of this tropical mammal's reproductive physiology is essential to improve captive breeding within conservation programs for this species. However, several aspects of its reproductive biology remain unexplored and have not been described sufficiently. The aim of this work was to describe the estrous cycle and reproductive physiology of two adult female C. hoffmanni by vaginal cytology, appearance of the external genitalia, and behavior. Vaginal cytology assay showed that the average duration of the estrous cycle was 15.1 ± 4.53 d. Positive correlations (P < 0.05) were found between the peak presence of superficial cells (estrous phase) and four parameters: aggressive behavior, pursuing behavior, vulvar swelling, and vaginal discharge. This pilot study, conducted on just two animals, forms a basis for a study design that may be employed for a more comprehensive assessment of the two-toed sloth reproductive physiology and behavior.

Extended Induction and Prognostic Indicators of Response in Patients Treated with Mirikizumab with Moderately to Severely Active Ulcerative Colitis in the LUCENT Trials.

BACKGROUND: Efficacy and safety of mirikizumab, a p19-targeted anti-interleukin-23 monoclonal antibody, for moderately to severely active ulcerative colitis was demonstrated previously. We evaluated clinical response, baseline characteristics, and clinical status in patients not responding by 12 weeks (W) of induction who then received extended induction treatment. METHOD: Patients unresponsive to 300 mg of intravenous (IV) mirikizumab every 4 weeks by W12 received 3 additional 300 mg IV doses every 4 weeks. Week-4 responders received 200 mg mirikizumab every 4 weeks subcutaneously until W52. Patients responding by W12 but subsequently losing response received rescue therapy with 300 mg IV for 3 doses every 4 weeks. Logistic regression modelling was performed for patients not achieving W12 clinical response to assess baseline characteristics and W12 efficacy parameters and potential prognostic factors of clinical response at W24. RESULTS: Of patients not achieving clinical response during induction, 53.7% achieved response following extended induction. After 52W, 72.2%, 43.1%, and 36.1% of patients achieved clinical response, endoscopic, and clinical remission, respectively. Of induction responders who subsequently lost response, 63.2% and 36.8% achieved symptomatic response and remission, respectively, after receiving rescue therapy No prior biologic or tofacitinib treatment, no immunomodulators at baseline, age older than 40 years, and W12 modified Mayo Score improvement were positively associated with a response to extended induction. The safety profile was similar to initial induction, with 38.3% treatment emergent adverse events, mostly mild. CONCLUSION: With "extended induction," total of 80.3% mirikizumab-treated patients achieved clinical response by W24. Potential prognostic factors determining response include disease severity, disease phenotype, C-reactive protein, and previous biologic therapy.

Extended induction with mirikizumab led to clinical response in more than half of primary nonresponders. Intravenous reinduction therapy in patients losing response during treatment led to more than 60% achieving symptomatic response, confirming the clinical benefit of these treatment strategies for harder to treat patients.

Clinical profiles and outcomes in patients with inflammatory bowel disease receiving standard and escalated doses of targeted therapies: findings from a global real-world study.

OBJECTIVE: Although dosing regimens of targeted therapies (TT) for ulcerative colitis (UC) and Crohn's disease (CD) are guided by market authorizations and clinical guidelines, little is known about clinical guideline adherence or outcomes in patients receiving escalated doses of TT due to lack of response. This real-world study explored the prevalence of dose escalation and compared outcomes between patients receiving standard and escalated TT doses. METHODS: Data were from the 2020-2021 Adelphi Disease Specific Programme for inflammatory bowel disease, a cross-sectional survey of gastroenterologists and their UC and CD patients across five European countries and the US. Physicians provided retrospective data collection of patient demographics, clinical characteristics, treatment history, and satisfaction; patients reported quality-of-life and work productivity. Patients were grouped by TT maintenance dose; standard and escalated dose groups were compared. Outcomes were adjusted for time on current TT and severity at current TT initiation using regression analyses. RESULTS: Of 1,241 UC and 1,477 CD patients, 19.1% and 24.1%, respectively, received escalated TT doses. Despite escalation, a substantial proportion of patients had not achieved remission, had moderate or severe disease activity, or were flaring. Most physicians were not fully satisfied with treatment in the escalated dose group and were more likely to switch patients to another treatment regimen than patients on standard dose. CONCLUSION: Dose escalation is not always an effective approach to resolve inadequate or loss of response in UC and CD, highlighting a need for more therapeutic options or alternative treatment strategies in patients unresponsive to TT.

