Zinc regulation of chlorophyll fluorescence and carbohydrate metabolism in saline-sodic stressed rice seedlings.

Saline-sodic stress can limit the absorption of available zinc in rice, subsequently impacting the normal photosynthesis and carbohydrate metabolism of rice plants. To investigate the impact of exogenous zinc application on photosynthesis and carbohydrate metabolism in rice grown in saline-sodic soil, this study simulated saline-sodic stress conditions using two rice varieties, 'Changbai 9' and 'Tonghe 899', as experimental materials. Rice seedlings at 4 weeks of age underwent various treatments including control (CT), 2 µmol·L-1 zinc treatment alone (Z), 50 mmol·L-1 saline-sodic treatment (S), and 50 mmol·L-1 saline-sodic treatment with 2 µmol·L-1 zinc (Z + S). We utilized JIP-test to analyze the variations in excitation fluorescence and MR820 signal in rice leaves resulting from zinc supplementation under saline-sodic stress, and examined the impact of zinc supplementation on carbohydrate metabolism in both rice leaves and roots under saline-sodic stress. Research shows that zinc increased the chloroplast pigment content, specific energy flow, quantum yield, and performance of active PSII reaction centers (PIABS), as well as the oxidation (VOX) and reduction rate (Vred) of PSI in rice leaves under saline-sodic stress. Additionally, it decreased the relative variable fluorescence (WK and VJ) and quantum energy dissipation yield (φDO) of the rice. Meanwhile, zinc application can reduce the content of soluble sugars and starch in rice leaves and increasing the starch content in the roots. Therefore, the addition of zinc promotes electron and energy transfer in the rice photosystem under saline-sodic stress. It enhances rice carbohydrate metabolism, improving the rice plants' ability to withstand saline-sodic stress and ultimately promoting rice growth and development.

[Clinical application of Flow-through bridge anterolateral thigh flap in repair of complex calf soft tissue defects].

Objective: To investigate the effectiveness of Flow-through bridge anterolateral thigh flap transplantation in the treatment of complex calf soft tissue defects. Methods: The clinical data of the patients with complicated calf soft tissue defects, who were treated with Flow-through bridge anterolateral thigh flap (study group, 23 cases) or bridge anterolateral thigh flap (control group, 23 cases) between January 2008 and January 2022, were retrospectively analyzed. All complex calf soft tissue defects in the two groups were caused by trauma or osteomyelitis, and there was only one major blood vessel in the calf or no blood vessel anastomosed with the grafted skin flap. There was no significant difference between the two groups in general data such as gender, age, etiology, size of leg soft tissue defect, and time from injury to operation ( P>0.05). The lower extremity functional scale (LEFS) was used to evaluate the sufferred lower extremity function of the both groups after operation, and the peripheral blood circulation score of the healthy side was evaluated according to the Chinese Medical Association Hand Surgery Society's functional evaluation standard for replantation of amputated limbs. Weber's quantitative method was used to detect static 2-point discrimination (S2PD) to evaluate peripheral sensation of the healthy side, and the popliteal artery flow velocity, toenail capillary filling time, foot temperature, toe blood oxygen saturation of the healthy side, and the incidence of complications were compared between the two groups. Results: No vascular or nerve injury occurred during operation. All flaps survived, and 1 case of partial flap necrosis occurred in both groups, which healed after free skin grafting. All patients were followed up 6 months to 8 years, with a median time of 26 months. The function of the sufferred limb of the two groups recovered satisfactorily, the blood supply of the flap was good, the texture was soft, and the appearance was fair. The incision in the donor site healed well with a linear scar, and the color of the skin graft area was similar. Only a rectangular scar could be seen in the skin donor area where have a satisfactory appearance. The blood supply of the distal limb of the healthy limb was good, and there was no obvious abnormality in color and skin temperature, and the blood supply of the limb was normal during activity. The popliteal artery flow velocity in the study group was significantly faster than that in the control group at 1 month after the pedicle was cut, and the foot temperature, toe blood oxygen saturation, S2PD, toenail capillary filling time, and peripheral blood circulation score were significantly better than those in the control group ( P<0.05). There were 8 cases of cold feet and 2 cases of numbness on the healthy side in the control group, while only 3 cases of cold feet occurred in the study group. The incidence of complications in the study group (13.04%) was significantly lower than that in the control group (43.47%) ( χ 2=3.860, P=0.049). There was no significant difference in LEFS score between the two groups at 6 months after operation ( P>0.05). Conclusion: Flow-through bridge anterolateral thigh flap can reduce postoperative complications of healthy feet and reduce the impact of surgery on blood supply and sensation of healthy feet. It is an effective method for repairing complex calf soft tissue defects.

