Phosphatidylinositol-4,5-Bisphosphate Binding to Amphiphysin-II Modulates T-Tubule Remodeling: Implications for Heart Failure

BIN1 (amphyphysin-II) is a structural protein involved in T-tubule (TT) formation and phosphatidylinositol-4,5-bisphosphate (PIP2) is responsible for localization of BIN1 to sarcolemma. The goal of this study was to determine if PIP2-mediated targeting of BIN1 to sarcolemma is compromised during the development of heart failure (HF) and is responsible for TT remodeling. Immunohistochemistry showed co-localization of BIN1, Cav1.2, PIP2, and phospholipase-Cβ1 (PLCβ1) in TTs in normal rat and human ventricular myocytes. PIP2 levels were reduced in spontaneously hypertensive rats during HF progression compared to age-matched controls. A PIP Strip assay of two native mouse cardiac-specific isoforms of BIN1 including the longest (cardiac BIN1 #4) and shortest (cardiac BIN1 #1) isoforms as well human skeletal BIN1 showed that all bound PIP2. In addition, overexpression of all three BIN1 isoforms caused tubule formation in HL-1 cells. A triple-lysine motif in a short loop segment between two helices was mutated and replaced by negative charges which abolished tubule formation, suggesting a possible location for PIP2 interaction aside from known consensus binding sites. Pharmacological PIP2 depletion in rat ventricular myocytes caused TT loss and was associated with changes in Ca2+ release typically found in myocytes during HF, including a higher variability in release along the cell length and a slowing in rise time, time to peak, and decay time in treated myocytes. These results demonstrate that depletion of PIP2 can lead to TT disruption and suggest that PIP2 interaction with cardiac BIN1 is required for TT maintenance and function.

Comparison of normal hindlimb lymphatic systems in rats with detours present after lymphatic flow blockage

In the present study, we aimed to identify the normal hindlimb lymphatic systems in rats and compare them with the detours after lymphatic flow blockage. The lymphatic systems of the hindlimbs of normal rats were investigated via lymphography using a near-infrared fluorescence imaging system. The lymphatic vessels were stained using Evans Blue. The lymphatic flow was blocked through lymphatic vessel ligation combined with inguinal and popliteal lymph node dissection. Detours that appeared after 30 days were visualized using lymphography and immunostaining with anti-podoplanin antibodies. Three main results were obtained in the present study. First, the deep medial system, the superficial medial system, a connection between the superficial and deep medial lymphatic systems, and the superficial lateral system, were elucidated. Second, three types of detours, namely the detour of the lateral abdomen, the detour to the lymphatic vessel near the midline of the abdomen, and the detour to the contralateral inguinal lymph node, were identified after lymphatic flow blockage. Lastly, detours were located in the fatty layer above the panniculus carnosus muscle and their lumina were wide. The histology suggested that the detour was a pre-collecting lymphatic vessel. Lymphatic routes in the rat hindlimbs after lymphatic flow blockage were different from those of the normal rat lymphatic system. It was suggested that the detour is a pre-collecting lymphatic vessel and that encouraging its development may be a new method of simple lymphatic drainage.

Bismuth Subgallate as a Local Hemostatic Agent

Background: Patients on clopidogrel increased bleeding risk after surgery. This drug prolonged bleeding time, increased bleeding volume and induced secondary bleeding because its active metabolite inhibited platelets aggregation and interfered with haemostatic plug stabilization. Conventional methods, such as pressing sterile gauze on the surgery site, showed less effective to stop bleeding in patients on clopidogrel. This research aims to prove the haemostatic effect of bismuth subgallate both on normal and delayed platelet aggregation due to clopidogrel.Methods: Twenty-eight Wistar rats were equally and randomly administered with clopidogrel (10 mg/kgBW) or NaCl 0.9% (saline) via oral gavage. After anesthetizing, we amputated transversely their tail 10 mm from the distal tip. Bleeding after amputation was controlled with pressing gauze soaked in saline or bismuth subgallate solution. After 60 seconds, bleeding assays (bleeding time, bleeding volume, and secondary bleeding) have been observed, recorded, and analysed both in normal and clopidogrel groups.Results: Clopidogrel groups had significantly longer bleeding time, greater bleeding volume, and had more secondary bleeding rather than saline groups (p <.05). Using bismuth subgallate as local haemostatic agent decreased bleeding time and bleeding volume significantly (p <.05) both in normal and clopidogrel groups. Conclusions: Bismuth subgallate has a haemostatic effect on both clopidogrel and normal rat tail bleeding models.

