Tacrolimus (FK506)

Biological Activity

FK-506 (also Tacrolimus or fujimycin) is a potent calcineurin (protein phosphatase 2B) inhibitor that requires FK 506-binding protein 12 (FKBP12) for activity (IC50 = 3 nM). FK-506 inhibits secretion of IL-1, IL-2 (IC50 = 1 nM), IL-3, IL-4, IL-6 (IC50 = 35 nM), GM-CSF, TNFα (IC50 = 10 nM), IFNγ and Myc from activated T-cells in vitro. FK-506 exhibits potent immunosuppressive, neuroprotective and anticonvulsant activity in vivo. The physiological effects of FK-506 also include regulation of nitric oxide neurotoxicity, neurotransmitter release, and regulation of Ca2+ release via the ryanodine and inositol-(1,4,5)-trisphosphate (IP3) receptors. Furthermore, it has become clear that, predominantly as a result of CaN inhibition, FK506 alters multiple biochemical processes in a variety of cells besides lymphocytes. FK506 and ascomycin inhibit signaling pathways in astrocytes and change the pattern of cytokine and neurotrophin gene expression.

*The compound is unstable in solutions, freshly prepared is recommended

Product Citations

• 

  Neural Plast. 2022 Feb 7;2022:2900875.

  Presynaptic NMDA Receptors Influence Ca2+ Dynamics by Interacting with Voltage-Dependent Calcium Channels during the Induction of Long-Term Depression
  Tacrolimus (FK506) purchased from AbMole

• 

  BMC Biol. 2021 May 20;19(1):108.

  Very long intergenic non-coding (vlinc) RNAs directly regulate multiple genes in cis and trans
  Tacrolimus (FK506) purchased from AbMole

• 

  J Neurosci. 2015 Jan 7;35(1):64-73.

  Sleep slow wave-related homo and heterosynaptic LTD of intrathalamic GABAAergic synapses: involvement of T-type Ca2+ channels and metabotropic glutamate receptors.
  Tacrolimus (FK506) purchased from AbMole

Customer Product Validations & Biological Datas

	Source	Univerrsite Pierre et Marie Curi (2015). Figure 4. FK-506 (Abmole Bioscience)
	Method	Electrophysiology
	Cell Lines	whole-cell
	Concentrations	50 μM
	Incubation Time	1 h
	Results	As shown in figure 4D, no plasticity could be induced in the 8 neurons challenged by the induction protocol in this condition (post-protocol IPSCs amplitude: 99 ± 11% of baseline, p>0.05).

	Source	The Journal of Neuroscience (2015). Figure 4.FK-506 from AbMole.
	Method	Electrophysiology patch-clamp technique
	Cell Lines	neuron
	Concentrations	incubated for 1 h in FK-506 (at 25 and 50 µM) and then perfused with 20 µM FK-506.
	Incubation Time	1 h
	Results	"No plasticity could be induced in the eight neurons challenged by the induction protocol in this condition (postprotocol IPSC amplitude: 99 ± 4% of baseline, p>0.05)."

	Source	The Journal of Neuroscience (2015). Figure 4.FK-506 from AbMole.
	Method	Electrophysiology patch-clamp technique
	Cell Lines	neuron
	Concentrations	incubated for 1 h in FK-506 (at 25 and 50 µM) and then perfused with 20 µM FK-506.
	Incubation Time	1 h
	Results	"No plasticity could be induced in the eight neurons challenged by the induction protocol in this condition (postprotocol IPSC amplitude: 99 ± 4% of baseline, p>0.05)."

Protocol (for reference only)

Cell Experiment
Cell lines	PMoH
Preparation method	PMoH (2.5 x 105 cells/well) were seeded in 12-well plates and treated with various concentrations of the immunosuppressants. At 24, 48 and 72 hr post-treatment, wells were washed twice with sterile PBS and cells were fixed and stained with 0.1% crystal violet in 1M citric acid containing 20% methanol for 20 minutes at room temperature. Wells were washed thoroughly with sterile PBS to remove excess crystal violet and then air-dried. Bound dye was solubilized with 100 μl 100% DMSO for 20 minutes and the absorbance of the supernatants was measured at 544 nm using the FluoStar Optima (BMG LabTech) plate reader.
Concentrations	0.005 µg/ml
Incubation time	24, 48, 72 h

Animal Experiment
Animal models	BDF1 mice
Formulation	Solubilized in DMSO and diluted with PBS containing 10% dimethylacetamide (Sigma-Aldrich) and 6% Solutol (Sigma-Aldrich).
Dosages	twice daily at 3.2, 10, 32 or 100 mg/kg for 5 days
Administration	oral gavage

Chemical Information

Molecular Weight	804.02
Formula	C44H69NO12
CAS Number	104987-11-3
Solubility (25°C)	DMSO 90 mg/mL Ethanol 80 mg/mL
Storage	2-8°C, protect from light

Conversion of different model animals based on BSA (PMID: 27057123)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

References

[1] Arunachalam Muthuraman, et al. J Brachial Plex Peripher Nerve Inj . Pharmacological evaluation of tacrolimus (FK-506) on ischemia reperfusion induced vasculatic neuropathic pain in rats

[2] Sierra-Paredes G, et al. CNS Neurosci Ther. Ascomycin and FK506: pharmacology and therapeutic potential as anticonvulsants and neuroprotectants.

[3] Murakami Y, et al. J Nucl Med. Pharmacokinetic animal PET study of FK506 as a potent neuroprotective agent.

[4] Dumont FJ. Curr Med Chem. FK506, an immunosuppressant targeting calcineurin function.