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Background and aimsThe initial description of a heterozygous dominant ACTG2 variant in familial visceral myopathy was followed by the identification of additional variants in other forms of intestinal dysmotility disorders. we aimed to describe the diverse phenotype of this newly reported and rare disease.MethodsReport of 4 new patients, and a systematic review of ACTG2-related disorders. we analyzed the population frequency and used in silico gene damaging predictions. Genotype-phenotype correlations were explored.ResultsOne hundred three patients (52% girls), from 14 publications, were included. Twenty-eight unique variants were analyzed, all exceedingly rare, and 27 predicted to be highly damaging. The median Combined Annotation Dependent Depletion (CADD) score was 29.2 (Interquartile range 26.3-29.4). Most patients underwent abdominal surgery (66%), about half required intermittent bladder catheterization (48.5%), and more than half were parenteral nutrition (PN)-dependent (53%). One-quarter of the patients died (25.7%), and 6 required transplant (5.8%). Girls had a higher rate of microcolon (P  = 0.009), PN dependency (P = 0.003), and death/transplant (P = 0.029) compared with boys, and early disease onset (

Grassland bird populations are being lost at an alarming rate due to human modifications to grassland ecosystems. Grassland restoration has been shown to mitigate population declines for many species that use these habitats at some point in their annual cycles. We examined capture rates of adult, breeding, and hatch-year birds at a restored grassland site in the piedmont of central Georgia to determine whether colonization, breeding success, hatching success, and recruitment processes were impacting populations of grassland birds. We banded birds approximately twice per month from January 2009 through December 2021 at Panola Mountain State Park. Restoration efforts started in 2001, and include annual prescribed burns, control of invasives, and revegetation with native grassland plants. We documented an increase in total capture rates when all grassland species were combined (p=0.03, [r.sup.2]=0.37) and for several grassland species, including Chipping Sparrows (p=0.01, [r.sup.2]=0.44) and Marsh Wrens (p=0.004, [r.sup.2]=0.55). Capture rates of grassland birds in breeding condition increased as well, including when grassland species were combined (p=0.01, [r.sup.2]=0.45), Common Yellowthroats (p=0.05, [r.sup.2]=0.30), Indigo Buntings (p=0.04, [r.sup.2]=0.34), and Field Sparrows (p=0.002, [r.sup.2]=0.59). Capture rates of hatch-year birds increased for Chipping Sparrows (p=0.02, [r.sup.2]=0.39). Species-specific responses to restoration occur at different rates depending on habitat preferences, yet the only species that significantly declined was the Red-winged Blackbird, a bird more associated with water than grasslands. We attribute these increases and, importantly, the lack of significant declines, to successful ongoing restoration, which is providing adequate and appropriate resources for grassland birds. If managers identify target species, we recommend that restoration efforts include activities that are aimed at species-specific habitat requirements and habitat-level threats of those target species. Keywords: grasslands, grassland restoration, mist netting, conservation, avian ecology, Passerellidae, Emberizidae, Passeriformes, Common Yellowthroat, Field Sparrow, sparrow., INTRODUCTION Grassland ecosystems are at risk throughout the United States, much of them having been lost or significantly altered by human actions such as conversion to agricultural lands, fire suppression, [...]

BackgroundChildren with very early onset inflammatory bowel diseases (VEO-IBD) often have a refractory and severe disease course. A significant number of described VEO-IBD-causing monogenic disorders can be attributed to defects in immune-related genes. The diagnosis of the underlying primary immunodeficiency (PID) often has critical implications for the treatment of patients with IBD-like phenotypes.MethodsTo identify the molecular etiology in 5 patients from 3 unrelated kindred with IBD-like symptoms, we conducted whole exome sequencing. Immune workup confirmed an underlying PID.ResultsWhole exome sequencing revealed 3 novel CARMIL2 loss-of-function mutations in our patients. Immunophenotyping of peripheral blood mononuclear cells showed reduction of regulatory and effector memory T cells and impaired B cell class switching. The T cell proliferation and activation assays confirmed defective responses to CD28 costimulation, consistent with CARMIL2 deficiency.ConclusionOur study highlights that human CARMIL2 deficiency can manifest with IBD-like symptoms. This example illustrates that early diagnosis of underlying PID is crucial for the treatment and prognosis of children with VEO-IBD.

