SIRT6 Knockdown in Buffalo Fetal Fibroblasts Exacerbates Premature Senescence Caused by DNA and Telomere Damage.

As a gene with antiaging functions, sirtuin6 (SIRT6) belonging to the sirtuin family plays a vital role in DNA repair, telomerase function, and cellular senescence, as well as maintains epigenomic stability and promotes longevity. However, its role in cell senescence in large animals, such as buffaloes, remains unknown. Fibroblasts are commonly used for somatic reprogramming, and their physiological characteristics affect the efficiency of this process. We aimed to elucidate the role of SIRT6 in cellular senescence and proliferation and analyze its effect on the biological function of buffalo fibroblasts to help improve the efficiency of buffalo somatic cell reprogramming. The expression of SIRT6 and related DNA damage was measured in buffalo fibroblasts obtained at different developmental stages (in the fetus and at 3 and 10 years of age), and the effect of SIRT6 knockdown on the senescence of buffalo fetal fibroblast was investigated. An inverse relationship was observed between SIRT6 expression and senescence in buffalo fibroblasts obtained from animals of various ages. This was accompanied by decreased cell growth, viability, and increased DNA damage. Short hairpin RNA-mediated SIRT6 knockdown accelerated the senescence of buffalo fetal fibroblasts. It blocked the cell cycle during in vitro cell culture, which further enhanced DNA damage, particularly with respect to the telomeres. Collectively, our findings suggest that SIRT6 expression was closely associated with buffalo senescence in fibroblasts. These findings serve as a foundation to better understand the cellular functions of SIRT6 and also aid in selecting donor cells for buffalo somatic cell reprogramming.

Two Small Molecule Inhibitors Promote Reprogramming of Guangxi Bama Mini-Pig Mesenchymal Stem Cells Into Naive-Like State Induced Pluripotent Stem Cells.

Past researches have shown that pluripotency maintenance of naive and primed-state pluripotent stem cells (PSCs) depends on different signaling pathways, and naive-state PSCs possess the ability to produce chimeras when they are introduced into a blastocyst. Considering porcine is an attractive model for preclinical studies, many researches about pig induced pluripotent stem cells (piPSCs) have been reported. Some cytokines and small molecule compounds could transform primed piPSCs into naive state. However, there are no suitable culture conditions for generation of naive-state piPSCs with high efficiency; other small molecule compounds need further exploration. In this study, we investigated whether p38 MAPK and JNK signal pathway inhibitor SB203580 and SP600125 could be of benefit for acquiring naive-state piPSCs. By comparing reprogramming efficiencies under conditions of different donor cells and culture environment, we found that porcine bone marrow mesenchymal stem cells (PBMSCs) have higher efficiency on piPSC induction, and the culture condition of CHIR99021+PD0325901(2i)+Lif+bFGF is more suitable for subculturing of piPSCs. Our results also indicate that SB203580 and SP600125 could promote reprogramming of PBMSCs into naive-like state piPSCs. These results provide guidance for choosing donor cells, culture conditions, and research of different state iPSCs during the process of reprogramming pig somatic cells.

Isolation and characterization of buffalo (bubalus bubalis) amniotic mesenchymal stem cells derived from amnion from the first trimester pregnancy.

Amniotic mesenchymal stem cells (AMSCs) from livestock are valuable resources for animal reproduction and veterinary therapeutic. The purpose of this study is to explore a suitable way to isolate and culture the buffalo AMSCs (bAMSCs), and to identify their biological characteristics. Digestion with a combination of trypsin-EDTA and collagenase type I could obtain pure bAMSCs more effectively than trypsin-EDTA or collagenase type I alone. bAMSCs could proliferate steadily in vitro culture and exhibited fibroblastic-like morphology in vortex-shaped colony. bAMSCs were positive for MSC-specific markers CD44, CD90, CD105, CD73, ß-integrin (CD29) and CD166, and pluripotent markers OCT4, SOX2, NANOG, REX-1, SSEA-1, SSEA-4 and TRA-1-81, but negative for hematopoietic markers CD34, CD45 and epithelial cells specific marker Cytokeratin 18. In addition, bAMSCs were capable of differentiating into adipogenic, osteogenic, chondrogenic and neural lineages, with expression of FABP4, Ost, ACAN, COL2A1, Nestin and ß III-tubulin. Glycogen synthase kinase 3 inhibitor: kenpaullone promoted bAMSCs to differentiate into neural lineage. This study provides an effective protocol to obtain and characterize bAMSCs, which have proven useful as a cell resource for buffalo cell reprogramming studies and transgenic animal production.

