Ginsenoside Rg1 induces senescence of leukemic stem cells by upregulating p16INK4a and downregulating hTERT expression.

BACKGROUND: Leukemic stem cells (LSCs) play an important role in the pathogenesis of leukemia. This research attempted to clarify effects of the telomere system on ginsenoside Rg1-induced senescence of LSCs. OBJECTIVES: This research attempted to clarify effects of the telomere system on ginsenoside Rg1-induced senescence of LSCs. MATERIAL AND METHODS: CD34+CD38- LSCs were isolated, sorted, and divided into a control group and a Rg1 group (treated with 40 µmol/L Rg1). Cell Counting Kit-8 (CCK-8) was used to evaluate cell proliferation, and flow cytometry was used to assess the cell cycle of CD34+CD38- LSCs. The senescence-associated ß-galactosidase (SA-ß-Gal) staining and CFU-Mix assay were conducted to measure senescence of CD34+CD38- LSCs. The mRNA transcription and protein expression of p16INK4a and human telomerase reverse transcriptase (hTERT) were determined using a real-time polymerase chain reaction (RT-PCR) and western blot assay, respectively. RESULTS: The Rg1 treatment significantly attenuated proliferative activity and decreased the proliferative index (PI) of CD34+CD38- LSCs compared to those of the control group (p < 0.05). It remarkably increased positive SA-ß-Gal staining rate, and suppressed formation of the CFU-Mix of CD34+CD38- LSCs compared with those of the control group (p < 0.05). The Rg1 treatment markedly boosted telomere effector, p16INK4a, in CD34+CD38- LSCs compared with that of control group (p < 0.05). Such treatment obviously reduced telomere regulator, hTERT, in CD34+CD38- LSCs compared with the control group (p < 0.05). CONCLUSIONS: Ginsenoside Rg1-induced senescence of CD34+CD38- LSCs through upregulating p16INK4a and downregulating hTERT expression, both of which are associated with telomere systems. The present study would be beneficial for the treatment of leukemia by providing a promising strategy to induce senescence of CD34+CD38- LSCs.

Revision of parasitoids of Massicus raddei (Blessig Solsky) (Coleoptera, Cerambycidae) in China, with one new species and genus.

Fifteen parasitoids of Massicus raddei (Blessig Solsky) (Coleoptera, Cerambycidae) are revised. The host is a serious pest of Quercus liaotungensis Koidz. and Q. mongolica Fisch. ex Ledeb. in NE China. All the parasitoids were reared from larvae of M. raddei. Pseudocyanopterus gen. nov. raddeivorus sp. nov., a new braconid wasp is described, and Cyanopterus tricolor (Ivanov) and Eubazus (E.) pallipes are new records for the Chinese fauna. An identification key to the parasitoids of M. raddei in China is provided. Detailed photographs of the parasitoids are provided.

Ginsenoside Rg1 protects against Sca-1+ HSC/HPC cell aging by regulating the SIRT1-FOXO3 and SIRT3-SOD2 signaling pathways in a γ-ray irradiation-induced aging mice model.

