NACA and LRP6 Are Part of a Common Genetic Pathway Necessary for Full Anabolic Response to Intermittent PTH

PTH induces phosphorylation of the transcriptional coregulator NACA on serine 99 through Gαs and PKA. This leads to nuclear translocation of NACA and expression of the target gene Lrp6, encoding a coreceptor of the PTH receptor (PTH1R) necessary for full anabolic response to intermittent PTH (iPTH) treatment. We hypothesized that maintaining enough functional PTH1R/LRP6 coreceptor complexes at the plasma membrane through NACA-dependent Lrp6 transcription is important to ensure maximal response to iPTH. To test this model, we generated compound heterozygous mice in which one allele each of Naca and Lrp6 is inactivated in osteoblasts and osteocytes, using a knock-in strain with a Naca99 Ser-to-Ala mutation and an Lrp6 floxed strain (test genotype: Naca99S/A; Lrp6+/fl;OCN-Cre). Four-month-old females were injected with vehicle or 100 μg/kg PTH(1-34) once daily, 5 days a week for 4 weeks. Control mice showed significant increases in vertebral trabecular bone mass and biomechanical properties that were abolished in compound heterozygotes. Lrp6 expression was reduced in compound heterozygotes vs. controls. The iPTH treatment increased Alpl and Col1a1 mRNA levels in the control but not in the test group. These results confirm that NACA and LRP6 form part of a common genetic pathway that is necessary for the full anabolic effect of iPTH.

Pathology and Anticatalytic Treatment of Exacerbated COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces immune-mediated inflammasome diseases. Moreover, its pathophysiology involves the angiotensin-converting enzyme 2 (ACE2) receptor, Toll-like receptor 4 (TLR4) pathway, neuropilin‑1 pathway, inflammasome activation pathway, sterile alpha motif (SAM) and histidine-aspartate domain (HD)-containing protein 1 (SAMHD1) tetramerization pathway, cytosolic DNA sensor cyclic-GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway, spike protein/inflammasome-genetic pathway, and immunological memory engram pathway. Therefore, it is necessary to prescribe anticatalytic treatments to alleviate the SARS-CoV-2 inflammasome, immunologic engram, and spike protein levels.

The Immunoglobulin Superfamily Members syg-2 and syg-1 Regulate Neurite Development in C. elegans

Neurons form elaborate networks by guiding axons and dendrites to appropriate destinations. Neurites require information about the relative body axes during the initial projection from the cell body, and failure to receive or interpret those cues correctly can result in outgrowth errors. We identified a mutation in the Ig superfamily member syg-2 in a screen for animals with anterior/posterior (A/P) axon guidance defects. We found that syg-2 and its cognate Ig family member syg-1 appear to function in a linear genetic pathway to control the outgrowth of GABAergic axons. We determined that this pathway works in parallel to Wnt signaling. Specifically, mutations in syg-2 or syg-1 selectively affected the embryonically derived Dorsal D-type (DD) GABAergic neurons. We found no evidence that these mutations affected the Ventral D-type neurons (VD) that form later, during the first larval stage. In addition, mutations in syg-1 or syg-2 could result in the DD neurons forming multiple processes, becoming bipolar, rather than the expected pseudounipolar morphology. Given SYG-2′s essential function in synaptogenesis of the hermaphrodite-specific neurons (HSNs), we also examined DD neuron synapses in syg-2 mutants. We found syg-2 mutants had a decreased number of synapses formed, but synaptic morphology was largely normal. These results provide further evidence that the GABAergic motorneurons use multiple guidance pathways during development.

