Infant and adult human intestinal enteroids are morphologically and functionally distinct.

Human intestinal enteroids (HIEs) are gaining recognition as physiologically relevant models of the intestinal epithelium. While HIEs from adults are used extensively in biomedical research, few studies have used HIEs from infants. Considering the dramatic developmental changes that occur during infancy, it is important to establish models that represent infant intestinal characteristics and physiological responses. We established jejunal HIEs from infant surgical samples and performed comparisons to jejunal HIEs from adults using RNA sequencing (RNA-Seq) and morphologic analyses. We then validated differences in key pathways through functional studies and determined whether these cultures recapitulate known features of the infant intestinal epithelium. RNA-Seq analysis showed significant differences in the transcriptome of infant and adult HIEs, including differences in genes and pathways associated with cell differentiation and proliferation, tissue development, lipid metabolism, innate immunity, and biological adhesion. Validating these results, we observed a higher abundance of cells expressing specific enterocyte, goblet cell, and enteroendocrine cell markers in differentiated infant HIE monolayers, and greater numbers of proliferative cells in undifferentiated 3D cultures. Compared to adult HIEs, infant HIEs portray characteristics of an immature gastrointestinal epithelium including significantly shorter cell height, lower epithelial barrier integrity, and lower innate immune responses to infection with an oral poliovirus vaccine. HIEs established from infant intestinal tissues reflect characteristics of the infant gut and are distinct from adult cultures. Our data support the use of infant HIEs as an ex vivo model to advance studies of infant-specific diseases and drug discovery for this population. IMPORTANCE: Tissue or biopsy stem cell-derived human intestinal enteroids are increasingly recognized as physiologically relevant models of the human gastrointestinal epithelium. While enteroids from adults and fetal tissues have been extensively used for studying many infectious and non-infectious diseases, there are few reports on enteroids from infants. We show that infant enteroids exhibit both transcriptomic and morphological differences compared to adult cultures. They also differ in functional responses to barrier disruption and innate immune responses to infection, suggesting that infant and adult enteroids are distinct model systems. Considering the dramatic changes in body composition and physiology that begin during infancy, tools that appropriately reflect intestinal development and diseases are critical. Infant enteroids exhibit key features of the infant gastrointestinal epithelium. This study is significant in establishing infant enteroids as age-appropriate models for infant intestinal physiology, infant-specific diseases, and responses to pathogens.

Infant and Adult Human Intestinal Enteroids are Morphologically and Functionally Distinct.

Background & Aims: Human intestinal enteroids (HIEs) are gaining recognition as physiologically relevant models of the intestinal epithelium. While HIEs from adults are used extensively in biomedical research, few studies have used HIEs from infants. Considering the dramatic developmental changes that occur during infancy, it is important to establish models that represent infant intestinal characteristics and physiological responses. Methods: We established jejunal HIEs from infant surgical samples and performed comparisons to jejunal HIEs from adults using RNA sequencing (RNA-Seq) and morphologic analyses. We validated differences in key pathways through functional studies and determined if these cultures recapitulate known features of the infant intestinal epithelium. Results: RNA-Seq analysis showed significant differences in the transcriptome of infant and adult HIEs, including differences in genes and pathways associated with cell differentiation and proliferation, tissue development, lipid metabolism, innate immunity, and biological adhesion. Validating these results, we observed a higher abundance of cells expressing specific enterocyte, goblet cell and enteroendocrine cell markers in differentiated infant HIE monolayers, and greater numbers of proliferative cells in undifferentiated 3D cultures. Compared to adult HIEs, infant HIEs portray characteristics of an immature gastrointestinal epithelium including significantly shorter cell height, lower epithelial barrier integrity, and lower innate immune responses to infection with an oral poliovirus vaccine. Conclusions: HIEs established from infant intestinal tissues reflect characteristics of the infant gut and are distinct from adult cultures. Our data support the use of infant HIEs as an ex-vivo model to advance studies of infant-specific diseases and drug discovery for this population.

Comparison of Bruker Biotyper® and Vitek® MS matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry platforms for the identification of filamentous fungi.

Aims: To evaluate the performance of two matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry platforms to identify molds isolated from clinical specimens. Methods: Fifty mold isolates were analyzed on Bruker Biotyper® and Vitek® MS platforms. Two Bruker Biotyper extraction protocols were assessed alongside the US FDA-approved extraction protocol for Vitek MS. Results: The Bruker Biotyper modified NIH-developed extraction protocol correctly identified more isolates than Bruker's protocol (56 vs 33%). For species in the manufacturers' databases, Vitek MS correctly identified 85% of isolates, with 8% misidentifications. The Bruker Biotyper identified 64%, with no misidentifications. For isolates not in the databases, the Bruker Biotyper did not misidentify any, and Vitek MS misidentified 36%. Conclusion: Both the Vitek MS and Bruker Biotyper accurately identified the fungal isolates, however Vitek MS was more likely to misidentify isolates than the Bruker Biotyper.

There are two different mass spectrometry systems that can be used in the hospital laboratory to find out what kind of mold is growing from a patient sample: the Vitek^® MS and Bruker Biotyper^® systems. This study compared how well they work for mold identification and also looked at two different ways to prepare the mold for testing. The Vitek MS system identified more molds, but also made more mistakes when identifying them. The Bruker Biotyper identified fewer molds but did not make any mistakes on the identification. The Vitek MS system sometimes gets the type of mold wrong, so more tests may be needed to be sure of the result. The Bruker Biotyper is more accurate because it got all of the molds correct, but it could not identify as many.

Association of Variants of Arginine Vasopressin and Arginine Vasopressin Receptor 1A With Severe Acetaminophen Liver Injury.

BACKGROUND & AIMS: Acetaminophen-related acute liver injury and liver failure (ALF) result from ingestion of supratherapeutic quantities of this analgesic, frequently in association with other forms of substance abuse including alcohol, opioids, and cocaine. Thus, overdosing represents a unique high-risk behavior associated with other forms of drug use disorder. METHODS: We examined a series of 21 single nucleotide polymorphisms (SNPs) in 9 genes related to impulsivity and/or stress responsivity that may modify response to stress. Study subjects were 229 white patients admitted to tertiary care liver centers for ALF that was determined to be due to acetaminophen toxicity after careful review of historical and biochemical data. Identification of relevant SNPs used Sanger sequencing, TaqMan, or custom microarray. Association tests were carried out to compare genotype frequencies between patients and healthy white controls. RESULTS: The mean age was 37 years, and 75.6% were female, with similar numbers classified as intentional overdose or unintentional (without suicidal intent, occurring for a period of several days, usually due to pain). There was concomitant alcohol abuse in 30%, opioid use in 33.6%, and use of other drugs of abuse in 30.6%. The genotype frequencies of 2 SNPs were found to be significantly different between the cases and controls, specifically SNP rs2282018 in the arginine vasopressin gene (AVP, odds ratio 1.64) and SNP rs11174811 in the AVP receptor 1A gene (AVPR1A, odds ratio 1.89), both of which have been previously linked to a drug use disorder diagnosis. CONCLUSIONS: Patients who develop acetaminophen-related ALF have increased frequency of gene variants that may cause altered stress responsivity, which has been shown to be associated with other unrelated substance use disorders.

Interactions of Renal-Clearable Gold Nanoparticles with Tumor Microenvironments: Vasculature and Acidity Effects.

The success of nanomedicines in the clinic depends on our comprehensive understanding of nano-bio interactions in tumor microenvironments, which are characterized by dense leaky microvasculature and acidic extracellular pH (pHe ) values. Herein, we investigated the accumulation of ultrasmall renal-clearable gold NPs (AuNPs) with and without acidity targeting in xenograft mouse models of two prostate cancer types, PC-3 and LNCaP, with distinct microenvironments. Our results show that both sets of AuNPs could easily penetrate into the tumors but their uptake and retention were mainly dictated by the tumor microvasculature and the enhanced permeability and retention effect over the entire targeting process. On the other hand, increased tumor acidity indeed enhanced the uptake of AuNPs with acidity targeting, but only for a limited period of time. By making use of simple surface chemistry, these two effects can be synchronized in time for high tumor targeting, opening new possibilities to further improve the targeting efficiencies of nanomedicines.

Luminescent gold nanoparticles with pH-dependent membrane adsorption.

pH regulates many cellular processes and is also an indicator of disease progression. Therefore, pH-responsive materials often serve as either tools in the fundamental understanding of cell biology or medicine for disease diagnosis and therapy. While gold nanoparticles have broad biomedical applications, very few of them exhibit pH-dependent interactions with live cells in a native biological environment due to nonspecific serum protein adsorption. Herein, we report that by coating luminescent gold nanoparticles with a natural peptide, glutathione, and the simplest stable aminothiol, cysteamine, we enabled the nanoparticles to exhibit not only high resistance to serum protein adsorption but also pH-dependent adsorption onto live cell membranes in the presence of serum proteins. Incorporating this pH-dependent membrane adsorption behavior into gold nanoparticles could potentially catalyze new biomedical applications of metal nanoparticles in the fundamental understanding of biological processes as well as disease diagnosis and therapy, where pH changes are involved.