scholarly journals Bioluminescence and Fluorescence in Littoral Earthworms

2020 ◽  
Author(s):  
Teerapong Seesamut ◽  
Daichi Yano ◽  
Jose Paitio ◽  
Ikuhiko Kin ◽  
Somsak Panha ◽  
...  
Keyword(s):  
Mechanical Stimulation ◽  
Coelomic Fluid ◽  
Congeneric Species ◽  
Strong Fluorescence ◽  
Spectral Maximum ◽  
Light Emitter ◽  
Close Relationship ◽  
Single Genus

Abstract Pontodrilus litoralis is a cosmopolitan littoral earthworm known to exhibit bioluminescence. Recently, a congeneric species Pontodrilus longissimus from Thailand was described. These species are sympatric but their burrowing depths on Thai beaches are different. In this study, we examined the in vivo and in vitro bioluminescence properties of P. longissimus and P. litoralis. Mechanical stimulation induced in vivo luminescence in P. litoralis, as reported previously, but not in P. longissimus. In vitro cross-reaction tests between these species revealed the absence of luciferin and luciferase activities in P. longissimus. P. litoralis had strong fluorescence in a coelomic fluid that matches to the spectral maximum of its bioluminescence, but P. longissimus did not. These results suggest that P. longissimus does not have luminescence ability due to the lack of all bioluminescent components, luciferin, luciferase, and light emitter, despite its close relationship to the luminous P. litoralis. The presence of both luminous and non-luminous species in a single genus is uncommon, and our present findings will shed insight on the possible functions of bioluminescence in the earthworm, such as avoiding predation by littoral earwigs.

scholarly journals Occurrence of bioluminescent and nonbioluminescent species in the littoral earthworm genus Pontodrilus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Teerapong Seesamut ◽  
Daichi Yano ◽  
José Paitio ◽  
Ikuhiko Kin ◽  
Somsak Panha ◽  
...  
Keyword(s):  
Mechanical Stimulation ◽  
Coelomic Fluid ◽  
Congeneric Species ◽  
Light Emitters ◽  
Strong Fluorescence ◽  
Spectral Maximum ◽  
Single Genus ◽  
Insight Into

AbstractPontodrilus litoralis is a cosmopolitan littoral earthworm known to exhibit bioluminescence. Recently, a congeneric species, Pontodrilus longissimus, from Thailand was described. These species are sympatric, but their burrowing depths on Thai beaches are different. In this study, we examined the in vivo and in vitro bioluminescent properties of P. longissimus and P. litoralis. Mechanical stimulation induced in vivo luminescence in P. litoralis, as reported previously, but not in P. longissimus. In vitro cross-reaction tests between these species revealed the absence of luciferin and luciferase activities in P. longissimus. The coelomic fluid of P. litoralis had strong fluorescence that matched the spectral maximum of its bioluminescence, but the same result was not observed for P. longissimus. These results suggest that P. litoralis has luminescence abilities due to the creation of bioluminescent components (i.e., luciferin, luciferase, and light emitters). The presence of both luminous and nonluminous species in a single genus is likely widespread, but only a few examples have been confirmed. Our findings provide insight into the possible functions of bioluminescence in earthworms, such as avoiding predation by littoral earwigs.

Toxicity of Heparinoids, with Special Reference to the Precipitation of Fibrinogen

1964 ◽  
Vol 12 (01) ◽  
pp. 232-261 ◽  
Author(s):  
S Sasaki ◽  
T Takemoto ◽  
S Oka
Keyword(s):  
Molecular Weight ◽  
Dextran Sulfate ◽  
Anticoagulant Activity ◽  
Molecular Structures ◽  
Severe Reaction ◽  
Clinical Use ◽  
Molecular Weights ◽  
Close Relationship