The promotive role of USP1 inhibition in coordinating osteogenic differentiation and fracture healing during nonunion.

BACKGROUND: Nonunion is a failure of fracture healing and a major complication after fractures. Ubiquitin-specific protease 1 (USP1) is a deubiquitinase that involved in cell differentiation and cell response to DNA damage. Herein we investigated the expression, function and mechanism of USP1 in nonunion. METHODS AND RESULTS: Clinical samples were used to detect the USP1 expression in nonunion. ML323 was selected to inhibit USP1 expression throughout the study. Rat models and mouse embryonic osteoblasts cells (MC3T3-E1) were used to investigate the effects of USP1 inhibition on fracture healing and osteogenesis in vivo and in vitro, respectively. Histological changes were examined by micro-computerized tomography (Micro-CT), hematoxylin & eosin (H&E) staining and Masson staining. Alkaline phosphatase (ALP) activity detection and alizarin red staining were used for osteogenic differentiation observation. The expression of related factors was detected by quantitative real-time PCR, western blot or immunohistochemistry (IHC). It was shown that USP1 was highly expressed in nonunion patients and nonunion rats. USP1 inhibition by ML323 promoted fracture healing in nonunion rats and facilitated the expression of osteogenesis-related factors and the signaling of PI3K/Akt pathway. In addition, USP1 inhibition accelerated osteogenic differentiation and promoting PI3K/Akt signaling in MC3T3-E1 cells. CONCLUSIONS: USP1 inhibition plays a promotive role in coordinating osteogenic differentiation and fracture healing during nonunion. PI3K/Akt may be the downstream pathway of USP1.

The formation of higher alcohols in rice wine fermentation using different rice cultivars.

Higher alcohols are closely related to the flavor and safety of rice wine. The formation of n-propanol, isobutanol, isoamyl alcohol, and phenylethanol during rice wine fermentations was for the first time investigated in this study among 10 rice cultivars from two main production regions. Rice wine made from Yashui rice, the long-grain non-glutinous rice from Guizhou, produced the highest yields of higher alcohols (487.45 mg/L), and rice wine made from five glutinous rice cultivars produced the lowest yields of higher alcohols (327.45-344.16 mg/L). An extremely strong correlation was found between the starch in rice and higher alcohols in rice wine. Further analysis first showed that the former fermentation period was key for the nutrient consumption and higher alcohol formation, with more than 55% of glucose being consumed and more than 75% of higher alcohols being synthesized in 48 h. Correlation analysis confirmed the strong correlation between nutrient consumption and higher alcohol formation including valine-isobutanol (coefficient higher than 0.8 in seven rice cultivars and higher than 0.6 in three rice cultivars), glucose-isoamyl alcohol (coefficient higher than 0.8 in five rice cultivars and higher than 0.6 in the other five rice cultivars), and glucose-phenylethanol (coefficient higher than 0.8). The correlation of threonine-n-propanol, leucine-isoamyl alcohol, phenylalanine-phenylethanol, glucose-n-propanol, and glucose-isobutanol varied among the rice wines made from 10 rice cultivars. RT-qPCR analysis on five target genes verified the variation caused by different rice cultivars. this study for the first time reported the special formation pattern of higher alcohols during rice wine fermentation, emphasizing the early contribution of glucose metabolism on the formation of isobutanol. This study highlighted the significance of rice selection for making rice wine with good quality and provided theoretical references for the control of higher alcohols, especially in the former period of rice wine fermentation.

Glutamine exerts a protective effect on osteoarthritis development by inhibiting the Jun N-terminal kinase and nuclear factor kappa-B signaling pathways.