Klotho deficiency intensifies hypoxia-induced expression of IFN-α/β through upregulation of RIG-I in kidneys

Hypoxia is a common pathway to the progression of end-stage kidney disease. Retinoic acid-inducible gene I (RIG-I) encodes an RNA helicase that recognizes viruses including SARS-CoV2, which is responsible for the production of interferon (IFN)-α/β to prevent the spread of viral infection. Recently, RIG-I activation was found under hypoxic conditions, and klotho deficiency was shown to intensify the activation of RIG-I in mouse brains. However, the roles of these functions in renal inflammation remain elusive. Here, for in vitro study, the expression of RIG-I and IFN-α/β was examined in normal rat kidney (NRK)-52E cells incubated under hypoxic conditions (1% O2). Next, siRNA targeting RIG-I or scramble siRNA was transfected into NRK52E cells to examine the expression of RIG-I and IFN-α/β under hypoxic conditions. We also investigated the expression levels of RIG-I and IFN-α/β in 33 human kidney biopsy samples diagnosed with IgA nephropathy. For in vivo study, we induced renal hypoxia by clamping the renal artery for 10 min in wild-type mice (WT mice) and Klotho-knockout mice (Kl−/− mice). Incubation under hypoxic conditions increased the expression of RIG-I and IFN-α/β in NRK52E cells. Their upregulation was inhibited in NRK52E cells transfected with siRNA targeting RIG-I. In patients with IgA nephropathy, immunohistochemical staining of renal biopsy samples revealed that the expression of RIG-I was correlated with that of IFN-α/β (r = 0.57, P<0.001, and r = 0.81, P<0.001, respectively). The expression levels of RIG-I and IFN-α/β were upregulated in kidneys of hypoxic WT mice and further upregulation was observed in hypoxic Kl−/− mice. These findings suggest that hypoxia induces the expression of IFN-α/β through the upregulation of RIG-I, and that klotho deficiency intensifies this hypoxia-induced expression in kidneys.

Effects of Four Local Species of Beans Consumed in South-eastern Nigeria on Selected Biochemical Indices of Wistar Albino Rats

The chemical composition and the effects of four local species of beans on the liver and kidney function of Wistar albino rats were examined. The four beans species are Cajanus Cajan, Vigna unguiculata subsp. sesquipedalis, Phaseolus vulgaris L ‘Red kidney’, and Phaseolus vulgaris 'Black turtle’. The results obtained for the proximate composition analysis revealed that the protein content of the bean species was higher in P. vulgaris L ‘Red kidney’ (18.54±0.01a %), and P. vulgaris 'Black turtle’ (18.36±0.01a %) with no significant difference at P< 0.05. The phytochemical composition analysis revealed that the beans contain various phytochemicals including some anti-nutritional factors. The mineral composition analysis shows that V. u. subsp. Sesquipedalis had a higher level of minerals (4.80±4.43a mg/100g) followed by C. cajan (3.24±2.64b mg/100g). The experimental design comprises of 30 male Wistar albino rats distributed into 5 groups of 6 rats each. Each group except the control received 50g of normal rat feed + 100g of beans body weight. The effects of the beans species on the biochemical parameters suggest no adverse effects when compared to the control. Despite that, these beans contain high nutritional components that are of nutritional interest as as well as some anti-nutritional factors.

Construction of IL-13 Receptor α2-Targeting Resveratrol Nanoparticles against Glioblastoma Cells: Therapeutic Efficacy and Molecular Effects

Glioblastoma multiforme (GBM) is the most common lethal primary brain malignancy without reliable therapeutic drugs. IL-13Rα2 is frequently expressed in GBMs as a molecular marker. Resveratrol (Res) effectively inhibits GBM cell growth but has not been applied in vivo because of its low brain bioavailability when administered systemically. A sustained-release and GBM-targeting resveratrol form may overcome this therapeutic dilemma. To achieve this goal, encapsulated Res 30 ± 4.8 nm IL-13Rα2-targeting nanoparticles (Pep-PP@Res) were constructed. Ultraviolet spectrophotometry revealed prolonged Res release (about 25%) from Pep-PP@Res in 48 h and fluorescent confocal microscopy showed the prolonged intracellular Res retention time of Pep-PP@Res (>24 h) in comparison with that of free Res (<4 h) and PP@Res (<4 h). MTT and EdU cell proliferation assays showed stronger suppressive effects of Pep-PP@Res on rat C6 GBM cells than that of PP@Res (p = 0.024) and Res (p = 0.009) when used twice for 4 h/day. Pep-PP@Res had little toxic effect on normal rat brain cells. The in vivo anti-glioblastoma effects of Res can be distinctly improved in the form of Pep-PP@Res nanoparticles via activating JNK signaling, upregulating proapoptosis gene expression and, finally, resulting in extensive apoptosis. Pep-PP@Res with sustained release and GBM-targeting properties would be suitable for in vivo management of GBMs.

