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This study conducted transcriptome sequencing of goat-mammary-gland tissue at the late lactation (LL), dry period (DP), and late gestation (LG) stages to reveal the expression characteristics and molecular functions of circRNAs during mammary involution. A total of 11,756 circRNAs were identified in this study, of which 2528 circRNAs were expressed in all three stages. The number of exonic circRNAs was the largest, and the least identified circRNAs were antisense circRNAs. circRNA source gene analysis found that 9282 circRNAs were derived from 3889 genes, and 127 circRNAs' source genes were unknown. Gene Ontology (GO) terms, such as histone modification, regulation of GTPase activity, and establishment or maintenance of cell polarity, were significantly enriched (FDR < 0.05), which indicates the functional diversity of circRNAs' source genes. A total of 218 differentially expressed circRNAs were identified during the non-lactation period. The number of specifically expressed circRNAs was the highest in the DP and the lowest in LL stages. These indicated temporal specificity of circRNA expression in mammary gland tissues at different developmental stages. In addition, this study also constructed circRNA–miRNA–mRNA competitive endogenous RNA (ceRNA) regulatory networks related to mammary development, immunity, substance metabolism, and apoptosis. These findings help understand the regulatory role of circRNAs in mammary cell involution and remodeling. [ABSTRACT FROM AUTHOR]

Long noncoding RNA (lncRNA) can regulate mammary gland development and lactation physiological activities. However, the molecular genetic mechanisms of lncRNA in mammary gland involution and cell remodeling remain unclear. This work analyzed the expression characteristics and molecular functions of lncRNA in goat mammary gland tissue at the late lactation (LL), dry period (DP), and late gestation (LG) stages. Sequencing results showed that 3074 lncRNAs were identified in non-lactating goat mammary gland tissue. Statistical analysis of lncRNA length characteristics and exon number found that goat lncRNAs were shorter in length, had fewer exons, and significantly lower expression levels than those of protein-coding genes. 331 differentially expressed lncRNAs were identified in the three comparison groups (LLvsDP, DPvsLG, and LLvsLG), which indicated that the lncRNAs expression at the transcriptional level were changed during mammary involution. Interestingly, lncRNAs were more actively expressed during the dry period compared to lactation, suggesting that lncRNAs in mammary glands are developmentally specific. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that lncRNAs could regulate immune function, cell proliferation, apoptosis, hormones, substance metabolism, transport, and intercellular communication in the mammary gland through various action modes. Among them, cis-acting lncRNAs enhanced the protection of mammary gland health during the dry period and late gestation. The above reflects the particular mechanisms of lncRNA to adapt to the developmental needs of mammary involution and remodeling. Furthermore, in the lncRNA-miRNA-mRNA network associated with mammary gland development, the expression of LOC102168552 was higher in late gestation than in the dry period and late lactation. Its expression was positively correlated with PRLR and negatively correlated with chi-miR-324-3p. Overexpression of LOC102168552 in goat mammary epithelial cells cultured in vitro could up-regulate PRLR to activate the prolactin signaling pathway by competitively binding to chi-miR-324-3p, promoting cell proliferation, reducing cell cycle arrest in the G1 / S phase, and inhibiting apoptosis. However, overexpression of LOC102168552 alone did not affect mammary cell growth status and the prolactin signaling pathway. This indicates that LOC102168552 must rely on chi-miR-324-3p to inhibit mammary cell apoptosis. In conclusion, the above analysis revealed that lncRNAs in goat mammary tissue are differentially expressed at different stages of involution. As expected, lncRNAs adaptively regulate various physiological activities during mammary gland involution through multiple modes of action, in preparation for a new round of lactation. These findings provide a reference and help further understand the regulatory role of lncRNAs in mammary cell involution and remodeling. • Characterization of lncRNAs in non-lactating mammary tissue of dairy goats. • The expression of lncRNA changes during mammary gland involution. • LncRNAs regulate multiple physiological activities to adapt to the mammary gland involution through various action modes. • Overexpression of LOC102168552 promotes the growth of mammary epithelial cells by competitively binding to chi-miR-324-3p. [ABSTRACT FROM AUTHOR]