Aging is characterized by a progressive deterioration in metabolic functions. The present study aimed to investigate the antagonistic effects of ginsenoside Rg1 (Rg1) on the γ-ray irradiation-induced aging of mixed hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs). C57BL/6 mice were divided into a control group, a γ-ray irradiation group that served as an aging mouse model, and an Rg1 group. The Rg1 group was treated with Rg1 at dosage of 20 mg/kg/day for 7 days prior to γ-ray irradiation. The aging mouse model was established by exposing the mice to 6.5-Gy γ-ray total-body irradiation. Stem cell antigen 1 positive (Sca-1+) HSC/HPCs isolated from the mice were examined using a senescence-associated ß-galactosidase (SA-ß-Gal) staining assay. The cell cycle of the HSC/HPCs was examined using flow cytometry. A mixed hematopoietic progenitor cell colony-forming unit (CFU-mix) assay was also conducted. The mRNA and protein expression levels of sirtuin 1 (SIRT1), SIRT3, forkhead box O3 (FOXO3) and superoxide dismutase (SOD2) were evaluated using western blot and reverse transcription-quantitative PCR assays. The results indicated that Rg1 treatment significantly increased white blood cell, red blood cell and platelet counts in peripheral blood compared with those in the γ-ray irradiation group (P<0.05). However, Rg1 significantly attenuated the senescence of Sca-1+ HSC/HPCs in the γ-ray irradiation aging mice model. The proportion of SA-ß-Gal stained HSC/HPCs was significantly decreased and CFU-Mix counts were significantly increased in the Rg1 group compared with the γ-ray irradiation group (P<0.05). Rg1 significantly increased the mRNA and protein levels of SIRT1, SIRT3, FOXO3 and SOD2 in the Sca-1+ HSC/HPCs compared with those in the γ-ray irradiation group (P<0.05). The percentage of Sca-1+ HSC/HPCs arrested at the G1 phase in the Rg1 group was significantly decreased compared with that in the γ-ray irradiation group (P<0.05). In conclusion, the present study indicates that Rg1 exerts anti-aging effects via the regulation of SIRT1-FOXO3 and SIRT3-SOD2 signaling pathways, and triggering the progression of Sca-1+ HSC/HPCs from the G1 phase to the S phase in γ-ray irradiation-induced aging mice.

Redescriptions of two parasitoids, Metapelma beijingense Yang (Hymenoptera, Eupelmidae) and Spathius ochus Nixon (Hymenoptera, Braconidae), parasitizing Coraebus cavifrons Descarpentries & Villiers (Coleoptera, Buprestidae) in China with keys to genera or species groups.

Two parasitoids, Metapelma beijingense Yang (Hymenoptera, Eupelmidae) and Spathius ochus Nixon (Hymenoptera, Braconidae) are redescribed and illustrated. Both were reared from Coraebus cavifrons Descarpentries & Villiers (Coleoptera, Buprestidae) boring in Symplocos stellaris Brand (Symplocaceae). Metapelma beijingense is a solitary parasitoid with a parasitism rate of about 13.5% and S. ochus is a gregarious parasitoid with a parasitism rate of about 21.2%. A revised key to Oriental and Palaearctic species of Metapelma Westwood and a key to the species of the Spathius labdacus-group are provided.

Ginsenoside Rg1 Inhibits Cell Proliferation and Induces Markers of Cell Senescence in CD34+CD38- Leukemia Stem Cells Derived from KG1α Acute Myeloid Leukemia Cells by Activating the Sirtuin 1 (SIRT1)/Tuberous Sclerosis Complex 2 (TSC2) Signaling Pathway.

BACKGROUND Clinical relapse in acute myeloid leukemia (AML) is associated with the reduced treatment response of leukemia stem cells (LSCs). This study aimed to investigate the effects of the ginseng derivative, ginsenoside Rg1 (Rg1), on CD34+CD38- LSCs derived from KG1a human acute myeloid leukemia cells. MATERIAL AND METHODS CD34+CD38- LSCs were isolated from KG1a human acute myeloid leukemia cells by cell sorting. CD34+CD38- KG1alpha LSCs were divided into the control group and the Rg1 group (treated with Rg1). The cell counting kit-8 (CCK-8) assay evaluated the proliferation of CD34+CD38- KG1alpha LSCs and flow cytometry studied the cell cycle. The mixed colony-forming unit (CFU-Mix) assay and staining for senescence-associated beta-galactosidase (SA-ß-Gal) evaluated cell senescence. Expression of sirtuin 1 (SIRT1) and tuberous sclerosis complex 2 (TSC2) were evaluated using Western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS CD34+CD38- KG1alpha LSCs were isolated at 98.72%. Rg1 significantly reduced the proliferation of CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05). Cells in the G0/G1 phase were significantly increased, and cells in the G2/M and S phase were significantly reduced compared with the control group (p<0.05). Rg1 significantly increased SA-ß-Gal and reduced CFU-Mix formation compared with the control group (p<0.05), significantly down-regulated SIRT1 expression in CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05), and significantly reduced TSC2 expression in CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05). CONCLUSIONS Rg1 inhibited cell proliferation and induced cell senescence markers in CD34+CD38- KG1alpha LSCs by activating the SIRT1/TSC2 signaling pathway.

