Environmental Regulation of Mitochondria-Rich Cells in Chalcalburnus tarichi (Pallas, 1811) During Reproductive Migration

Osmoregulatory and immunological role of new canceled cells: Mitochondrial rich cells and its future perspective: A concise review

Mitochondrial-rich cells (MRCs) are one of the most significant canceled type of epithelial cells. Morphologically these cells are totally different from other epithelial cells. These cells primarily implicated in sea-water and fresh-water adaptation, and acid-base regulation. However, in this review paper, we explored some of the most intriguing biological and immune-related functional developmental networks of MRCs. The main pinpoint, MRCs perform a dynamic osmoregulatory and immunological functional role in the gut and male reproductive system. The Na+/K+_ATPase (NKA) and Na+/K+/2Cl cotransporter (NKCC) are key acidifying proteins of MRCs for the ion-transporting function for intestinal homeostasis and maintenance of acidifying the luminal microenvironment in the male reproductive system. Further more importantly, MRCs play a novel immunological role through the exocrine secretion of nano-scale exosomes and multivesicular bodies (MVBs) pathway, which is very essential for sperm maturation, motility, acrosome reaction, and male sex hormones, and these an essential events to produce male gametes with optimal fertilizing ability. This effort is expected to promote the novel immunological role of MRCs, which might be essential for nano-scale exosome secretion.

Investigation of gill mucus cells of Lake Van fish (Alburnus tarichi) during reproductive migration

Lake Van is the largest lake in Turkey. It is one of the few soda lakes in the world. Its water is brackish and soda. The lake water has a salinity rate of 19‰ and a pH of 9.8. The salty-soda content of the lake greatly limits biodiversity. Since the Lake Van fish is anadromous, it migrates from the extreme conditions of Lake Van to the freshwater pouring into the lake to spawn. In the same way, once they have emerged from the eggs, the newly hatched fish return to the lake environment to feed again. In this study, the changes in Lake Van fish gill mucus cell histochemistry were examined using different histological stains. The area and density of the mucus cells were observed to have changed in the aquatic areas of different physicochemical properties due to reproductive migration. The intensity of the mucus staining was also found to vary in different aquatic locations and gill regions. As a result, it was clearly demonstrated that mucus cell glycoprotein contents and levels found in Lake Van fish gills varied in different lake freshwater and aquatic environments. In addition, it was determined that the area and density of the mucus cells varied during reproductive migration. It is thought that the change in mucus cells was caused by salinity, pH, and bacterial and parasitic infections encountered in different aquatic environments. These changes in the gill mucus cells play an important role in the aquatic adaptation of fish.

An investigation on systematic history and distribution areas of tarek (Alburnus tarichi (Güldenstädt, 1814))

This study aimed to determine the distribution area of tarek (Alburnus tarichi (Güldenstädt, 1814)) and to define how it must be called according to the scientific name by evaluating its previous studies made by various systematisers and their reports on its distribution, and by comparing literature knowledge. The taxonomic characteristics of the collected samples were evaluated and several measurements and counts were taken on the samples; analfin origin 0-4 scales behind dorsal fin-base; 72-91 lateral line scales; 21-29 gill rakers; 7½-10 branched dorsal-fin rays and 10-12½ branched anal-fin rays. Body and caudal peduncle was moderately compressed. Body was covered by overlapping scales. Tarek has five different populations in the Basin. They are Van, Erçek, Nazik and Aygır Lakes and Koçköprü Dam Lake populations. The main living area of the tarek population is Lake Van; however, between May and June, mature individuals of tarek enter to tributaries of Van Lake. Some of them are Karasu, Bendimahi, Deliçay, Zilan, Karmuç, Sapur, Yanıkçay, Gevaş, Engil, Kurubaş and Akköprü Streams. At the end of study, it was concluded that tarek should be called as Alburnus tarichi (Güldenstädt, 1814) and it is an endemic fish species distributed only in Van Lake Basin.

Multivesicular bodies containing exosomes in immune-related cells of the intestine in zebrafish (Danio rerio): Ultrastructural evidence

Exosomes are secreted from various cells by multivesicular bodies (MVBs) that fuse with the plasma membrane and are involved in the intestinal immune response to maintain intestinal homeostasis. Here, we demonstrate the ultrastructural characteristics of MVBs and their exosomes in immune-related cells of the zebrafish intestine, including goblet cells (GCs), mitochondria-rich cells (MRCs), high endothelial cells (HECs) and lymphocytes. In GCs, MVBs with a low electron density were present under the nucleus. MVBs with exosomes were observed among mucin granules. "Heterogeneous" MVBs were identified within the cytoplasm around mucin granules. MRCs were observed in the intestinal mucosa epithelium, including "open-type" MRCs and "close-type" MRCs. Typical MVBs were identified in these MRCs. MVBs with a variety of exosomes were observed in the HECs of the capillary located in the lamina propria (LP). The HEC basement membrane budded outward to LP cells to form a plurality of basal blebs, later containing a large number of exosomes. MVBs also existed in the LP lymphocytes. A schematic diagram of the ultrastructural distribution of MVBs and their exosomes in the intestinal mucosal immune-related cells was created. Our findings provide cytological evidence for the source and ultrastructural distribution of exosomes within the different intestine cells of zebrafish. Component analysis and immunological functions of exosomes require future study.