Clinical profiles and outcomes in patients with ulcerative colitis receiving standard and higher-than-standard doses of vedolizumab: findings from a real-world study in Europe.

OBJECTIVE: Vedolizumab is an antibody targeting α4ß7 integrin used in the treatment of ulcerative colitis (UC). Patients are commonly prescribed higher-than-standard doses if treatment response is inadequate, but little is known about the drivers and impact of increased dosing. Our objective was to use real-world data to describe vedolizumab dosages in current clinical practice, patient characteristics, physicians' reasons for prescribing vedolizumab, and physician treatment satisfaction. METHODS: Data were derived from the Adelphi Real World UC vedolizumab Chart Review, a cross-sectional survey of gastroenterologists and their UC patients, conducted in France, Germany, Italy, Spain, and the United Kingdom between December 2022 and March 2023. Gastroenterologists provided data on patient demographics, clinical characteristics, treatment and vedolizumab dosage history, reasons for dose choice, and treatment satisfaction. RESULTS: Data were returned on 448 patients by 112 gastroenterologists. Overall, 83.5% of patients were on a standard vedolizumab dose and 10.3% were on a higher-than-standard dose. The worsening of symptoms was the most cited reason for higher doses. Most reported symptoms at survey were fatigue, abdominal distention or pain, diarrhea, and bowel urgency, with the latter particularly in higher-than-standard dose patients. Patients on higher-than-standard dose had high rates of mild (37.0%) or moderate (26.1%) disease, and low rates of remission (33.8%). Physicians were dissatisfied with treatment control for 2.7% of standard and 26.1% of higher-than-standard dose patients. CONCLUSIONS: Over 10% of patients were receiving a higher-than-standard dose of vedolizumab, but despite this were found to have suboptimal clinical outcomes and low physician satisfaction.

Bowel Urgency in Ulcerative Colitis: Current Perspectives and Future Directions.

Bowel urgency (BU), the sudden or immediate need for a bowel movement, is one of the most common and disruptive symptoms experienced by patients with ulcerative colitis (UC). Distinct from the separate symptom of increased stool frequency, BU has a substantial negative impact on quality of life and psychosocial functioning. Among patients with UC, BU is one of the top reasons for treatment dissatisfaction and one of the symptoms patients most want improved. Patients may not discuss BU often due to embarrassment, and healthcare providers may not address the symptom adequately due to the lack of awareness of validated tools and/or knowledge of the importance of assessing BU. The mechanism of BU in UC is multifactorial and includes inflammatory changes in the rectum that may be linked to hypersensitivity and reduced compliance of the rectum. Responsive and reliable patient-reported outcome measures of BU are needed to provide evidence of treatment benefits in clinical trials and facilitate communication in clinical practice. This review discusses the pathophysiology and clinical importance of BU in UC and its impact on the quality of life and psychosocial functioning. Patient-reported outcome measures developed to assess the severity of BU in UC are discussed alongside overviews of treatment options and clinical guidelines. Implications for the future management of UC from the perspective of BU are also explored.

Resolving Histological Inflammation in Ulcerative Colitis With Mirikizumab in the LUCENT Induction and Maintenance Trial Programmes.

BACKGROUND AND AIMS: To evaluate the effect of mirikizumab, a p19-targeted anti-interleukin-23, on histological and/or endoscopic outcomes in moderately-to-severely active ulcerative colitis [UC]. METHODS: Endoscopic remission [ER], histological improvement [HI], histological remission [HR], histological-endoscopic mucosal improvement [HEMI], and histological-endoscopic mucosal remission [HEMR] were assessed at Week [W]12 [LUCENT-1: N = 1162, induction] and W40 [LUCENT-2: N = 544, maintenance] for patients randomised to mirikizumab or placebo. Analyses were performed to evaluate predictors of: HEMI at W12 with mirikizumab and HEMR at W40 in patients re-randomised to subcutaneous [SC] mirikizumab; associations between W12 histological/endoscopic endpoints and W40 outcomes in mirikizumab responders re-randomised to mirikizumab SC; and associations between W40 endoscopic normalisation [EN] with/without HR. RESULTS: Significantly more patients treated with mirikizumab achieved HI, HR, ER, HEMI, and HEMR vs placebo [p <0.001], irrespective of prior biologic/tofacitinib failure [p <0.05]. Lower clinical baseline disease activity, female sex, no baseline immunomodulator use, and no prior biologic/tofacitinib failure were predictors of HEMI at W12 [p <0.05]. Corticosteroid use and longer disease duration were negative predictors of achieving HEMR at W40 [p <0.05]. W12 HI, HR, or ER was associated with W40 HEMI or HEMR [p <0.05]; ER at W12 was associated with clinical remission [CR] [p <0.05] and corticosteroid-free remission [CSFR] at W40 [p = 0.052]. HR and HEMR at W12 were associated with CSFR, CR, and symptomatic remission at W40. Alternate HEMR [EN + HR] at W40 was associated with bowel urgency remission at W40 [p <0.05]. CONCLUSIONS: Early resolution of endoscopic and histological inflammation with mirikizumab is associated with better UC outcomes. Clinicaltrials.gov: LUCENT-1, NCT03518086; LUCENT-2, NCT03524092.