Predicting 3D Structure, Cross Talks, and Prognostic Significance of KLF9 in Cervical Cancer

Our study aimed to identify the new blood-based biomarkers for the diagnosis and prognosis of cervical cancer. Moreover, the three-dimensional (3D) structure of Kruppel-like factor 9 (KLF9) was also determined in order to better understand its function, and a signaling pathway was constructed to identity its upstream and downstream targets. In the current study, the co-expressions of tumor protein D52 (TPD52), KLF9, microRNA 223 (miR-223), and protein kinase C epsilon (PKCϵ) were evaluated in cervical cancer patients and a possible relation with disease outcome was revealed. The expressions of TPD52, KLF9, miR-223, and PKCϵ were studied in the blood of 100 cervical cancer patients and 100 healthy controls using real-time PCR. The 3D structure of KLF9 was determined through homology modeling via the SWISS-MODEL and assessed using the Ramachandran plot. The predicted 3D structure of KLF9 had a similarity index of 62% with its template (KLF4) with no bad bonds in it. In order to construct a genetic pathway, depicting the crosstalk between understudied genes, STRING analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG), and DAVID software were used. The constructed genetic pathway showed that all the understudied genes are linked to each other and involved in the PI3K/Akt signaling pathway. There was a 23-fold increase in TPD52 expression, a 2-fold increase in miR-223 expression, a 0.14-fold decrease in KLF9 expression, and a 0.05-fold decrease of PKCϵ expression in cervical cancer. In the present study, we observed an association of the expressions of TPD52, KLF9, miR-223, and PKCϵ with tumor stage, metastasis, and treatment status of cervical cancer patients. Elevated expressions of TPD52 and miR-223 and reduced expressions of KLF9 and PKCϵ in peripheral blood of cervical cancer patients may serve as predictors of disease diagnosis and prognosis. Nevertheless, further in vitro and tissue-level studies are required to strengthen their role as potential diagnostic and prognostic biomarkers.

Three orphan histidine kinases inhibit Clostridioides difficile sporulation

The ability of the anaerobic gastrointestinal pathogen, Clostridioides difficile, to survive outside the host relies on the formation of dormant endospores. Spore formation is contingent on the activation of a conserved transcription factor, Spo0A, by phosphorylation. Multiple kinases and phosphatases regulate Spo0A activity in other spore-forming organisms; however, these factors are not well conserved in C. difficile. Previously, we discovered that deletion of a conserved phosphotransfer protein, CD1492, increases sporulation, indicating that CD1492 inhibits C. difficile spore formation. In this study, we investigate the functions of additional conserved orphan phosphotransfer proteins, CD2492, CD1579, and CD1949 which are hypothesized to regulate Spo0A phosphorylation. Disruption of the conserved phosphotransfer protein, CD2492, also increased sporulation frequency, similarly to the CD1492 mutant, and in contrast to a previous study. A CD1492 CD2492 mutant phenocopied the sporulation and gene expression patterns of the single mutants, suggesting that these proteins function in the same genetic pathway to repress sporulation. Deletion of the conserved CD1579 phosphotransfer protein also variably increased sporulation frequency; however, knockdown of CD1949 expression did not influence sporulation. We provide evidence that CD1492, CD2492 and CD1579 function as phosphatases, as mutation of the conserved histidine residue for phosphate transfer abolished CD2492 function, and expression of the CD1492 or CD2492 histidine site-directed mutants or the wild-type CD1579 allele in a parent strain resulted in a dominant negative hypersporulation phenotype. Altogether, at least three phosphotransfer proteins, CD1492, CD2492 and CD1579 (herein, PtpA, PtpB and PtpC) repress C. difficile sporulation initiation by regulating activity of Spo0A.

A Rare Case of Serrated Polyposis Syndrome with the MSH6 and SMARCA4 variants

Serrated polyposis syndrome (SPS) is the most common form of polyposis syndrome and has been shown to increase the risk of colorectal cancer (CRC). The genetic pathway of CRC in SPS is different from the classic adenomatous polyposis coli (APC) pathway, which accounts for 70–80% of cases of CRC. Most commonly, SPS mutations include BRAF and KRAS, with activation of the RAS-RAF-MAP kinase pathway involved in the pathogenesis of serrated lesions. We present a rare case of SPS in a 32-year-old woman with MSH6 and SMARCA4 variants, which have not previously been reported in the literature.