SummaryTo demonstrate whether the intravascular precipitation of fibrinogen is responsible for the toxicity of heparinoid, the relation between the toxicity of heparinoid in vivo and the precipitation of fibrinogen in vitro was investigated, using dextran sulfate of various molecular weights and various heparinoids.1. There are close relationships between the molecular weight of dextran sulfate, its toxicity, and the quantity of fibrinogen precipitated.2. The close relationship between the toxicity and the precipitation of fibrinogen found for dextran sulfate holds good for other heparinoids regardless of their molecular structures.3. Histological findings suggest strongly that the pathological changes produced with dextran sulfate are caused primarily by the intravascular precipitates with occlusion of the capillaries.From these facts, it is concluded that the precipitates of fibrinogen with heparinoid may be the cause or at least the major cause of the toxicity of heparinoid.4. The most suitable molecular weight of dextran sulfate for clinical use was found to be 5,300 ~ 6,700, from the maximum value of the product (LD50 · Anticoagulant activity). This product (LD50 · Anticoagulant activity) can be employed generally to assess the comparative merits of various heparinoids.5. Clinical use of the dextran sulfate prepared on this basis gave satisfactory results. No severe reaction was observed. However, two delayed reactions, alopecia and thrombocytopenia, were observed. These two reactions seem to come from the cause other than intravascular precipitation.

scholarly journals Low Intensity Pulsed Ultrasound for Bone Tissue Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1488
Author(s):  
Colleen McCarthy ◽  
Gulden Camci-Unal
Keyword(s):  
Bone Formation ◽  
Bone Tissue ◽  
Mechanical Stimulation ◽  
Synergistic Effects ◽  
In Vivo Studies ◽  
Pulsed Ultrasound ◽  
Low Intensity Pulsed Ultrasound ◽  
Low Intensity

As explained by Wolff’s law and the mechanostat hypothesis, mechanical stimulation can be used to promote bone formation. Low intensity pulsed ultrasound (LIPUS) is a source of mechanical stimulation that can activate the integrin/phosphatidylinositol 3-OH kinase/Akt pathway and upregulate osteogenic proteins through the production of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). This paper analyzes the results of in vitro and in vivo studies that have evaluated the effects of LIPUS on cell behavior within three-dimensional (3D) titanium, ceramic, and hydrogel scaffolds. We focus specifically on cell morphology and attachment, cell proliferation and viability, osteogenic differentiation, mineralization, bone volume, and osseointegration. As shown by upregulated levels of alkaline phosphatase and osteocalcin, increased mineral deposition, improved cell ingrowth, greater scaffold pore occupancy by bone tissue, and superior vascularization, LIPUS generally has a positive effect and promotes bone formation within engineered scaffolds. Additionally, LIPUS can have synergistic effects by producing the piezoelectric effect and enhancing the benefits of 3D hydrogel encapsulation, growth factor delivery, and scaffold modification. Additional research should be conducted to optimize the ultrasound parameters and evaluate the effects of LIPUS with other types of scaffold materials and cell types.

scholarly journals Exosomal PD-L1 and N-cadherin predict pulmonary metastasis progression for osteosarcoma patients

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jun Wang ◽  
Hongliang Zhang ◽  
Xin Sun ◽  
Xiaofang Wang ◽  
Tingting Ren ◽  
...  
Keyword(s):  
Pulmonary Metastasis ◽  
Characteristic Curve ◽  
Bioinformatic Analysis ◽  
Benign Tumors ◽  
Cancer Pathogenesis ◽  
Healthy Donors ◽  
Close Relationship ◽  
Serum Exosomes

Abstract Background Recent studies indicated that exosomal programmed death-ligand 1 (PD-L1) derived from cancers could induce immunosuppression and tumor pathogenesis. However, it is unclear how exosomes influence osteosarcoma (OS) progression and whether PD-L1 also exists in serum exosomes (Sr-exosomes) of patients with osteosarcoma. We examined serum exosomes from 70 OS patients, 9 patients with benign tumors and 22 healthy donors. OS-derived exosomes were functionally evaluated in vivo and in vitro. Results The characteristics of exosomes derived from OS patient serum and OS cell lines were confirmed by several methods. We found OS patients had a higher level of exosomal PD-L1 compared to healthy donors. Meanwhile, OS patients with pulmonary metastasis also showed a relatively higher level of exosomal PD-L1 than patients without metastasis. Next, bioinformatic analysis demonstrated that Sr-exosomes isolated from OS patients may involve in the important process of immune function and cancer pathogenesis for OS patients. Co-expression network centered with PD-L1 among Sr-exosomal differently expressed mRNA demonstrated exosomal N-cadherin had a close relationship with exosomal PD-L1 expression. Then, we confirmed higher level of Sr-exosomal N-cadherin in OS patients with pulmonary metastasis compared to ones without metastasis. Furthermore, we elucidated osteosarcoma-derived exosomes and exosomal-PD-L1 promoted the pulmonary metastasis in metastatic models. ROC (Receiver Operating Characteristic Curve) analysis showed AUC (Area Under Curve) of 0.823 for exosomal PD-L1, 0.806 for exosomal N-cadherin and 0.817 for exosomal N-cadherin/E-cadherin to distinguish OS patients with pulmonary metastasis from ones without metastasis. Conclusions Osteosarcoma stimulates pulmonary metastasis by releasing exosomes, that carry PD-L1 and N-cadherin. Detection of exosomal PD-L1 and N-cadherin from serum of OS patients may predict pulmonary metastasis progression for OS patients.