Strategies for treating osteoarthritis (OA) have become a research focus because an effective treatment for OA is unavailable. The objective of this study was to explore the effects and underlying mechanisms of glutamine (Gln) in OA. First, the chondrocytes were identified and a standard IL-1ß-induced OA model was established. After treatment with Gln or saline, the viability and apoptosis of chondrocytes were evaluated using a CCK-8 assay and flow cytometry analysis, which revealed that Gln can improve the IL-1ß-induced OA cells. Meanwhile, Gln can enhance the expression of aggrecan and collagen II, which are protective proteins for articular cartilage. Instead, Gln inhibited the expression of matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-13 (MMP-13), which can degrade cartilage. To better understand the underlying mechanisms of Gln in IL-1ß-induced chondrocytes, the classical OA pathways of JNK and NF-κB were examined at the protein and mRNA levels using western blot and qRT-PCR analyses. We found that JNK and NF-κB were downregulated gradually depending on the Gln dose and protective and destructive factors changed based on changes of JNK and NF-κB. The effects of high-dose Gln were more effective than low-dose. Moreover, Gln was applied to the animal OA model to check the effects in vivo. The results showed that Gln attenuated cartilage degeneration and decreased OARSI scores, which demonstrated that Gln can improve OA. The experiments showed that Gln can benefit mice with OA by inhibiting the JNK and NF-κB signaling pathways.

[Application of anterolateral thigh bridge flap with free skin graft wrapping vascular bridge in complex calf soft tissue defects].

Objective: To explore the effectiveness of anterolateral thigh bridge flap with free skin graft wrapping vascular bridge in repairing complex calf soft tissue defects. Methods: The clinical data of 11 patients with complex calf soft tissue defects between April 2018 and October 2021 were retrospectively analyzed, including 9 males and 2 females, aged 11-60 years, with a median age of 39 years. There were 8 cases of calf soft tissue defect caused by traffic accident, and 3 cases of calf skin infection caused by chronic osteomyelitis. The skin and soft tissue defects ranged from 10 cm×8 cm to 35 cm×10 cm after thorough debridement and accompanied with bone and tendon exposure. There was only one main vessel in calf of 9 cases and no blood vessel that could be anastomosed with the flap vessel could be found in the recipient site of 2 cases. The anterolateral thigh skin flap (the flap size ranged from 12 cm×10 cm to 37 cm×12 cm) was taken to repair the soft tissue defect. The donor site of the flap was treated with direct suture (8 cases) or partial suture followed by skin grafting (3 cases), and the vascular bridge was wrapped with medium-thickness skin graft. Results: The flaps of 11 patients survived completely without necrosis, infection, and vascular crisis. The blood supply of the vascular bridge was unobstructed and the pulse was good. The color of the medium-thickness skin graft were ruddy. All 11 patients were followed up 2-40 months, with an average of 19.4 months. The flaps healed well with the surrounding tissues without obvious exudation and color difference. The flaps had normal color and temperature, good blood supply, and soft texture. The shape of the flap and calf contour were satisfactory and the function of the limb recovered well. The donor area of thigh flap healed by first intention without obvious scar formation. The donor area of skin healed well with a longitudinal oblong scar only and the appearance was satisfactory. Conclusion: The anterolateral thigh bridge flap transplantation with free skin wrapping vascular bridge is an effective method for the treatment of complex calf soft tissue defects.

Modified donor blood flow-preserved cross-leg anterolateral thigh flap procedure for complex lower extremity reconstruction.

