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Nature and Culture of Earth's Grandest Island
The Definitive Autobiography
A Guide to Finding and Identifying Prehistoric Life

Abstract

Impaired energy metabolism may play a role in the pathogenesis of neurodevelopmental disorders including fragile X syndrome (FXS). We checked brain energy status and some aspects of cell bioenergetics, namely the activity of key glycolytic enzymes, glycerol-3-phosphate shuttle and mitochondrial respiratory chain (MRC) complexes, in the cerebral cortex of the Fmr1 knockout (KO) mouse model of FXS. We found that, despite a hyperactivation of MRC complexes, adenosine triphosphate (ATP) production via mitochondrial oxidative phosphorylation (OXPHOS) is compromised, resulting in brain energy impairment in juvenile and late-adult Fmr1 KO mice. Thus, an altered mitochondrial energy metabolism may contribute to neurological impairment in FXS.

Abstract

This study determines the length distribution, length– weight relationship, age, growth parameters, mortality rate, sex ratios, length at first maturity and reproduction of saddled seabream (Oblada melanura) collected monthly by fishermen around the Northern Aegean Sea between November 2017 and October 2018. The length–weight relationship was calculated as W=0.0091×L 3.11 (R 2=0.95) and positive allometric growth was found. The condition factor and GSI varied between 0.81–1.58 and 0.01–9.61, respectively. The spawning season extended from May to July and peaked in June. Total lengths at 50% maturity were 18.97 cm for males and 18.83 cm for females. Parameters of the von Bertalanffy growth equation were: L∞ =29.91 cm, K =0.27 per year, t 0 =−0.82 year and age varied between 1 and 8. The instantaneous rates of total mortality (Z) and natural mortality (M) were 1.36 and 0.58 per year, respectively. Rates for fishing mortality F and exploitation E were 0.78 and 0.57 per year, respectively. The mean absolute fecundity (F) was 117 075±23 243 oocytes, ranging from 19130 to 470 132.

Abstract

Heat shock protein 90 (Hsp90) is a dimeric molecular chaperone that plays an essential role in cellular homeostasis. It functions in the context of a structurally dynamic ATP-dependent cycle to promote conformational changes in its clientele to aid stability, maturation, and activation. The client activation cycle is tightly regulated by a cohort of co-chaperone proteins that display specific binding preferences for certain conformations of Hsp90, guiding Hsp90 through its functional ATPase cycle. Aha-type co-chaperones are well-known to robustly stimulate the ATPase activity of Hsp90 but other roles in regulating the functional cycle are being revealed. In this review, we summarize the work done on the Aha-type co-chaperones since the 1990s and highlight recent discoveries with respect to the complexity of Hsp90 cycle regulation.

Abstract

The present study aimed at evaluating the mechanism by which functionality of hepatic stellate cells (HSCs) is modulated by bone marrow stromal cells (BMSCs). Induction of apoptosis in HSCs was found to be caused by directly co-culturing HSCs with BMSCs, where the expression of α-smooth muscle actin (α-SMA) increased significantly in HSCs, along with an increase in their proliferation rate. Additionally, expression of Hes1 and Notch1 in HSCs co-cultured with BMSCs increased significantly at both protein and mRNA levels. Blocking of the notch signaling pathway (NSP) either by Notch1 siRNA or by DAPT treatment increased the proliferation rate while decreasing apoptosis and led to activation of the NF-κB signaling pathway in HSCs co-cultured with BMSCs. These effects were found to be reversed in HSCs overexpressing IκB S32/S36 mutants. The Notch signaling-mediated cell-cell contact was partially involved in the significant inhibition of proliferation of HSCs by BMSCs. Additionally, the NF-κB pathway was found to be responsible for NSP-mediated inhibition of growth of HSCs in the co-culture system. Thus, BMSCs might have a potential therapeutic significance in treating hepatic fibrosis.

Abstract

The cyclic guanosine monophosphate (cGMP) signaling system is one of the most prominent regulators of a variety of physiological and pathophysiological processes in many mammalian and non-mammalian tissues. Targeting this pathway by increasing cGMP levels has been a very successful approach in pharmacology as shown for nitrates, phosphodiesterase (PDE) inhibitors and stimulators of nitric oxide-guanylyl cyclase (NO-GC) and particulate GC (pGC). This is an introductory review to the cGMP signaling system intended to introduce those readers to this system, who do not work in this area. This article does not intend an in-depth review of this system. Signal transduction by cGMP is controlled by the generating enzymes GCs, the degrading enzymes PDEs and the cGMP-regulated enzymes cyclic nucleotide-gated ion channels, cGMP-dependent protein kinases and cGMP-regulated PDEs. Part A gives a very concise introduction to the components. Part B gives a very concise introduction to the functions modulated by cGMP. The article cites many recent reviews for those who want a deeper insight.

Abstract

Metastasis is the main cause of increasing cancer morbidity and mortality. However, the underlying mechanism of cancer metastasis remains largely unknown. In the present study, we identified one circular RNA (circRNA) closely related to the metastasis of colorectal cancer (CRC), namely hsa_circ_0001178. CRC patients with high hsa_circ_0001178 were more prone to have metastatic clinical features, advanced TNM stage and adverse prognosis. Stable knockdown of hsa_circ_0001178 significantly weakened CRC cell migratory and invasive capabilities in vitro as well as lung and liver metastases in vivo. Mechanistic study revealed that hsa_circ_0001178 acted as a competing endogenous RNA (ceRNA) for miR-382/587/616 to upregulate ZEB1 (a key trigger of epithelial-to-mesenchymal transition), thereby promoting CRC metastatic dissemination. Of note, ZEB1 could also increase hsa_circ_0001178 expression via physically binding to hsa_circ_0001178 promoter region. Collectively, our data uncover the crucial role of hsa_circ_0001178 in CRC metastasis, and targeted therapy based on this positive feedback ceRNA axis may be a promising treatment for metastatic CRC patients.

Abstract

The present study describes a finding of the demodecid mite Demodex phocidi in the seal Phoca vitulina in the Baltic Sea. This is the first identification in Europe and the second in the world. This is also the first observation of the Demodecidae family in the pinnipeds outside North America. A high density of demodecid mites was observed in the skin of the examined seal, but no symptoms of parasitosis were observed. Our findings also supplement the taxonomic description and morphometry of D. phocidi.