Multiscale Modeling of Trabecular Bone Marrow: Understanding the Micromechanical Environment of Mesenchymal Stem Cells During Osteoporosis

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
T. J. Vaughan ◽  
M. Voisin ◽  
G. L. Niebur ◽  
L. M. McNamara
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Trabecular Bone ◽  
Mechanical Stimulation ◽  
Cell Level ◽  
Mechanical Environment ◽  
Stimulation Of

Mechanical loading directs the differentiation of mesenchymal stem cells (MSCs) in vitro and it has been hypothesized that the mechanical environment plays a role in directing the cellular fate of MSCs in vivo. However, the complex multicellular composition of trabecular bone marrow means that the precise nature of mechanical stimulation that MSCs experience in their native environment is not fully understood. In this study, we developed a multiscale model that discretely represents the cellular constituents of trabecular bone marrow and applied this model to characterize mechanical stimulation of MCSs in vivo. We predicted that cell-level strains in certain locations of the trabecular marrow microenvironment were greater in magnitude (maximum ε12 = ∼24,000 με) than levels that have been found to result in osteogenic differentiation of MSCs in vitro (>8000 με), which may indicate that the native mechanical environment of MSCs could direct cellular fate in vivo. The results also showed that cell–cell adhesions could play an important role in mediating mechanical stimulation within the MSC population in vivo. The model was applied to investigate how changes that occur during osteoporosis affected mechanical stimulation in the cellular microenvironment of trabecular bone marrow. Specifically, a reduced bone volume (BV) resulted in an overall increase in bone deformation, leading to greater cell-level mechanical stimulation in trabecular bone marrow (maximum ε12 = ∼48,000 με). An increased marrow adipocyte content resulted in slightly lower levels of stimulation within the adjacent cell population due to a shielding effect caused by the more compliant behavior of adipocytes (maximum ε12 = ∼41,000 με). Despite this reduction, stimulation levels in trabecular bone marrow during osteoporosis remained much higher than those predicted to occur under healthy conditions. It was found that compensatory mechanobiological responses that occur during osteoporosis, such as increased trabecular stiffness and axial alignment of trabeculae, would be effective in returning MSC stimulation in trabecular marrow to normal levels. These results have provided novel insight into the mechanical stimulation of the trabecular marrow MSC population in both healthy and osteoporotic bone, and could inform the design three-dimensional (3D) in vitro bioreactor strategies techniques, which seek to emulate physiological conditions.

scholarly journals Dog Red Blood Cells

1973 ◽  
Vol 62 (2) ◽  
pp. 147-156 ◽  
Author(s):  
John C. Parker
Keyword(s):  
Sodium Chloride ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Extracellular Potassium ◽  
Sodium Potassium ◽  
Sodium Removal ◽  
Close Relationship ◽  
The Media

Dog red blood cells (RBC) lack a ouabain-sensitive sodium pump, and yet they are capable of volume regulation in vivo. The present study was designed to find in vitro conditions under which dog RBC could transport sodium outward, against an electrochemical gradient. Cells were first loaded with sodium chloride and water by preincubation in hypertonic saline. They were then incubated at 37°C in media containing physiologic concentrations of sodium, potassium, chloride, bicarbonate, glucose, and calcium. The cells returned to a normal salt and water content in 16–20 h. Without calcium in the medium the cells continued slowly to accumulate sodium. Removal of glucose caused rapid swelling and lysis, whether or not calcium was present. The net efflux of sodium showed a close relationship to medium calcium over a concentration range from 0 to 5 mM. Extrusion of salt and water was also demonstrated in fresh RBC (no hypertonic preincubation) when calcium levels in the media were sufficiently raised. The ion and water movements in these experiments were not influenced by ouabain or by removal of extracellular potassium. Magnesium could not substitute for calcium. It is concluded that dog RBC have an energy-dependent mechanism for extruding sodium chloride which requires external calcium and is quite distinct from the sodium-potassium exchange pump.