[Ginsenoside Rg_1 induces leukemia stem cell senescence via SIRT1/TSC_2 signal axis].

The aim of this paper was to investigate the effect of SIRT1/TSC_2 signal axis on leukemia stem cell senescence induced by ginsenoside Rg_1. CD34~+CD38~- leukemia stem cells(CD34~+CD38~-LSCs) was isolated by magnetic cell sorting(MACS) and divided into two groups. The control group cells were routinely cultured, 40 µmol·L~(-1) ginsenoside Rg_1 was added to the control group for co-culture in Rg_1 group. The effect of Rg_l to induce CD34~+CD38~-LSCs senescence were evaluated by senescence-associated ß-Galactosidase(SA-ß-Gal) staining, cell cycle assay, CCK-8 and Colony-Assay. The expression of senescence associated SIRT1, TSC_2 mRNA and protein was examined by Real-time fluorescence quantitative PCR(FQ-PCR) and Western blot. The results showed that the CD34~+CD38~-LSCs could effectively be isolated by MACS, and the purity of CD34~+CD38~-LSCs is up to(95.86±3.04)%. Compared with the control group, the percentage of positive cells expressed SA-ß-Gal in the Rg_1 group is increased, the senescence morphological changes were observed in the CD34~+CD38~-LSCs in the Rg_1 group. The proliferation inhibition rate and the number of cells entered G_0/G_1 phase in the Rg_1 group were increased, but the colony-formed ability was decreased, Rg_1 could significantly inhibit the proliferation and self-renewal ability of CD34~+CD38~-LSCs. The expression of SIRT1 and TSC_2 mRNA and protein were down regulated in the Rg_1 group compared with the control group. Our research implied that Rg_1 may induce the senescence of CD34~+CD38~-LSCs and SIRT1/TSC_2 signal axis plays a significant role in this process.

Insect Behavior and Physiological Adaptation Mechanisms Under Starvation Stress.

Intermittent food shortages are commonly encountered in the wild. During winter or starvation stress, mammals often choose to hibernate while insects-in the form of eggs, mature larvae, pupae, or adults opt to enter diapause. In response to food shortages, insects may try to find sufficient food to maintain normal growth and metabolism through distribution of populations or even migration. In the face of hunger or starvation, insect responses can include changes in behavior and/or maintenance of a low metabolic rate through physiological adaptations or regulation. For instance, in order to maintain homeostasis of the blood sugar, trehalose under starvation stress, other sugars can be transformed to sustain basic energy metabolism. Furthermore, as the severity of starvation increases, lipids (especially triglycerides) are broken down to improve hunger resistance. Starvation stress simultaneously initiates a series of neural signals and hormone regulation processes in insects. These processes involve neurons or neuropeptides, immunity-related genes, levels of autophagy, heat shock proteins and juvenile hormone levels which maintain lower levels of physiological metabolic activity. This work focuses on hunger stress in insects and reviews its effects on behavior, energy reserve utilization, and physiological regulation. In summary, we highlight the diversity in adaptive strategies of insects to hunger stress and provides potential ideas to improve hunger resistance and cold storage development of natural enemy insects. This gist of literature on insects also broadens our understanding of the factors that dictate phenotypic plasticity in adjusting development and life histories around nutritionally optimal environmental conditions.

Screening behaviorally active compounds based on fluorescence quenching in combination with binding mechanism analyses of SspOBP7, an odorant binding protein from Sclerodermus sp.

Reverse chemical ecology approaches based on the recognition and transport function of odorant binding proteins (OBPs) have been used to screen behaviorally active compounds of insects. In the first place, behaviorally active compounds from Sclerodermus sp., an important ectoparasite of Monochamus alternatus Hope, were screened by SspOBP7. The Fluorescence quenching assays revealed that only six of 19 ligands that had binding affinities in fluorescence competition-binding assays formed complexes with SspOBP7. Pursuing this further, two non-polar ligands, terpinolene and (+)-α-longipinene showed strong attractant activities for Sclerodermus sp. The pH change could lead to conformational transition of SspOBP7 from one state to another, which results in low binding affinities at low pH. Finally, a mutational analysis of the SspOBP7 binding cavity proved that changing the cavity had a greater effect on non-polar ligands, and the specific recognition of ligands by SspOBP7 might depend mainly on the appropriate shapes of the cavity and ligands. The most obvious finding to emerge from this work is that the use of fluorescence quenching to study the binding mechanism of OBPs could aid reverse chemical ecology approaches by narrowing the scope of candidate behaviorally active compounds.

