Current understanding of osteoarthritis pathogenesis and relevant new approaches

Osteoarthritis(OA)is the most common degenerative joint disease that causes painful swelling and permanent damage to the joints in the body.The molecular mechanisms of OA are currently unknown.OA is a heterogeneous disease that affects the entire joint,and multiple tissues are altered during OA development.To better understand the pathological mechanisms of OA,new approaches,methods,and techniques need to be used to understand OA pathogenesis.In this review,we first focus on the epigenetic regulation of OA,with a particular focus on DNA methylation,histone modification,and microRNA regulation,followed by a summary of several key mediators in OA-associated pain.We then introduce several innovative techniques that have been and will continue to be used in the fields of OA and OA-associated pain,such as CRISPR,scRNA sequencing,and lineage tracing.Next,we discuss the timely updates concerning cell death regulation in OA pathology,including pyroptosis,ferroptosis,and autophagy,as well as their individual roles in OA and potential molecular targets in treating OA.Finally,our review highlights new directions on the role of the synovial lymphatic system in OA.An improved understanding of OA pathogenesis will aid in the development of more specific and effective therapeutic interventions for OA.

Influence of Reaction Conditions on Methanol Synthesis and WGS Reaction in the Syngas-to-DME Process

A series of CuO-ZnO catalysts （with different Cu/Zn molar ratios） were prepared, and evaluated under the reaction conditions of syngas-to-dimethyl ether （DME） with three sorts of feed gas and different space velocity. The catalysts were characterized by X-ray diffraction （XRD） and temperatureprogrammed reduction （TPR）. The experiment results showed that the reaction conditions of syngas-to- DME process greatly affected the methanol synthesis and WGS reaction. The influence caused by Cu/Zn molar ratio was quite different on the two reactions; increasing of percentage of CO2 in feed gas was unfavorable for catalyst activity, and also inhibited both reactions; enhancement of reaction space velocity heavily influenced the performance of the catalyst, and the benefits were relatively less for methanol synthesis than for the WGS reaction.

互花米草有利于我国海岸带蓝碳功能提升

Spartina alterniflora has rapidly and extensively encroached on China's coastline over the past decades.Among the coastal areas invaded by S.alterniflora,at most 93%are mudflats.However,the effect of S.alterniflora invasion on soil organic carbon(SOC)stocks of coastal mudflats has not been systematically studied on a national scale.Here,we quantified the nationwide changes in SOC stocks in coastal mudflats associated with S.alterniflora invasion between 1990 and 2020.We found that S.alterniflora invasion significantly enhanced SOC stocks in coastal China.Nonetheless,the benefit of S.alterniflora invasion of coastal SOC stock may be weakened by continuing human intervention.We found that S.alterniflora invading mudflats added 2.3 Tg SOC stocks to China's coastal blue carbon,while 1.78 Tg SOC stocks were lost mainly due to human activities,resulted in a net SOC stock gain of 0.52 Tg C.These findings overturned the traditionally thought that S.alterniflora invasion would reduce ecosystem services by highlighting that the historical invasion of S.alterniflora has broadly and consistently enhanced blue carbon stock in coastal China.

Novel strategies for the treatment of osteoarthritis based on biomaterials and critical molecular signaling

Osteoarthritis(OA)is a degenerative disease involving entire joint.It is often initiated from the low-grade inflammation in synovial tissue and then affects articular cartilage and subchondral bone.Multiple risk factors,such as aging,mechanical overloading,trauma,overuse,etc.are involved in OA development.Several approaches have been utilized to repair cartilage defects.Among them,biomaterials-based mes-enchymal stromal cell(MSCs)therapy is considered as the most promising modality.The burgeoning material science and manufacturing technologies,such as 3D printing,allow us to mimic native articu-lar cartilage and regulate the artificial cartilage development,regeneration and functional restoration.In this review article,we will summarize the recent progress of biomaterials combined with MSCs or chon-drocytes in repairing cartilage damage induced by OA.Several typical natural and synthetic biomaterials,such as collagen,alginate,hyaluronic acid and poly(ethylene glycol),polylactide acid,polyurethane,etc.for cartilage repairing will be introduced.Moreover,critical signaling pathways associated with the pro-gression of OA,as well as the targeted pharmacologic,genetic therapies and tissue engineering scaffolds for OA and cartilage repairing are presented.We will also provide our prospects for future directions in this active research area.

Improving the Cpf1-mediated base editing system by combining dCas9/dead sgRNA with human APOBEC3A variants

Base editor-mediated C-to-T base conversion obviates the requirements of double-strand breaks,thereby showing promise as a tool for disease modeling and gene therapy(Gaudelli et al.,2017;Rees and Liu 2018).The most actively used base editor comprises a Cas9 nickase(nCas9)with cytidine deaminase and fused uracil DNA glycosylase inhibitor at the carboxy terminus of nCas9 to inhibit uracil N-glycosylase effects(Pearl,2000;Kunz et al.,2009;Rees and Liu 2018).