Microbial Translocation and Perinatal Asphyxia/Hypoxia: A Systematic Review

The microbiome is vital for the proper function of the gastrointestinal tract (GIT) and the maintenance of overall wellbeing. Gut ischemia may lead to disruption of the intestinal mucosal barrier, resulting in bacterial translocation. In this systematic review, according to PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, we constructed a search query using the PICOT (Patient, Intervention, Comparison, Outcome, Time) framework. Eligible studies reported in PubMed, up to April 2021 were selected, from which, 57 publications’ data were included. According to these, escape of intraluminal potentially harmful factors into the systemic circulation and their transmission to distant organs and tissues, in utero, at birth, or immediately after, can be caused by reduced blood oxygenation. Various factors are involved in this situation. The GIT is a target organ, with high sensitivity to ischemia–hypoxia, and even short periods of ischemia may cause significant local tissue damage. Fetal hypoxia and perinatal asphyxia reduce bowel motility, especially in preterm neonates. Despite the fact that microbiome arouse the interest of scientists in recent decades, the pathophysiologic patterns which mediate in perinatal hypoxia/asphyxia conditions and gut function have not yet been well understood.

Golgi Metal Ion Homeostasis in Human Health and Diseases

The Golgi apparatus is a membrane organelle located in the center of the protein processing and trafficking pathway. It consists of sub-compartments with distinct biochemical compositions and functions. Main functions of the Golgi, including membrane trafficking, protein glycosylation, and sorting, require a well-maintained stable microenvironment in the sub-compartments of the Golgi, along with metal ion homeostasis. Metal ions, such as Ca2+, Mn2+, Zn2+, and Cu2+, are important cofactors of many Golgi resident glycosylation enzymes. The homeostasis of metal ions in the secretory pathway, which is required for proper function and stress response of the Golgi, is tightly regulated and maintained by transporters. Mutations in the transporters cause human diseases. Here we provide a review specifically focusing on the transporters that maintain Golgi metal ion homeostasis under physiological conditions and their alterations in diseases.

Research on the Relationship Between Service Guarantee Perception and Customer Value in the Chinese Context

As an excellent management tool, service guarantee can improve the competitive advantage of enterprises and allow consumers to obtain high-quality products and services. However, in the current Chinese context, this tool has not played its proper function. One important reason is the perception deviation of Chinese consumers. This research analyzes the main reasons for this deviation, puts forward related hypotheses and research models, and discusses the influence of disposition to trust of contract, perceived structural assurance (PSA), and subjective norm on service guarantee perception (SGP). Also, this study discusses SGP of customers through perceived risk and quality. Through the verification of 574 sample data, the main conclusions are as follows: (1) Disposition to trust of contract, subjective norms, and PSA significantly affect SGP positively; (2) SGP positively affects customer value (CUV); and (3) SGP s are obviously different between people of different ages, education levels, and income levels. Hopefully, these conclusions can have the following enlightenment to enterprises serving Chinese consumers: (1) in the designing stage of service guarantee, perception of customers of this guarantee should be a consideration; (2) CUV can be a proper direction if an enterprise wish to lead the guarantee perception of the customer; (3) Not all products need the same level of service guarantee; and (4)The proper service guarantee level depends on various statistical characteristics of target customers of the service.

M-CSFR/CSF1R signaling regulates myeloid fates in zebrafish via distinct action of its receptors and ligands