The phenotypic plasticity of Cryptococcus neoformans is widely studied and demonstrated in vitro, but its influence on pathogenicity remains unclear. In this study, we investigated the dynamics of cryptococcal cell and transcriptional remodeling during pulmonary infection in a murine model. We showed that in Cryptococcus neoformans, cell size reduction (cell body ≤ 3 µm) is important for initial adaptation during infection. This change was associated with reproductive fitness and tissue invasion. Subsequently, the fungus develops mechanisms aimed at resistance to the host's immune response, which is determinant for virulence. We investigated the transcriptional changes involved in this cellular remodeling and found an upregulation of transcripts related to ribosome biogenesis at the beginning (6 h) of infection and a later (10 days) upregulation of transcripts involved in the inositol pathway, energy production, and the proteasome. Consistent with a role for the proteasome, we found that its inhibition delayed cell remodeling during infection with the H99 strain. Altogether, these results further our understanding of the infection biology of C. neoformans and provide perspectives to support therapeutic and diagnostic targets for cryptococcosis. [ABSTRACT FROM AUTHOR]

Plasmodium falciparum undergoes a series of asexual replications in human erythrocytes after infection, which are effective targets for combatting malaria. Here, we report roles of an ApiAP2 transcription factor PfAP2-EXP2 (PF3D7_0611200) in the intraerythrocytic developmental cycle of P. falciparum. PfAP2-EXP2 conditional knockdown resulted in an asexual growth defect but without an appreciable effect on parasite morphology. Further ChIP-seq analysis revealed that PfAP2-EXP2 targeted genes related to virulence and interaction between erythrocytes and parasites. Especially, PfAP2-EXP2 regulation of euchromatic genes does not depend on recognizing specific DNA sequences, while a CCCTAAACCC motif is found in its heterochromatic binding sites. Combined with transcriptome profiling, we suggest that PfAP2-EXP2 is participated in the intraerythrocytic development by affecting the expression of genes related to cell remodeling at the schizont stage. In summary, this study explores an ApiAP2 member plays an important role for the P. falciparum blood-stage replication, which suggests a new perspective for malaria elimination.

• S100A11 is highly expressed in chronic rhinitis and sinusitis with nasal polyps (CRSwNPs). • Upregulation of S100A11 expression inhibits proliferation and promotes apoptosis and inflammation of nasal epithelial cells. • S100A11 can activate the AMPK signaling pathway and inhibit the STAT3 signaling pathway in a RAGE-mediated manner. • S100A11 plays an important role in nasal mucosal epithelial remodeling and inflammation of CRSwNPs. Abnormal remodeling of the nasal mucosal epithelium and persistent chronic inflammation are important pathological features of chronic sinusitis with nasal polyps (CRSwNPs). In order to explore the molecular regulation mechanism of CRSwNPs, we performed iTRAQ protein profile analysis on 18 clinical samples collected (9 patients with nasal polyps and 9 healthy patients) and found that S100A11, a Ca2+-binding protein, was significantly higher in CRSwNPs. Subsequently, we demonstrated that S100A11 was mainly located in nasal mucosal epithelial cells and is up-regulated in human nasal epithelial stem/progenitor cells (hNESPCs) from CRSwNPs patients and CRSwNPs epithelial cell model established with S. aureus. To determine the functional role of S100A11 and the signal pathways in epithelial cells, we constructed S100A11 overexpression vector, small interfering RNA, recombinant protein-S100A11 (rh-S100A11) and RAGE inhibitor (sRAGE). Results showed that upregulation of S100A11 inhibited epithelial cell viability and promoted apoptosis and inflammation, in addition, S100A11 can regulate the signal homeostasis of AMPK-STAT3 via RAGE mediation in epithelial cells. Our findings suggest that S100A11 is involved in CRSwNPs epithelial tissue remodeling and inflammatory response regulation and may be a useful target for CRSwNPs therapy. [ABSTRACT FROM AUTHOR]

The microalga Haematococcus lacustris (formerly H. pluvialis) is able to accumulate high amounts of the carotenoid astaxanthin in the course of adaptation to stresses like salinity. Technologies aimed at production of natural astaxanthin for commercial purposes often involve salinity stress; however, after a switch to stressful conditions, H. lacustris experiences massive cell death which negatively influences astaxanthin yield. This study addressed the possibility to improve cell survival in H. lacustris subjected to salinity via manipulation of the levels of autophagy using AZD8055, a known inhibitor of TOR kinase previously shown to accelerate autophagy in several microalgae. Addition of NaCl in concentrations of 0.2% or 0.8% to the growth medium induced formation of autophagosomes in H. lacustris, while simultaneous addition of AZD8055 up to a final concentration of 0.2 µM further stimulated this process. AZD8055 significantly improved the yield of H. lacustris cells after 5 days of exposure to 0.2% NaCl. Strikingly, this occurred by acceleration of cell growth, and not by acceleration of aplanospore formation. The level of astaxanthin synthesis was not affected by AZD8055. However, cytological data suggested a role of autophagosomes, lysosomes and Golgi cisternae in cell remodeling during high salt stress.