Zrsr2 and functional U12-dependent spliceosome are necessary for follicular development.

ZRSR2 is a splicing factor involved in recognition of 3'-intron splice sites that is frequently mutated in myeloid malignancies and several tumors; however, the role of mutations of Zrsr2 in other tissues has not been analyzed. To explore the biological role of ZRSR2, we generated three Zrsr2 mutant mouse lines. All Zrsr2 mutant lines exhibited blood cell anomalies, and in two lines, oogenesis was blocked at the secondary follicle stage. RNA-seq of Zrsr2 mu secondary follicles showed aberrations in gene expression and showed altered alternative splicing (AS) events involving enrichment of U12-type intron retention (IR), supporting the functional Zrsr2 action in minor spliceosomes. IR events were preferentially associated with centriole replication, protein phosphorylation, and DNA damage checkpoint. Notably, we found alterations in AS events of 50 meiotic genes. These results indicate that ZRSR2 mutations alter splicing mainly in U12-type introns, which may affect peripheral blood cells, and impede oogenesis and female fertility.

Role of Alternative Splicing in Sex Determination in Vertebrates.

During the process of sex determination, a germ-cell-containing undifferentiated gonad is converted into either a male or a female reproductive organ. Both the composition of sex chromosomes and the environment determine sex in vertebrates. It is assumed that transcription level regulation drives this cascade of mechanisms; however, transcription factors can alter gene expression beyond transcription initiation by controlling pre-mRNA splicing and thereby mRNA isoform production. Using the key time window in sex determination and gonad development in mice, it has been reported that new non-transcriptional events, such as alternative splicing, could play a key role in sex determination in mammals. We know the role of key regulatory factors, like WT1(+/-KTS) or FGFR2(b/c) in pre-mRNA splicing and sex determination, indicating that important steps in the vertebrate sex determination process probably operate at a post-transcriptional level. Here, we discuss the role of pre-mRNA splicing regulators in sex determination in vertebrates, focusing on the new RNA-seq data reported from mice fetal gonadal transcriptome.

Aberrant Alternative Splicing in U2af1/Tet2 Double Mutant Mice Contributes to Major Hematological Phenotypes.

Mutations in splicing factors are recurrent somatic alterations identified in myelodysplastic syndromes (MDS) and they frequently coincide with mutations in epigenetic factors. About 25% of patients present concurrent mutations in such pathways, suggesting a cooperative role in the pathogenesis of MDS. We focused on the splicing factor U2AF1 involved in the recognition of the 3' splice site during pre-mRNA splicing. Using a CRISPR/Cas9 system, we created heterozygous mice with a carboxy-terminal truncated U2af1 allele (U2af1mut/+), studied the U2af1mut/+ hematopoietic system, and did not observe any gross differences in both young (12-13 weeks) and old (23 months) U2af1mut/+ mice, except for a reduction in size of approximately 20%. However, hematopoietic stem/progenitor cells lacked reconstitution capacity in transplantation assays and displayed an aberrant RNA splicing by RNA sequencing. We also evaluated U2af1mut/+ in conjunction with Tet2-deficiency. Novel double mutant U2af1mut/+Tet2-/- mice showed increased monogranulocytic precursors. Hematopoietic stem/progenitor cells were also enhanced and presented functional and transcriptomic alterations. Nonetheless, U2af1mut/+Tet2-/- mice did not succumb to MDS disease over a 6-month observation period. Collectively, our data suggest that cooperation between mutant U2af1 and Tet2 loss is not sufficient for MDS initiation in mice.

MicroRNAs in amniotic fluid and maternal blood plasma associated with sex determination and early gonad differentiation in cattle†.