scholarly journals Mechanically stimulated ATP release from murine bone cells is regulated by a balance of injury and repair

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Nicholas Mikolajewicz ◽  
Elizabeth A Zimmermann ◽  
Bettina M Willie ◽  
Svetlana V Komarova
Keyword(s):  
Mechanical Stimulation ◽  
Cell Injury ◽  
Bone Cells ◽  
Atp Release ◽  
Membrane Repair ◽  
Membrane Injury ◽  
Vesicular Release ◽  
Injury And Repair

Bone cells sense and actively adapt to physical perturbations to prevent critical damage. ATP release is among the earliest cellular responses to mechanical stimulation. Mechanical stimulation of a single murine osteoblast led to the release of 70 ± 24 amole ATP, which stimulated calcium responses in neighboring cells. Osteoblasts contained ATP-rich vesicles that were released upon mechanical stimulation. Surprisingly, interventions that promoted vesicular release reduced ATP release, while inhibitors of vesicular release potentiated ATP release. Searching for an alternative ATP release route, we found that mechanical stresses induced reversible cell membrane injury in vitro and in vivo. Ca2+/PLC/PKC-dependent vesicular exocytosis facilitated membrane repair, thereby minimizing cell injury and reducing ATP release. Priming cellular repair machinery prior to mechanical stimulation reduced subsequent membrane injury and ATP release, linking cellular mechanosensitivity to prior mechanical exposure. Thus, our findings position ATP release as an integrated readout of membrane injury and repair.

scholarly journals Thrombin infusion in endotoxin-treated rabbits reduces the plasma levels of plasminogen activator inhibitor: evidence for a protein-C- mediated mechanism [see comments]

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 1976-1982
Author(s):  
M Colucci ◽  
R Triggiani ◽  
LG Cavallo ◽  
N Semeraro
Keyword(s):  
Plasminogen Activator ◽  
Plasma Levels ◽  
Protein C ◽  
Plasminogen Activator Inhibitor ◽  
Rabbit Serum ◽  
Functional Assay ◽  
Blood Clots ◽  
Close Relationship

Plasminogen activator inhibitors (PAIs) play a pivotal role in the control of fibrinolysis. The mechanisms regulating the plasma levels of PAI(s) are still unknown. We report here that the infusion of bovine thrombin (1 U/kg/min, over 60 minutes) in rabbits treated with 0.5 microgram/kg endotoxin (to induce an increase in circulating fast- acting PAI) causes a marked reduction of PAI (50% of preinfusion value), as indicated by functional assay and reverse fibrin autography. Moreover, blood clots prepared from samples obtained after thrombin infusion lysed faster than preinfusion clots when exposed, in vitro, to tissue plasminogen activator. Donor-receiver transfusion experiments showed that the half-life of circulating PAI activity was shorter in thrombin-infused rabbits than in controls (4.1 minutes versus 7.4 minutes), suggesting an accelerated clearance. As expected, thrombin infusion resulted also in activation of protein C (PC). The following observations suggest a close relationship between PC activation and PAI reduction. (1) Infusion of thrombin in rabbits made deficient in vitamin K-dependent plasma proteins by warfarin treatment did not result in modification of PAI activity. (2) Treatment of the latter animals with a barium citrate eluate (PE) of rabbit plasma restored both the anticoagulant and profibrinolytic response to thrombin. (3) Short infusion of thrombin-activated PE (containing activated PC, PCa), but not of unactivated PE, induced both anticoagulation and reduction of PAI activity. In vitro, incubation of PAI-rich rabbit serum with thrombin-activated PE and phospholipids resulted in a progressive disappearance of PAI activity with a t1/2 of 30 minutes. However, this slow inactivation rate does not fully explain the results obtained in vivo. Our data suggest that thrombin infusion in rabbits causes a reduction of circulating PAI activity and that activation of PC is the intermediary mechanism involved in this phenomenon.

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