BACKGROUND: Complex lower limb reconstruction due to severe trauma remains a challenge for reconstructive surgeons. Here, we introduce a modified donor blood flow-preserved cross-leg anterolateral thigh flap procedure and evaluate its clinical efficacy. METHODS: Between January 2013 and December 2019, 22 patients (range 10 to 64 years old) with unilateral lower limb injury underwent modified donor blood flow-preserved cross-leg anterolateral thigh flap procedures. Among them, 16 cases were traffic accidents, 5 cases were persistent ulcers, and 1 case was a degloving injury. The arterial pedicle of the flap was prepared in a Y-shaped fashion and microanastomosed to the posterior tibial artery of intact leg in a flow-through style. A split-thickness skin graft was applied to wrap the vascular pedicle after anastomosis. The flap was designed in a single or bilobed fashion according to the shape of the tissue defect. The operation time, the intraoperative blood loss and the length of hospital stays were recorded. The vascular pedicle was divided 4 weeks after anastomosis. Doppler ultrasound was performed to evaluate the blood flow of the donor posterior tibial artery during postoperative follow-up. RESULTS: All 22 flaps survived. The tissue defects ranged from 12 × 6 to 21 × 18 cm2. The flap sizes ranged from 14 × 7.5 to 24 × 21 cm2. The average operation time, intraoperative blood loss and length of hospital stays were 6.73 ± 1.49 h, 280.95 ± 59.25 ml and 30.55 ± 2.52 days, respectively. Eighteen flaps were designed in a single fashion, while four were in bilobed fashion. Twenty patients underwent fasciocutaneous flap transplantations, while two underwent musculocutaneous flap transplantations. Two cases developed local lysis of the flap which healed after further debridement. Direct suture of the incision after flap harvest was performed in 16 cases, while additional full-thickness skin grafting was performed in the remaining 6 cases. Further bone transport procedures were performed in 15 patients who had severe tibia bone defects. The blood flow of donor posterior tibial artery was confirmed in all patients during follow-ups. All patients recovered flap sensation at the final follow-up. The postoperative follow-ups ranged from 18 to 84 months, and no long-term complications were observed. CONCLUSIONS: The modified donor blood flow-preserved cross-leg anterolateral thigh flap procedure is an ideal method to repair severe lower limb trauma with tibial artery occlusion which avoids sacrificing the major artery of the uninjured lower limb.

Shikonin, a promising therapeutic drug for osteoarthritis that acts via autophagy activation.

Osteoarthritis (OA) is a chronic joint degenerative disease characterised by narrowed articular space, formation of surrounding osteophytes, and subchondral bone sclerosis. OA is caused by cartilage degeneration, which is closely correlated with the disequilibrium of anabolism and catabolism in chondrocytes. Previous studies have revealed that autophagy plays a significant role in maintaining the balance of anabolic and catabolic activities. Thus, targeting autophagy may be a promising therapeutic strategy for OA. Shikonin, a traditional Chinese herbal medicine isolated from flavonoid glucuronide, has drawn focus for its role in activating autophagy. In this study, the mRNA and protein level of a disintegrin and metalloproteinase with thrombospondin motifs-5 and matrix metalloproteinases-1 decreased with shikonin treatment, in the IL-1ß-induced OA cell model. On the contrary, IL-1ß-induced downregulation of Aggrecan and Collagen II was ameliorated following shikonin treatment. In addition, the upregulation of autophagy-related marker genes Beclin-1 and LC3II/LC3I in chondrocytes indicated that autophagy could be activated upon shikonin treatment. Moreover, shikonin's promotion of anabolism in chondrocytes through autophagy activation corresponded with the results from the examination using chloroquine, an autophagy inhibitor. OA mouse cartilage tissues were stained with safranin O and fast green dyes. Results were analysed using the Osteoarthritis Research Society International (OARSI) score, and suggested that mice cartilage degeneration was alleviated after shikonin treatment. Altogether, we identified that shikonin might be a novel promising drug for OA treatment.

Identification of the Fosl1/AMPK/autophagy axis involved in apoptotic and inflammatory effects following spinal cord injury.

Strategies for reducing spinal cord injury (SCI) have become a research focus because an effective treatment of SCI is unavailable. The objective of this study was to explore the underlying mechanisms of Fosl1 following SCI. Based on the analysis of the Gene Expression Omnibus (GEO) database, Fosl1 was found to be highly enhanced in SCI. This result was confirmed in our animal model, and Fosl1 was found to be obviously expressed in neurons. Next, we treated PC-12 cells with H2O2 to mimic injured neurons and further verified that Fosl1 silencing upregulated AMPK expression, promoted autophagy and inhibited inflammation and apoptosis. Subsequently, a special inhibitor of AMPK was used to examine the role of AMPK, and we learned that the inhibition of AMPK suppressed autophagy and promoted inflammation and apoptosis following Fosl1 silencing. These changes completely reversed the beneficial effects of Fosl1 silencing on injured PC-12 cells. Moreover, treatment with an AMPK activator resulted in effects that were opposite those of the inhibitor. Finally, rats were injected intrathecally with si-Fosl1 to detect its role in vivo. The results showed that si-Fosl1 improved neurological function and decreased apoptosis and inflammation at 14 d postoperation, and the activator further benefited the rats of si-Fosl1 treatment. In conclusion, Fosl1 inhibits autophagy and promotes inflammation and apoptosis through the AMPK signaling pathway following SCI in vivo and in vitro.