Fbxo7 is the substrate-recognition subunit of an SCF-type ubiquitin E3 ligase complex. It has physiologically important functions in regulating mitophagy, proteasome activity and the cell cycle in multiple cell types, like neurons, lymphocytes and erythrocytes. Here, we show that in addition to the previously known Parkinsonian and hematopoietic phenotypes, male mice with reduced Fbxo7 expression are sterile. In these males, despite successful meiosis, nuclear elongation and eviction of histones from chromatin, the developing spermatids are phagocytosed by Sertoli cells during late spermiogenesis, as the spermatids undergo cytoplasmic remodeling. Surprisingly, despite the loss of all germ cells, there was no evidence of the symplast formation and cell sloughing that is typically associated with spermatid death in other mouse sterility models, suggesting that novel cell death and/or cell disposal mechanisms may be engaged in Fbxo7 mutant males. Mutation of the Drosophila Fbxo7 ortholog, nutcracker (ntc) also leads to sterility with germ cell death during cytoplasmic remodeling, indicating that the requirement for Fbxo7 at this stage is conserved. The ntc phenotype was attributed to decreased levels of the proteasome regulator, DmPI31 and reduced proteasome activity. Consistent with the fly model, we observe a reduction in PI31 levels in mutant mice; however, there is no alteration in proteasome activity in whole mouse testes. Our results are consistent with findings that Fbxo7 regulates PI31 protein levels, and indicates that a defect at the late stages of spermiogenesis, possibly due to faulty spatial dynamics of proteasomes during cytoplasmic remodeling, may underlie the fertility phenotype in mice.

Fbxo7 is the substrate-recognition subunit of an SCF-type ubiquitin E3 ligase complex. It has physiologically important functions in regulating mitophagy, proteasome activity and the cell cycle in multiple cell types, like neurons, lymphocytes and erythrocytes. Here, we show that in addition to the previously known Parkinsonian and hematopoietic phenotypes, male mice with reduced Fbxo7 expression are sterile. In these males, despite successful meiosis, nuclear elongation and eviction of histones from chromatin, the developing spermatids are phagocytosed by Sertoli cells during late spermiogenesis, as the spermatids undergo cytoplasmic remodeling. Surprisingly, despite the loss of all germ cells, there was no evidence of the symplast formation and cell sloughing that is typically associated with spermatid death in other mouse sterility models, suggesting that novel cell death and/or cell disposal mechanisms may be engaged in Fbxo7 mutant males. Mutation of the Drosophila Fbxo7 ortholog, nutcracker (ntc) also leads to sterility with germ cell death during cytoplasmic remodeling, indicating that the requirement for Fbxo7 at this stage is conserved. The ntc phenotype was attributed to decreased levels of the proteasome regulator, DmPI31 and reduced proteasome activity. Consistent with the fly model, we observe a reduction in PI31 levels in mutant mice; however, there is no alteration in proteasome activity in whole mouse testes. Our results are consistent with findings that Fbxo7 regulates PI31 protein levels, and indicates that a defect at the late stages of spermiogenesis, possibly due to faulty spatial dynamics of proteasomes during cytoplasmic remodeling, may underlie the fertility phenotype in mice. [ABSTRACT FROM AUTHOR]

Previous studies have reported the pathogenic role of C-reactive protein (CRP) during diabetic kidney disease (DKD) in human CRP transgenic and Crp-/- mice. However, because humans and mice have inverse acute phase expression patterns of CRP and serum amyloid P component, this could lead to the inaccurate evaluation of CRP function with the above-mentioned CRP transgenic mouse. But different from mice, rats have the same acute phase protein expression pattern as human, which might avoid this problem and be a better choice for CRP function studies. To dispel this doubt and accurately define the role of CRP during diabetic nephropathy, we created the first Crp-/- rat model, which we treated with streptozocin to induce DKD for in vivo studies. Moreover, an established cell line (human kidney 2) was used to further investigate the pathologic mechanisms of CRP. We found that CRP promotes epithelial-mesenchymal transition (EMT) through Wnt/β-catenin and ERK1/2 signaling, which are dependent on CRP binding to FcyRII on apoptotic cells. By promoting EMT, CRP was demonstrated to accelerate the development of DKD. We thus present convincing evidence demonstrating CRP as a therapeutic target for DKD treatment. [ABSTRACT FROM AUTHOR]