Diarrhea is common in infants (children less than 2 years of age), usually acute, and, if chronic, commonly caused by allergies and occasionally by infectious agents. Congenital diarrheas and enteropathies (CODEs) are rare causes of devastating chronic diarrhea in infants. Evaluation of CODEs is a lengthy process and infrequently leads to a clear diagnosis. However, genomic analyses and the development of model systems have increased our understanding of CODE pathogenesis. With these advances, a new diagnostic approach is needed. We propose a revised approach to determine causes of diarrhea in infants, including CODEs, based on stool analysis, histologic features, responses to dietary modifications, and genetic tests. After exclusion of common causes of diarrhea in infants, the evaluation proceeds through analyses of stool characteristics (watery, fatty, or bloody) and histologic features, such as the villus to crypt ratio in intestinal biopsies. Infants with CODEs resulting from defects in digestion, absorption, transport of nutrients and electrolytes, or enteroendocrine cell development or function have normal villi to crypt ratios; defects in enterocyte structure or immune-mediated conditions result in an abnormal villus to crypt ratios and morphology. Whole-exome and genome sequencing in the early stages of evaluation can reduce the time required for a definitive diagnosis of CODEs, or lead to identification of new variants associated with these enteropathies. The functional effects of gene mutations can be analyzed in model systems such as enteroids or induced pluripotent stem cells and are facilitated by recent advances in gene editing procedures. Characterization and investigation of new CODE disorders will improve management of patients and advance our understanding of epithelial cells and other cells in the intestinal mucosa.

Background & aimsCrohn's disease (CD) has the highest prevalence in Ashkenazi Jewish populations. We sought to identify rare, CD-associated frameshift variants of high functional and statistical effects.MethodsWe performed exome sequencing and array-based genotype analyses of 1477 Ashkenazi Jewish individuals with CD and 2614 Ashkenazi Jewish individuals without CD (controls). To validate our findings, we performed genotype analyses of an additional 1515 CD cases and 7052 controls for frameshift mutations in the colony-stimulating factor 2-receptor β common subunit gene (CSF2RB). Intestinal tissues and blood samples were collected from patients with CD; lamina propria leukocytes were isolated and expression of CSF2RB and granulocyte-macrophage colony-stimulating factor-responsive cells were defined by adenomatous polyposis coli (APC) time-of-flight mass cytometry (CyTOF analysis). Variants of CSF2RB were transfected into HEK293 cells and the expression and functions of gene products were compared.ResultsIn the discovery cohort, we associated CD with a frameshift mutation in CSF2RB (P = 8.52 × 10(-4)); the finding was validated in the replication cohort (combined P = 3.42 × 10(-6)). Incubation of intestinal lamina propria leukocytes with granulocyte-macrophage colony-stimulating factor resulted in high levels of phosphorylation of signal transducer and activator of transcription (STAT5) and lesser increases in phosphorylation of extracellular signal-regulated kinase and AK straining transforming (AKT). Cells co-transfected with full-length and mutant forms of CSF2RB had reduced pSTAT5 after stimulation with granulocyte-macrophage colony-stimulating factor, compared with cells transfected with control CSF2RB, indicating a dominant-negative effect of the mutant gene. Monocytes from patients with CD who were heterozygous for the frameshift mutation (6% of CD cases analyzed) had reduced responses to granulocyte-macrophage colony-stimulating factor and markedly decreased activity of aldehyde dehydrogenase; activity of this enzyme has been associated with immune tolerance.ConclusionsIn a genetic analysis of Ashkenazi Jewish individuals, we associated CD with a frameshift mutation in CSF2RB. Intestinal monocytes from carriers of this mutation had reduced responses to granulocyte-macrophage colony-stimulating factor, providing an additional mechanism for alterations to the innate immune response in individuals with CD.