Macrophage colony-stimulating factor receptor (M-CSFR/CSF1R) signaling is crucial for the differentiation, proliferation, and survival of myeloid cells. The CSF1R pathway is a promising therapeutic target in many human diseases, including neurological disorders or cancer. Zebrafish are commonly used for human disease modeling and preclinical therapeutic screening. Therefore, it is necessary to understand the proper function of cytokine signaling in zebrafish to reliably model human-related diseases. Here, we investigate the roles of zebrafish Csf1rs and their ligands - Csf1a, Csf1b and Il34, in embryonic and adult myelopoiesis. The proliferative effect of exogenous Csf1a on embryonic macrophages is connected to both receptors, Csf1ra and Csf1rb, however there is no evident effect of Csf1b in zebrafish embryonic myelopoiesis. Furthermore, we uncover an unknown role of Csf1rb in zebrafish granulopoiesis. Deregulation of Csf1rb signaling leads to failure in myeloid differentiation resulting in neutropenia throughout the whole lifespan. Surprisingly, Il34 signaling through Csf1rb seems to be of high importance as both csf1rbΔ4bp and il34Δ5bp deficient zebrafish larvae lack granulocytes. Our single-cell RNA sequencing analysis of adult whole kidney marrow (WKM) hematopoietic cells suggests that csf1rb is expressed mainly by blood and myeloid progenitors and that the expression of csf1ra and csf1rb is non-overlapping. We point out differentially expressed genes important in hematopoietic cell differentiation and immune response in selected WKM populations. Our findings could improve the understanding of myeloid cell function and lead to the further study of CSF1R pathway deregulation in disease, mostly in cancerogenesis.

Guide RNA acrobatics: the one-for-two shuffle

RNA modifications are crucial for the proper function of the RNAs. The sites of pseudouridines are often specified by dual hairpin guide RNAs, with one or both hairpins identifying a target uridine. In this issue of Genes & Development, Jády and colleagues (pp. 70–83) identify a novel mechanism by which a single guide RNA hairpin can specify two uridines adjacent to each other or separated by 1 nt; i.e., one for two or guide RNA acrobatics.

Development and Psychometric Evaluation of Persian Dynamic Spatial Quick Speech-in-Noise Test in Adults with Normal Hearing

Background and Aim: Spatial hearing is a prerequisite for the proper function of the listener in complex auditory environments. In the present study, a Persian version of the dynamic spatial-quick speech in noise (DS-QSIN) has been developed with respect to all possible factors affecting the test and to run five lists for normal hearing subjects and assessment of reliability. Methods: To construct five new lists according to the original quick speech in noise (QSIN) test, we used frequent, familiar, and difficult words to construct unpredictable sentences. After determining the content and face validity of the sentences, 30 selected sentences were played using a DS-QSIN software for 35 subjects aged 18–25 years. The reliability of the test was assessed after repeating the test after two weeks. Results: According to expert judges, these 30 sentences showed acceptable content and face validity with the changes. The average signal-to-noise ratio (SNR) loss of five lists was –5.2 dB. No significant difference was seen between men and women in all lists. The results indicate no difference in the average SNR loss between the five lists. Regarding the reliability assessment, the test-retest correlation coefficient was 0.5 to 0.7 (p<0.05). The intra-class correlation coefficient between test-retest was statistically significant (p>0.001) and confirmed that the lists have high reliability and repeatability. Conclusion: DS-QSIN test showed good validity and reliability and can be helpful in diagnosis and selecting the best method for rehabilitation of people with a spatial hearing disorder.

p166 links membrane and intramitochondrial modules of the trypanosomal tripartite attachment complex

The protist parasite Trypanosoma brucei has a single mitochondrion with a single unit genome termed kinetoplast DNA (kDNA). Faithfull segregation of replicated kDNA is ensured by a complicated structure termed tripartite attachment complex (TAC). The TAC physically links the basal body of the flagellum with the kDNA spanning the two mitochondrial membranes. Here, we characterized p166 as the only TAC subunit that is anchored in the inner membrane. Its C-terminal transmembrane domain separates the protein into a large N-terminal region that interacts with the kDNA-localized TAC102 and a 34 aa C-tail that binds to the intermembrane space-exposed loop of the integral outer membrane protein TAC60. Thus, in contrast to the outer membrane TAC region which requires four essential subunits for proper function a single inner membrane TAC subunit is sufficient to bridge the distance from the OM to the kDNA. Surprisingly, non-functional p166 lacking the C-terminal 34 aa still localizes to the TAC region. This suggests the existence of nonessential TAC-associated proteins in the OM. These proteins can loosely bind to non-functional p166 lacking the C-terminal 34 aa and keep it at the TAC but their binding would not be strong enough to withstand the mechanical force upon kDNA segregation.