Diabetic kidney disease (DKD) is a prevalent complication of diabetes and a major secondary factor leading to end-stage renal disease. The kidney, a vital organ, is composed of a heterogeneous group of intrinsic cells, including glomerular endothelial cells, podocytes, mesangial cells, tubular epithelial cells, and interstitial fibroblasts. In the context of DKD, hyperglycemia elicits direct or indirect injury to these intrinsic cells, leading to their structural and functional changes, such as cell proliferation, apoptosis, and transdifferentiation. The dynamic remodeling of intrinsic cells represents an adaptive response to stimulus during the pathogenesis of diabetic kidney disease. However, the persistent stimulus may trigger an irreversible remodeling, leading to fibrosis and functional deterioration of the kidney. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, a new class of hypoglycemic drugs, exhibit efficacy in reducing blood glucose levels by curtailing renal tubular glucose reabsorption. Furthermore, SGLT2 inhibitors have been shown to modulate intrinsic cell remodeling in the kidney, ameliorate kidney structure and function, and decelerate DKD progression. This review will elaborate on the intrinsic cell remodeling in DKD and the underlying mechanism of SGLT2 inhibitors in modulating it from the perspective of the renal intrinsic cell, providing insights into the pathogenesis of DKD and the renal protective action of SGLT2 inhibitors. [ABSTRACT FROM AUTHOR]

Summary How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation. [ABSTRACT FROM AUTHOR]

Background: Members of the proteolipid protein family, including the four-transmembrane glycoprotein M6a, are involved in neuronal plasticity in mammals. Results from our group previously demonstrated that M6, the only proteolipid protein expressed in Drosophila, localizes to the cell membrane in follicle cells. M6 loss triggers female sterility, which suggests a role for M6 in follicular cell remodeling. These results were the basis of the present study, which focused on the function and requirements of M6 in the fly nervous system. Results: The present study identified two novel, tissue-regulated M6 isoforms with variable N- and C- termini, and showed that M6 is the functional fly ortholog of Gpm6a. In the adult brain, the protein was localized to several neuropils, such as the optic lobe, the central complex, and the mushroom bodies. Interestingly, although reduced M6 levels triggered a mild rough-eye phenotype, hypomorphic M6 mutants exhibited a defective response to light. Conclusions: Based on its ability to induce filopodium formation we propose that M6 is key in cell remodeling processes underlying visual system function. These results bring further insight into the role of M6/M6a in biological processes involving neuronal plasticity and behavior in flies and mammals. [ABSTRACT FROM AUTHOR]

Cardiac myocytes are known to be influenced by the rigidity and topography of their physical microenvironment. It was hypothesized that 3D heterogeneity introduced by purely physical microdomains regulates cardiac myocyte size and contraction. This was tested in vitro using polymeric microstructures (G′ = 1.66 GPa) suspended with random orientation in 3D by a soft Matrigel matrix (G′ = 22.9 Pa). After 10 days of culture, the presence of 100 μm-long microstructures in 3D gels induced fold increases in neonatal rat ventricular myocyte size (1.61 ± 0.06, p < 0.01) and total protein/cell ratios (1.43 ± 0.08, p < 0.05) that were comparable to those induced chemically by 50 μM phenylephrine treatment. Upon attachment to microstructures, individual myocytes also had larger cross-sectional areas (1.57 ± 0.05, p < 0.01) and higher average rates of spontaneous contraction (2.01 ± 0.08, p < 0.01) than unattached myocytes. Furthermore, the inclusion of microstructures in myocyte-seeded gels caused significant increases in the expression of beta-1 adrenergic receptor (β1-AR, 1.19 ± 0.01), cardiac ankyrin repeat protein (CARP, 1.26 ± 0.02), and sarcoplasmic reticulum calcium-ATPase (SERCA2, 1.59 ± 0.12, p < 0.05), genes implicated in hypertrophy and contractile activity. Together, the results demonstrate that cardiac myocyte behavior can be controlled through local 3D microdomains alone. This approach of defining physical cues as independent features may help to advance the elemental design considerations for scaffolds in cardiac tissue engineering and therapeutic microdevices. [ABSTRACT FROM AUTHOR]

