[Recent progress in the study of HIV-1 transcription factor NF-kappaB and its inhibitors].

Human immunodeficiency virus type 1 (HIV-1) transcription is a crucial step in the viral replication cycle, which is considered to be a potential target for inhibition of HIV-1 replication. Among the factors involved in this step, the cellular protein nuclear factor NF-kappaB is the most powerful inducer of HIV-1 transcription. HIV-1 transcription is initiated by the binding of NF-kappaB to the enhancer region in the long terminal repeat (LTR) of HIV-1. Several compounds suppress HIV-1 transcription through the inhibition of NF-kappaB activation. The mechanisms of NF-kappaB in the transcription of HIV-1 and progress of the current inhibitors of NF-kappaB are reviewed.

Follistatin-like 1 suppresses sensory afferent transmission by activating Na+,K+-ATPase.

Excitatory synaptic transmission is modulated by inhibitory neurotransmitters and neuromodulators. We found that the synaptic transmission of somatic sensory afferents can be rapidly regulated by a presynaptically secreted protein, follistatin-like 1 (FSTL1), which serves as a direct activator of Na(+),K(+)-ATPase (NKA). The FSTL1 protein is highly expressed in small-diameter neurons of the dorsal root ganglion (DRG). It is transported to axon terminals via small translucent vesicles and secreted in both spontaneous and depolarization-induced manners. Biochemical assays showed that FSTL1 binds to the α1 subunit of NKA and elevates NKA activity. Extracellular FSTL1 induced membrane hyperpolarization in cultured cells and inhibited afferent synaptic transmission in spinal cord slices by activating NKA. Genetic deletion of FSTL1 in small DRG neurons of mice resulted in enhanced afferent synaptic transmission and sensory hypersensitivity, which could be reduced by intrathecally applied FSTL1 protein. Thus, FSTL1-dependent activation of NKA regulates the threshold of somatic sensation.