LRP/LR specific antibody IgG1-iS18 impedes neurodegeneration in Alzheimer's disease mice

Downregulation of LRP/LR with siRNA inhibits several cancer hallmarks in lung cancer cells

The incidence and mortality rates of cancer are growing rapidly worldwide, with lung cancer being the most commonly occurring cancer in males. Human carcinomas circumvent the inhibitory pathways induced by DNA damage and senescence through the upregulation of telomerase activity. The 37 kDa/67 kDa laminin receptor (LRP/LR) is a cell surface receptor which plays a role in several cancer hallmarks, including metastasis, angiogenesis, cell viability maintenance, apoptotic evasion, and mediating telomerase activity. We have previously shown that the knockdown of LRP/LR with an LRP-specific siRNA significantly impedes adhesion and invasion, induces apoptosis, and inhibits telomerase activity in various cancer cell lines in vitro. Here, we investigated the effect of downregulating LRP/LR with LRP-specific siRNA in A549 lung cancer cells. Downregulation of LRP/LR resulted in a significant decrease in cell viability, migration potential, and telomerase activity, as well as a significant increase in apoptosis. Proteomic analysis further suggested the re-establishment of immune control over the lung cancer cells, a previously unidentified facet of LRP downregulation in cancer. Altogether, we suggest that targeting LRP/LR for downregulation may have therapeutic potential for inhibiting several cancer hallmarks.

LRP::FLAG Reduces Phosphorylated Tau Levels in Alzheimer's Disease Cell Culture Models

BACKGROUND

Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) plaque and neurofibrillary tangle formation, respectively. Neurofibrillary tangles form as a result of the intracellular accumulation of hyperphosphorylated tau. Telomerase activity and levels of the human reverse transcriptase (hTERT) subunit of telomerase are significantly decreased in AD. Recently, it has been demonstrated that the 37 kDa/67 kDa laminin receptor (LRP/LR) interacts with telomerase and is implicated in Aβ pathology. Since both LRP/LR and telomerase are known to play a role in the Aβ facet of AD, we hypothesized that they might also play a role in tauopathy.

OBJECTIVE

This study aimed to determine if LRP/LR has a relationship with tau and whether overexpression of LRP::FLAG has an effect on tauopathy-related proteins.

METHODS

We employed confocal microscopy and FRET to determine whether LRP/LR and tau co-localize and interact. LRP::FLAG overexpression in HEK-293 and SH-SY5Y cells as well as analysis of tauopathy-related proteins was assessed by western blotting.

RESULTS

We demonstrate that LRP/LR co-localizes with tau in the perinuclear cell compartment and confirmed a direct interaction between LRP/LR and tau in HEK-293 cells. Overexpression of LRP::FLAG in HEK-293 and SH-SY5Y cells decreased total and phosphorylated tau levels with a concomitant decrease in PrPc levels, a tauopathy-related protein. LRP::FLAG overexpression also resulted in increased hTERT levels.

CONCLUSION

This data suggest that LRP/LR extends its role in AD through a direct interaction with tau, and recommend LRP::FLAG as a possible alternative AD therapeutic via decreasing phosphorylated tau levels.

The Crocus sativus Compounds trans-Crocin 4 and trans-Crocetin Modulate the Amyloidogenic Pathway and Tau Misprocessing in Alzheimer Disease Neuronal Cell Culture Models

Crocus sativus L. natural compounds have been extensively used in traditional medicine for thousands of years. Recent research evidence is now emerging in support of its therapeutic potential for different pathologies including neurodegenerative diseases. Herein, the C. sativus L. natural compounds trans-crocin 4 and trans-crocetin were selected for in depth molecular characterization of their potentially protective effects against Alzheimer’s Disease (AD), utilizing two AD neuronal cell culture models (SH-SY5Y overexpressing APP and PC12 expressing hyperphosphorylated tau). Biologically relevant concentrations, ranging from 0.1 μM to 1 mM, applied for 24 h or 72 h, were well tolerated by differentiated wild type SH-SY5Y and PC12 cells. When tested on neuronally differentiated SH-SY5Y-APP both trans-crocin 4 and trans-crocetin had significant effects against amyloidogenic pathways. Trans-crocin 4 significantly decreased of β-secretase, a key enzyme of the amyloidogenic pathway, and APP-C99, while it decreased γ-secretases that generate toxic beta-amyloid peptides. Similarly, trans-crocetin treatment led to a reduction in β- and γ-secretases, as well as to accumulation of cellular AβPP. When tested on the neuronally differentiated PC12-htau cells, both compounds proved effective in suppressing the active forms of GSK3β and ERK1/2 kinases, as well as significantly reducing total tau and tau phosphorylation. Collectively, our data demonstrate a potent effect of trans-crocin 4 and trans-crocetin in suppressing key molecular pathways of AD pathogenesis, rendering them a promising tool in the prevention and potentially the treatment of AD.