The microalga Haematococcus lacustris (formerly H. pluvialis) is able to accumulate high amounts of the carotenoid astaxanthin in the course of adaptation to stresses like salinity. Technologies aimed at production of natural astaxanthin for commercial purposes often involve salinity stress; however, after a switch to stressful conditions, H. lacustris experiences massive cell death which negatively influences astaxanthin yield. This study addressed the possibility to improve cell survival in H. lacustris subjected to salinity via manipulation of the levels of autophagy using AZD8055, a known inhibitor of TOR kinase previously shown to accelerate autophagy in several microalgae. Addition of NaCl in concentrations of 0.2% or 0.8% to the growth medium induced formation of autophagosomes in H. lacustris, while simultaneous addition of AZD8055 up to a final concentration of 0.2 µM further stimulated this process. AZD8055 significantly improved the yield of H. lacustris cells after 5 days of exposure to 0.2% NaCl. Strikingly, this occurred by acceleration of cell growth, and not by acceleration of aplanospore formation. The level of astaxanthin synthesis was not affected by AZD8055. However, cytological data suggested a role of autophagosomes, lysosomes and Golgi cisternae in cell remodeling during high salt stress. [ABSTRACT FROM AUTHOR]

Skeletal muscle cells, albeit classified as vitamin D receptor (VDR)-poor cells, are finely controlled by vitamin D through genomic and non-genomic mechanisms. Skeletal muscle constantly undergoes cell remodeling, a complex system under multilevel regulation, mainly orchestrated by the satellite niche in response to a variety of stimuli. Cell remodeling is not limited to satisfy reparative and hypertrophic needs, but, through myocyte transcriptome/proteome renewal, it warrants the adaptations necessary to maintain tissue integrity. While vitamin D insufficiency promotes cell maladaptation, restoring vitamin D levels can correct/enhance the myogenic program. Hence, vitamin D fortified foods or supplementation potentially represents the desired approach to limit or avoid muscle wasting and ameliorate health. Nevertheless, consensus on protocols for vitamin D measurement and supplementation is still lacking, due to the high variability of lab tests and of the levels required in different contexts (i.e., age, sex, heath status, lifestyle). This review aims to describe how vitamin D can orchestrate skeletal muscle cell remodeling and myogenic programming, after reviewing the main processes and cell populations involved in this important process, whose correct progress highly impacts on human health. Topics on vitamin D optimal levels, supplementation and blood determination, which are still under debate, will be addressed. [ABSTRACT FROM AUTHOR]

Background: High-mobility graoup box protein 1 (HMGB1) has been shown to mediate a wide range of pathologic responses by interacting with RAGE (receptor for advanced glycation endproducts) and TLRs (Toll-like receptors). Our previous study showed that HMGB1 has been involved in pathogenesis of airway remodeling in an allergen-induced chronic mice asthma model. Increased airway smooth muscle (ASM) mass is a vital feature of airway remodeling., Objective: To evaluate the effect of HMGB1 on proliferation of ASMs and the underlying mechanisms., Methods: Rat airway smooth muscle cells (RASMs) were obtained by primary explant techniques. We investigated the effect of HMGB1 on the proliferation of RASMs. To identify which receptors and signaling pathways be involved in proliferation of RASMs, we performed western blot and CCK-8 assay by specific receptor blockade and inhibition of MAPK (p38, JNK and ERK) and NF- κ B signaling pathways., Results: HMGB1 stimulated RASMs proliferation in a dose- and time-dependent manner and also increased proliferating cell nuclear antigen (PCNA) and RAGE expression of RASMs. The inhibitor of RAGE, but not TLR2 and TLR4, reversed HMGB1-induced RASM proliferation and PCNA expression. Incubation of RASMs with HMGB1 caused a rapid increase in P65 and ERK phosphorylation. RASM proliferation and PCNA expression toward HMGB1 were significantly inhibited by the inhibitors of ERK and NF- κ B., Conclusion: HMGB1 induces proliferation of RASMs through a RAGE-dependent activation of ERK and NF- κ B signaling pathways., Competing Interests: None., (IJCEP Copyright © 2019.)