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Small heat shock proteins (sHSPs) comprise numerous proteins with diverse structure and function. As molecular chaperones, they play essential roles in various biological processes, especially under thermal stresses. In this study, we identified three sHSP-encoding genes, LtHSP19.5 , LtHSP20.8 and LtHSP21.7b from Liriomyza trifolii , an important insect pest of ornamental and vegetable crops worldwide. Putative proteins encoded by these genes all contain a conserved α-crystallin domain that is typical of the sHSP family. Their expression patterns during temperature stresses and at different insect development stages were studied by reverse-transcription quantitative PCR (RT-qPCR). In addition, the expression patterns were compared with those of LtHSP21.3 and LtHSP21.7 , two previously published sHSPs. When pupae were exposed to temperatures ranging from -20 to 45 °C for 1 h, all LtsHSP s were strongly induced by either heat or cold stresses, but the magnitude was lower under the low temperature range than high temperatures. Developmentally regulated differential expression was also detected, with pupae and prepupae featuring the highest expression of sHSPs. Results suggest that LtsHSP s play a role in the development of the invasive leaf miner fly and may facilitate insect adaptation to climate change.

Aquaporins (AQPs), which are members of the major intrinsic protein (MIP) family, play an important role in the transport of water and other small, uncharged solutes across membranes. In this study, we identified gene encoding two aquaporin 12-like (AQP12L) proteins, CsAqp12L_v1 and CsAqp12L_v2 , from Chilo suppressalis , a serious rice pest in Asia. Phylogenetic analysis indicated that Cs AQP12L_V1 and Cs AQP12L_V2 were grouped in a well-supported cluster that included other members of Lepidoptera. The two proteins are almost identical, except that Cs AQP12L_V1 lacks 34 amino acids that are present in Cs AQP12L_V2 at site 217. The qRT-PCR indicated that both CsAqp12L and CsAqp12L_v2 were expressed in heads, epidermis, foregut, midgut, and hindguts, with the highest level of expression in hindguts, heads, and epidermis. Expression of CsAqp12L and CsAqp12L_v2 was detected in all life stages and both sexes and was highest in first instar larvae and lowest in eggs. Expression of CsAqp12L and CsAqp12L_v2 was not significantly altered by exposure to brief changes in temperature. There were no significant differences in the third instar larvae, male and female pupae, and female adults in response to adverse humidity. However, the mRNA level of CsAqp12L in the fifth instar larvae and CsAqp12L_v2 in male adults was induced significantly by low humidity, respectively. Moreover, Xenopus oocytes injected with cRNAs of Cs AQP12L_V1 and Cs AQP12L_V2 showed no significant changes in permeability to water, glycerol, trehalose, or urea. The two Cs AQP12L variants likely localize to an intracellular location in C. suppressalis and may respond to novel stimuli.

Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. In this manuscript, acankoreagenin isolated from the leaves of Acanthopanax gracilistylus (LAG) is thought to possess excellent anti-diabetic properties. In vitro, anti-diabetic activities were assessed based on the inhibitory activities with α-glucosidase (IC 50 13.01 μM), α-amylase (IC 50 30.81 μM), and PTP1B (IC 50 16.39 μM). Acankoreagenin showed better anti-diabetic effects. Then, an investigation was performed to analyze the insulin secretion effects of the insulin-secreting cell line in RIN-m5F cells. It was found that acankoreagenin could increase the insulin release in RIN-m5F cells. It was also found that acankoreagenin reduced NO production, activity of caspase-3, and the reactive oxygen species levels in the cells injured by processing of cytokines. In western blotting, inactivation of NF-κB signaling was confirmed. Acankoreagenin (20 μM) showed a higher I-κBα expression and lower NF-κB expression than the control group and showed a better expression than the positive control L-NAME (1 mM) ( p < 0.05). This study demonstrates the anti-diabetic effects of acankoreagenin in vitro and suggests acankoreagenin might offer therapeutic potential for treating diabetes mellitus.

The pink stem borer, Sesamia inferens (Walker), is a major pest of rice and is endemic in China and other parts of Asia. Small heat shock proteins (sHSPs) encompass a diverse, widespread class of stress proteins that have not been characterized in S. inferens. In the present study, we isolated and characterized three S. inferens genes that encode members of the α-crystallin/sHSP family, namely, Sihsp21.4, Sihsp20.6, and Sihsp19.6. The three cDNAs encoded proteins of 187, 183 and 174 amino acids with calculated molecular weights of 21.4, 20.6 and 19.6 kDa, respectively. The deduced amino acid sequences of the three genes showed strong similarity to sHSPs identified in other lepidopteran insects. Sihsp21.4 contained an intron, but Sihsp20.6 and Sihsp19.6 lacked introns. Real-time quantitative PCR analyses revealed that Sihsp21.4 was most strongly expressed in S. inferens heads; Whereas expression of Sihsp20.6 and Sihsp19.6 was highest in eggs. The three S. inferens sHSP genes were up-regulated during low temperature stress. In summary, our results show that S. inferens sHSP genes have distinct regulatory roles in the physiology of S. inferens.

Apoptosis is executed through the activity of the caspases that are aspartyl-specific proteases. In this study, we isolated the caspase gene (Cscaspase-1) of Chilo suppressalis (one of the leading pests responsible for destruction of rice crops). It possesses the open reading frame (ORF) of 295 amino acids including prodomain, large subunit and small subunits, and two cleavage sites (Asp23 and Asp194) were found to be located among them. In addition to these profiles, Cscaspase-1 contains two active sites (His134 and Cys176). Genomic analysis demonstrated there was no intron in the genome of Cscaspase-1. The Cscaspase-1 transcripts were found in all tissues of the fifth instar larvae, and higher levels were found in the midgut, hindgut and Malpighian tubules. Examination of Cscaspase-1 expression in different developmental stages indicated low constitutive levels in the eggs and early larvae stages, and higher abundances were exhibited in the last larvae and pupae stages. The relative mRNA levels of Cscaspase-1 were induced by heat and cold temperatures. For example, the highest increase of Cscaspase-1 transcription was at -3 °C and 36 °C respectively. In a word, Cscaspase-1 plays a role of effector in the apoptosis of C. suppressalis. It also correlates with development, metamorphosis and thermotolerance of C. suppreassalis.