Schizophrenia Plays a Negative Role in the Pathological Development of Myocardial Infarction at Multiple Biological Levels

It has shown that schizophrenia (SCZ) is associated with a higher chance of myocardial infarction (MI) and increased mortality. However, the underlying mechanism is largely unknown. Here, we first constructed a literature-based genetic pathway linking SCZ and MI, and then we tested the expression levels of the genes involved in the pathway by a meta-analysis using nine gene expression datasets of MI. In addition, a literature-based data mining process was conducted to explore the connection between SCZ at different levels: small molecules, complex molecules, and functional classes. The genetic pathway revealed nine genes connecting SCZ and MI. Specifically, SCZ activates two promoters of MI (IL6 and CRP) and deactivates seven inhibitors of MI (ADIPOQ, SOD2, TXN, NGF, ADORA1, NOS1, and CTNNB1), suggesting that no protective role of SCZ in MI was detected. Meta-analysis showed that one promoter of MI (CRP) presented no significant increase, and six out of seven genetic inhibitors of MI demonstrated minor to moderately increased expression. Therefore, the elevation of CRP and inhibition of the six inhibitors of MI by SCZ could be critical pathways to promote MI. Nine other regulators of MI were influenced by SCZ, including two gene families (inflammatory cytokine and IL1 family), five small molecules (lipid peroxide, superoxide, ATP, ascorbic acid, melatonin, arachidonic acid), and two complexes (CaM kinase 2 and IL23). Our results suggested that SCZ promotes the development and progression of MI at different levels, including genes, small molecules, complex molecules, and functional classes.

A forward genetic screen identifies Dolk as a regulator of startle magnitude through the potassium channel subunit Kv1.1

The acoustic startle response is an evolutionarily conserved avoidance behavior. Disruptions in startle behavior, particularly startle magnitude, are a hallmark of several human neurological disorders. While the neural circuitry underlying startle behavior has been studied extensively, the repertoire of genes and genetic pathways that regulate this locomotor behavior has not been explored using an unbiased genetic approach. To identify such genes, we took advantage of the stereotypic startle behavior in zebrafish larvae and performed a forward genetic screen coupled with whole genome analysis. We uncovered mutations in eight genes critical for startle behavior, including two genes encoding proteins associated with human neurological disorders, Dolichol kinase (Dolk), a broadly expressed regulator of the glycoprotein biosynthesis pathway, and the potassium Shaker-like channel subunit Kv1.1. We demonstrate that Kv1.1 and Dolk play critical roles in the spinal cord to regulate movement magnitude during the startle response and spontaneous swim movements. Moreover, we show that Kv1.1 protein is mislocalized in dolk mutants, suggesting they act in a common genetic pathway. Combined, our results identify a diverse set of eight genes, all associated with human disorders, that regulate zebrafish startle behavior and reveal a previously unappreciated role for Dolk and Kv1.1 in regulating movement magnitude via a common genetic pathway.

Polycystic Kidney Disease in Rough Toothed Dolphins (Steno bredanensis) founded in the Paraná coast, Southern Brazil

