

Untukx Kevin
2K posts

@UntukxK
Meneliti perilaku manusia di internet. Berita viral = bahan penelitian. Kadang lucu. Kadang tragis. Selalu menarik.



Blocking all incels who says "Sepakat"💞 thanks for starting this trend cus it's much easier & recognizable to filter people now.


Summertime = Hair growth maxing🦁 Why? Hair follicles have vitamin D receptors that are proven to help regulate the growth cycle. Now in case you have no clue what VDR and DBP are, give me 28 seconds to show you the basics. Let's start with vitamin D binding protein (DBP). DBP, also known as Gc-globulin (from “group-specific component”) is the primary carrier protein for vitamin D metabolites in the blood. It plays a central role not only in vitamin D transport but also in its bioavailability, activation and clearance. It’s a 58 kDa glycoprotein belonging to the albumin family (structurally related to albumin and alpha-fetoprotein) that’s produced mainly in the liver (also minor synthesis in other tissues like kidney and adipose) and its circulating concentration is quite high at ~4–8 μM. It binds multiple ligands with high affinity: -25(OH)D (calcidiol, the main circulating form): strongest affinity. -1,25(OH)₂D (calcitriol): lower affinity but still significant. -Vitamin D₂/D₃: weaker binding. -Actin (G-actin): a unique non-vitamin D role.DBP binds G-actin released during tissue injury or cell death → forms DBP-actin complexes → cleared by the liver. It basically prevents actin polymerization into harmful filaments that could obstruct microcirculation. This “actin clearance” role is critical in acute inflammation and tissue damage. Now DBP binds 85–90% of circulating 25(OH)D and 1,25(OH)₂D to prevent rapid clearance and protect them from degradation. The DBP-vitamin D complex has a long half-life of 2–3 weeks for 25(OH)D. Of course, only the free (unbound) fraction of 25(OH)D and 1,25(OH)₂D is biologically active and can enter cells to bind the vitamin D receptor (VDR). DBP acts as a reservoir, releasing vitamin D metabolites to target tissues whether that’s called kidney for activation by 1α-hydroxylase or immune cells for local immunomodulation. In the kidney for example, DBP-bound 25(OH)D is taken up via megalin and cubilin receptors (endocytosis), gets internalized and converted to 1,25(OH)₂D by CYP27B1. This is especially important in immune cells (macrophages, dendritic cells, T cells) that express CYP27B1 → produce local 1,25(OH)₂D for autocrine/paracrine immune regulation. Also, DBP itself has direct immunomodulatory effects and even modulates neutrophil and monocyte migration for example. If all these were too complicated, simply keep in mind that vitamin D3 metabolites, including 1,25(OH)2D3, are carried by serum vitamin D binding protein for now. Moving on to the vitamin D receptor. The Vitamin D Receptor (VDR) is a ligand-activated transcription factor that belongs to the steroid/thyroid hormone receptor superfamily. When bound to its active ligand (1,25-dihydroxyvitamin D / calcitriol), VDR directly regulates gene expression by binding to specific DNA sequences called vitamin D response elements (VDREs). This allows vitamin D to influence thousands of genes involved in things we discussed such as immune regulation, inflammation control, barrier function, cell growth, calcium homeostasis, and more. Now, in the inactive state (no ligand bound) VDR is primarily located in the cytoplasm, often associated with chaperone proteins that keep it stable and prevent premature activation. Upon ligand binding, VDR undergoes a conformational change, dissociates from chaperones, forms a heterodimer with the retinoid X receptor (RXR), translocates to the nucleus, and binds VDREs to regulate target genes. Some VDR is constitutively nuclear in certain cell types such as immune cells and keratinocytes. VDR is one of the most widely distributed nuclear receptors expressed in nearly every cell type in the human body. There’s particularly high expression in: Immune cells (the highest density is found here). Epithelial cells such as: -Intestinal epithelial cells (gut mucosa) -Keratinocytes (skin) -Alveolar epithelial cells (lung) -Renal tubular cells (kidney) -Bone cells -Neurons -Microglia -Muscle (skeletal and smooth) -Pancreas (beta cells) -Thyroid -Parathyroid -Adrenal glands -Adipose tissue -Liver -Cardiovascular endothelium And pretty much everywhere. So.......go and test your levels as a starting point. For more: fitandball.gumroad.com/l/bundlehelpds…



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