SIRT6/NF-κB signaling axis in ginsenoside Rg1-delayed hematopoietic stem/progenitor cell senescence.

OBJECTIVE: To investigate the role of SIRT6/NF-κB signaling axis in ginsenoside Rg1-delayed hematopoietic stem/progenitor cell senescence and to provide theoretical and experimental evidence for delaying HSC/HPC senescence pathway. METHODS: After the separation and purification by immunomagnetic sorting, Sca-1+HSC/HPC was divided into: normal control group; aging group; positive control group; Rg1 delaying group and Rg1 treatment group. Senescence-associated ß-galactosidase (SA-ß-Gal) staining, flow cytometry analysis of cell cycle and hematopoietic progenitor cells mixed colony (CFU-Mix) culture were performed to determine the delaying or curing roles of Rg1 in Sca-1+HSC/HPC senescence. Quantitative PCR and Western blotting were used to detect the mRNA and protein expression of senescence regulatory molecules, such as SIRT6 and NF-κB. RESULTS: Compared with the aging group, the positive rate of SA-ß-gal staining cells and the proportion of cells in G1 phase decreased; the number of CFU-Mix increased; mRNA and protein expression of SIRT6 increased; mRNA and protein expression of NF-κB was down-regulated in Rg1 delaying and treatment groups; the changes of the indicators in Rg1 delaying group were more significant than those in Rg1 treatment group. CONCLUSION: Rg1 may fight against Sca-1+HSC/HPC senescence induced by t-BHP through regulating SIRT6-NF-κB signaling pathway.

[Effect of SIRT6/NF-κB signal axis in delaying hematopoietic stem/progenitor cell senescence with ginsenoside Rg1].

OBJECTIVE: To investigate the effect of SIRT6/NF-κB signal axis in delaying hematopoietic stem/progenitor cell senescence with ginsenoside Rg1, in order to provide theatrical and experimental basis for looking for methods for delaying HSC senescence. METHOD: Sca-1 + HSC/HPC was isolated by magnetic cell sorting (MACS) and divided into five groups: the normal control group, the aging group, the positive control group, the Rg1 anti-senescence group, and the Rg1-treated group. Senescence-associated ß-galactosidase (SA-ß-Gal) staining, cell cycle analysis and hemopoietic progenitor cell mix (CFU-Mix) were adopted to determine the effect Rg1 in delaying or treating Sca-1 + HSC/HPC senescence biology. The mRNA and protein of senescence regulation molecules SIRT6 and NF-KB were examined by realtime fluorescence quantitative PCR (FQ-PCR) and western blotting. RESULT: Compared with the senescence group, the Rg1 anti-senescence group and the Rg1-treated group showed lower percentage in SA-ß-Gal-stained positive cells, decreased cell proportion in G1 phase, increased number of CFU-Mix, up-regulated in SIRT6 mRNA and protein expression, down-regulation in NF-KB mRNA and protein expression. The Rg1 anti-senescence group showed more evident changes in indexes than the Rg1-treated group. CONCLUSION: Rg, may inhibit Sca-1 + HSC/HPC senescence induced by t-BHP by regulating SIRT6/NF-KB signal path.

Cerchysiella mesosae Yang sp. nov. (Hymenoptera: Encyrtidae), a parasitoid of Mesosa myops (Dalman) (Coleoptera: Cerambycidae) larvae in China.

Cerchysiella mesosae Yang sp. nov. (Hymenoptera: Chalcidoidea: Encyrtidae), is described from China. It is a gregarious koinobiont endoparasitoid in mature larvae of Mesosa myops (Dalman) (Coleoptera: Cerambycidae), a wood boring pest of many broad-leaved tree species in China, particularly Quercus mongolica and Q. liaotungensis (Fagaceae) in forest areas of northeastern China. The new species is one of the principal natural enemies of the wood borer and it may have potential as a biological control agent for suppression of the pest.