Background: Renal cystic diseases (RCD) are characterized by cystic structures on renal parenchyma associated with obstructive lesions, membranous disruptions, and/or growth disturbances. The polycystic kidney disease (PKD) shows specific pathological characteristics, related to mutations on PKD1 and/or PKD2 chromosome locus on humans. In Persian cats and bull terriers the condition is like the human “adult-onset” PKD, while in Perendale sheep the “childhood”-like is described. In cetaceans, RCD are reported, however the characterization of PKD is scarcely described. This report aims to describe two cases of PKD and one of RCD in stranded Steno bredanensis, and to discuss the disease associated factors.Cases: Four rough-toothed-dolphins were found stranded in the Paraná coast, southern Brazil between 2016 to 2018, through the Santos Basin Beach Monitoring Project (PMP-BS), one of the systematic monitoring programs required by Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) for the environmental licensing process of oil production and transport by Petrobras in the presalt province. In three animals histological sampling was performed. One of them (animal 3) was founded alive, presenting altered buoyancy with lateralization to the right and signs of pneumonia. The blood analysis showed anemia and leukocytosis. The animal showed poor clinical prognosis, and even with supportive treatment, come to death four days after the rescue. Routine autopsies were performed on all animals. Animals 1 and 2 presented macroscopically enlarged kidneys containing disseminated cystic structures in the parenchyma. On microscopic examination, the cortical region showed diffuse cystic structures delimited by variable thickness of fibrous tissue, usually compressing adjacent glomeruli, without concomitant inflammatory process. In these cases, the death was associated with the end stage renal disease. Animal 3 showed grossly few cystic structures, well delimited and replacing some reniculi. Tracheitis, granulomatous pneumonia, esophagitis, gastritis, enteritis and papilloma on penis and palate were observed. Microscopically, the cysts were lined by a single layer of columnar to cuboidal epithelial cells surrounded by extensive fibrotic tissue. Multifocal tubular necrosis was also noticed. Multifocal moderate nonsuppurative encephalitis with parasitic eggs and bacterial granulomatous hemorrhagic pneumonia were observed. In this case, the death was associated with the lesions in the nervous system. Discussion: Data concerning polycystic kidney disease on cetaceans and wild animals is limited, and no primary genetic pathway was associated. In the present study, the gross and histological aspects observed on two animals (1 and 2) are similar to the characteristics found in the human adult form of PKD, while the characteristics observed on animal 3 are consistent with usual cystic disease. In addition, the animals are aged like humans where the end stage renal disease occurs in patients around 70 years old. The kidney histological aspects observed in all animals are similar, however, animal 3 showed no renomegaly, a characteristic of PKD. Considering the genetic pathway involved in humans and some animal’s breeds, investigation on gene mutations in S. bredanensis could help to define if this is also a genetic disorder and increase the knowledge about PKD. Keywords: kidney, delphinidae, PKD, diagnostic pathology, cystic disease, rough toothed dolphin.

Major components of the KARRIKIN INSENSITIVE2-dependent signaling pathway are conserved in the liverwort Marchantia polymorpha

KARRIKIN INSENSITIVE2 (KAI2) was first identified as a receptor of karrikins, smoke-derived germination stimulants. KAI2 is also considered a receptor of an unidentified endogenous molecule called the KAI2-ligand (KL). Upon KAI2 activation, signals are transmitted through degradation of D53/SMXL proteins via MAX2-dependent ubiquitination. Although components in the KAI2-dependent signaling pathway, namely MpKAI2A and MpKAI2B, MpMAX2, and MpSMXL, exist in the genome of the liverwort Marchantia polymorpha, their functions remain unknown. Here, we show that early thallus growth is retarded and gemma dormancy in the dark is suppressed in Mpkai2a and Mpmax2 loss-of-function mutants. These defects are counteracted in Mpkai2a Mpsmxl and Mpmax2 Mpsmxl double mutants indicating that MpKAI2A, MpMAX2 and MpSMXL act in the same genetic pathway. Introduction of MpSMXLd53, in which a domain required for degradation is mutated, into wild-type plants mimicks Mpkai2a and Mpmax2 plants. In addition, detection of citrine fluorescence in Nicotiana benthamiana cells transiently expressing a SMXL-Citrine fusion protein requires treatment with MG132, a proteasome inhibitor. These findings imply that MpSMXL is subjected to degradation, and that degradation of MpSMXL is crucial for MpKAI2A-dependent signaling in M. polymorpha. Therefore, we claim that the basic mechanisms in the KAI2-dependent signaling pathway are conserved in M. polymorpha.