Role of HIF-1 on phosphofructokinase and fructose 1, 6-bisphosphatase expression during hypoxia in the white shrimp Litopenaeus vannamei

HIF-1 is a transcription factor that controls a widespread range of genes in metazoan organisms in response to hypoxia and is composed of a and (3 subunits. In shrimp, phosphofructokinase (PFK) and fructose bisphosphatase (FBP) are up-regulated in hypoxia. We hypothesized that HIF-1 is involved in the regulation of PFK and FBP genes in shrimp hepatopancreas under hypoxia. Long double stranded RNA (dsRNA) intramuscular injection was utilized to silence simultaneously both HIF-1 subunits, and then, we measured the relative expression of PFK and FBP, as well as their corresponding enzymatic activities in hypoxic shrimp hepatopancreas. The results indicated that HIF-1 participates in the up-regulation of PFK transcripts under short-term hypoxia since the induction caused by hypoxia (similar to 1.6 and similar to 4.2-fold after 3 and 48 h, respectively) is significantly reduced in the dsRNA animals treated. Moreover, PFK activity was significantly similar to 2.8-fold augmented after 3 h in hypoxia alongside to an similar to 1.9-fold increment in lactate. However, when animals were dsRNA treated, both were significantly reduced. On the other hand, FBP transcripts were similar to 53-fold up-regulated in long-term hypoxic conditions (48 h). HIF-1 is involved in this process since FBP transcripts were not induced by hypoxia when HIF-1 was silenced. Conversely, the FBP activity was not affected by hypoxia, which suggests its possible regulation at post-translational level. Taken together, these results position HIF-1 as a prime transcription factor in coordinating glucose metabolism through the PFK and FBP genes among others, in shrimp under low oxygen environments. (C) 2016 Elsevier Inc. All rights reserved.