Pseudomonas aeruginosa is an opportunistic pathogen that can infect a wide variety of hosts including humans, plants, and animals. The production of virulence factors is the determinant of the infection paradigm and is under orchestrated regulation via cell-to-cell communication process called quorum sensing (QS). To disable QS circuits and prevent bacterial infections, a large battery of anti-QS agents, particularly from traditional Chinese medicine have been developed. Here, we used P. aeruginosa as a model microorganism to investigate the effect of traditional Chinese medicine Tanreqing (TRQ) formula on bacterial pathogenicity. Phenotypic analysis showed that TRQ treatment could completely inhibit the production of phenazine pyocyanin and moderately inhibit the production of virulence factors such as rhamnolipids, elastase, and alkaline protease. Further transcriptomic analyses revealed that TRQ treatment could significantly attenuate the expression of QS-regulated genes in P. aeruginosa and TRQ-treated P. aeruginosa regulon shared a large overlap with QS regulon. Component contribution to QS inhibition shed light on the indispensable role of all five components in TRQ formula. Further genetic analysis indicated that upstream regulators of QS systems, including two-component systems GacS/GacA and PprA/PprB, were both inhibited by TRQ treatment. Finally, our TRQ formula could efficiently protect Caenorhabditis elegans from killing by P. aeruginosa. Altogether, we have proved TRQ formula as an effective and specific agent to attenuate bacterial virulence and combat bacterial infections.

The primary goal of wound healing therapy is to quickly close the wound and form healthy and functional scar tissue. As capillary system regeneration is an important condition for skin wound healing, it is important to dynamically monitor angiogenesis with multiple methods based on the 3D reconstruction of dermal microcirculation. In this study, we established a quantitative system to comprehensively evaluate angiogenesis and perfusion during wound healing. Full-thickness skin wounds were generated on the back of rats. Laser Doppler anemometer (LDA), laser speckle contrast imaging (LSCI), and medical electronic dermoscopy (MED) are used to observe the vasculature from the horizontal plane and quantify blood perfusion in wounds. We combined immunofluorescence staining and two-photon excited fluorescence microscopy (TPEF) to reconstruct 3D vessels for longitudinal quantification. These results indicated that new blood vessels around the wound grew parallel to the wound surface. The shape of the blood vessels changed from curved to straight, and the density of the surrounding vascular network gradually decreased as manifested by a decrease in the nodes and branches and the total length of the blood vessels. There were dense blood vessels that grew vertically to the wound surface in the center of the wound. This study established a real-time, non-invasive system to monitor re-epithelialization and angiogenesis and quantitatively assess blood vessels during wound healing, which facilitates the evaluation of new treatments for wound healing.

Staphylococcus aureus has been recognized as an important human pathogen and poses a serious health threat worldwide. With the advent of antibiotic resistance, such as the increased number of methicillin-resistant Staphylococcus aureus (MRSA), there is an urgent need to develop new therapeutical agents. In this study, Chinese traditional medicine Tanreqing (TRQ) has been used as an alternative treating agent against MRSA and we aim to unravel the mode of action of TRQ underlying MRSA inhibition. TRQ treatment affected numerous gene expression as revealed by RNA-seq analysis. Meanwhile, TRQ targeted cell division to inhibit cell growth as shown by illumination microscopy. Besides, we confirmed that TRQ downregulates the expression of virulence factors such as hemolysin and autolysin. Finally, we used a murine model to demonstrate that TRQ efficiently reduces bacterial virulence. Altogether, we have proved TRQ formula to be an effective agent against S. aureus infections.

Prevalent methods for monitoring burn injuries and testing drug efficacies rely on fixed tissue sections. However, this may leave out cellular details in the living state. In vivo assessments of burn healing has been long sought after and are of scientific and clinical interest. Nicotinamide adenine dinucleotide (phosphate) (NAD(P)H), collagen, and melanin are endogenous fluorescent molecules and their signals can be captured by two-photon microscopy (TPM), therefore providing information on epidermal histological features and collagen growth in real-time. In addition, TMP imaging on exogenous fluorescent substances provides a basis for detecting blood vessels. In this work, two-photon microscopy was used to capture the exogenous fluorescent substances and endogenous fluorescent molecules at different times to assess and track burn healing in vivo. Combining TPM imaging and morphological characteristics, proliferation and differentiation of the keratinocytes in different layers of skin, collagen contents, and angiogenesis were identified and quantified. The TPM monitoring method provides an effective tool to systemically evaluate skin healing of deep burns in vivo.

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