The decline of grassland ecosystems throughout the United States has caused population declines of many bird species, especially grassland specialists, which has led to greater interest in restoring these dwindling habitats with a combination of natural fire regimes and the replanting of native vegetation. In the southeastern United States, several species of birds use grassland habitats at critical points throughout the annual cycle, as breeding or wintering grounds or as migration stopover sites. Since April 2007, we have operated 9-11 mist nets at Panola Mountain State Park, in Rockdale County, Georgia, in an area that is being actively restored to native warm-season grasses. We captured 6,786 birds of 90 species between April 2007 and April 2019. Monthly capture rates overall increased significantly during critical times of the year--spring migration (March, F = 6.62, P = 0.03) and fall migration (August, F = 18.06, P = 0.003 and September, F = 6.31, P = 0.03). Capture rates of Indigo Buntings (Passerina cyanea) increased significantly from 2007 to 2019 (F = 7.75, P = 0.006) during fall migration (F = 16.44, P = 0.0007) and in August (F = 17.97, P = 0.003). Capture rates of Field Sparrows (Spizella pusilla) increased significantly during the breeding season (F = 4.90, P = 0.03), fall migration (F = 13.30, P = 0.001), April (F = 6.03, P = 0.03), August (F = 9.68, P = 0.01), and September (F = 15.18, P = 0.003). Given that the increases include wintering season, breeding season, and year-round resident species, we conclude that the restoration efforts at Panola Mountain State Park have had positive impacts on the avian community that uses this habitat throughout all portions of the year. Increases during fall migration (and August and September) and during March when some species are migrating north indicate that changes in habitat have resulted in Panola being an important site for migrating birds, potentially being used as a migratory stopover site. While a breeding analysis would reveal more concrete trends, the increases in grassland residents like Field Sparrows and grassland breeders like Indigo Buntings certainly suggest that breeding habitat has improved with the restoration of this site. Keywords: avian ecology, mist netting, grasslands, grassland restoration, banding, conservation, Indigo Bunting, Field Sparrow, INTRODUCTION Grassland ecosystems have declined throughout the United States in the last hundred years primarily from habitat conversion to agriculture and vegetation changes from fire suppression (Askins et al. 2007; [...]

The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. Although the actin-related protein 2/3 (Arp2/3) complex is necessary and sufficient for Listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation. Here, we show that Arp2/3 localized to only a minor portion of the protrusion. Moreover, treatment of L. monocytogenes-infected HeLa cells with a formin FH2-domain inhibitor significantly reduced protrusion length. In addition, the Diaphanous-related formins 1-3 (mDia1-3) localized to protrusions, and knockdown of mDia1, mDia2, and mDia3 substantially decreased cell-to-cell spread of L. monocytogenes. Rho GTPases are known to be involved in formin activation. Our studies also show that knockdown of several Rho family members significantly influenced bacterial cell-to-cell spread. Collectively, these findings identify a Rho GTPase-formin network that is critically involved in the cell-to-cell spread of L. monocytogenes.

BackgroundInherited deficiencies of IL-10 or IL-10 receptor (IL-10R) lead to immune dysregulation with life-threatening early-onset enterocolitis.ObjectivesWe sought to gather clinical data of IL-10/IL-10R-deficient patients and devise guidelines for diagnosis and management, including hematopoietic stem cell transplantation (HSCT).MethodsWe enrolled 40 patients with early-onset enterocolitis and screened for mutations in IL10/IL10R using genetic studies, functional studies, or both of the IL-10 signaling pathway. Medical records of IL-10/IL-10R-deficient patients were reviewed and compiled.ResultsOf 40 patients, we identified 7 with novel mutations, predominantly in consanguineous families with more than 1 affected member. IL-10/IL-10R-deficient patients had intractable enterocolitis, perianal disease, and fistula formation. HSCT was carried out in 2 patients with IL-10 deficiency and 1 patient with IL-10R α chain deficiency and proved to be an effective therapy, leading to rapid improvement of clinical symptoms and quality of life.ConclusionBecause the defect in patients with IL-10/IL-10R deficiency resides in hematopoietic lineage cells and their colitis is resistant to standard immunosuppressive therapy, HSCT should be considered early as a potentially curative therapeutic option.

Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium) model of colitis. In response to infection, Rac2(-/-) mice showed i) worsened clinical symptoms (days 13-18), ii) increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT), and iii) marked mononuclear cell infiltration characterized by higher numbers of T (CD3(+)) cells (day 22), compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2(-/-) mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2(-/-) mice did not appear to stem from Rac2's role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2(-/-) mice compared to WT. Collectively, our findings demonstrate that Rac2(-/-) mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans.