Biology subjects

Thymann, T.

Publications and source records attributed to Thymann, T..

3 recordsLinked to original sources

bioRxiv2024

Reduced glucose supply during neonatal infection attenuates neurological and renal pathology via modulation of innate and Th1 immunity

BackgroundPremature infants are highly susceptible to infections that can lead to sepsis with life-threatening organ dysfunctions. The clinical practice of high parenteral glucose supply in preterm infants can exacerbate infection outcomes through excessive glycolysis-induced inflammatory response. This in turn can affect the health of vital preterm organs, including the brain and kidneys. We hypothesized that reducing glucose supply in infected preterm newborns may help protect against pathology in these two key organs. MethodsCaesarean-delivered preterm pigs were nourished with high or low parenteral glucose levels, infected with Staphylococcus epidermidis or saline, and cared for until 22h. Blood, brain, and kidney samples were collected at the end of the study for analyses. ResultsInfection led to multiple pathological changes, increased inflammation and tissue injury and dysfunction in both brain and kidneys of preterm piglets. Reduced glucose supply in infected animals alleviated neurological degradation, hyperemia and enhanced M2 microglial phenotype in the brain. This intervention also reduced plasma creatinine, renal edema, tubular vacuolization and dilatation. Multiple genes related to innate and Th1 immunity in both organs were highly correlated and dampened by reduced glucose supply, but there were clear signs that renal inflammation was closely connected to systemic inflammation while neuroinflammation was likely driven by immune response to the bacteria translocated into the brain. ConclusionReduced glucose supply can protect brain and kidney health in infected preterm neonates.

immunology↗

bioRxiv2023

Insulin-like Growth Factor-1 Supplementation Promotes Kidney Development and Alleviate Renal Inflammation in Preterm Pigs

BackgroundPreterm birth and its associated complications cause disruption of normal prenatal renal development, leading to postnatal kidney injury and failure. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a critical growth factor that stimulates tissue perfusion and development. Using necrotizing enterocolitis-sensitive preterm pigs as a model for preterm infants, we investigated whether IGF-1 supplementation during early life could improve kidney development and health. MethodsCaesarean-delivered preterm pigs were allocated into two groups, either consistently receiving vehicle or IGF-1 immediately after birth for 5, 9 or 19 days. Postnatal age-matched term pigs were selected and served as term control on postnatal day (PND) 5, 9, and 19. Blood, urine and kidney tissue were collected for biochemical, histological and gene expression analyses. ResultsPreterm pigs showed impaired kidney development and increased kidney insults, as indicated by reduced average glomerular area, increased abnormal glomeruli percentage and increased markers of renal injury and inflammation compared to term pigs. IGF-1 supplementation significantly reduced the abnormal glomeruli percentage, renal injury and inflammation related markers, and up-regulated certain maturation-related genes on PND5. ConclusionIGF-1 supplementation supports kidney maturation and restoration of kidney insults after preterm birth in the early life of newborns. ImpactO_LIPreterm birth disrupts kidney development in preterm pigs. C_LIO_LIPreterm birth leads to kidney injury and inflammation in preterm pigs. C_LIO_LIIGF-1 supplementation might promote kidney maturation and alleviate preterm birth associated kidney injury and inflammation in preterm pigs. C_LI

physiology↗

bioRxiv2020

Fecal filtrate transfer protects against necrotizing enterocolitis in preterm pigs

Background and aimsNecrotizing enterocolitis (NEC) is an acute and life-threatening gastrointestinal disorder afflicting preterm infants, which is currently unpreventable. Fecal microbiota transplantation (FMT) is a promising preventative therapy, but potential side effects raise concern. Removal of bacteria from donor fecal water may reduce side effects while maintaining wanted effects. We aimed to assess preclinical efficacy and safety of bacteria-free fecal filtrate transfer (FFT). MethodsUsing fecal material from healthy suckling piglets, we administered rectal FMT or cognate FFT by either rectal or oro-gastric administration to formula-fed preterm, cesarean piglets, and compared gut pathology and related safety parameters with saline controls. We then analyzed mucosa and luminal bacterial and viral composition using 16S rRNA gene amplicon and metavirome sequencing, respectively. Finally, we used isolated ileal mucosa, coupled with RNA-Seq, to gauge the host response to the different treatments. ResultsOro-gastric FFT eliminated NEC, which was confirmed by microscopy, whereas FMT did not perform better than control. Moreover, FFT but not FMT reduced intestinal permeability, whereas FMT animals had reduced body weight increase and intestinal growth. Oro-gastric FFT increased viral diversity and reduced Proteobacteria abundance in ileal mucosa relative to control. Global gene expression of host mucosa responded to FMT but not FFT with increased and decreased bacterial and viral defense mechanisms, respectively. ConclusionsAs preterm infants are extremely vulnerable, rational therapies need incontestable safety profiles. Here we show in a clinically relevant animal model that FFT, as opposed to FMT, efficiently prevents NEC without any recognizable side effects. If translatable to preterm infants, this could lead to a change of practice and in turn a reduction in NEC burden.

microbiology↗