We hypothesized that sexually dimorphic differences exist in the expression of miRNAs in amniotic fluid (AF) and maternal blood plasma (MP) in association with the process of sex determination and gonad differentiation in cattle. Amniotic fluid and MP were collected from six pregnant heifers (three carrying a single male and three a single female embryo) following slaughter on Day 39 postinsemination, coinciding with the peak of SRY expression. Samples (six AF and six MP) were profiled using an miRNA Serum/Plasma Focus PCR Panel. Differentially expressed (DE) miRNAs were identified in AF (n = 5) and associated MP (n = 56) of male vs. female embryos (P < 0.05). Functional analysis showed that inflammatory and immune response were among the 13 biological processes enriched by miRNAs DE in MP in the male group (FDR < 0.05), suggesting that these sex-dependent DE miRNAs may be implicated in modulating the receptivity of the dam to a male embryo. Further, we compared the downstream targets of the sex-dependent DE miRNAs detected in MP with genes previously identified as DE in male vs. female genital ridges. The analyses revealed potential targets that might be important during this developmental stage such as SHROOM2, DDX3Y, SOX9, SRY, PPP1CB, JARID2, USP9X, KDM6A, and EIF2S3. Results from this study highlight novel aspects of sex determination and embryo-maternal communication in cattle such as the potential role of miRNAs in gonad development as well as in the modulation of the receptivity of the dam to a male embryo.

Genome-wide DNA methylation dynamics during epigenetic reprogramming in the porcine germline.

BACKGROUND: Prior work in mice has shown that some retrotransposed elements remain substantially methylated during DNA methylation reprogramming of germ cells. In the pig, however, information about this process is scarce. The present study was designed to examine the methylation profiles of porcine germ cells during the time course of epigenetic reprogramming. RESULTS: Sows were artificially inseminated, and their fetuses were collected 28, 32, 36, 39, and 42 days later. At each time point, genital ridges were dissected from the mesonephros and germ cells were isolated through magnetic-activated cell sorting using an anti-SSEA-1 antibody, and recovered germ cells were subjected to whole-genome bisulphite sequencing. Methylation levels were quantified using SeqMonk software by performing an unbiased analysis, and persistently methylated regions (PMRs) in each sex were determined to extract those regions showing 50% or more methylation. Most genomic elements underwent a dramatic loss of methylation from day 28 to day 36, when the lowest levels were shown. By day 42, there was evidence for the initiation of genomic re-methylation. We identified a total of 1456 and 1122 PMRs in male and female germ cells, respectively, and large numbers of transposable elements (SINEs, LINEs, and LTRs) were found to be located within these PMRs. Twenty-one percent of the introns located in these PMRs were found to be the first introns of a gene, suggesting their regulatory role in the expression of these genes. Interestingly, most of the identified PMRs were demethylated at the blastocyst stage. CONCLUSIONS: Our findings indicate that methylation reprogramming in pig germ cells follows the general dynamics shown in mice and human, unveiling genomic elements that behave differently between male and female germ cells.

Minor Splicing Factors Zrsr1 and Zrsr2 Are Essential for Early Embryo Development and 2-Cell-Like Conversion.

Minor splicing plays an important role in vertebrate development. Zrsr1 and Zrsr2 paralog genes have essential roles in alternative splicing, mainly participating in the recognition of minor (U12) introns. To further explore their roles during early embryo development, we produced Zrsr1mu and Zrsr2mu mutant mice, containing truncating mutations within the second zinc finger domain. Both homozygous mutant mice were viable with a normal lifespan. When we crossed a homozygous Zrsr2mu/mu female with Zrsr1mu/mu male, the double heterozygotes were non-viable, giving rise to embryos that stopped developing mainly between the 2- and 4-cell stages, just after zygotic gene activation. RNA-seq analysis of Zrsr1/2mu 2-cell embryos showed altered gene and isoform expression of thousands of genes enriched in gene ontology terms and biological pathways related to ribosome, RNA transport, spliceosome, and essential zygotic gene activation steps. Alternative splicing was analyzed, showing a significant increase in intron retention in both U2 and U12 intron-containing genes related to cell cycle and mitotic nuclear division. Remarkably, both Zrsr1 and Zrsr2 were required for the conversion of mouse-induced pluripotent stem cells into 2C-like cells. According to our results, Zrsr1 or Zrsr2 are necessary for ZGA and both are indispensable for the conversion of induced pluripotent stem cells into 2C-like cells.

Gene expression profiles of bovine genital ridges during sex determination and early differentiation of the gonads†.