The bile acid-sensitive ion channel (BASIC) mediates bile acid-dependent currents in bile duct epithelial cells

The bile acid-sensitive ion channel (BASIC) is a member of the Deg/ENaC family of ion channels that is activated by bile acids. Despite the identification of cholangiocytes in the liver and unipolar brush cells in the cerebellum as sites of expression, the physiological function of BASIC in these cell types is not yet understood. Here we used a cholangiocyte cell line, normal rat cholangiocytes (NRCs), which expresses BASIC to study the role of the channel in epithelial transport using Ussing chamber experiments. Apical application of bile acids induced robust and transient increases in transepithelial currents that were carried by Na+ and partly blocked by the BASIC inhibitor diminazene. Genetic ablation of the BASIC gene in NRC using a CRISPR-cas9 approach resulted in a decrease of the bile acid-mediated response that matched the diminazene-sensitive current in NRC WT cells, suggesting that cholangiocytes respond to bile acids with a BASIC-mediated Na+ influx. Taken together, we have identified BASIC as a component of the cholangiocyte transport machinery, which might mediate a bile acid-dependent modification of the bile and thus control bile flux and composition.

Silent Information Regulating Factor 2 Related Enzyme 1 Regulates the Formation of Osteoblasts and Osteoclasts Through the AKT/β-Catenin Pathway

Bone remodeling participates in osteoporosis (OP). Silent information regulating factor 2 related enzyme 1 (sirtuin1, SIRT1) regulates cell survival, differentiation, metabolism and inflammation. However, the regulatory effect of SIRT1 on the formation of osteoblasts and osteoclasts has not been reported. OP and normal rat BMSCs were assigned into control group, OP group, and SIRT1 group (Resveratrol) followed by measuring cell proliferation by MTT assay, ALP activity, expression of SIRT1, RUNX2 and OP by Real time PCR, AKT/β-catenin signaling protein expression by Western blot. Rat BMSCs were cultured and treated with RANKL to induce osteoclast culture in the presence or absence of Resveratrol followed by analysis of cell proliferation and c-Fos and TRAP expression. SIRT1 expression and secretion in BMSCs cells and supernatant of OP group were significantly reduced and cell proliferation was significantly inhibited along with reduced RUNX2 and OP expression, ALP activity as well as decreased AKT/β-catenin phosphorylation compared to control group (P < 0.05); addition of Resveratrol can significantly reverse the above changes (P <0.05). Resveratrol can significantly promote SIRT1 expression, inhibit osteoclast proliferation, and reduce c-Fos and TRAP expression (P < 0.05). SIRT1 expression is reduced in osteoporosis and its upregulation promotes osteogenesis through AKT/β-catenin pathway, inhibits osteoclast formation, and improves osteoporosis.

Novel Molecule Nell-1 Promotes the Angiogenic Differentiation of Dental Pulp Stem Cells

IntroductionThis work aimed to reveal the crucial role of Nell-1 in the angiogenic differentiation of human dental pulp stem cells (DPSCs) alone or co-cultured with human umbilical vein endothelial cell (HUVECs) in vitro and whether this molecule is involved in the pulp exposure model in vivo.MethodsImmunofluorescence was conducted to ascertain the location of Nell-1 on DPSCs, HUVECs, and normal rat dental tissues. RT-PCR, Western blot, and ELISA were performed to observe the expression levels of angiogenic markers and determine the angiogenic differentiation of Nell-1 on DPSCs alone or co-cultured with HUVECs, as well as in vitro tube formation assay. Blood vessel number for all groups was observed and compared using immunohistochemistry by establishing a rat pulp exposure model.ResultsNell-1 is highly expressed in the nucleus of DPSCs and HUVECs and is co-expressed with angiogenic markers in normal rat pulp tissues. Hence, Nell-1 can promote the angiogenic marker expression in DPSCs alone and co-cultured with other cells and can enhance angiogenesis in vitro as well as in the pulp exposure model.ConclusionNell-1 may play a positive role in the angiogenic differentiation of DPSCs.

Profound changes in cerebrospinal fluid proteome and metabolic profile are associated with congenital hydrocephalus

The aetiology of congenital hydrocephalus (cHC) has yet to be resolved. cHC manifests late in rodent gestation, and by 18–22 weeks in human fetuses, coinciding with the start of the major phase of cerebral cortex development. Previously we found that cerebrospinal fluid (CSF) accumulation is associated with compositional changes, folate metabolic impairment and consequential arrest in cortical development. Here, we report a proteomics study on hydrocephalic and normal rat CSF using LC-MSMS and a metabolic pathway analysis to determine the major changes in metabolic and signalling pathways. Non-targeted analysis revealed a proteome transformation across embryonic days 17–20, with the largest changes between day 19 and 20. This provides evidence for a physiological shift in CSF composition and identifies some of the molecular mechanisms unleashed during the onset of cHC. Top molecular regulators that may control the shift in the CSF metabolic signature are also predicted, with potential key biomarkers proposed for early detection of these changes that might be used to develop targeted early therapies for this condition. This study confirms previous findings of a folate metabolic imbalance as well as providing more in depth metabolic analysis and understanding of cHC CSF.