Seasonal exploration of ultrastructure and Na+/K+-ATPase, Na+/K+/2Cl- cotransporter of mitochondria-rich cells in the small intestine of turtles

Despite the exploration of mitochondria-rich cells (MRCs) in different animal classes, very limited information has been documented about MRCs in reptiles. The present study was designed to investigate the effect of seasonal variation on the cell ultrastructure and ion transport protein activity of MRCs during hibernation and non-hibernation of Chinese soft-shelled turtle's intestine. Transmission electron microscopy revealed that, during hibernation the high-density cytoplasm of MRCs occupied large cross-sectional area and showed heterogeneous abundance of mitochondria and an expanded extensive tubular system as compared to non-hibernation. During hibernation the cytoplasm of MRCs exhibited more mitochondrial vacuolization, autophagosomes, phagophore formation and well-structured endoplasmic reticulum. During hibernation, MRCs connected with absorptive cells through wide interdigitation, and created tight junction and more desmosomes as compared to non-hibernation. Immunohistochemistry and immunofluorescence showed, the strong immunopositive reactions and immunosignaling of Na⁺/K⁺-ATPase (NKA) and Na⁺/K⁺/2Cl- cotransporter (NKCC) at basolateral region of mucosal surface of intestine during hibernation. However, weak immunopositive reactions and immunosignaling of NKA and NKCC during non-hibernation. The statistical analysis showed that the number and size of MRCs with NKA-associated immunoreactivity were significantly increased during hibernation. NKA and NKCC mRNA expression was significantly increased during hibernation via qPCR. Further confirmed, the intensity of NKA and NKCC proteins was more elevated during hibernation than non-hibernation shown by immunobloting. However, the concentrations of the plasma ions Na⁺ and Cl- were significantly higher during hibernation; conversely, K⁺ concentration was significantly higher during non-hibernation. The findings suggest that the potential role of MRCs is affected by seasonal fluctuations, during which intestinal homeostasis and hydromineral balance are essential for turtles.

The effect of hydraulic flowback and produced water on gill morphology, oxidative stress and antioxidant response in rainbow trout (Oncorhynchus mykiss)

Hydraulic fracturing fluid are complex mixtures containing high concentrations of salts (up to 330,000 ppm), organic, and metal contaminants. However, little data exist on the potential mechanisms of toxicity of these flowback and produced wastewaters (FPW) on aquatic biota. Juvenile rainbow trout were exposed to either control, FPW (2.5 or 7.5%), FPW that had been treated with activated charcoal (AC), or a custom salt-matched control (SW; replicating only the salt content of FPW) for 48 hours. Gill histology revealed decreases in interlamellar cell mass (ILCM) and mean lamellar length in all treatments (FPW, AC and SW) compared to control, indicative of hyperosmotic stress. Liver CYP1A1 activity was significantly elevated by 7.5-fold in the FPW 7.5% treatment only, indicative of Phase I metabolism. Superoxide dismutase activity significantly decreased in the gills to all treatments with the lowest activity occurring in the 7.5% FPW group. Catalase activity increased in liver with the highest values noted in fish exposed to 7.5% FPW. No changes were observed with respect to glutathione-S-transferase, while increased lipid peroxidation was only observed in both FPW treatments (2.5, 7.5%). These data suggest a characteristic signature of FPW impact which may help in risk assessment and biomonitoring of FPW spills.

Determination of selected endocrine disrupting chemicals in Lake Van, Turkey

In the present study, we investigated the distribution of 17β-estradiol (E2), 17α-ethynylestradiol (EE2), alkylphenol ethoxylates (APEs) and organochlorine pesticides (DDE/DDT) in water and sediment samples in the Eastern Anatolia of Turkey, Lake Van, which is the largest soda lake in the world. The procedure consisted of solid phase extraction performed with OASIS HLB cartridges followed by non-competitive enzyme-linked immunosorbent assays (ELISA). The endocrine disrupting compounds E2, EE2, and DDT/DDE were detected in most of the lake samples with mean concentrations of 0.996 ± 0.304, 0.050 ± 0.022, and 0.749 ± 0.658 ng/L in water, respectively. Mean concentrations of E2, EE2 and DDT/DDE in sediment were 0.098 ± 0.053, 0.091 ± 0.072, and 1.281 ± 0.754 ng/g, respectively. APEs were not measured in the sediment samples. The EDCs levels in surface water and sediment samples were lower than that of other countries. The EDCs were also found in effluent and influent municipal sewage samples. Van city municipal wastewater treatment plant has no removal efficiency for EDCs.