Easy Expression and Purification of Fluorescent N-Terminal BCL11B CCHC Zinc Finger Domain

Zinc finger proteins play pivotal roles in health and disease and exert critical functions in various cellular processes. A majority of zinc finger proteins bind DNA and act as transcription factors. B-cell lymphoma/leukemia 11B (BCL11B) represents one member of the large family of zinc finger proteins. The N-terminal domain of BCL11B was shown to be crucial for BCL11B to exert its proper function by homodimerization. Here, we describe an easy and fast preparation protocol to yield the fluorescently tagged protein of the recombinant N-terminal BCL11B zinc finger domain (BCL11B42-94) for in vitro studies. First, we expressed fluorescently tagged BCL11B42-94 in E. coli and described the subsequent purification utilizing immobilized metal ion affinity chromatography to achieve very high yields of a purified fusion protein of 200 mg/L culture. We proceeded with characterizing the atypical zinc finger domain using circular dichroism and size exclusion chromatography. Validation of the functional fluorescent pair CyPet-/EYFP-BCL11B42-94 was achieved with Förster resonance energy transfer. Our protocol can be utilized to study other zinc finger domains to expand the knowledge in this field.

How Localized Z-Disc Damage Affects Force Generation and Gene Expression in Cardiomyocytes

The proper function of cardiomyocytes (CMs) is highly related to the Z-disc, which has a pivotal role in orchestrating the sarcomeric cytoskeletal function. To better understand Z-disc related cardiomyopathies, novel models of Z-disc damage have to be developed. Human pluripotent stem cell (hPSC)-derived CMs can serve as an in vitro model to better understand the sarcomeric cytoskeleton. A femtosecond laser system can be applied for localized and defined damage application within cells as single Z-discs can be removed. We have investigated the changes in force generation via traction force microscopy, and in gene expression after Z-disc manipulation in hPSC-derived CMs. We observed a significant weakening of force generation after removal of a Z-disc. However, no significant changes of the number of contractions after manipulation were detected. The stress related gene NF-kB was significantly upregulated. Additionally, α-actinin (ACTN2) and filamin-C (FLNc) were upregulated, pointing to remodeling of the Z-disc and the sarcomeric cytoskeleton. Ultimately, cardiac troponin I (TNNI3) and cardiac muscle troponin T (TNNT2) were significantly downregulated. Our results allow a better understanding of transcriptional coupling of Z-disc damage and the relation of damage to force generation and can therefore finally pave the way to novel therapies of sarcomeric disorders.

Fractalkine-induced microglial vasoregulation occurs within the retina and is altered early in diabetic retinopathy

Local blood flow control within the central nervous system (CNS) is critical to proper function and is dependent on coordination between neurons, glia, and blood vessels. Macroglia, such as astrocytes and Müller cells, contribute to this neurovascular unit within the brain and retina, respectively. This study explored the role of microglia, the innate immune cell of the CNS, in retinal vasoregulation, and highlights changes during early diabetes. Structurally, microglia were found to contact retinal capillaries and neuronal synapses. In the brain and retinal explants, the addition of fractalkine, the sole ligand for monocyte receptor Cx3cr1, resulted in capillary constriction at regions of microglial contact. This vascular regulation was dependent on microglial Cx3cr1 involvement, since genetic and pharmacological inhibition of Cx3cr1 abolished fractalkine-induced constriction. Analysis of the microglial transcriptome identified several vasoactive genes, including angiotensinogen, a constituent of the renin-angiotensin system (RAS). Subsequent functional analysis showed that RAS blockade via candesartan abolished microglial-induced capillary constriction. Microglial regulation was explored in a rat streptozotocin (STZ) model of diabetic retinopathy. Retinal blood flow was reduced after 4 wk due to reduced capillary diameter and this was coincident with increased microglial association. Functional assessment showed loss of microglial–capillary response in STZ-treated animals and transcriptome analysis showed evidence of RAS pathway dysregulation in microglia. While candesartan treatment reversed capillary constriction in STZ-treated animals, blood flow remained decreased likely due to dilation of larger vessels. This work shows microglia actively participate in the neurovascular unit, with aberrant microglial–vascular function possibly contributing to the early vascular compromise during diabetic retinopathy.