Decrease,SIRT1(sirtuin 1) levels leads to Increase activation, Nuclear factor kappa B (NF-kB)

• SIRT1 can inhibit NF-κB signaling directly or indirectly, in turn the NF-κB system suppresses SIRT1-mediated functions by inhibiting the downstream targets of SIRT1. Given that SIRT1 and NF-κB signaling have antagonistic characteristics, these pathways control many of the physiologically relevant metabolic and inflammatory switches required for the maintenance of cellular and organismal homeostasis.
• PGC-1 is a downstream target of the SIRT/AMPK signalling cascade that promotes oxidative metabolism by promoting mitochondrial biogenesis (Fernandez et al.,2011). In cardiac cells, Alvarez-Guardia et al. found that the RelA/p65 member of the NF-B complex was constitutively linked to the PGC-1 protein. They also discovered that activating NF-B after TNF exposure boosted the association between the RelA/p65 and PGC-1 proteins, resulting in an increase in glucose oxidation (Alvarez et al., 2010). These findings show that deacetylation of PGC-1 promotes mitochondrial oxidative respiration, whereas activation of NF-B signalling inhibits SIRT1/PGC-1 communication and activates aerobic glycolysis. This shift is known as the Warburg effect, which can be seen in cancer cells but also in ageing (Salminen et al., 2010). Overexpression of PGC-1, on the other hand, decreased the transcriptional activity of NF-B by lowering the phosphorylation of the transactivating RelA/p65 component(Eisele et al.,2013)

- Studies have been done on pancreatic cancer cells, Joudah et colleagues investigated the processes and correlations between SIRT1 and NF-B activation .The results showed that a 1 µM  SIRT1 aptamer might limit NF-B activation by increasing SIRT1 protein activity(Joudah et al.,2021). According to the findings of SIRT1 aptamer mechanisms, it is possible that SIRT1 aptamer will be used in the treatment of pancreatic cancer in the future.

-To explore the mechanism of SIRT1 aptamer in cell lines, SIRT1 activity was measured in parallel on Aspc-1, BxPc-3, and Capan-2 cell lines under the same conditions. SIRT1 activity was measured in BxPc-3 cell lines using SIRT1 aptamer at 0.25, 0.5, and 1M. Then, using 100M resveratrol (SIRT1 activator control), 100M suramin, and nicotinamide(SIRT1 inhibitor control), assess its activity .

-The results revealed that using SIRT1 aptamer at 1M boosted SIRT1 activity in Capan-2 cells when compared to high concentrations of 100M resveratrol, 100M Suramin, and 100M Nicotinamide.

-The activation of SIRT1 in the Aspc-1 cell line when treated with SIRT1 at 1µM was higher than that of 100µM resveratrol, Suramin, and Nicotinamide.

-the effect of SIRT1 aptamer on NF-kB activation was determined in nuclear extracts of BxPC-3, Capan-2, and AsPC-1 cell lines using an ELISA-based test to measure the capacity of NF-kB p65 subunit for DNA-binding.

-At 1 µM, adding a SIRT1 aptamer caused biphasic alterations in NF-kB. At 8 hours, NF-kB binding activity in Bx-PC-3, Capan-2, and AsPC-1 cell lines was reduced by 150 percent, 130 percent, and 130 percent, respectively, compared to control 100 percent. In Bx-PC-3,Capan-2, and AsPC-1 cell lines, the decline was 180 percent, 145 percent, and 140 percent of the control 100 percent, P<0.005 at 16 hours respectively.

The events connected by this KER occur within hours.

• SIRT1 and AMPK have a close interaction in the control of energy metabolism and inflammation as they can promote each other's activity (Ruderman et al., 2010). SIRT1 stimulates AMPK by deacetylating LKB1, which then activates AMPK (Lan et al., 2008), whereas AMPK promotes the synthesis of cellular NAD+, which is necessary for SIRT1 activity (Canto et al.,2009). SIRT1 and AMPK have many similar activities in the control of energy metabolism as a result of this positive feedback.
• AMPK appears to be an efficient inhibitor of NF-B signalling and inflammatory reactions, according to new research. This topic was recent discussed in depth (Salminen et al.,2011). In a nutshell, AMPK inhibits RelA/p65 by activating SIRT1. PGC-1 is also phosphorylated by AMPK, which increases its activation (Canto et al.,2009). As a result, PGC-1 can block RelA/p65-mediated NF-B signalling.
• The transcription factor FoxO3a, which is involved in metabolic and immunological homeostasis, was activated by AMPK (Eijkelenboom et al.,2013). Overexpression of FoxO3a decreased NF-B activation in cultured cells, such as after TNF treatment, by suppressing nuclear translocation of the RelA/p65 component. The inhibition of NF-B signalling by FoxO3a was corroborated in a study (Lee et al.,2008) who found that overexpression of FoxO3a caused the production of B-Ras1, an inhibitor of NF-B activation. However, FoxO3a has recently been discovered to activate the NF-B system via BCL10, which is expressed in B lymphocytes (Li et al., 2012).