Most current knowledge of sex determination in mammals has emerged from mouse and human studies. To investigate the molecular regulation of the sex determination process in cattle, we used an RNA sequencing strategy to analyze the transcriptome landscape of male and female bovine fetal gonads collected in vivo at key developmental stages: before, during, and after SRY gene activation on fetal days D35 (bipotential gonad formation), D39 (peak SRY expression), and D43 (early gonad differentiation). Differentially expressed genes (DEGs) were identified in male vs. female germinal ridges and among group genes showing similar expression profiles during the three periods. There were 143, 96, and 658 DEG between males and female fetuses at D35, D39, and D43, respectively. On D35, genes upregulated in females were enriched in translation, nuclear export, RNA localization, and mRNA splicing events, whereas those upregulated in males were enriched in cell proliferation regulation and male sex determination terms. In time-course experiments, 767 DEGs in males and 545 DEGs in females were identified between D35 vs. D39, and 3157 DEGs in males and 2008 in females were identified between D39 vs. D43. Results highlight unique aspects of sex determination in cattle, such as the expression of several Y chromosome genes (absent in mice and humans) before SRY expression and an abrupt increase in the nuclear expression of SOX10 (instead of SOX9 expression in the Sertoli cell cytoplasm as observed in mice) during male determination and early differentiation.

Soluble human Suppression of Tumorigenicity 2 is associated with endoscopic activity in patients with moderate-to-severe ulcerative colitis treated with golimumab.

BACKGROUND: Suppressor of Tumorigenicity 2 (ST2) is an IL33 receptor detected in the mucosa and serum of ulcerative colitis (UC) patients. We evaluated soluble ST2 (sST2) as a surrogate biomarker of disease outcome and therapeutic response, in moderate-to-severe UC patients treated with golimumab. METHODS: We conducted an open-label single-arm multicentre prospective study. At screening/baseline, week 6 (W6) and week 16 (W16), clinical and endoscopic activity (total Mayo score), histologic activity (Geboes index) and biomarkers were evaluated. RESULTS: From 38 patients, 34 (89.5%) completed W6 and 29 (76.3%) completed W16. Mean age (±SD) was 34.6 ± 12.6 years; 55.9% were female. At W16, 62.1% achieved clinical response. Patients with endoscopic activity at W6 (n = 20) had higher baseline sST2 (median, 24.5 versus 18.7 ng/ml, p = 0.026) and no decrease from baseline (median change, 0.8 versus -2.7, p = 0.029). At W6, sST2 levels correlated with endoscopic activity (rs = 0.45, p = 0.007) but not with histological activity (rs = 0.25, p = 0.151). The best cut-offs for endoscopic activity were sST2 = 16.9 ng/ml (sensitivity = 85%; specificity = 71%) and faecal calprotectin (FC) = 353 µg/g (sensitivity = 90%, specificity = 67%). Patients with histological activity at W6 (n = 27) had higher baseline ST2 levels (median, 23.0 versus 13.7 ng/ml, p = 0.035). sST2 did not correlate with FC or serum C-reactive protein. FC levels correlated with histological activity and baseline FC were higher when Geboes ⩾3.1 at W6. CONCLUSIONS: sST2 may be a surrogate biomarker of UC activity and therapeutic response as it correlates with endoscopic and clinical activity at W6 of golimumab treatment, and subjects with endoscopic and histological activity at W6 had higher baseline ST2 levels.

Sex-Dimorphic Behavioral Alterations and Altered Neurogenesis in U12 Intron Splicing-Defective Zrsr1 Mutant Mice.

Mutant mice with respect to the splicing factor Zrsr1 present altered spermatogenesis and infertility. To investigate whether Zrsr1 is involved in the homeostatic control that the hypothalamus exerts over reproductive functions, we first analyzed both differential gene and isoform expression and alternative splicing alterations in Zrsr1 mutant (Zrsr1mu) hypothalamus; second, we analyzed the spontaneous and social behavior of Zrsr1mu mice; and third, we analyzed adult cell proliferation and survival in the Zrsr1mu hypothalamus. The Zrsr1mu hypothalamus showed altered expression of genes and isoforms related to the glutathione metabolic process, synaptonemal complex assembly, mRNA transport, and altered splicing events involving the enrichment of U12-type intron retention (IR). Furthermore, increased IR in U12-containing genes related with the prolactin, progesterone, and gonadotropin-releasing hormone (GnRH) reproductive signaling pathway was observed. This was associated with a hyperactive phenotype in both males and females, with an anxious phenotype in females, and with increased social interaction in males, instead of the classical aggressive behavior. In addition, Zrsr1mu females but not males exhibited reduced cell proliferation in both the hypothalamus and the subventricular zone. Overall, these results suggest that Zrsr1 expression and function are relevant to organization of the hypothalamic cell network controlling behavior.