Narrow-linewidth microwave generation using AlGaInAs/InP microdisk lasers subject to optical injection and optoelectronic feedback.

Narrow-linewidth and low phase noise photonic microwave generation under sideband-injection locking are demonstrated using an 8-µm-radius AlGaInAs/InP microdisk laser subject to optical injection and optoelectronic feedback. Microdisk laser subject to external optical injection at the period-one state provides the microwave subcarrier seed signal, and the optoelectronic feedback serves as direct current modulation to stabilize and lock the generated microwave signal without using the electrical filter. High-quality photonic microwave signals are realized with the 3-dB linewidth of less than 1 kHz and the frequency tunable range from 8.8 to 17 GHz. Single sideband phase noise of -101 dBc/Hz is obtained at a frequency offset of 10 kHz for the generated 14.7 GHz signal. Furthermore, the dependences of photonic microwave signal on the optical injection and optoelectronic feedback parameters are investigated.

Dual-transverse-mode microsquare lasers with tunable wavelength interval.

A dual-transverse-mode microsquare laser with a tunable wavelength interval is designed and realized by using a square-ring-patterned contact window. For a 30-µm-side-length microsquare laser with the square-ring width of 4 µm, the wavelength interval varies from 0.25 to 0.37 nm with the intensity ratio less than 2.5 dB as the injection current increases from 89 to 108 mA. Based on the dual-transverse-mode microsquare laser, the microwave signals with the frequencies of 30.56, 32.70, 35.12, and 39.51 GHz and the 3-dB bandwidths of 47, 53, 54, and 47 MHz are obtained at the injection currents of 90, 95, 100, and 105 mA, respectively.

Thermal and high speed modulation characteristics for AlGaInAs/InP microdisk lasers.

Thermal and high speed modulation characteristics are investigated for a unidirectional-emission microdisk laser with a radius of 7 µm surrounded by BCB-cladding layer, with a threshold current of 1.5 mA at the temperature of 287 K. The lasing spectra under different widths of pulsed current are measured to characterize the temperature rise during the pulse period, and the thermal distribution in the microdisk laser is simulated by the finite-element modeling technique. A temperature rise of 25 K is estimated for the microdisk laser biased at 20 mA. Furthermore, small signal modulation response with 3dB bandwidth up to 20 GHz is obtained for the microdisk laser at the biasing current of 18 mA, and eye-diagrams at the modulation bit rates of 20, 25, and 30 GHz are also measured at the temperature of 287 K.

Four-wavelength microdisk laser array laterally coupled with a bus waveguide.

A four-wavelength microdisk laser array laterally coupled with a bus waveguide is demonstrated numerically and experimentally. The coupled-mode characteristics as well as scattering loss in the bus waveguide caused by the connected microdisks are simulated by a 2D finite-difference time-domain technique. An AlGaInAs/InP microdisk laser array with circular radii of 10.1, 10.2, 10.3, and 10.4 µm is designed and fabricated by common photolithography and an inductively coupled-plasma etching technique. Continuous-wave electrically injected operation is realized at room temperature with the lowest threshold current of 3 mA. Four-wavelength lasing operation is realized with wavelength intervals of 3-4 nm and side mode suppression ratios larger than 25 dB. Finally, the influences of heating effect and thermal cross talk on lasing mode wavelength tuning are investigated experimentally.

Analysis of vertical radiation loss and far-field pattern for microcylinder lasers with an output waveguide.

