Gold nanoparticles (AuNPs) with simultaneous plasmonic and biocatalytic properties provide a promising approach to developing versatile bioassays. However, the combination of AuNPs' intrinsic enzyme-mimicking properties with their surface-enhanced Raman scattering (SERS) activities has yet to be explored. Here we designed a peroxidase-mimicking nanozyme by in situ growing AuNPs into a highly porous and thermally stable metal-organic framework called MIL-101. The obtained AuNPs@MIL-101 nanozymes acted as peroxidase mimics to oxidize Raman-inactive reporter leucomalachite green into the active malachite green (MG) with hydrogen peroxide and simultaneously as the SERS substrates to enhance the Raman signals of the as-produced MG. We then assembled glucose oxidase (GOx) and lactate oxidase (LOx) onto AuNPs@MIL-101 to form AuNPs@MIL-101@GOx and AuNPs@MIL-101@LOx integrative nanozymes for in vitro detection of glucose and lactate via SERS. Moreover, the integrative nanozymes were further explored for monitoring the change of glucose and lactate in living brains, which are associated with ischemic stroke. The integrative nanozymes were then used to evaluate the therapeutic efficacy of potential drugs (such as astaxanthin for alleviating cerebral ischemic injuries) in living rats. They were also employed to determine glucose and lactate metabolism in tumors. This study not only demonstrated the great promise of combining AuNPs' multiple functionalities for versatile bioassays but also provided an interesting approach to designing nanozymes for biomedical and catalytic applications.

In humans, exposure to aristolochic acid (AA) is associated with urothelial carcinoma of the upper urinary tract (UTUC). Exome sequencing of UTUCs from 19 individuals with documented exposure to AA revealed a remarkably large number of somatic mutations and an unusual mutational signature attributable to AA. Most of the mutations (72%) in these tumors were A:T-to-T:A transversions, located predominantly on the nontranscribed strand, with a strong preference for deoxyadenosine in a consensus sequence (T/CAG). This trinucleotide motif overlaps the canonical splice acceptor site, possibly accounting for the excess of splice site mutations observed in these tumors. The AA mutational fingerprint was found frequently in oncogenes and tumor suppressor genes in AA-associated UTUC. The AA mutational signature was observed in one patient’s tumor from a UTUC cohort without previous indication of AA exposure. Together, these results directly link an established environmental mutagen to cancer through genome-wide sequencing and highlight its power to reveal individual exposure to carcinogens.

Objective To investigate the role of proteinase‐activated receptor 4 (PAR‐4) in mediating joint inflammation and pain in mice. Methods Knee joint blood flow, edema, and pain sensitivity (as induced by thermal and mechanical stimuli) were assessed in C57BL/6 mice following intraarticular injection of either the selective PAR‐4 agonist AYPGKF‐NH2 or the inactive control peptide YAPGKF‐NH2. The mechanism of action of AYPGKF‐NH2 was examined by pretreatment of each mouse with either the PAR‐4 antagonist pepducin P4pal‐10 or the bradykinin antagonist HOE 140. Finally, the role of PAR‐4 in mediating joint inflammation was tested by pretreating mice with acutely inflamed knees with pepducin P4pal‐10. Results PAR‐4 activation caused a long‐lasting increase in joint blood flow and edema formation, which was not seen following injection of the control peptide. The PAR‐4–activating peptide was also found to be pronociceptive in the joint, where it enhanced sensitivity to a noxious thermal stimulus and caused mechanical allodynia and hyperalgesia. The proinflammatory and pronociceptive effects of AYPGKF‐NH2 could be inhibited by pepducin P4pal‐10 and HOE 140. Finally, pepducin P4pal‐10 ameliorated the clinical and physiologic signs of acute joint inflammation. Conclusion This study demonstrates that local activation of PAR‐4 leads to proinflammatory changes in the knee joint that are dependent on the kallikrein–kinin system. We also show for the first time that PARs are involved in the modulation of joint pain, with PAR‐4 being pronociceptive in this tissue. Thus, blockade of articular PAR‐4 may be a useful means of controlling joint inflammation and pain.