Modulating Antibody-Drug Conjugate Payload Metabolism by Conjugation Site and Linker Modification.

Previous investigations on antibody-drug conjugate (ADC) stability have focused on drug release by linker-deconjugation due to the relatively stable payloads such as maytansines. Recent development of ADCs has been focused on exploring technologies to produce homogeneous ADCs and new classes of payloads to expand the mechanisms of action of the delivered drugs. Certain new ADC payloads could undergo metabolism in circulation while attached to antibodies and thus affect ADC stability, pharmacokinetics, and efficacy and toxicity profiles. Herein, we investigate payload stability specifically and seek general guidelines to address payload metabolism and therefore increase the overall ADC stability. Investigation was performed on various payloads with different functionalities (e.g., PNU-159682 analog, tubulysin, cryptophycin, and taxoid) using different conjugation sites (HC-A118C, LC-K149C, and HC-A140C) on THIOMAB antibodies. We were able to reduce metabolism and inactivation of a broad range of payloads of THIOMAB antibody-drug conjugates by employing optimal conjugation sites (LC-K149C and HC-A140C). Additionally, further payload stability was achieved by optimizing the linkers. Coupling relatively stable sites with optimized linkers provided optimal stability and reduction of payloads metabolism in circulation in vivo.

Stabilizing a Tubulysin Antibody-Drug Conjugate To Enable Activity Against Multidrug-Resistant Tumors.

The tubulysins are promising anticancer cytotoxic agents due to the clinical validation of their mechanism of action (microtubule inhibition) and their particular activity against multidrug-resistant tumor cells. Yet their high potency and subsequent systemic toxicity make them prime candidates for targeted therapy, particularly in the form of antibody-drug conjugates (ADCs). Here we report a strategy to prepare stable and bioreversible conjugates of tubulysins to antibodies without loss of activity. A peptide trigger along with a quaternary ammonium salt linker connection to the tertiary amine of tubulysin provided ADCs that were potent in vitro. However, we observed metabolism of a critical acetate ester of the drug in vivo, resulting in diminished conjugate activity. We were able to circumvent this metabolic liability with the judicious choice of a propyl ether replacement. This modified tubulysin ADC was stable and effective against multidrug-resistant lymphoma cell lines and tumors.

High-Resolution Accurate-Mass Mass Spectrometry Enabling In-Depth Characterization of in Vivo Biotransformations for Intact Antibody-Drug Conjugates.

Antibody-drug conjugates (ADCs) represent a promising class of therapeutics for the targeted delivery of highly potent cytotoxic drugs to tumor cells to improve bioactivity while minimizing side effects. ADCs are composed of both small and large molecules and therefore have complex molecular structures. In vivo biotransformations may further increase the complexity of ADCs, representing a unique challenge for bioanalytical assays. Quadrupole-time-of-flight mass spectrometry (Q-TOF MS) with electrospray ionization has been widely used for characterization of intact ADCs. However, interpretation of ADC biotransformations with small mass changes, for the intact molecule, remains a limitation due to the insufficient mass resolution and accuracy of Q-TOF MS. Here, we have investigated in vivo biotransformations of multiple site-specific THIOMAB antibody-drug conjugates (TDCs), in the intact form, using a high-resolution, accurate-mass (HR/AM) MS approach. Compared with conventional Q-TOF MS, HR/AM Orbitrap MS enabled more comprehensive identification of ADC biotransformations. It was particularly beneficial for characterizing ADC modifications with small mass changes such as partial drug loss and hydrolysis. This strategy has significantly enhanced our capability to elucidate ADC biotransformations and help understand ADC efficacy and safety in vivo.