Vertical radiation loss and far-field pattern are investigated for microcylinder lasers by 3D FDTD simulation and experimentally. The numerical results show that an output waveguide connected to the microcylinder resonator can result in additional vertical radiation loss for high Q coupled modes and affect the far field pattern. The vertical radiation loss can be controlled by adjusting the up cladding layer thickness. Furthermore, two lobes of vertical far-field patterns are observed for a 15-µm-radius microcylinder laser connected with an output waveguide, which confirms the vertical radiation loss.

Dietary L-proline supplementation confers immunostimulatory effects on inactivated Pasteurella multocida vaccine immunized mice.

This study was conducted to determine the immunostimulatory effect of L-proline on inactivated vaccine immunized mice. Ninety-five female KM mice were randomly divided into five groups: (1) mice received dietary supplementation with 0.4% L-proline and immunized with inactivated vaccine (V-P group); (2) mice received dietary supplementation with 0.3% L-alanine (isonitrogenous control) and immunized with inactivated vaccine (V-A group, negative control); (3) mice were immunized with inactivated vaccine with oil adjuvant (V-O group, positive control); (4) mice were immunized with inactivated vaccine with aluminum hydroxide adjuvant (V-H group, positive control); (5) mice immunized with phosphate-buffered saline (control group). All mice were dead in the control group between 36 and 48 h post infection. Mice in the V-P group showed 100% protection after challenge with P. multocida serotype A (CQ2) at dose of 4.4 × 10(5) CFU (2LD50). Meanwhile, serum antibody titers in the V-P group were higher than those in the V-A group before infection and those in the V-A and V-O groups at 36 h post infection. Moreover, serum IL-1ß levels in the V-P group were lower than those in V-O group. Furthermore, serum GSH-PX levels in the V-P group were higher than those in the V-A and V-O groups. Collectively, dietary proline supplementation confers beneficial immunostimulatory effects in inactivated P. multocida vaccine immunized mice.

High-Q modes in defected microcircular resonator confined by metal layer for unidirectional emission.

Defected circular resonators laterally confined by a metal layer with a flat side as an emitting window are numerically investigated based on the boundary element method for realizing unidirectional emission microlasers. The results indicate that Fabry-Pérot (FP) modes become high Q confined modes in the defected circular resonator with a metallic layer. The mode coupling between the FP mode and chaotic-like mode can result in high Q confined mode for unidirectional emission with a narrow far field pattern.

Dietary arginine supplementation enhances immune responses to inactivated Pasteurella multocida vaccination in mice.

The present study was conducted to determine the adjuvant effect of arginine in mice immunised with inactivated vaccine. Mice immunised with an inactivated Pasteurella multocida vaccine and fed diets supplemented with 0·2 % (vaccine-0·2 %) or 0·5 % (vaccine-0·5 %) arginine exhibited 100 % protection from a challenge with P. multocida serotype A (CQ2) at a dose of 4·4 × 105 colony-forming units (2LD50; median lethal dose), when compared with mice receiving no arginine supplementation. Meanwhile, antibody titres in the vaccine-0·2 % arginine group were much higher than those in the vaccine-oil adjuvant group before challenge and at 36 h post-infection. Furthermore, immunisation with the inactivated vaccine and dietary supplementation with 0·2 % arginine increased serum levels of glutathione peroxidase, in comparison with immunisation with the inactivated vaccine and an oil adjuvant. Collectively, dietary arginine supplementation confers an immunostimulatory effect in mice immunised with the inactivated P. multocida vaccine. The present results also indicate that optimal supplemental doses of arginine are 0·2-0·5 % in the mouse model.

Wide-angle emission and single-mode deformed circular microlasers with a flat side.

We demonstrate wide-angle emission and single mode operation in deformed circular microlasers with a flat side. The mode characteristics of a metallic confined deformed circular resonator with a flat side are investigated by finite-difference time-domain simulation. The numerical results indicate that this structure is suitable to realize wide-angle emission. Furthermore, metallic confined deformed circular microlasers with a flat side are fabricated using common photolithography and inductively coupled-plasma etching techniques. A continuous-wave single-mode operation with a side mode suppression ratio of 25 dB is achieved at an injection current of 4 mA for an 8 µm radius microlaser with a flat side. Additionally, wide angle emission over 120° is observed from the far-field pattern.